summaryrefslogtreecommitdiff
path: root/graphics/asymptote/gc/os_dep.c
diff options
context:
space:
mode:
Diffstat (limited to 'graphics/asymptote/gc/os_dep.c')
-rw-r--r--graphics/asymptote/gc/os_dep.c5485
1 files changed, 5485 insertions, 0 deletions
diff --git a/graphics/asymptote/gc/os_dep.c b/graphics/asymptote/gc/os_dep.c
new file mode 100644
index 0000000000..e90c772501
--- /dev/null
+++ b/graphics/asymptote/gc/os_dep.c
@@ -0,0 +1,5485 @@
+/*
+ * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
+ * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
+ * Copyright (c) 2008-2021 Ivan Maidanski
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
+#include "private/gc_priv.h"
+
+#if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
+ && !defined(MSWINCE) && !defined(SN_TARGET_ORBIS) \
+ && !defined(SN_TARGET_PSP2) && !defined(__CC_ARM)
+# include <sys/types.h>
+# if !defined(MSWIN32) && !defined(MSWIN_XBOX1)
+# include <unistd.h>
+# endif
+#endif
+
+#include <stdio.h>
+#if defined(MSWINCE) || defined(SN_TARGET_PS3)
+# define SIGSEGV 0 /* value is irrelevant */
+#else
+# include <signal.h>
+#endif
+
+#if defined(UNIX_LIKE) || defined(CYGWIN32) || defined(NACL) \
+ || defined(SYMBIAN)
+# include <fcntl.h>
+#endif
+
+#if defined(LINUX) || defined(LINUX_STACKBOTTOM)
+# include <ctype.h>
+#endif
+
+/* Blatantly OS dependent routines, except for those that are related */
+/* to dynamic loading. */
+
+#ifdef AMIGA
+# define GC_AMIGA_DEF
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_DEF
+#endif
+
+#ifdef MACOS
+# include <Processes.h>
+#endif
+
+#ifdef IRIX5
+# include <sys/uio.h>
+# include <malloc.h> /* for locking */
+#endif
+
+#if defined(MMAP_SUPPORTED) || defined(ADD_HEAP_GUARD_PAGES)
+# if defined(USE_MUNMAP) && !defined(USE_MMAP) && !defined(CPPCHECK)
+# error Invalid config: USE_MUNMAP requires USE_MMAP
+# endif
+# include <sys/types.h>
+# include <sys/mman.h>
+# include <sys/stat.h>
+#endif
+
+#if defined(ADD_HEAP_GUARD_PAGES) || defined(LINUX_STACKBOTTOM) \
+ || defined(MMAP_SUPPORTED) || defined(NEED_PROC_MAPS)
+# include <errno.h>
+#endif
+
+#ifdef DARWIN
+ /* for get_etext and friends */
+# include <mach-o/getsect.h>
+#endif
+
+#ifdef DJGPP
+ /* Apparently necessary for djgpp 2.01. May cause problems with */
+ /* other versions. */
+ typedef long unsigned int caddr_t;
+#endif
+
+#ifdef PCR
+# include "il/PCR_IL.h"
+# include "th/PCR_ThCtl.h"
+# include "mm/PCR_MM.h"
+#endif
+
+#if defined(GC_DARWIN_THREADS) && defined(MPROTECT_VDB)
+ /* Declare GC_mprotect_stop and GC_mprotect_resume as extern "C". */
+# include "private/darwin_stop_world.h"
+#endif
+
+#if !defined(NO_EXECUTE_PERMISSION)
+ STATIC GC_bool GC_pages_executable = TRUE;
+#else
+ STATIC GC_bool GC_pages_executable = FALSE;
+#endif
+#define IGNORE_PAGES_EXECUTABLE 1
+ /* Undefined on GC_pages_executable real use. */
+
+#if ((defined(LINUX_STACKBOTTOM) || defined(NEED_PROC_MAPS) \
+ || defined(PROC_VDB) || defined(SOFT_VDB)) && !defined(PROC_READ)) \
+ || defined(CPPCHECK)
+# define PROC_READ read
+ /* Should probably call the real read, if read is wrapped. */
+#endif
+
+#if defined(LINUX_STACKBOTTOM) || defined(NEED_PROC_MAPS)
+ /* Repeatedly perform a read call until the buffer is filled */
+ /* up, or we encounter EOF or an error. */
+ STATIC ssize_t GC_repeat_read(int fd, char *buf, size_t count)
+ {
+ size_t num_read = 0;
+
+ ASSERT_CANCEL_DISABLED();
+ while (num_read < count) {
+ ssize_t result = PROC_READ(fd, buf + num_read, count - num_read);
+
+ if (result < 0) return result;
+ if (result == 0) break;
+ num_read += result;
+ }
+ return num_read;
+ }
+#endif /* LINUX_STACKBOTTOM || NEED_PROC_MAPS */
+
+#ifdef NEED_PROC_MAPS
+/* We need to parse /proc/self/maps, either to find dynamic libraries, */
+/* and/or to find the register backing store base (IA64). Do it once */
+/* here. */
+
+#ifdef THREADS
+ /* Determine the length of a file by incrementally reading it into a */
+ /* buffer. This would be silly to use it on a file supporting lseek, */
+ /* but Linux /proc files usually do not. */
+ /* As of Linux 4.15.0, lseek(SEEK_END) fails for /proc/self/maps. */
+ STATIC size_t GC_get_file_len(int f)
+ {
+ size_t total = 0;
+ ssize_t result;
+# define GET_FILE_LEN_BUF_SZ 500
+ char buf[GET_FILE_LEN_BUF_SZ];
+
+ do {
+ result = PROC_READ(f, buf, sizeof(buf));
+ if (result == -1) return 0;
+ total += result;
+ } while (result > 0);
+ return total;
+ }
+
+ STATIC size_t GC_get_maps_len(void)
+ {
+ int f = open("/proc/self/maps", O_RDONLY);
+ size_t result;
+ if (f < 0) return 0; /* treat missing file as empty */
+ result = GC_get_file_len(f);
+ close(f);
+ return result;
+ }
+#endif /* THREADS */
+
+/* Copy the contents of /proc/self/maps to a buffer in our address */
+/* space. Return the address of the buffer. */
+GC_INNER const char * GC_get_maps(void)
+{
+ ssize_t result;
+ static char *maps_buf = NULL;
+ static size_t maps_buf_sz = 1;
+ size_t maps_size;
+# ifdef THREADS
+ size_t old_maps_size = 0;
+# endif
+
+ /* The buffer is essentially static, so there must be a single client. */
+ GC_ASSERT(I_HOLD_LOCK());
+
+ /* Note that in the presence of threads, the maps file can */
+ /* essentially shrink asynchronously and unexpectedly as */
+ /* threads that we already think of as dead release their */
+ /* stacks. And there is no easy way to read the entire */
+ /* file atomically. This is arguably a misfeature of the */
+ /* /proc/self/maps interface. */
+ /* Since we expect the file can grow asynchronously in rare */
+ /* cases, it should suffice to first determine */
+ /* the size (using read), and then to reread the file. */
+ /* If the size is inconsistent we have to retry. */
+ /* This only matters with threads enabled, and if we use */
+ /* this to locate roots (not the default). */
+
+# ifdef THREADS
+ /* Determine the initial size of /proc/self/maps. */
+ maps_size = GC_get_maps_len();
+ if (0 == maps_size)
+ ABORT("Cannot determine length of /proc/self/maps");
+# else
+ maps_size = 4000; /* Guess */
+# endif
+
+ /* Read /proc/self/maps, growing maps_buf as necessary. */
+ /* Note that we may not allocate conventionally, and */
+ /* thus can't use stdio. */
+ do {
+ int f;
+
+ while (maps_size >= maps_buf_sz) {
+# ifdef LINT2
+ /* Workaround passing tainted maps_buf to a tainted sink. */
+ GC_noop1((word)maps_buf);
+# else
+ GC_scratch_recycle_no_gww(maps_buf, maps_buf_sz);
+# endif
+ /* Grow only by powers of 2, since we leak "too small" buffers.*/
+ while (maps_size >= maps_buf_sz) maps_buf_sz *= 2;
+ maps_buf = GC_scratch_alloc(maps_buf_sz);
+ if (NULL == maps_buf)
+ ABORT_ARG1("Insufficient space for /proc/self/maps buffer",
+ ", %lu bytes requested", (unsigned long)maps_buf_sz);
+# ifdef THREADS
+ /* Recompute initial length, since we allocated. */
+ /* This can only happen a few times per program */
+ /* execution. */
+ maps_size = GC_get_maps_len();
+ if (0 == maps_size)
+ ABORT("Cannot determine length of /proc/self/maps");
+# endif
+ }
+ GC_ASSERT(maps_buf_sz >= maps_size + 1);
+ f = open("/proc/self/maps", O_RDONLY);
+ if (-1 == f)
+ ABORT_ARG1("Cannot open /proc/self/maps",
+ ": errno= %d", errno);
+# ifdef THREADS
+ old_maps_size = maps_size;
+# endif
+ maps_size = 0;
+ do {
+ result = GC_repeat_read(f, maps_buf, maps_buf_sz-1);
+ if (result < 0) {
+ ABORT_ARG1("Failed to read /proc/self/maps",
+ ": errno= %d", errno);
+ }
+ maps_size += result;
+ } while ((size_t)result == maps_buf_sz-1);
+ close(f);
+ if (0 == maps_size)
+ ABORT("Empty /proc/self/maps");
+# ifdef THREADS
+ if (maps_size > old_maps_size) {
+ /* This might be caused by e.g. thread creation. */
+ WARN("Unexpected asynchronous /proc/self/maps growth"
+ " (to %" WARN_PRIuPTR " bytes)\n", maps_size);
+ }
+# endif
+ } while (maps_size >= maps_buf_sz
+# ifdef THREADS
+ || maps_size < old_maps_size
+# endif
+ );
+ maps_buf[maps_size] = '\0';
+ return maps_buf;
+}
+
+/*
+ * GC_parse_map_entry parses an entry from /proc/self/maps so we can
+ * locate all writable data segments that belong to shared libraries.
+ * The format of one of these entries and the fields we care about
+ * is as follows:
+ * XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n
+ * ^^^^^^^^ ^^^^^^^^ ^^^^ ^^
+ * start end prot maj_dev
+ *
+ * Note that since about august 2003 kernels, the columns no longer have
+ * fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets
+ * anywhere, which is safer anyway.
+ */
+
+/* Assign various fields of the first line in maps_ptr to (*start), */
+/* (*end), (*prot), (*maj_dev) and (*mapping_name). mapping_name may */
+/* be NULL. (*prot) and (*mapping_name) are assigned pointers into the */
+/* original buffer. */
+#if (defined(DYNAMIC_LOADING) && defined(USE_PROC_FOR_LIBRARIES)) \
+ || defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR) \
+ || (defined(REDIRECT_MALLOC) && defined(GC_LINUX_THREADS))
+ GC_INNER const char *GC_parse_map_entry(const char *maps_ptr,
+ ptr_t *start, ptr_t *end,
+ const char **prot, unsigned *maj_dev,
+ const char **mapping_name)
+ {
+ const unsigned char *start_start, *end_start, *maj_dev_start;
+ const unsigned char *p; /* unsigned for isspace, isxdigit */
+
+ if (maps_ptr == NULL || *maps_ptr == '\0') {
+ return NULL;
+ }
+
+ p = (const unsigned char *)maps_ptr;
+ while (isspace(*p)) ++p;
+ start_start = p;
+ GC_ASSERT(isxdigit(*start_start));
+ *start = (ptr_t)strtoul((const char *)start_start, (char **)&p, 16);
+ GC_ASSERT(*p=='-');
+
+ ++p;
+ end_start = p;
+ GC_ASSERT(isxdigit(*end_start));
+ *end = (ptr_t)strtoul((const char *)end_start, (char **)&p, 16);
+ GC_ASSERT(isspace(*p));
+
+ while (isspace(*p)) ++p;
+ GC_ASSERT(*p == 'r' || *p == '-');
+ *prot = (const char *)p;
+ /* Skip past protection field to offset field */
+ while (!isspace(*p)) ++p;
+ while (isspace(*p)) p++;
+ GC_ASSERT(isxdigit(*p));
+ /* Skip past offset field, which we ignore */
+ while (!isspace(*p)) ++p;
+ while (isspace(*p)) p++;
+ maj_dev_start = p;
+ GC_ASSERT(isxdigit(*maj_dev_start));
+ *maj_dev = strtoul((const char *)maj_dev_start, NULL, 16);
+
+ if (mapping_name != NULL) {
+ while (*p && *p != '\n' && *p != '/' && *p != '[') p++;
+ *mapping_name = (const char *)p;
+ }
+ while (*p && *p++ != '\n');
+ return (const char *)p;
+ }
+#endif /* REDIRECT_MALLOC || DYNAMIC_LOADING || IA64 || ... */
+
+#if defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR)
+ /* Try to read the backing store base from /proc/self/maps. */
+ /* Return the bounds of the writable mapping with a 0 major device, */
+ /* which includes the address passed as data. */
+ /* Return FALSE if there is no such mapping. */
+ GC_INNER GC_bool GC_enclosing_mapping(ptr_t addr, ptr_t *startp,
+ ptr_t *endp)
+ {
+ const char *prot;
+ ptr_t my_start, my_end;
+ unsigned int maj_dev;
+ const char *maps_ptr = GC_get_maps();
+
+ for (;;) {
+ maps_ptr = GC_parse_map_entry(maps_ptr, &my_start, &my_end,
+ &prot, &maj_dev, 0);
+ if (NULL == maps_ptr) break;
+
+ if (prot[1] == 'w' && maj_dev == 0
+ && (word)my_end > (word)addr && (word)my_start <= (word)addr) {
+ *startp = my_start;
+ *endp = my_end;
+ return TRUE;
+ }
+ }
+ return FALSE;
+ }
+#endif /* IA64 || INCLUDE_LINUX_THREAD_DESCR */
+
+#if defined(REDIRECT_MALLOC) && defined(GC_LINUX_THREADS)
+ /* Find the text(code) mapping for the library whose name, after */
+ /* stripping the directory part, starts with nm. */
+ GC_INNER GC_bool GC_text_mapping(char *nm, ptr_t *startp, ptr_t *endp)
+ {
+ size_t nm_len = strlen(nm);
+ const char *prot, *map_path;
+ ptr_t my_start, my_end;
+ unsigned int maj_dev;
+ const char *maps_ptr = GC_get_maps();
+
+ for (;;) {
+ maps_ptr = GC_parse_map_entry(maps_ptr, &my_start, &my_end,
+ &prot, &maj_dev, &map_path);
+ if (NULL == maps_ptr) break;
+
+ if (prot[0] == 'r' && prot[1] == '-' && prot[2] == 'x') {
+ const char *p = map_path;
+
+ /* Set p to point just past last slash, if any. */
+ while (*p != '\0' && *p != '\n' && *p != ' ' && *p != '\t') ++p;
+ while ((word)p >= (word)map_path && *p != '/') --p;
+ ++p;
+ if (strncmp(nm, p, nm_len) == 0) {
+ *startp = my_start;
+ *endp = my_end;
+ return TRUE;
+ }
+ }
+ }
+ return FALSE;
+ }
+#endif /* REDIRECT_MALLOC */
+
+#ifdef IA64
+ static ptr_t backing_store_base_from_proc(void)
+ {
+ ptr_t my_start, my_end;
+ if (!GC_enclosing_mapping(GC_save_regs_in_stack(), &my_start, &my_end)) {
+ GC_COND_LOG_PRINTF("Failed to find backing store base from /proc\n");
+ return 0;
+ }
+ return my_start;
+ }
+#endif
+
+#endif /* NEED_PROC_MAPS */
+
+#if defined(SEARCH_FOR_DATA_START)
+ /* The x86 case can be handled without a search. The Alpha case */
+ /* used to be handled differently as well, but the rules changed */
+ /* for recent Linux versions. This seems to be the easiest way to */
+ /* cover all versions. */
+
+# if defined(LINUX) || defined(HURD)
+ /* Some Linux distributions arrange to define __data_start. Some */
+ /* define data_start as a weak symbol. The latter is technically */
+ /* broken, since the user program may define data_start, in which */
+ /* case we lose. Nonetheless, we try both, preferring __data_start.*/
+ /* We assume gcc-compatible pragmas. */
+ EXTERN_C_BEGIN
+# pragma weak __data_start
+# pragma weak data_start
+ extern int __data_start[], data_start[];
+ EXTERN_C_END
+# endif /* LINUX */
+
+ ptr_t GC_data_start = NULL;
+
+ GC_INNER void GC_init_linux_data_start(void)
+ {
+ ptr_t data_end = DATAEND;
+
+# if (defined(LINUX) || defined(HURD)) && defined(USE_PROG_DATA_START)
+ /* Try the easy approaches first: */
+ /* However, this may lead to wrong data start value if libgc */
+ /* code is put into a shared library (directly or indirectly) */
+ /* which is linked with -Bsymbolic-functions option. Thus, */
+ /* the following is not used by default. */
+ if (COVERT_DATAFLOW(__data_start) != 0) {
+ GC_data_start = (ptr_t)(__data_start);
+ } else {
+ GC_data_start = (ptr_t)(data_start);
+ }
+ if (COVERT_DATAFLOW(GC_data_start) != 0) {
+ if ((word)GC_data_start > (word)data_end)
+ ABORT_ARG2("Wrong __data_start/_end pair",
+ ": %p .. %p", (void *)GC_data_start, (void *)data_end);
+ return;
+ }
+# ifdef DEBUG_ADD_DEL_ROOTS
+ GC_log_printf("__data_start not provided\n");
+# endif
+# endif /* LINUX */
+
+ if (GC_no_dls) {
+ /* Not needed, avoids the SIGSEGV caused by */
+ /* GC_find_limit which complicates debugging. */
+ GC_data_start = data_end; /* set data root size to 0 */
+ return;
+ }
+
+ GC_data_start = (ptr_t)GC_find_limit(data_end, FALSE);
+ }
+#endif /* SEARCH_FOR_DATA_START */
+
+#ifdef ECOS
+
+# ifndef ECOS_GC_MEMORY_SIZE
+# define ECOS_GC_MEMORY_SIZE (448 * 1024)
+# endif /* ECOS_GC_MEMORY_SIZE */
+
+ /* TODO: This is a simple way of allocating memory which is */
+ /* compatible with ECOS early releases. Later releases use a more */
+ /* sophisticated means of allocating memory than this simple static */
+ /* allocator, but this method is at least bound to work. */
+ static char ecos_gc_memory[ECOS_GC_MEMORY_SIZE];
+ static char *ecos_gc_brk = ecos_gc_memory;
+
+ static void *tiny_sbrk(ptrdiff_t increment)
+ {
+ void *p = ecos_gc_brk;
+ ecos_gc_brk += increment;
+ if ((word)ecos_gc_brk > (word)(ecos_gc_memory + sizeof(ecos_gc_memory))) {
+ ecos_gc_brk -= increment;
+ return NULL;
+ }
+ return p;
+ }
+# define sbrk tiny_sbrk
+#endif /* ECOS */
+
+#if defined(NETBSD) && defined(__ELF__)
+ ptr_t GC_data_start = NULL;
+
+ EXTERN_C_BEGIN
+ extern char **environ;
+ EXTERN_C_END
+
+ GC_INNER void GC_init_netbsd_elf(void)
+ {
+ /* This may need to be environ, without the underscore, for */
+ /* some versions. */
+ GC_data_start = (ptr_t)GC_find_limit(&environ, FALSE);
+ }
+#endif /* NETBSD */
+
+#if defined(ADDRESS_SANITIZER) && (defined(UNIX_LIKE) \
+ || defined(NEED_FIND_LIMIT) || defined(MPROTECT_VDB)) \
+ && !defined(CUSTOM_ASAN_DEF_OPTIONS)
+ EXTERN_C_BEGIN
+ GC_API const char *__asan_default_options(void);
+ EXTERN_C_END
+
+ /* To tell ASan to allow GC to use its own SIGBUS/SEGV handlers. */
+ /* The function is exported just to be visible to ASan library. */
+ GC_API const char *__asan_default_options(void)
+ {
+ return "allow_user_segv_handler=1";
+ }
+#endif
+
+#ifdef OPENBSD
+ static struct sigaction old_segv_act;
+ STATIC JMP_BUF GC_jmp_buf_openbsd;
+
+ STATIC void GC_fault_handler_openbsd(int sig GC_ATTR_UNUSED)
+ {
+ LONGJMP(GC_jmp_buf_openbsd, 1);
+ }
+
+# ifdef GC_OPENBSD_UTHREADS
+# include <sys/syscall.h>
+ EXTERN_C_BEGIN
+ extern sigset_t __syscall(quad_t, ...);
+ EXTERN_C_END
+
+ /* Don't use GC_find_limit() because siglongjmp() outside of the */
+ /* signal handler by-passes our userland pthreads lib, leaving */
+ /* SIGSEGV and SIGPROF masked. Instead, use this custom one that */
+ /* works-around the issues. */
+
+ /* Return the first non-addressable location > p or bound. */
+ /* Requires the allocation lock. */
+ STATIC ptr_t GC_find_limit_openbsd(ptr_t p, ptr_t bound)
+ {
+ static volatile ptr_t result;
+ /* Safer if static, since otherwise it may not be */
+ /* preserved across the longjmp. Can safely be */
+ /* static since it's only called with the */
+ /* allocation lock held. */
+
+ struct sigaction act;
+ word pgsz = (word)sysconf(_SC_PAGESIZE);
+
+ GC_ASSERT((word)bound >= pgsz);
+ GC_ASSERT(I_HOLD_LOCK());
+
+ act.sa_handler = GC_fault_handler_openbsd;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_RESTART;
+ /* act.sa_restorer is deprecated and should not be initialized. */
+ sigaction(SIGSEGV, &act, &old_segv_act);
+
+ if (SETJMP(GC_jmp_buf_openbsd) == 0) {
+ result = (ptr_t)((word)p & ~(pgsz-1));
+ for (;;) {
+ if ((word)result >= (word)bound - pgsz) {
+ result = bound;
+ break;
+ }
+ result += pgsz; /* no overflow expected */
+ GC_noop1((word)(*result));
+ }
+ }
+
+# ifdef THREADS
+ /* Due to the siglongjump we need to manually unmask SIGPROF. */
+ __syscall(SYS_sigprocmask, SIG_UNBLOCK, sigmask(SIGPROF));
+# endif
+
+ sigaction(SIGSEGV, &old_segv_act, 0);
+ return(result);
+ }
+# endif /* GC_OPENBSD_UTHREADS */
+
+ static volatile int firstpass;
+
+ /* Return first addressable location > p or bound. */
+ /* Requires the allocation lock. */
+ STATIC ptr_t GC_skip_hole_openbsd(ptr_t p, ptr_t bound)
+ {
+ static volatile ptr_t result;
+
+ struct sigaction act;
+ word pgsz = (word)sysconf(_SC_PAGESIZE);
+
+ GC_ASSERT((word)bound >= pgsz);
+ GC_ASSERT(I_HOLD_LOCK());
+
+ act.sa_handler = GC_fault_handler_openbsd;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_RESTART;
+ /* act.sa_restorer is deprecated and should not be initialized. */
+ sigaction(SIGSEGV, &act, &old_segv_act);
+
+ firstpass = 1;
+ result = (ptr_t)((word)p & ~(pgsz-1));
+ if (SETJMP(GC_jmp_buf_openbsd) != 0 || firstpass) {
+ firstpass = 0;
+ if ((word)result >= (word)bound - pgsz) {
+ result = bound;
+ } else {
+ result += pgsz; /* no overflow expected */
+ GC_noop1((word)(unsigned char)(*result));
+ }
+ }
+
+ sigaction(SIGSEGV, &old_segv_act, 0);
+ return(result);
+ }
+#endif /* OPENBSD */
+
+# ifdef OS2
+
+# include <stddef.h>
+
+# if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
+
+struct exe_hdr {
+ unsigned short magic_number;
+ unsigned short padding[29];
+ long new_exe_offset;
+};
+
+#define E_MAGIC(x) (x).magic_number
+#define EMAGIC 0x5A4D
+#define E_LFANEW(x) (x).new_exe_offset
+
+struct e32_exe {
+ unsigned char magic_number[2];
+ unsigned char byte_order;
+ unsigned char word_order;
+ unsigned long exe_format_level;
+ unsigned short cpu;
+ unsigned short os;
+ unsigned long padding1[13];
+ unsigned long object_table_offset;
+ unsigned long object_count;
+ unsigned long padding2[31];
+};
+
+#define E32_MAGIC1(x) (x).magic_number[0]
+#define E32MAGIC1 'L'
+#define E32_MAGIC2(x) (x).magic_number[1]
+#define E32MAGIC2 'X'
+#define E32_BORDER(x) (x).byte_order
+#define E32LEBO 0
+#define E32_WORDER(x) (x).word_order
+#define E32LEWO 0
+#define E32_CPU(x) (x).cpu
+#define E32CPU286 1
+#define E32_OBJTAB(x) (x).object_table_offset
+#define E32_OBJCNT(x) (x).object_count
+
+struct o32_obj {
+ unsigned long size;
+ unsigned long base;
+ unsigned long flags;
+ unsigned long pagemap;
+ unsigned long mapsize;
+ unsigned long reserved;
+};
+
+#define O32_FLAGS(x) (x).flags
+#define OBJREAD 0x0001L
+#define OBJWRITE 0x0002L
+#define OBJINVALID 0x0080L
+#define O32_SIZE(x) (x).size
+#define O32_BASE(x) (x).base
+
+# else /* IBM's compiler */
+
+/* A kludge to get around what appears to be a header file bug */
+# ifndef WORD
+# define WORD unsigned short
+# endif
+# ifndef DWORD
+# define DWORD unsigned long
+# endif
+
+# define EXE386 1
+# include <newexe.h>
+# include <exe386.h>
+
+# endif /* __IBMC__ */
+
+# define INCL_DOSEXCEPTIONS
+# define INCL_DOSPROCESS
+# define INCL_DOSERRORS
+# define INCL_DOSMODULEMGR
+# define INCL_DOSMEMMGR
+# include <os2.h>
+
+# endif /* OS/2 */
+
+/* Find the page size */
+GC_INNER size_t GC_page_size = 0;
+
+#if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+# ifndef VER_PLATFORM_WIN32_CE
+# define VER_PLATFORM_WIN32_CE 3
+# endif
+
+# if defined(MSWINCE) && defined(THREADS)
+ GC_INNER GC_bool GC_dont_query_stack_min = FALSE;
+# endif
+
+ GC_INNER SYSTEM_INFO GC_sysinfo;
+
+ GC_INNER void GC_setpagesize(void)
+ {
+ GetSystemInfo(&GC_sysinfo);
+# if defined(CYGWIN32) && (defined(MPROTECT_VDB) || defined(USE_MUNMAP))
+ /* Allocations made with mmap() are aligned to the allocation */
+ /* granularity, which (at least on Win64) is not the */
+ /* same as the page size. Probably a separate variable could */
+ /* be added to distinguish the allocation granularity from the */
+ /* actual page size, but in practice there is no good reason to */
+ /* make allocations smaller than dwAllocationGranularity, so we */
+ /* just use it instead of the actual page size here (as Cygwin */
+ /* itself does in many cases). */
+ GC_page_size = (size_t)GC_sysinfo.dwAllocationGranularity;
+ GC_ASSERT(GC_page_size >= (size_t)GC_sysinfo.dwPageSize);
+# else
+ GC_page_size = (size_t)GC_sysinfo.dwPageSize;
+# endif
+# if defined(MSWINCE) && !defined(_WIN32_WCE_EMULATION)
+ {
+ OSVERSIONINFO verInfo;
+ /* Check the current WinCE version. */
+ verInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+ if (!GetVersionEx(&verInfo))
+ ABORT("GetVersionEx failed");
+ if (verInfo.dwPlatformId == VER_PLATFORM_WIN32_CE &&
+ verInfo.dwMajorVersion < 6) {
+ /* Only the first 32 MB of address space belongs to the */
+ /* current process (unless WinCE 6.0+ or emulation). */
+ GC_sysinfo.lpMaximumApplicationAddress = (LPVOID)((word)32 << 20);
+# ifdef THREADS
+ /* On some old WinCE versions, it's observed that */
+ /* VirtualQuery calls don't work properly when used to */
+ /* get thread current stack committed minimum. */
+ if (verInfo.dwMajorVersion < 5)
+ GC_dont_query_stack_min = TRUE;
+# endif
+ }
+ }
+# endif
+ }
+
+# ifndef CYGWIN32
+# define is_writable(prot) ((prot) == PAGE_READWRITE \
+ || (prot) == PAGE_WRITECOPY \
+ || (prot) == PAGE_EXECUTE_READWRITE \
+ || (prot) == PAGE_EXECUTE_WRITECOPY)
+ /* Return the number of bytes that are writable starting at p. */
+ /* The pointer p is assumed to be page aligned. */
+ /* If base is not 0, *base becomes the beginning of the */
+ /* allocation region containing p. */
+ STATIC word GC_get_writable_length(ptr_t p, ptr_t *base)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ word result;
+ word protect;
+
+ result = VirtualQuery(p, &buf, sizeof(buf));
+ if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
+ if (base != 0) *base = (ptr_t)(buf.AllocationBase);
+ protect = buf.Protect & ~(word)(PAGE_GUARD | PAGE_NOCACHE);
+ if (!is_writable(protect)) {
+ return(0);
+ }
+ if (buf.State != MEM_COMMIT) return(0);
+ return(buf.RegionSize);
+ }
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ ptr_t trunc_sp;
+ word size;
+
+ /* Set page size if it is not ready (so client can use this */
+ /* function even before GC is initialized). */
+ if (!GC_page_size) GC_setpagesize();
+
+ trunc_sp = (ptr_t)((word)GC_approx_sp() & ~(word)(GC_page_size-1));
+ /* FIXME: This won't work if called from a deeply recursive */
+ /* client code (and the committed stack space has grown). */
+ size = GC_get_writable_length(trunc_sp, 0);
+ GC_ASSERT(size != 0);
+ sb -> mem_base = trunc_sp + size;
+ return GC_SUCCESS;
+ }
+# else /* CYGWIN32 */
+ /* An alternate version for Cygwin (adapted from Dave Korn's */
+ /* gcc version of boehm-gc). */
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+# ifdef X86_64
+ sb -> mem_base = ((NT_TIB*)NtCurrentTeb())->StackBase;
+# else
+ void * _tlsbase;
+
+ __asm__ ("movl %%fs:4, %0"
+ : "=r" (_tlsbase));
+ sb -> mem_base = _tlsbase;
+# endif
+ return GC_SUCCESS;
+ }
+# endif /* CYGWIN32 */
+# define HAVE_GET_STACK_BASE
+
+#else /* !MSWIN32 */
+ GC_INNER void GC_setpagesize(void)
+ {
+# if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(SOFT_VDB) \
+ || defined(USE_MMAP)
+ GC_page_size = (size_t)GETPAGESIZE();
+# if !defined(CPPCHECK)
+ if (0 == GC_page_size)
+ ABORT("getpagesize failed");
+# endif
+# else
+ /* It's acceptable to fake it. */
+ GC_page_size = HBLKSIZE;
+# endif
+ }
+#endif /* !MSWIN32 */
+
+#ifdef HAIKU
+# include <kernel/OS.h>
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ thread_info th;
+ get_thread_info(find_thread(NULL),&th);
+ sb->mem_base = th.stack_end;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* HAIKU */
+
+#ifdef OS2
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ PTIB ptib; /* thread information block */
+ PPIB ppib;
+ if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
+ WARN("DosGetInfoBlocks failed\n", 0);
+ return GC_UNIMPLEMENTED;
+ }
+ sb->mem_base = ptib->tib_pstacklimit;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* OS2 */
+
+# ifdef AMIGA
+# define GC_AMIGA_SB
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_SB
+# define GET_MAIN_STACKBASE_SPECIAL
+# endif /* AMIGA */
+
+# if defined(NEED_FIND_LIMIT) \
+ || (defined(UNIX_LIKE) && !defined(NO_DEBUGGING)) \
+ || (defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS)) \
+ || (defined(WRAP_MARK_SOME) && defined(__GNUC__))
+
+ typedef void (*GC_fault_handler_t)(int);
+
+# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
+ || defined(HAIKU) || defined(HURD) || defined(FREEBSD) \
+ || defined(NETBSD)
+ static struct sigaction old_segv_act;
+# if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) \
+ || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
+ static struct sigaction old_bus_act;
+# endif
+# elif !defined(OPENBSD)
+ static GC_fault_handler_t old_segv_handler;
+# ifdef HAVE_SIGBUS
+ static GC_fault_handler_t old_bus_handler;
+# endif
+# endif
+
+ GC_INNER void GC_set_and_save_fault_handler(GC_fault_handler_t h)
+ {
+# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
+ || defined(HAIKU) || defined(HURD) || defined(FREEBSD) \
+ || defined(NETBSD) || defined(OPENBSD)
+ struct sigaction act;
+
+ act.sa_handler = h;
+# ifdef SIGACTION_FLAGS_NODEFER_HACK
+ /* Was necessary for Solaris 2.3 and very temporary */
+ /* NetBSD bugs. */
+ act.sa_flags = SA_RESTART | SA_NODEFER;
+# else
+ act.sa_flags = SA_RESTART;
+# endif
+
+ (void) sigemptyset(&act.sa_mask);
+ /* act.sa_restorer is deprecated and should not be initialized. */
+# ifdef GC_IRIX_THREADS
+ /* Older versions have a bug related to retrieving and */
+ /* and setting a handler at the same time. */
+ (void) sigaction(SIGSEGV, 0, &old_segv_act);
+ (void) sigaction(SIGSEGV, &act, 0);
+# else
+ (void) sigaction(SIGSEGV, &act, &old_segv_act);
+# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
+ || defined(HPUX) || defined(HURD) || defined(NETBSD) \
+ || defined(FREEBSD)
+ /* Under Irix 5.x or HP/UX, we may get SIGBUS. */
+ /* Pthreads doesn't exist under Irix 5.x, so we */
+ /* don't have to worry in the threads case. */
+ (void) sigaction(SIGBUS, &act, &old_bus_act);
+# endif
+# endif /* !GC_IRIX_THREADS */
+# else
+ old_segv_handler = signal(SIGSEGV, h);
+# ifdef HAVE_SIGBUS
+ old_bus_handler = signal(SIGBUS, h);
+# endif
+# endif
+# if defined(CPPCHECK) && defined(ADDRESS_SANITIZER)
+ GC_noop1((word)&__asan_default_options);
+# endif
+ }
+# endif /* NEED_FIND_LIMIT || UNIX_LIKE */
+
+# if defined(NEED_FIND_LIMIT) \
+ || (defined(WRAP_MARK_SOME) && defined(__GNUC__)) \
+ || (defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS))
+ /* Some tools to implement HEURISTIC2 */
+# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
+
+ GC_INNER JMP_BUF GC_jmp_buf;
+
+ STATIC void GC_fault_handler(int sig GC_ATTR_UNUSED)
+ {
+ LONGJMP(GC_jmp_buf, 1);
+ }
+
+ GC_INNER void GC_setup_temporary_fault_handler(void)
+ {
+ /* Handler is process-wide, so this should only happen in */
+ /* one thread at a time. */
+ GC_ASSERT(I_HOLD_LOCK());
+ GC_set_and_save_fault_handler(GC_fault_handler);
+ }
+
+ GC_INNER void GC_reset_fault_handler(void)
+ {
+# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
+ || defined(HAIKU) || defined(HURD) || defined(FREEBSD) \
+ || defined(NETBSD) || defined(OPENBSD)
+ (void) sigaction(SIGSEGV, &old_segv_act, 0);
+# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
+ || defined(HPUX) || defined(HURD) || defined(NETBSD) \
+ || defined(FREEBSD)
+ (void) sigaction(SIGBUS, &old_bus_act, 0);
+# endif
+# else
+ (void) signal(SIGSEGV, old_segv_handler);
+# ifdef HAVE_SIGBUS
+ (void) signal(SIGBUS, old_bus_handler);
+# endif
+# endif
+ }
+
+ /* Return the first non-addressable location > p (up) or */
+ /* the smallest location q s.t. [q,p) is addressable (!up). */
+ /* We assume that p (up) or p-1 (!up) is addressable. */
+ /* Requires allocation lock. */
+ GC_ATTR_NO_SANITIZE_ADDR
+ STATIC ptr_t GC_find_limit_with_bound(ptr_t p, GC_bool up, ptr_t bound)
+ {
+ static volatile ptr_t result;
+ /* Safer if static, since otherwise it may not be */
+ /* preserved across the longjmp. Can safely be */
+ /* static since it's only called with the */
+ /* allocation lock held. */
+
+ GC_ASSERT(up ? (word)bound >= MIN_PAGE_SIZE
+ : (word)bound <= ~(word)MIN_PAGE_SIZE);
+ GC_ASSERT(I_HOLD_LOCK());
+ GC_setup_temporary_fault_handler();
+ if (SETJMP(GC_jmp_buf) == 0) {
+ result = (ptr_t)((word)p & ~(word)(MIN_PAGE_SIZE-1));
+ for (;;) {
+ if (up) {
+ if ((word)result >= (word)bound - MIN_PAGE_SIZE) {
+ result = bound;
+ break;
+ }
+ result += MIN_PAGE_SIZE; /* no overflow expected */
+ } else {
+ if ((word)result <= (word)bound + MIN_PAGE_SIZE) {
+ result = bound - MIN_PAGE_SIZE;
+ /* This is to compensate */
+ /* further result increment (we */
+ /* do not modify "up" variable */
+ /* since it might be clobbered */
+ /* by setjmp otherwise). */
+ break;
+ }
+ result -= MIN_PAGE_SIZE; /* no underflow expected */
+ }
+ GC_noop1((word)(unsigned char)(*result));
+ }
+ }
+ GC_reset_fault_handler();
+ if (!up) {
+ result += MIN_PAGE_SIZE;
+ }
+ return(result);
+ }
+
+ void * GC_find_limit(void * p, int up)
+ {
+ return GC_find_limit_with_bound((ptr_t)p, (GC_bool)up,
+ up ? (ptr_t)GC_WORD_MAX : 0);
+ }
+# endif /* NEED_FIND_LIMIT || USE_PROC_FOR_LIBRARIES */
+
+#ifdef HPUX_MAIN_STACKBOTTOM
+# include <sys/param.h>
+# include <sys/pstat.h>
+
+ STATIC ptr_t GC_hpux_main_stack_base(void)
+ {
+ struct pst_vm_status vm_status;
+ int i = 0;
+
+ while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
+ if (vm_status.pst_type == PS_STACK)
+ return (ptr_t)vm_status.pst_vaddr;
+ }
+
+ /* Old way to get the stack bottom. */
+# ifdef STACK_GROWS_UP
+ return (ptr_t)GC_find_limit(GC_approx_sp(), /* up= */ FALSE);
+# else /* not HP_PA */
+ return (ptr_t)GC_find_limit(GC_approx_sp(), TRUE);
+# endif
+ }
+#endif /* HPUX_MAIN_STACKBOTTOM */
+
+#ifdef HPUX_STACKBOTTOM
+
+#include <sys/param.h>
+#include <sys/pstat.h>
+
+ GC_INNER ptr_t GC_get_register_stack_base(void)
+ {
+ struct pst_vm_status vm_status;
+
+ int i = 0;
+ while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
+ if (vm_status.pst_type == PS_RSESTACK) {
+ return (ptr_t) vm_status.pst_vaddr;
+ }
+ }
+
+ /* old way to get the register stackbottom */
+ return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1)
+ & ~(word)(BACKING_STORE_ALIGNMENT-1));
+ }
+
+#endif /* HPUX_STACK_BOTTOM */
+
+#ifdef LINUX_STACKBOTTOM
+
+# include <sys/types.h>
+# include <sys/stat.h>
+
+# define STAT_SKIP 27 /* Number of fields preceding startstack */
+ /* field in /proc/self/stat */
+
+# ifdef USE_LIBC_PRIVATES
+ EXTERN_C_BEGIN
+# pragma weak __libc_stack_end
+ extern ptr_t __libc_stack_end;
+# ifdef IA64
+# pragma weak __libc_ia64_register_backing_store_base
+ extern ptr_t __libc_ia64_register_backing_store_base;
+# endif
+ EXTERN_C_END
+# endif
+
+# ifdef IA64
+ GC_INNER ptr_t GC_get_register_stack_base(void)
+ {
+ ptr_t result;
+
+# ifdef USE_LIBC_PRIVATES
+ if (0 != &__libc_ia64_register_backing_store_base
+ && 0 != __libc_ia64_register_backing_store_base) {
+ /* Glibc 2.2.4 has a bug such that for dynamically linked */
+ /* executables __libc_ia64_register_backing_store_base is */
+ /* defined but uninitialized during constructor calls. */
+ /* Hence we check for both nonzero address and value. */
+ return __libc_ia64_register_backing_store_base;
+ }
+# endif
+ result = backing_store_base_from_proc();
+ if (0 == result) {
+ result = (ptr_t)GC_find_limit(GC_save_regs_in_stack(), FALSE);
+ /* This works better than a constant displacement heuristic. */
+ }
+ return result;
+ }
+# endif /* IA64 */
+
+ STATIC ptr_t GC_linux_main_stack_base(void)
+ {
+ /* We read the stack bottom value from /proc/self/stat. We do this */
+ /* using direct I/O system calls in order to avoid calling malloc */
+ /* in case REDIRECT_MALLOC is defined. */
+# define STAT_BUF_SIZE 4096
+ char stat_buf[STAT_BUF_SIZE];
+ int f;
+ word result;
+ ssize_t i, buf_offset = 0, len;
+
+ /* First try the easy way. This should work for glibc 2.2 */
+ /* This fails in a prelinked ("prelink" command) executable */
+ /* since the correct value of __libc_stack_end never */
+ /* becomes visible to us. The second test works around */
+ /* this. */
+# ifdef USE_LIBC_PRIVATES
+ if (0 != &__libc_stack_end && 0 != __libc_stack_end ) {
+# if defined(IA64)
+ /* Some versions of glibc set the address 16 bytes too */
+ /* low while the initialization code is running. */
+ if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
+ return __libc_stack_end + 0x10;
+ } /* Otherwise it's not safe to add 16 bytes and we fall */
+ /* back to using /proc. */
+# elif defined(SPARC)
+ /* Older versions of glibc for 64-bit SPARC do not set this */
+ /* variable correctly, it gets set to either zero or one. */
+ if (__libc_stack_end != (ptr_t) (unsigned long)0x1)
+ return __libc_stack_end;
+# else
+ return __libc_stack_end;
+# endif
+ }
+# endif
+
+ f = open("/proc/self/stat", O_RDONLY);
+ if (-1 == f)
+ ABORT_ARG1("Could not open /proc/self/stat", ": errno= %d", errno);
+ len = GC_repeat_read(f, stat_buf, sizeof(stat_buf));
+ if (len < 0)
+ ABORT_ARG1("Failed to read /proc/self/stat",
+ ": errno= %d", errno);
+ close(f);
+
+ /* Skip the required number of fields. This number is hopefully */
+ /* constant across all Linux implementations. */
+ for (i = 0; i < STAT_SKIP; ++i) {
+ while (buf_offset < len && isspace(stat_buf[buf_offset++])) {
+ /* empty */
+ }
+ while (buf_offset < len && !isspace(stat_buf[buf_offset++])) {
+ /* empty */
+ }
+ }
+ /* Skip spaces. */
+ while (buf_offset < len && isspace(stat_buf[buf_offset])) {
+ buf_offset++;
+ }
+ /* Find the end of the number and cut the buffer there. */
+ for (i = 0; buf_offset + i < len; i++) {
+ if (!isdigit(stat_buf[buf_offset + i])) break;
+ }
+ if (buf_offset + i >= len) ABORT("Could not parse /proc/self/stat");
+ stat_buf[buf_offset + i] = '\0';
+
+ result = (word)STRTOULL(&stat_buf[buf_offset], NULL, 10);
+ if (result < 0x100000 || (result & (sizeof(word) - 1)) != 0)
+ ABORT_ARG1("Absurd stack bottom value",
+ ": 0x%lx", (unsigned long)result);
+ return (ptr_t)result;
+ }
+#endif /* LINUX_STACKBOTTOM */
+
+#ifdef FREEBSD_STACKBOTTOM
+ /* This uses an undocumented sysctl call, but at least one expert */
+ /* believes it will stay. */
+
+# include <unistd.h>
+# include <sys/types.h>
+# include <sys/sysctl.h>
+
+ STATIC ptr_t GC_freebsd_main_stack_base(void)
+ {
+ int nm[2] = {CTL_KERN, KERN_USRSTACK};
+ ptr_t base;
+ size_t len = sizeof(ptr_t);
+ int r = sysctl(nm, 2, &base, &len, NULL, 0);
+ if (r) ABORT("Error getting main stack base");
+ return base;
+ }
+#endif /* FREEBSD_STACKBOTTOM */
+
+#if defined(ECOS) || defined(NOSYS)
+ ptr_t GC_get_main_stack_base(void)
+ {
+ return STACKBOTTOM;
+ }
+# define GET_MAIN_STACKBASE_SPECIAL
+#elif defined(SYMBIAN)
+ EXTERN_C_BEGIN
+ extern int GC_get_main_symbian_stack_base(void);
+ EXTERN_C_END
+
+ ptr_t GC_get_main_stack_base(void)
+ {
+ return (ptr_t)GC_get_main_symbian_stack_base();
+ }
+# define GET_MAIN_STACKBASE_SPECIAL
+#elif defined(EMSCRIPTEN)
+
+# if defined(USE_EMSCRIPTEN_SCAN_STACK) && defined(EMSCRIPTEN_ASYNCIFY)
+ /* According to the documentation, emscripten_scan_stack() is only */
+ /* guaranteed to be available when building with ASYNCIFY. */
+# include <emscripten.h>
+
+ static void *emscripten_stack_base;
+
+ static void scan_stack_cb(void *begin, void *end)
+ {
+ (void)begin;
+ emscripten_stack_base = end;
+ }
+# else
+# include <emscripten/stack.h>
+# endif
+
+ ptr_t GC_get_main_stack_base(void)
+ {
+# if defined(USE_EMSCRIPTEN_SCAN_STACK) && defined(EMSCRIPTEN_ASYNCIFY)
+ emscripten_scan_stack(scan_stack_cb);
+ return (ptr_t)emscripten_stack_base;
+# else
+ return (ptr_t)emscripten_stack_get_base();
+# endif
+ }
+# define GET_MAIN_STACKBASE_SPECIAL
+#elif !defined(AMIGA) && !defined(HAIKU) && !defined(OS2) \
+ && !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32) \
+ && !defined(GC_OPENBSD_THREADS) \
+ && (!defined(GC_SOLARIS_THREADS) || defined(_STRICT_STDC))
+
+# if (defined(HAVE_PTHREAD_ATTR_GET_NP) || defined(HAVE_PTHREAD_GETATTR_NP)) \
+ && (defined(THREADS) || defined(USE_GET_STACKBASE_FOR_MAIN))
+# include <pthread.h>
+# ifdef HAVE_PTHREAD_NP_H
+# include <pthread_np.h> /* for pthread_attr_get_np() */
+# endif
+# elif defined(DARWIN) && !defined(NO_PTHREAD_GET_STACKADDR_NP)
+ /* We could use pthread_get_stackaddr_np even in case of a */
+ /* single-threaded gclib (there is no -lpthread on Darwin). */
+# include <pthread.h>
+# undef STACKBOTTOM
+# define STACKBOTTOM (ptr_t)pthread_get_stackaddr_np(pthread_self())
+# endif
+
+ ptr_t GC_get_main_stack_base(void)
+ {
+ ptr_t result;
+# if (defined(HAVE_PTHREAD_ATTR_GET_NP) \
+ || defined(HAVE_PTHREAD_GETATTR_NP)) \
+ && (defined(USE_GET_STACKBASE_FOR_MAIN) \
+ || (defined(THREADS) && !defined(REDIRECT_MALLOC)))
+ pthread_attr_t attr;
+ void *stackaddr;
+ size_t size;
+
+# ifdef HAVE_PTHREAD_ATTR_GET_NP
+ if (pthread_attr_init(&attr) == 0
+ && (pthread_attr_get_np(pthread_self(), &attr) == 0
+ ? TRUE : (pthread_attr_destroy(&attr), FALSE)))
+# else /* HAVE_PTHREAD_GETATTR_NP */
+ if (pthread_getattr_np(pthread_self(), &attr) == 0)
+# endif
+ {
+ if (pthread_attr_getstack(&attr, &stackaddr, &size) == 0
+ && stackaddr != NULL) {
+ (void)pthread_attr_destroy(&attr);
+# ifdef STACK_GROWS_DOWN
+ stackaddr = (char *)stackaddr + size;
+# endif
+ return (ptr_t)stackaddr;
+ }
+ (void)pthread_attr_destroy(&attr);
+ }
+ WARN("pthread_getattr_np or pthread_attr_getstack failed"
+ " for main thread\n", 0);
+# endif
+# ifdef STACKBOTTOM
+ result = STACKBOTTOM;
+# else
+# ifdef HEURISTIC1
+# define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
+# ifdef STACK_GROWS_DOWN
+ result = (ptr_t)(((word)GC_approx_sp() + STACKBOTTOM_ALIGNMENT_M1)
+ & ~(word)STACKBOTTOM_ALIGNMENT_M1);
+# else
+ result = (ptr_t)((word)GC_approx_sp()
+ & ~(word)STACKBOTTOM_ALIGNMENT_M1);
+# endif
+# elif defined(HPUX_MAIN_STACKBOTTOM)
+ result = GC_hpux_main_stack_base();
+# elif defined(LINUX_STACKBOTTOM)
+ result = GC_linux_main_stack_base();
+# elif defined(FREEBSD_STACKBOTTOM)
+ result = GC_freebsd_main_stack_base();
+# elif defined(HEURISTIC2)
+ {
+ ptr_t sp = GC_approx_sp();
+# ifdef STACK_GROWS_DOWN
+ result = (ptr_t)GC_find_limit(sp, TRUE);
+# if defined(HEURISTIC2_LIMIT) && !defined(CPPCHECK)
+ if ((word)result > (word)HEURISTIC2_LIMIT
+ && (word)sp < (word)HEURISTIC2_LIMIT) {
+ result = HEURISTIC2_LIMIT;
+ }
+# endif
+# else
+ result = (ptr_t)GC_find_limit(sp, FALSE);
+# if defined(HEURISTIC2_LIMIT) && !defined(CPPCHECK)
+ if ((word)result < (word)HEURISTIC2_LIMIT
+ && (word)sp > (word)HEURISTIC2_LIMIT) {
+ result = HEURISTIC2_LIMIT;
+ }
+# endif
+# endif
+ }
+# elif defined(STACK_NOT_SCANNED) || defined(CPPCHECK)
+ result = NULL;
+# else
+# error None of HEURISTIC* and *STACKBOTTOM defined!
+# endif
+# if defined(STACK_GROWS_DOWN) && !defined(CPPCHECK)
+ if (result == 0)
+ result = (ptr_t)(signed_word)(-sizeof(ptr_t));
+# endif
+# endif
+# if !defined(CPPCHECK)
+ GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)result);
+# endif
+ return(result);
+ }
+# define GET_MAIN_STACKBASE_SPECIAL
+#endif /* !AMIGA, !HAIKU, !OPENBSD, !OS2, !Windows */
+
+#if (defined(HAVE_PTHREAD_ATTR_GET_NP) || defined(HAVE_PTHREAD_GETATTR_NP)) \
+ && defined(THREADS) && !defined(HAVE_GET_STACK_BASE)
+# include <pthread.h>
+# ifdef HAVE_PTHREAD_NP_H
+# include <pthread_np.h>
+# endif
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ pthread_attr_t attr;
+ size_t size;
+# ifdef IA64
+ DCL_LOCK_STATE;
+# endif
+
+# ifdef HAVE_PTHREAD_ATTR_GET_NP
+ if (pthread_attr_init(&attr) != 0)
+ ABORT("pthread_attr_init failed");
+ if (pthread_attr_get_np(pthread_self(), &attr) != 0) {
+ WARN("pthread_attr_get_np failed\n", 0);
+ (void)pthread_attr_destroy(&attr);
+ return GC_UNIMPLEMENTED;
+ }
+# else /* HAVE_PTHREAD_GETATTR_NP */
+ if (pthread_getattr_np(pthread_self(), &attr) != 0) {
+ WARN("pthread_getattr_np failed\n", 0);
+ return GC_UNIMPLEMENTED;
+ }
+# endif
+ if (pthread_attr_getstack(&attr, &(b -> mem_base), &size) != 0) {
+ ABORT("pthread_attr_getstack failed");
+ }
+ (void)pthread_attr_destroy(&attr);
+# ifdef STACK_GROWS_DOWN
+ b -> mem_base = (char *)(b -> mem_base) + size;
+# endif
+# ifdef IA64
+ /* We could try backing_store_base_from_proc, but that's safe */
+ /* only if no mappings are being asynchronously created. */
+ /* Subtracting the size from the stack base doesn't work for at */
+ /* least the main thread. */
+ LOCK();
+ {
+ IF_CANCEL(int cancel_state;)
+ ptr_t bsp;
+ ptr_t next_stack;
+
+ DISABLE_CANCEL(cancel_state);
+ bsp = GC_save_regs_in_stack();
+ next_stack = GC_greatest_stack_base_below(bsp);
+ if (0 == next_stack) {
+ b -> reg_base = GC_find_limit(bsp, FALSE);
+ } else {
+ /* Avoid walking backwards into preceding memory stack and */
+ /* growing it. */
+ b -> reg_base = GC_find_limit_with_bound(bsp, FALSE, next_stack);
+ }
+ RESTORE_CANCEL(cancel_state);
+ }
+ UNLOCK();
+# elif defined(E2K)
+ b -> reg_base = NULL;
+# endif
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* THREADS && (HAVE_PTHREAD_ATTR_GET_NP || HAVE_PTHREAD_GETATTR_NP) */
+
+#if defined(GC_DARWIN_THREADS) && !defined(NO_PTHREAD_GET_STACKADDR_NP)
+# include <pthread.h>
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ /* pthread_get_stackaddr_np() should return stack bottom (highest */
+ /* stack address plus 1). */
+ b->mem_base = pthread_get_stackaddr_np(pthread_self());
+ GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)b->mem_base);
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_DARWIN_THREADS */
+
+#ifdef GC_OPENBSD_THREADS
+# include <sys/signal.h>
+# include <pthread.h>
+# include <pthread_np.h>
+
+ /* Find the stack using pthread_stackseg_np(). */
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ stack_t stack;
+ if (pthread_stackseg_np(pthread_self(), &stack))
+ ABORT("pthread_stackseg_np(self) failed");
+ sb->mem_base = stack.ss_sp;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_OPENBSD_THREADS */
+
+#if defined(GC_SOLARIS_THREADS) && !defined(_STRICT_STDC)
+
+# include <thread.h>
+# include <signal.h>
+# include <pthread.h>
+
+ /* These variables are used to cache ss_sp value for the primordial */
+ /* thread (it's better not to call thr_stksegment() twice for this */
+ /* thread - see JDK bug #4352906). */
+ static pthread_t stackbase_main_self = 0;
+ /* 0 means stackbase_main_ss_sp value is unset. */
+ static void *stackbase_main_ss_sp = NULL;
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ stack_t s;
+ pthread_t self = pthread_self();
+
+ if (self == stackbase_main_self)
+ {
+ /* If the client calls GC_get_stack_base() from the main thread */
+ /* then just return the cached value. */
+ b -> mem_base = stackbase_main_ss_sp;
+ GC_ASSERT(b -> mem_base != NULL);
+ return GC_SUCCESS;
+ }
+
+ if (thr_stksegment(&s)) {
+ /* According to the manual, the only failure error code returned */
+ /* is EAGAIN meaning "the information is not available due to the */
+ /* thread is not yet completely initialized or it is an internal */
+ /* thread" - this shouldn't happen here. */
+ ABORT("thr_stksegment failed");
+ }
+ /* s.ss_sp holds the pointer to the stack bottom. */
+ GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)s.ss_sp);
+
+ if (!stackbase_main_self && thr_main() != 0)
+ {
+ /* Cache the stack bottom pointer for the primordial thread */
+ /* (this is done during GC_init, so there is no race). */
+ stackbase_main_ss_sp = s.ss_sp;
+ stackbase_main_self = self;
+ }
+
+ b -> mem_base = s.ss_sp;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_SOLARIS_THREADS */
+
+#ifdef GC_RTEMS_PTHREADS
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ sb->mem_base = rtems_get_stack_bottom();
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_RTEMS_PTHREADS */
+
+#ifndef HAVE_GET_STACK_BASE
+# ifdef NEED_FIND_LIMIT
+ /* Retrieve the stack bottom. */
+ /* Using the GC_find_limit version is risky. */
+ /* On IA64, for example, there is no guard page between the */
+ /* stack of one thread and the register backing store of the */
+ /* next. Thus this is likely to identify way too large a */
+ /* "stack" and thus at least result in disastrous performance. */
+ /* TODO: Implement better strategies here. */
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ IF_CANCEL(int cancel_state;)
+ DCL_LOCK_STATE;
+
+ LOCK();
+ DISABLE_CANCEL(cancel_state); /* May be unnecessary? */
+# ifdef STACK_GROWS_DOWN
+ b -> mem_base = GC_find_limit(GC_approx_sp(), TRUE);
+# else
+ b -> mem_base = GC_find_limit(GC_approx_sp(), FALSE);
+# endif
+# ifdef IA64
+ b -> reg_base = GC_find_limit(GC_save_regs_in_stack(), FALSE);
+# elif defined(E2K)
+ b -> reg_base = NULL;
+# endif
+ RESTORE_CANCEL(cancel_state);
+ UNLOCK();
+ return GC_SUCCESS;
+ }
+# else
+ GC_API int GC_CALL GC_get_stack_base(
+ struct GC_stack_base *b GC_ATTR_UNUSED)
+ {
+# if defined(GET_MAIN_STACKBASE_SPECIAL) && !defined(THREADS) \
+ && !defined(IA64)
+ b->mem_base = GC_get_main_stack_base();
+ return GC_SUCCESS;
+# else
+ return GC_UNIMPLEMENTED;
+# endif
+ }
+# endif /* !NEED_FIND_LIMIT */
+#endif /* !HAVE_GET_STACK_BASE */
+
+#ifndef GET_MAIN_STACKBASE_SPECIAL
+ /* This is always called from the main thread. Default implementation. */
+ ptr_t GC_get_main_stack_base(void)
+ {
+ struct GC_stack_base sb;
+
+ if (GC_get_stack_base(&sb) != GC_SUCCESS)
+ ABORT("GC_get_stack_base failed");
+ GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)sb.mem_base);
+ return (ptr_t)sb.mem_base;
+ }
+#endif /* !GET_MAIN_STACKBASE_SPECIAL */
+
+/* Register static data segment(s) as roots. If more data segments are */
+/* added later then they need to be registered at that point (as we do */
+/* with SunOS dynamic loading), or GC_mark_roots needs to check for */
+/* them (as we do with PCR). Called with allocator lock held. */
+# ifdef OS2
+
+void GC_register_data_segments(void)
+{
+ PTIB ptib;
+ PPIB ppib;
+ HMODULE module_handle;
+# define PBUFSIZ 512
+ UCHAR path[PBUFSIZ];
+ FILE * myexefile;
+ struct exe_hdr hdrdos; /* MSDOS header. */
+ struct e32_exe hdr386; /* Real header for my executable */
+ struct o32_obj seg; /* Current segment */
+ int nsegs;
+
+# if defined(CPPCHECK)
+ hdrdos.padding[0] = 0; /* to prevent "field unused" warnings */
+ hdr386.exe_format_level = 0;
+ hdr386.os = 0;
+ hdr386.padding1[0] = 0;
+ hdr386.padding2[0] = 0;
+ seg.pagemap = 0;
+ seg.mapsize = 0;
+ seg.reserved = 0;
+# endif
+ if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
+ ABORT("DosGetInfoBlocks failed");
+ }
+ module_handle = ppib -> pib_hmte;
+ if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
+ ABORT("DosQueryModuleName failed");
+ }
+ myexefile = fopen(path, "rb");
+ if (myexefile == 0) {
+ ABORT_ARG1("Failed to open executable", ": %s", path);
+ }
+ if (fread((char *)(&hdrdos), 1, sizeof(hdrdos), myexefile)
+ < sizeof(hdrdos)) {
+ ABORT_ARG1("Could not read MSDOS header", " from: %s", path);
+ }
+ if (E_MAGIC(hdrdos) != EMAGIC) {
+ ABORT_ARG1("Bad DOS magic number", " in file: %s", path);
+ }
+ if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
+ ABORT_ARG1("Bad DOS magic number", " in file: %s", path);
+ }
+ if (fread((char *)(&hdr386), 1, sizeof(hdr386), myexefile)
+ < sizeof(hdr386)) {
+ ABORT_ARG1("Could not read OS/2 header", " from: %s", path);
+ }
+ if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
+ ABORT_ARG1("Bad OS/2 magic number", " in file: %s", path);
+ }
+ if (E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
+ ABORT_ARG1("Bad byte order in executable", " file: %s", path);
+ }
+ if (E32_CPU(hdr386) == E32CPU286) {
+ ABORT_ARG1("GC cannot handle 80286 executables", ": %s", path);
+ }
+ if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
+ SEEK_SET) != 0) {
+ ABORT_ARG1("Seek to object table failed", " in file: %s", path);
+ }
+ for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
+ int flags;
+ if (fread((char *)(&seg), 1, sizeof(seg), myexefile) < sizeof(seg)) {
+ ABORT_ARG1("Could not read obj table entry", " from file: %s", path);
+ }
+ flags = O32_FLAGS(seg);
+ if (!(flags & OBJWRITE)) continue;
+ if (!(flags & OBJREAD)) continue;
+ if (flags & OBJINVALID) {
+ GC_err_printf("Object with invalid pages?\n");
+ continue;
+ }
+ GC_add_roots_inner((ptr_t)O32_BASE(seg),
+ (ptr_t)(O32_BASE(seg)+O32_SIZE(seg)), FALSE);
+ }
+ (void)fclose(myexefile);
+}
+
+# else /* !OS2 */
+
+# if defined(GWW_VDB)
+# ifndef MEM_WRITE_WATCH
+# define MEM_WRITE_WATCH 0x200000
+# endif
+# ifndef WRITE_WATCH_FLAG_RESET
+# define WRITE_WATCH_FLAG_RESET 1
+# endif
+
+ /* Since we can't easily check whether ULONG_PTR and SIZE_T are */
+ /* defined in Win32 basetsd.h, we define own ULONG_PTR. */
+# define GC_ULONG_PTR word
+
+ typedef UINT (WINAPI * GetWriteWatch_type)(
+ DWORD, PVOID, GC_ULONG_PTR /* SIZE_T */,
+ PVOID *, GC_ULONG_PTR *, PULONG);
+ static FARPROC GetWriteWatch_func;
+ static DWORD GetWriteWatch_alloc_flag;
+
+# define GC_GWW_AVAILABLE() (GetWriteWatch_func != 0)
+
+ static void detect_GetWriteWatch(void)
+ {
+ static GC_bool done;
+ HMODULE hK32;
+ if (done)
+ return;
+
+# if defined(MPROTECT_VDB)
+ {
+ char * str = GETENV("GC_USE_GETWRITEWATCH");
+# if defined(GC_PREFER_MPROTECT_VDB)
+ if (str == NULL || (*str == '0' && *(str + 1) == '\0')) {
+ /* GC_USE_GETWRITEWATCH is unset or set to "0". */
+ done = TRUE; /* falling back to MPROTECT_VDB strategy. */
+ /* This should work as if GWW_VDB is undefined. */
+ return;
+ }
+# else
+ if (str != NULL && *str == '0' && *(str + 1) == '\0') {
+ /* GC_USE_GETWRITEWATCH is set "0". */
+ done = TRUE; /* falling back to MPROTECT_VDB strategy. */
+ return;
+ }
+# endif
+ }
+# endif
+
+# ifdef MSWINRT_FLAVOR
+ {
+ MEMORY_BASIC_INFORMATION memInfo;
+ SIZE_T result = VirtualQuery((void*)(word)GetProcAddress,
+ &memInfo, sizeof(memInfo));
+ if (result != sizeof(memInfo))
+ ABORT("Weird VirtualQuery result");
+ hK32 = (HMODULE)memInfo.AllocationBase;
+ }
+# else
+ hK32 = GetModuleHandle(TEXT("kernel32.dll"));
+# endif
+ if (hK32 != (HMODULE)0 &&
+ (GetWriteWatch_func = GetProcAddress(hK32, "GetWriteWatch")) != 0) {
+ /* Also check whether VirtualAlloc accepts MEM_WRITE_WATCH, */
+ /* as some versions of kernel32.dll have one but not the */
+ /* other, making the feature completely broken. */
+ void * page;
+
+ GC_ASSERT(GC_page_size != 0);
+ page = VirtualAlloc(NULL, GC_page_size, MEM_WRITE_WATCH | MEM_RESERVE,
+ PAGE_READWRITE);
+ if (page != NULL) {
+ PVOID pages[16];
+ GC_ULONG_PTR count = 16;
+ DWORD page_size;
+ /* Check that it actually works. In spite of some */
+ /* documentation it actually seems to exist on Win2K. */
+ /* This test may be unnecessary, but ... */
+ if ((*(GetWriteWatch_type)(word)GetWriteWatch_func)(
+ WRITE_WATCH_FLAG_RESET, page,
+ GC_page_size, pages, &count,
+ &page_size) != 0) {
+ /* GetWriteWatch always fails. */
+ GetWriteWatch_func = 0;
+ } else {
+ GetWriteWatch_alloc_flag = MEM_WRITE_WATCH;
+ }
+ VirtualFree(page, 0 /* dwSize */, MEM_RELEASE);
+ } else {
+ /* GetWriteWatch will be useless. */
+ GetWriteWatch_func = 0;
+ }
+ }
+ done = TRUE;
+ }
+
+# else
+# define GetWriteWatch_alloc_flag 0
+# endif /* !GWW_VDB */
+
+# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+
+# ifdef MSWIN32
+ /* Unfortunately, we have to handle win32s very differently from NT, */
+ /* Since VirtualQuery has very different semantics. In particular, */
+ /* under win32s a VirtualQuery call on an unmapped page returns an */
+ /* invalid result. Under NT, GC_register_data_segments is a no-op */
+ /* and all real work is done by GC_register_dynamic_libraries. Under */
+ /* win32s, we cannot find the data segments associated with dll's. */
+ /* We register the main data segment here. */
+ GC_INNER GC_bool GC_no_win32_dlls = FALSE;
+ /* This used to be set for gcc, to avoid dealing with */
+ /* the structured exception handling issues. But we now have */
+ /* assembly code to do that right. */
+
+ GC_INNER GC_bool GC_wnt = FALSE;
+ /* This is a Windows NT derivative, i.e. NT, Win2K, XP or later. */
+
+ GC_INNER void GC_init_win32(void)
+ {
+# if defined(_WIN64) || (defined(_MSC_VER) && _MSC_VER >= 1800)
+ /* MS Visual Studio 2013 deprecates GetVersion, but on the other */
+ /* hand it cannot be used to target pre-Win2K. */
+ GC_wnt = TRUE;
+# else
+ /* Set GC_wnt. If we're running under win32s, assume that no */
+ /* DLLs will be loaded. I doubt anyone still runs win32s, but... */
+ DWORD v = GetVersion();
+
+ GC_wnt = !(v & 0x80000000);
+ GC_no_win32_dlls |= ((!GC_wnt) && (v & 0xff) <= 3);
+# endif
+# ifdef USE_MUNMAP
+ if (GC_no_win32_dlls) {
+ /* Turn off unmapping for safety (since may not work well with */
+ /* GlobalAlloc). */
+ GC_unmap_threshold = 0;
+ }
+# endif
+ }
+
+ /* Return the smallest address a such that VirtualQuery */
+ /* returns correct results for all addresses between a and start. */
+ /* Assumes VirtualQuery returns correct information for start. */
+ STATIC ptr_t GC_least_described_address(ptr_t start)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ LPVOID limit = GC_sysinfo.lpMinimumApplicationAddress;
+ ptr_t p = (ptr_t)((word)start & ~(word)(GC_page_size-1));
+
+ GC_ASSERT(GC_page_size != 0);
+ for (;;) {
+ size_t result;
+ LPVOID q = (LPVOID)(p - GC_page_size);
+
+ if ((word)q > (word)p /* underflow */ || (word)q < (word)limit) break;
+ result = VirtualQuery(q, &buf, sizeof(buf));
+ if (result != sizeof(buf) || buf.AllocationBase == 0) break;
+ p = (ptr_t)(buf.AllocationBase);
+ }
+ return p;
+ }
+# endif /* MSWIN32 */
+
+# if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC)
+ /* We maintain a linked list of AllocationBase values that we know */
+ /* correspond to malloc heap sections. Currently this is only called */
+ /* during a GC. But there is some hope that for long running */
+ /* programs we will eventually see most heap sections. */
+
+ /* In the long run, it would be more reliable to occasionally walk */
+ /* the malloc heap with HeapWalk on the default heap. But that */
+ /* apparently works only for NT-based Windows. */
+
+ STATIC size_t GC_max_root_size = 100000; /* Appr. largest root size. */
+
+ /* In the long run, a better data structure would also be nice ... */
+ STATIC struct GC_malloc_heap_list {
+ void * allocation_base;
+ struct GC_malloc_heap_list *next;
+ } *GC_malloc_heap_l = 0;
+
+ /* Is p the base of one of the malloc heap sections we already know */
+ /* about? */
+ STATIC GC_bool GC_is_malloc_heap_base(void *p)
+ {
+ struct GC_malloc_heap_list *q = GC_malloc_heap_l;
+
+ while (0 != q) {
+ if (q -> allocation_base == p) return TRUE;
+ q = q -> next;
+ }
+ return FALSE;
+ }
+
+ STATIC void *GC_get_allocation_base(void *p)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ size_t result = VirtualQuery(p, &buf, sizeof(buf));
+ if (result != sizeof(buf)) {
+ ABORT("Weird VirtualQuery result");
+ }
+ return buf.AllocationBase;
+ }
+
+ GC_INNER void GC_add_current_malloc_heap(void)
+ {
+ struct GC_malloc_heap_list *new_l = (struct GC_malloc_heap_list *)
+ malloc(sizeof(struct GC_malloc_heap_list));
+ void *candidate;
+
+ if (NULL == new_l) return;
+ new_l -> allocation_base = NULL;
+ /* to suppress maybe-uninitialized gcc warning */
+
+ candidate = GC_get_allocation_base(new_l);
+ if (GC_is_malloc_heap_base(candidate)) {
+ /* Try a little harder to find malloc heap. */
+ size_t req_size = 10000;
+ do {
+ void *p = malloc(req_size);
+ if (0 == p) {
+ free(new_l);
+ return;
+ }
+ candidate = GC_get_allocation_base(p);
+ free(p);
+ req_size *= 2;
+ } while (GC_is_malloc_heap_base(candidate)
+ && req_size < GC_max_root_size/10 && req_size < 500000);
+ if (GC_is_malloc_heap_base(candidate)) {
+ free(new_l);
+ return;
+ }
+ }
+ GC_COND_LOG_PRINTF("Found new system malloc AllocationBase at %p\n",
+ candidate);
+ new_l -> allocation_base = candidate;
+ new_l -> next = GC_malloc_heap_l;
+ GC_malloc_heap_l = new_l;
+ }
+
+ /* Free all the linked list nodes. Could be invoked at process exit */
+ /* to avoid memory leak complains of a dynamic code analysis tool. */
+ STATIC void GC_free_malloc_heap_list(void)
+ {
+ struct GC_malloc_heap_list *q = GC_malloc_heap_l;
+
+ GC_malloc_heap_l = NULL;
+ while (q != NULL) {
+ struct GC_malloc_heap_list *next = q -> next;
+ free(q);
+ q = next;
+ }
+ }
+# endif /* USE_WINALLOC && !REDIRECT_MALLOC */
+
+ /* Is p the start of either the malloc heap, or of one of our */
+ /* heap sections? */
+ GC_INNER GC_bool GC_is_heap_base(void *p)
+ {
+ int i;
+
+# if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC)
+ if (GC_root_size > GC_max_root_size)
+ GC_max_root_size = GC_root_size;
+ if (GC_is_malloc_heap_base(p))
+ return TRUE;
+# endif
+ for (i = 0; i < (int)GC_n_heap_bases; i++) {
+ if (GC_heap_bases[i] == p) return TRUE;
+ }
+ return FALSE;
+ }
+
+#ifdef MSWIN32
+ STATIC void GC_register_root_section(ptr_t static_root)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ LPVOID p;
+ char * base;
+ char * limit;
+
+ if (!GC_no_win32_dlls) return;
+ p = base = limit = GC_least_described_address(static_root);
+ while ((word)p < (word)GC_sysinfo.lpMaximumApplicationAddress) {
+ size_t result = VirtualQuery(p, &buf, sizeof(buf));
+ DWORD protect;
+
+ if (result != sizeof(buf) || buf.AllocationBase == 0
+ || GC_is_heap_base(buf.AllocationBase)) break;
+ if ((word)p > GC_WORD_MAX - buf.RegionSize) break; /* overflow */
+ protect = buf.Protect;
+ if (buf.State == MEM_COMMIT
+ && is_writable(protect)) {
+ if ((char *)p != limit) {
+ if (base != limit) GC_add_roots_inner(base, limit, FALSE);
+ base = (char *)p;
+ }
+ limit = (char *)p + buf.RegionSize;
+ }
+ p = (char *)p + buf.RegionSize;
+ }
+ if (base != limit) GC_add_roots_inner(base, limit, FALSE);
+ }
+#endif /* MSWIN32 */
+
+ void GC_register_data_segments(void)
+ {
+# ifdef MSWIN32
+ GC_register_root_section((ptr_t)&GC_pages_executable);
+ /* any other GC global variable would fit too. */
+# endif
+ }
+
+# else /* !OS2 && !Windows */
+
+# if (defined(SVR4) || defined(AIX) || defined(DGUX) \
+ || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
+ ptr_t GC_SysVGetDataStart(size_t max_page_size, ptr_t etext_addr)
+ {
+ word text_end = ((word)(etext_addr) + sizeof(word) - 1)
+ & ~(word)(sizeof(word) - 1);
+ /* etext rounded to word boundary */
+ word next_page = ((text_end + (word)max_page_size - 1)
+ & ~((word)max_page_size - 1));
+ word page_offset = (text_end & ((word)max_page_size - 1));
+ volatile ptr_t result = (char *)(next_page + page_offset);
+ /* Note that this isn't equivalent to just adding */
+ /* max_page_size to &etext if &etext is at a page boundary */
+
+ GC_setup_temporary_fault_handler();
+ if (SETJMP(GC_jmp_buf) == 0) {
+ /* Try writing to the address. */
+# ifdef AO_HAVE_fetch_and_add
+ volatile AO_t zero = 0;
+ (void)AO_fetch_and_add((volatile AO_t *)result, zero);
+# else
+ /* Fallback to non-atomic fetch-and-store. */
+ char v = *result;
+# if defined(CPPCHECK)
+ GC_noop1((word)&v);
+# endif
+ *result = v;
+# endif
+ GC_reset_fault_handler();
+ } else {
+ GC_reset_fault_handler();
+ /* We got here via a longjmp. The address is not readable. */
+ /* This is known to happen under Solaris 2.4 + gcc, which */
+ /* places string constants in the text segment, but after */
+ /* etext. Use plan B. Note that we now know there is a gap */
+ /* between text and data segments, so plan A brought us */
+ /* something. */
+ result = (char *)GC_find_limit(DATAEND, FALSE);
+ }
+ return (/* no volatile */ ptr_t)result;
+ }
+# endif
+
+#ifdef DATASTART_USES_BSDGETDATASTART
+/* It's unclear whether this should be identical to the above, or */
+/* whether it should apply to non-x86 architectures. */
+/* For now we don't assume that there is always an empty page after */
+/* etext. But in some cases there actually seems to be slightly more. */
+/* This also deals with holes between read-only data and writable data. */
+ GC_INNER ptr_t GC_FreeBSDGetDataStart(size_t max_page_size,
+ ptr_t etext_addr)
+ {
+ word text_end = ((word)(etext_addr) + sizeof(word) - 1)
+ & ~(word)(sizeof(word) - 1);
+ /* etext rounded to word boundary */
+ volatile word next_page = (text_end + (word)max_page_size - 1)
+ & ~((word)max_page_size - 1);
+ volatile ptr_t result = (ptr_t)text_end;
+ GC_setup_temporary_fault_handler();
+ if (SETJMP(GC_jmp_buf) == 0) {
+ /* Try reading at the address. */
+ /* This should happen before there is another thread. */
+ for (; next_page < (word)DATAEND; next_page += (word)max_page_size)
+ GC_noop1((word)(*(volatile unsigned char *)next_page));
+ GC_reset_fault_handler();
+ } else {
+ GC_reset_fault_handler();
+ /* As above, we go to plan B */
+ result = (ptr_t)GC_find_limit(DATAEND, FALSE);
+ }
+ return(result);
+ }
+#endif /* DATASTART_USES_BSDGETDATASTART */
+
+#ifdef AMIGA
+
+# define GC_AMIGA_DS
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_DS
+
+#elif defined(OPENBSD)
+
+/* Depending on arch alignment, there can be multiple holes */
+/* between DATASTART and DATAEND. Scan in DATASTART .. DATAEND */
+/* and register each region. */
+void GC_register_data_segments(void)
+{
+ ptr_t region_start = DATASTART;
+
+ if ((word)region_start - 1U >= (word)DATAEND)
+ ABORT_ARG2("Wrong DATASTART/END pair",
+ ": %p .. %p", (void *)region_start, (void *)DATAEND);
+ for (;;) {
+# ifdef GC_OPENBSD_UTHREADS
+ ptr_t region_end = GC_find_limit_openbsd(region_start, DATAEND);
+# else
+ ptr_t region_end = GC_find_limit_with_bound(region_start, TRUE, DATAEND);
+# endif
+
+ GC_add_roots_inner(region_start, region_end, FALSE);
+ if ((word)region_end >= (word)DATAEND)
+ break;
+ region_start = GC_skip_hole_openbsd(region_end, DATAEND);
+ }
+}
+
+# else /* !OS2 && !Windows && !AMIGA && !OPENBSD */
+
+# if !defined(PCR) && !defined(MACOS) && defined(REDIRECT_MALLOC) \
+ && defined(GC_SOLARIS_THREADS)
+ EXTERN_C_BEGIN
+ extern caddr_t sbrk(int);
+ EXTERN_C_END
+# endif
+
+ void GC_register_data_segments(void)
+ {
+# if !defined(DYNAMIC_LOADING) && defined(GC_DONT_REGISTER_MAIN_STATIC_DATA)
+ /* Avoid even referencing DATASTART and DATAEND as they are */
+ /* unnecessary and cause linker errors when bitcode is enabled. */
+ /* GC_register_data_segments() is not called anyway. */
+# elif !defined(PCR) && !defined(MACOS)
+# if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
+ /* As of Solaris 2.3, the Solaris threads implementation */
+ /* allocates the data structure for the initial thread with */
+ /* sbrk at process startup. It needs to be scanned, so that */
+ /* we don't lose some malloc allocated data structures */
+ /* hanging from it. We're on thin ice here ... */
+ GC_ASSERT(DATASTART);
+ {
+ ptr_t p = (ptr_t)sbrk(0);
+ if ((word)DATASTART < (word)p)
+ GC_add_roots_inner(DATASTART, p, FALSE);
+ }
+# else
+ if ((word)DATASTART - 1U >= (word)DATAEND) {
+ /* Subtract one to check also for NULL */
+ /* without a compiler warning. */
+ ABORT_ARG2("Wrong DATASTART/END pair",
+ ": %p .. %p", (void *)DATASTART, (void *)DATAEND);
+ }
+ GC_add_roots_inner(DATASTART, DATAEND, FALSE);
+# ifdef GC_HAVE_DATAREGION2
+ if ((word)DATASTART2 - 1U >= (word)DATAEND2)
+ ABORT_ARG2("Wrong DATASTART/END2 pair",
+ ": %p .. %p", (void *)DATASTART2, (void *)DATAEND2);
+ GC_add_roots_inner(DATASTART2, DATAEND2, FALSE);
+# endif
+# endif
+# endif
+# if defined(MACOS)
+ {
+# if defined(THINK_C)
+ extern void* GC_MacGetDataStart(void);
+ /* globals begin above stack and end at a5. */
+ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
+ (ptr_t)LMGetCurrentA5(), FALSE);
+# else
+# if defined(__MWERKS__)
+# if !__POWERPC__
+ extern void* GC_MacGetDataStart(void);
+ /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
+# if __option(far_data)
+ extern void* GC_MacGetDataEnd(void);
+# endif
+ /* globals begin above stack and end at a5. */
+ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
+ (ptr_t)LMGetCurrentA5(), FALSE);
+ /* MATTHEW: Handle Far Globals */
+# if __option(far_data)
+ /* Far globals follow the QD globals: */
+ GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
+ (ptr_t)GC_MacGetDataEnd(), FALSE);
+# endif
+# else
+ extern char __data_start__[], __data_end__[];
+ GC_add_roots_inner((ptr_t)&__data_start__,
+ (ptr_t)&__data_end__, FALSE);
+# endif /* __POWERPC__ */
+# endif /* __MWERKS__ */
+# endif /* !THINK_C */
+ }
+# endif /* MACOS */
+
+ /* Dynamic libraries are added at every collection, since they may */
+ /* change. */
+ }
+
+# endif /* !AMIGA */
+# endif /* !MSWIN32 && !MSWINCE */
+# endif /* !OS2 */
+
+/*
+ * Auxiliary routines for obtaining memory from OS.
+ */
+
+# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \
+ && !defined(USE_WINALLOC) && !defined(MACOS) && !defined(DOS4GW) \
+ && !defined(NINTENDO_SWITCH) && !defined(NONSTOP) \
+ && !defined(SN_TARGET_ORBIS) && !defined(SN_TARGET_PS3) \
+ && !defined(SN_TARGET_PSP2) && !defined(RTEMS) && !defined(__CC_ARM)
+
+# define SBRK_ARG_T ptrdiff_t
+
+#if defined(MMAP_SUPPORTED)
+
+#ifdef USE_MMAP_FIXED
+# define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
+ /* Seems to yield better performance on Solaris 2, but can */
+ /* be unreliable if something is already mapped at the address. */
+#else
+# define GC_MMAP_FLAGS MAP_PRIVATE
+#endif
+
+#ifdef USE_MMAP_ANON
+# define zero_fd -1
+# if defined(MAP_ANONYMOUS) && !defined(CPPCHECK)
+# define OPT_MAP_ANON MAP_ANONYMOUS
+# else
+# define OPT_MAP_ANON MAP_ANON
+# endif
+#else
+ static int zero_fd = -1;
+# define OPT_MAP_ANON 0
+#endif
+
+# ifndef MSWIN_XBOX1
+# if defined(SYMBIAN) && !defined(USE_MMAP_ANON)
+ EXTERN_C_BEGIN
+ extern char *GC_get_private_path_and_zero_file(void);
+ EXTERN_C_END
+# endif
+
+ STATIC ptr_t GC_unix_mmap_get_mem(size_t bytes)
+ {
+ void *result;
+ static ptr_t last_addr = HEAP_START;
+
+# ifndef USE_MMAP_ANON
+ static GC_bool initialized = FALSE;
+
+ if (!EXPECT(initialized, TRUE)) {
+# ifdef SYMBIAN
+ char *path = GC_get_private_path_and_zero_file();
+ if (path != NULL) {
+ zero_fd = open(path, O_RDWR | O_CREAT, 0644);
+ free(path);
+ }
+# else
+ zero_fd = open("/dev/zero", O_RDONLY);
+# endif
+ if (zero_fd == -1)
+ ABORT("Could not open /dev/zero");
+ if (fcntl(zero_fd, F_SETFD, FD_CLOEXEC) == -1)
+ WARN("Could not set FD_CLOEXEC for /dev/zero\n", 0);
+
+ initialized = TRUE;
+ }
+# endif
+
+ GC_ASSERT(GC_page_size != 0);
+ if (bytes & (GC_page_size - 1)) ABORT("Bad GET_MEM arg");
+ result = mmap(last_addr, bytes, (PROT_READ | PROT_WRITE)
+ | (GC_pages_executable ? PROT_EXEC : 0),
+ GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */);
+# undef IGNORE_PAGES_EXECUTABLE
+
+ if (EXPECT(MAP_FAILED == result, FALSE)) {
+ if (HEAP_START == last_addr && GC_pages_executable
+ && (EACCES == errno || EPERM == errno))
+ ABORT("Cannot allocate executable pages");
+ return NULL;
+ }
+ last_addr = (ptr_t)(((word)result + bytes + GC_page_size - 1)
+ & ~(word)(GC_page_size - 1));
+# if !defined(LINUX)
+ if (last_addr == 0) {
+ /* Oops. We got the end of the address space. This isn't */
+ /* usable by arbitrary C code, since one-past-end pointers */
+ /* don't work, so we discard it and try again. */
+ munmap(result, ~GC_page_size - (size_t)result + 1);
+ /* Leave last page mapped, so we can't repeat. */
+ return GC_unix_mmap_get_mem(bytes);
+ }
+# else
+ GC_ASSERT(last_addr != 0);
+# endif
+ if (((word)result % HBLKSIZE) != 0)
+ ABORT(
+ "GC_unix_get_mem: Memory returned by mmap is not aligned to HBLKSIZE.");
+ return((ptr_t)result);
+ }
+# endif /* !MSWIN_XBOX1 */
+
+#endif /* MMAP_SUPPORTED */
+
+#if defined(USE_MMAP)
+ ptr_t GC_unix_get_mem(size_t bytes)
+ {
+ return GC_unix_mmap_get_mem(bytes);
+ }
+#else /* !USE_MMAP */
+
+STATIC ptr_t GC_unix_sbrk_get_mem(size_t bytes)
+{
+ ptr_t result;
+# ifdef IRIX5
+ /* Bare sbrk isn't thread safe. Play by malloc rules. */
+ /* The equivalent may be needed on other systems as well. */
+ __LOCK_MALLOC();
+# endif
+ {
+ ptr_t cur_brk = (ptr_t)sbrk(0);
+ SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
+
+ GC_ASSERT(GC_page_size != 0);
+ if ((SBRK_ARG_T)bytes < 0) {
+ result = 0; /* too big */
+ goto out;
+ }
+ if (lsbs != 0) {
+ if ((ptr_t)sbrk((SBRK_ARG_T)GC_page_size - lsbs) == (ptr_t)(-1)) {
+ result = 0;
+ goto out;
+ }
+ }
+# ifdef ADD_HEAP_GUARD_PAGES
+ /* This is useful for catching severe memory overwrite problems that */
+ /* span heap sections. It shouldn't otherwise be turned on. */
+ {
+ ptr_t guard = (ptr_t)sbrk((SBRK_ARG_T)GC_page_size);
+ if (mprotect(guard, GC_page_size, PROT_NONE) != 0)
+ ABORT("ADD_HEAP_GUARD_PAGES: mprotect failed");
+ }
+# endif /* ADD_HEAP_GUARD_PAGES */
+ result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
+ if (result == (ptr_t)(-1)) result = 0;
+ }
+ out:
+# ifdef IRIX5
+ __UNLOCK_MALLOC();
+# endif
+ return(result);
+}
+
+ptr_t GC_unix_get_mem(size_t bytes)
+{
+# if defined(MMAP_SUPPORTED)
+ /* By default, we try both sbrk and mmap, in that order. */
+ static GC_bool sbrk_failed = FALSE;
+ ptr_t result = 0;
+
+ if (GC_pages_executable) {
+ /* If the allocated memory should have the execute permission */
+ /* then sbrk() cannot be used. */
+ return GC_unix_mmap_get_mem(bytes);
+ }
+ if (!sbrk_failed) result = GC_unix_sbrk_get_mem(bytes);
+ if (0 == result) {
+ sbrk_failed = TRUE;
+ result = GC_unix_mmap_get_mem(bytes);
+ }
+ if (0 == result) {
+ /* Try sbrk again, in case sbrk memory became available. */
+ result = GC_unix_sbrk_get_mem(bytes);
+ }
+ return result;
+# else /* !MMAP_SUPPORTED */
+ return GC_unix_sbrk_get_mem(bytes);
+# endif
+}
+
+#endif /* !USE_MMAP */
+
+# endif /* UN*X */
+
+# ifdef OS2
+
+void * os2_alloc(size_t bytes)
+{
+ void * result;
+
+ if (DosAllocMem(&result, bytes, (PAG_READ | PAG_WRITE | PAG_COMMIT)
+ | (GC_pages_executable ? PAG_EXECUTE : 0))
+ != NO_ERROR) {
+ return(0);
+ }
+ /* FIXME: What's the purpose of this recursion? (Probably, if */
+ /* DosAllocMem returns memory at 0 address then just retry once.) */
+ if (result == 0) return(os2_alloc(bytes));
+ return(result);
+}
+
+# endif /* OS2 */
+
+#ifdef MSWIN_XBOX1
+ ptr_t GC_durango_get_mem(size_t bytes)
+ {
+ if (0 == bytes) return NULL;
+ return (ptr_t)VirtualAlloc(NULL, bytes, MEM_COMMIT | MEM_TOP_DOWN,
+ PAGE_READWRITE);
+ }
+#elif defined(MSWINCE)
+ ptr_t GC_wince_get_mem(size_t bytes)
+ {
+ ptr_t result = 0; /* initialized to prevent warning. */
+ word i;
+
+ GC_ASSERT(GC_page_size != 0);
+ bytes = ROUNDUP_PAGESIZE(bytes);
+
+ /* Try to find reserved, uncommitted pages */
+ for (i = 0; i < GC_n_heap_bases; i++) {
+ if (((word)(-(signed_word)GC_heap_lengths[i])
+ & (GC_sysinfo.dwAllocationGranularity-1))
+ >= bytes) {
+ result = GC_heap_bases[i] + GC_heap_lengths[i];
+ break;
+ }
+ }
+
+ if (i == GC_n_heap_bases) {
+ /* Reserve more pages */
+ size_t res_bytes =
+ SIZET_SAT_ADD(bytes, (size_t)GC_sysinfo.dwAllocationGranularity-1)
+ & ~((size_t)GC_sysinfo.dwAllocationGranularity-1);
+ /* If we ever support MPROTECT_VDB here, we will probably need to */
+ /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */
+ /* never spans regions. It seems to be OK for a VirtualFree */
+ /* argument to span regions, so we should be OK for now. */
+ result = (ptr_t) VirtualAlloc(NULL, res_bytes,
+ MEM_RESERVE | MEM_TOP_DOWN,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
+ /* If I read the documentation correctly, this can */
+ /* only happen if HBLKSIZE > 64 KB or not a power of 2. */
+ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
+ if (result == NULL) return NULL;
+ GC_heap_bases[GC_n_heap_bases] = result;
+ GC_heap_lengths[GC_n_heap_bases] = 0;
+ GC_n_heap_bases++;
+ }
+
+ /* Commit pages */
+ result = (ptr_t) VirtualAlloc(result, bytes, MEM_COMMIT,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+# undef IGNORE_PAGES_EXECUTABLE
+
+ if (result != NULL) {
+ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
+ GC_heap_lengths[i] += bytes;
+ }
+
+ return(result);
+ }
+
+#elif defined(USE_WINALLOC) /* && !MSWIN_XBOX1 */ || defined(CYGWIN32)
+
+# ifdef USE_GLOBAL_ALLOC
+# define GLOBAL_ALLOC_TEST 1
+# else
+# define GLOBAL_ALLOC_TEST GC_no_win32_dlls
+# endif
+
+# if (defined(GC_USE_MEM_TOP_DOWN) && defined(USE_WINALLOC)) \
+ || defined(CPPCHECK)
+ DWORD GC_mem_top_down = MEM_TOP_DOWN;
+ /* Use GC_USE_MEM_TOP_DOWN for better 64-bit */
+ /* testing. Otherwise all addresses tend to */
+ /* end up in first 4 GB, hiding bugs. */
+# else
+# define GC_mem_top_down 0
+# endif /* !GC_USE_MEM_TOP_DOWN */
+
+ ptr_t GC_win32_get_mem(size_t bytes)
+ {
+ ptr_t result;
+
+# ifndef USE_WINALLOC
+ result = GC_unix_get_mem(bytes);
+# else
+# if defined(MSWIN32) && !defined(MSWINRT_FLAVOR)
+ if (GLOBAL_ALLOC_TEST) {
+ /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
+ /* There are also unconfirmed rumors of other */
+ /* problems, so we dodge the issue. */
+ result = (ptr_t)GlobalAlloc(0, SIZET_SAT_ADD(bytes, HBLKSIZE));
+ /* Align it at HBLKSIZE boundary. */
+ result = (ptr_t)(((word)result + HBLKSIZE - 1)
+ & ~(word)(HBLKSIZE - 1));
+ } else
+# endif
+ /* else */ {
+ /* VirtualProtect only works on regions returned by a */
+ /* single VirtualAlloc call. Thus we allocate one */
+ /* extra page, which will prevent merging of blocks */
+ /* in separate regions, and eliminate any temptation */
+ /* to call VirtualProtect on a range spanning regions. */
+ /* This wastes a small amount of memory, and risks */
+ /* increased fragmentation. But better alternatives */
+ /* would require effort. */
+# ifdef MPROTECT_VDB
+ /* We can't check for GC_incremental here (because */
+ /* GC_enable_incremental() might be called some time */
+ /* later after the GC initialization). */
+# ifdef GWW_VDB
+# define VIRTUAL_ALLOC_PAD (GC_GWW_AVAILABLE() ? 0 : 1)
+# else
+# define VIRTUAL_ALLOC_PAD 1
+# endif
+# else
+# define VIRTUAL_ALLOC_PAD 0
+# endif
+ /* Pass the MEM_WRITE_WATCH only if GetWriteWatch-based */
+ /* VDBs are enabled and the GetWriteWatch function is */
+ /* available. Otherwise we waste resources or possibly */
+ /* cause VirtualAlloc to fail (observed in Windows 2000 */
+ /* SP2). */
+ result = (ptr_t) VirtualAlloc(NULL,
+ SIZET_SAT_ADD(bytes, VIRTUAL_ALLOC_PAD),
+ GetWriteWatch_alloc_flag
+ | (MEM_COMMIT | MEM_RESERVE)
+ | GC_mem_top_down,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+# undef IGNORE_PAGES_EXECUTABLE
+ }
+# endif /* USE_WINALLOC */
+ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
+ /* If I read the documentation correctly, this can */
+ /* only happen if HBLKSIZE > 64 KB or not a power of 2. */
+ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
+ if (0 != result) GC_heap_bases[GC_n_heap_bases++] = result;
+ return(result);
+ }
+#endif /* USE_WINALLOC || CYGWIN32 */
+
+#if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) \
+ || defined(MSWIN_XBOX1)
+ GC_API void GC_CALL GC_win32_free_heap(void)
+ {
+# if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC) \
+ && !defined(MSWIN_XBOX1)
+ GC_free_malloc_heap_list();
+# endif
+# if (defined(USE_WINALLOC) && !defined(MSWIN_XBOX1) \
+ && !defined(MSWINCE)) || defined(CYGWIN32)
+# ifndef MSWINRT_FLAVOR
+# ifndef CYGWIN32
+ if (GLOBAL_ALLOC_TEST)
+# endif
+ {
+ while (GC_n_heap_bases-- > 0) {
+# ifdef CYGWIN32
+ /* FIXME: Is it OK to use non-GC free() here? */
+# else
+ GlobalFree(GC_heap_bases[GC_n_heap_bases]);
+# endif
+ GC_heap_bases[GC_n_heap_bases] = 0;
+ }
+ return;
+ }
+# endif /* !MSWINRT_FLAVOR */
+# ifndef CYGWIN32
+ /* Avoiding VirtualAlloc leak. */
+ while (GC_n_heap_bases > 0) {
+ VirtualFree(GC_heap_bases[--GC_n_heap_bases], 0, MEM_RELEASE);
+ GC_heap_bases[GC_n_heap_bases] = 0;
+ }
+# endif
+# endif /* USE_WINALLOC || CYGWIN32 */
+ }
+#endif /* Windows */
+
+#ifdef AMIGA
+# define GC_AMIGA_AM
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_AM
+#endif
+
+#if defined(HAIKU)
+# include <stdlib.h>
+ ptr_t GC_haiku_get_mem(size_t bytes)
+ {
+ void* mem;
+
+ GC_ASSERT(GC_page_size != 0);
+ if (posix_memalign(&mem, GC_page_size, bytes) == 0)
+ return mem;
+ return NULL;
+ }
+#endif /* HAIKU */
+
+#if (defined(USE_MUNMAP) || defined(MPROTECT_VDB)) && !defined(USE_WINALLOC)
+# define ABORT_ON_REMAP_FAIL(C_msg_prefix, start_addr, len) \
+ ABORT_ARG3(C_msg_prefix " failed", \
+ " at %p (length %lu), errno= %d", \
+ (void *)(start_addr), (unsigned long)(len), errno)
+#endif
+
+#ifdef USE_MUNMAP
+
+/* For now, this only works on Win32/WinCE and some Unix-like */
+/* systems. If you have something else, don't define */
+/* USE_MUNMAP. */
+
+#if !defined(NN_PLATFORM_CTR) && !defined(MSWIN32) && !defined(MSWINCE) \
+ && !defined(MSWIN_XBOX1)
+# include <unistd.h>
+# ifdef SN_TARGET_PS3
+# include <sys/memory.h>
+# else
+# include <sys/mman.h>
+# endif
+# include <sys/stat.h>
+# include <sys/types.h>
+#endif
+
+/* Compute a page aligned starting address for the unmap */
+/* operation on a block of size bytes starting at start. */
+/* Return 0 if the block is too small to make this feasible. */
+STATIC ptr_t GC_unmap_start(ptr_t start, size_t bytes)
+{
+ ptr_t result = (ptr_t)(((word)start + GC_page_size - 1)
+ & ~(word)(GC_page_size - 1));
+
+ GC_ASSERT(GC_page_size != 0);
+ if ((word)(result + GC_page_size) > (word)(start + bytes)) return 0;
+ return result;
+}
+
+/* Under Win32/WinCE we commit (map) and decommit (unmap) */
+/* memory using VirtualAlloc and VirtualFree. These functions */
+/* work on individual allocations of virtual memory, made */
+/* previously using VirtualAlloc with the MEM_RESERVE flag. */
+/* The ranges we need to (de)commit may span several of these */
+/* allocations; therefore we use VirtualQuery to check */
+/* allocation lengths, and split up the range as necessary. */
+
+/* We assume that GC_remap is called on exactly the same range */
+/* as a previous call to GC_unmap. It is safe to consistently */
+/* round the endpoints in both places. */
+
+static void block_unmap_inner(ptr_t start_addr, size_t len)
+{
+ if (0 == start_addr) return;
+
+# ifdef USE_WINALLOC
+ while (len != 0) {
+ MEMORY_BASIC_INFORMATION mem_info;
+ word free_len;
+
+ if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
+ != sizeof(mem_info))
+ ABORT("Weird VirtualQuery result");
+ free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
+ if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
+ ABORT("VirtualFree failed");
+ GC_unmapped_bytes += free_len;
+ start_addr += free_len;
+ len -= free_len;
+ }
+# else
+ /* We immediately remap it to prevent an intervening mmap from */
+ /* accidentally grabbing the same address space. */
+ if (len != 0) {
+# ifdef SN_TARGET_PS3
+ ps3_free_mem(start_addr, len);
+# elif defined(AIX) || defined(CYGWIN32) || defined(HAIKU) \
+ || (defined(LINUX) && !defined(PREFER_MMAP_PROT_NONE)) \
+ || defined(HPUX)
+ /* On AIX, mmap(PROT_NONE) fails with ENOMEM unless the */
+ /* environment variable XPG_SUS_ENV is set to ON. */
+ /* On Cygwin, calling mmap() with the new protection flags on */
+ /* an existing memory map with MAP_FIXED is broken. */
+ /* However, calling mprotect() on the given address range */
+ /* with PROT_NONE seems to work fine. */
+ /* On Linux, low RLIMIT_AS value may lead to mmap failure. */
+# if defined(LINUX) && !defined(FORCE_MPROTECT_BEFORE_MADVISE)
+ /* On Linux, at least, madvise() should be sufficient. */
+# else
+ if (mprotect(start_addr, len, PROT_NONE))
+ ABORT_ON_REMAP_FAIL("unmap: mprotect", start_addr, len);
+# endif
+# if !defined(CYGWIN32)
+ /* On Linux (and some other platforms probably), */
+ /* mprotect(PROT_NONE) is just disabling access to */
+ /* the pages but not returning them to OS. */
+ if (madvise(start_addr, len, MADV_DONTNEED) == -1)
+ ABORT_ON_REMAP_FAIL("unmap: madvise", start_addr, len);
+# endif
+# elif defined(EMSCRIPTEN)
+ /* Nothing to do, mmap(PROT_NONE) is not supported and */
+ /* mprotect() is just a no-op. */
+# else
+ void * result = mmap(start_addr, len, PROT_NONE,
+ MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
+ zero_fd, 0/* offset */);
+
+ if (EXPECT(MAP_FAILED == result, FALSE))
+ ABORT_ON_REMAP_FAIL("unmap: mmap", start_addr, len);
+ if (result != (void *)start_addr)
+ ABORT("unmap: mmap() result differs from start_addr");
+# if defined(CPPCHECK) || defined(LINT2)
+ /* Explicitly store the resource handle to a global variable. */
+ GC_noop1((word)result);
+# endif
+# endif
+ GC_unmapped_bytes += len;
+ }
+# endif
+}
+
+GC_INNER void GC_unmap(ptr_t start, size_t bytes)
+{
+ ptr_t start_addr = GC_unmap_start(start, bytes);
+ ptr_t end_addr = GC_unmap_end(start, bytes);
+
+ block_unmap_inner(start_addr, (size_t)(end_addr - start_addr));
+}
+
+GC_INNER void GC_remap(ptr_t start, size_t bytes)
+{
+ ptr_t start_addr = GC_unmap_start(start, bytes);
+ ptr_t end_addr = GC_unmap_end(start, bytes);
+ word len = end_addr - start_addr;
+ if (0 == start_addr) return;
+
+ /* FIXME: Handle out-of-memory correctly (at least for Win32) */
+# ifdef USE_WINALLOC
+ while (len != 0) {
+ MEMORY_BASIC_INFORMATION mem_info;
+ word alloc_len;
+ ptr_t result;
+
+ if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
+ != sizeof(mem_info))
+ ABORT("Weird VirtualQuery result");
+ alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
+ result = (ptr_t)VirtualAlloc(start_addr, alloc_len, MEM_COMMIT,
+ GC_pages_executable
+ ? PAGE_EXECUTE_READWRITE
+ : PAGE_READWRITE);
+ if (result != start_addr) {
+ if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY ||
+ GetLastError() == ERROR_OUTOFMEMORY) {
+ ABORT("Not enough memory to process remapping");
+ } else {
+ ABORT("VirtualAlloc remapping failed");
+ }
+ }
+# ifdef LINT2
+ GC_noop1((word)result);
+# endif
+ GC_unmapped_bytes -= alloc_len;
+ start_addr += alloc_len;
+ len -= alloc_len;
+ }
+# undef IGNORE_PAGES_EXECUTABLE
+# else
+ /* It was already remapped with PROT_NONE. */
+ {
+# if !defined(SN_TARGET_PS3) && !defined(FORCE_MPROTECT_BEFORE_MADVISE) \
+ && defined(LINUX) && !defined(PREFER_MMAP_PROT_NONE)
+ /* Nothing to unprotect as madvise() is just a hint. */
+# elif defined(NACL) || defined(NETBSD)
+ /* NaCl does not expose mprotect, but mmap should work fine. */
+ /* In case of NetBSD, mprotect fails (unlike mmap) even */
+ /* without PROT_EXEC if PaX MPROTECT feature is enabled. */
+ void *result = mmap(start_addr, len, (PROT_READ | PROT_WRITE)
+ | (GC_pages_executable ? PROT_EXEC : 0),
+ MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
+ zero_fd, 0 /* offset */);
+ if (EXPECT(MAP_FAILED == result, FALSE))
+ ABORT_ON_REMAP_FAIL("remap: mmap", start_addr, len);
+ if (result != (void *)start_addr)
+ ABORT("remap: mmap() result differs from start_addr");
+# if defined(CPPCHECK) || defined(LINT2)
+ GC_noop1((word)result);
+# endif
+# undef IGNORE_PAGES_EXECUTABLE
+# else
+ if (mprotect(start_addr, len, (PROT_READ | PROT_WRITE)
+ | (GC_pages_executable ? PROT_EXEC : 0)))
+ ABORT_ON_REMAP_FAIL("remap: mprotect", start_addr, len);
+# undef IGNORE_PAGES_EXECUTABLE
+# endif /* !NACL */
+ }
+ GC_unmapped_bytes -= len;
+# endif
+}
+
+/* Two adjacent blocks have already been unmapped and are about to */
+/* be merged. Unmap the whole block. This typically requires */
+/* that we unmap a small section in the middle that was not previously */
+/* unmapped due to alignment constraints. */
+GC_INNER void GC_unmap_gap(ptr_t start1, size_t bytes1, ptr_t start2,
+ size_t bytes2)
+{
+ ptr_t start1_addr = GC_unmap_start(start1, bytes1);
+ ptr_t end1_addr = GC_unmap_end(start1, bytes1);
+ ptr_t start2_addr = GC_unmap_start(start2, bytes2);
+ ptr_t start_addr = end1_addr;
+ ptr_t end_addr = start2_addr;
+
+ GC_ASSERT(start1 + bytes1 == start2);
+ if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
+ if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
+ block_unmap_inner(start_addr, (size_t)(end_addr - start_addr));
+}
+
+#endif /* USE_MUNMAP */
+
+/* Routine for pushing any additional roots. In THREADS */
+/* environment, this is also responsible for marking from */
+/* thread stacks. */
+#ifndef THREADS
+
+# if defined(EMSCRIPTEN) && defined(EMSCRIPTEN_ASYNCIFY)
+# include <emscripten.h>
+
+ static void scan_regs_cb(void *begin, void *end)
+ {
+ GC_push_all_stack((ptr_t)begin, (ptr_t)end);
+ }
+
+ STATIC void GC_CALLBACK GC_default_push_other_roots(void)
+ {
+ /* Note: this needs -sASYNCIFY linker flag. */
+ emscripten_scan_registers(scan_regs_cb);
+ }
+
+# else
+# define GC_default_push_other_roots 0
+# endif
+
+#else /* THREADS */
+
+# ifdef PCR
+PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
+{
+ struct PCR_ThCtl_TInfoRep info;
+ PCR_ERes result;
+
+ info.ti_stkLow = info.ti_stkHi = 0;
+ result = PCR_ThCtl_GetInfo(t, &info);
+ GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
+ return(result);
+}
+
+/* Push the contents of an old object. We treat this as stack */
+/* data only because that makes it robust against mark stack */
+/* overflow. */
+PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
+{
+ GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
+ return(PCR_ERes_okay);
+}
+
+extern struct PCR_MM_ProcsRep * GC_old_allocator;
+ /* defined in pcr_interface.c. */
+
+STATIC void GC_CALLBACK GC_default_push_other_roots(void)
+{
+ /* Traverse data allocated by previous memory managers. */
+ if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
+ GC_push_old_obj, 0)
+ != PCR_ERes_okay) {
+ ABORT("Old object enumeration failed");
+ }
+ /* Traverse all thread stacks. */
+ if (PCR_ERes_IsErr(
+ PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
+ || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
+ ABORT("Thread stack marking failed");
+ }
+}
+
+# elif defined(SN_TARGET_PS3)
+ STATIC void GC_CALLBACK GC_default_push_other_roots(void)
+ {
+ ABORT("GC_default_push_other_roots is not implemented");
+ }
+
+ void GC_push_thread_structures(void)
+ {
+ ABORT("GC_push_thread_structures is not implemented");
+ }
+
+# else /* GC_PTHREADS, or GC_WIN32_THREADS, etc. */
+ STATIC void GC_CALLBACK GC_default_push_other_roots(void)
+ {
+ GC_push_all_stacks();
+ }
+# endif
+
+#endif /* THREADS */
+
+GC_push_other_roots_proc GC_push_other_roots = GC_default_push_other_roots;
+
+GC_API void GC_CALL GC_set_push_other_roots(GC_push_other_roots_proc fn)
+{
+ GC_push_other_roots = fn;
+}
+
+GC_API GC_push_other_roots_proc GC_CALL GC_get_push_other_roots(void)
+{
+ return GC_push_other_roots;
+}
+
+#if defined(SOFT_VDB) && !defined(NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK) \
+ || (defined(GLIBC_2_19_TSX_BUG) && defined(PARALLEL_MARK))
+ GC_INNER int GC_parse_version(int *pminor, const char *pverstr) {
+ char *endp;
+ unsigned long value = strtoul(pverstr, &endp, 10);
+ int major = (int)value;
+
+ if (major < 0 || (char *)pverstr == endp || (unsigned)major != value) {
+ /* Parse error. */
+ return -1;
+ }
+ if (*endp != '.') {
+ /* No minor part. */
+ *pminor = -1;
+ } else {
+ value = strtoul(endp + 1, &endp, 10);
+ *pminor = (int)value;
+ if (*pminor < 0 || (unsigned)(*pminor) != value) {
+ return -1;
+ }
+ }
+ return major;
+ }
+#endif
+
+/*
+ * Routines for accessing dirty bits on virtual pages.
+ * There are six ways to maintain this information:
+ * DEFAULT_VDB: A simple dummy implementation that treats every page
+ * as possibly dirty. This makes incremental collection
+ * useless, but the implementation is still correct.
+ * Manual VDB: Stacks and static data are always considered dirty.
+ * Heap pages are considered dirty if GC_dirty(p) has been
+ * called on some pointer p pointing to somewhere inside
+ * an object on that page. A GC_dirty() call on a large
+ * object directly dirties only a single page, but for the
+ * manual VDB we are careful to treat an object with a dirty
+ * page as completely dirty.
+ * In order to avoid races, an object must be marked dirty
+ * after it is written, and a reference to the object
+ * must be kept on a stack or in a register in the interim.
+ * With threads enabled, an object directly reachable from the
+ * stack at the time of a collection is treated as dirty.
+ * In single-threaded mode, it suffices to ensure that no
+ * collection can take place between the pointer assignment
+ * and the GC_dirty() call.
+ * PCR_VDB: Use PPCRs virtual dirty bit facility.
+ * PROC_VDB: Use the /proc facility for reading dirty bits. Only
+ * works under some SVR4 variants. Even then, it may be
+ * too slow to be entirely satisfactory. Requires reading
+ * dirty bits for entire address space. Implementations tend
+ * to assume that the client is a (slow) debugger.
+ * SOFT_VDB: Use the /proc facility for reading soft-dirty PTEs.
+ * Works on Linux 3.18+ if the kernel is properly configured.
+ * The proposed implementation iterates over GC_heap_sects and
+ * GC_static_roots examining the soft-dirty bit of the words
+ * in /proc/self/pagemap corresponding to the pages of the
+ * sections; finally all soft-dirty bits of the process are
+ * cleared (by writing some special value to
+ * /proc/self/clear_refs file). In case the soft-dirty bit is
+ * not supported by the kernel, MPROTECT_VDB may be defined as
+ * a fallback strategy.
+ * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
+ * dirtied pages. The implementation (and implementability)
+ * is highly system dependent. This usually fails when system
+ * calls write to a protected page. We prevent the read system
+ * call from doing so. It is the clients responsibility to
+ * make sure that other system calls are similarly protected
+ * or write only to the stack.
+ * GWW_VDB: Use the Win32 GetWriteWatch functions, if available, to
+ * read dirty bits. In case it is not available (because we
+ * are running on Windows 95, Windows 2000 or earlier),
+ * MPROTECT_VDB may be defined as a fallback strategy.
+ */
+
+#if (defined(CHECKSUMS) && (defined(GWW_VDB) || defined(SOFT_VDB))) \
+ || defined(PROC_VDB)
+ /* Add all pages in pht2 to pht1. */
+ STATIC void GC_or_pages(page_hash_table pht1, page_hash_table pht2)
+ {
+ unsigned i;
+ for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
+ }
+#endif /* CHECKSUMS && (GWW_VDB || SOFT_VDB) || PROC_VDB */
+
+#ifdef GWW_VDB
+
+# define GC_GWW_BUF_LEN (MAXHINCR * HBLKSIZE / 4096 /* x86 page size */)
+ /* Still susceptible to overflow, if there are very large allocations, */
+ /* and everything is dirty. */
+ static PVOID gww_buf[GC_GWW_BUF_LEN];
+
+# ifndef MPROTECT_VDB
+# define GC_gww_dirty_init GC_dirty_init
+# endif
+
+ GC_INNER GC_bool GC_gww_dirty_init(void)
+ {
+ detect_GetWriteWatch();
+ return GC_GWW_AVAILABLE();
+ }
+
+ GC_INLINE void GC_gww_read_dirty(GC_bool output_unneeded)
+ {
+ word i;
+
+ if (!output_unneeded)
+ BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
+
+ for (i = 0; i != GC_n_heap_sects; ++i) {
+ GC_ULONG_PTR count;
+
+ do {
+ PVOID * pages = gww_buf;
+ DWORD page_size;
+
+ count = GC_GWW_BUF_LEN;
+ /* GetWriteWatch is documented as returning non-zero when it */
+ /* fails, but the documentation doesn't explicitly say why it */
+ /* would fail or what its behavior will be if it fails. It */
+ /* does appear to fail, at least on recent Win2K instances, if */
+ /* the underlying memory was not allocated with the appropriate */
+ /* flag. This is common if GC_enable_incremental is called */
+ /* shortly after GC initialization. To avoid modifying the */
+ /* interface, we silently work around such a failure, it only */
+ /* affects the initial (small) heap allocation. If there are */
+ /* more dirty pages than will fit in the buffer, this is not */
+ /* treated as a failure; we must check the page count in the */
+ /* loop condition. Since each partial call will reset the */
+ /* status of some pages, this should eventually terminate even */
+ /* in the overflow case. */
+ if ((*(GetWriteWatch_type)(word)GetWriteWatch_func)(
+ WRITE_WATCH_FLAG_RESET,
+ GC_heap_sects[i].hs_start,
+ GC_heap_sects[i].hs_bytes,
+ pages, &count, &page_size) != 0) {
+ static int warn_count = 0;
+ struct hblk * start = (struct hblk *)GC_heap_sects[i].hs_start;
+ static struct hblk *last_warned = 0;
+ size_t nblocks = divHBLKSZ(GC_heap_sects[i].hs_bytes);
+
+ if (i != 0 && last_warned != start && warn_count++ < 5) {
+ last_warned = start;
+ WARN("GC_gww_read_dirty unexpectedly failed at %p: "
+ "Falling back to marking all pages dirty\n", start);
+ }
+ if (!output_unneeded) {
+ unsigned j;
+
+ for (j = 0; j < nblocks; ++j) {
+ word hash = PHT_HASH(start + j);
+ set_pht_entry_from_index(GC_grungy_pages, hash);
+ }
+ }
+ count = 1; /* Done with this section. */
+ } else /* succeeded */ if (!output_unneeded) {
+ PVOID * pages_end = pages + count;
+
+ while (pages != pages_end) {
+ struct hblk * h = (struct hblk *) *pages++;
+ struct hblk * h_end = (struct hblk *) ((char *) h + page_size);
+ do {
+ set_pht_entry_from_index(GC_grungy_pages, PHT_HASH(h));
+ } while ((word)(++h) < (word)h_end);
+ }
+ }
+ } while (count == GC_GWW_BUF_LEN);
+ /* FIXME: It's unclear from Microsoft's documentation if this loop */
+ /* is useful. We suspect the call just fails if the buffer fills */
+ /* up. But that should still be handled correctly. */
+ }
+
+# ifdef CHECKSUMS
+ GC_ASSERT(!output_unneeded);
+ GC_or_pages(GC_written_pages, GC_grungy_pages);
+# endif
+ }
+
+#elif defined(SOFT_VDB)
+ static int clear_refs_fd = -1;
+# define GC_GWW_AVAILABLE() (clear_refs_fd != -1)
+#else
+# define GC_GWW_AVAILABLE() FALSE
+#endif /* !GWW_VDB && !SOFT_VDB */
+
+#ifdef DEFAULT_VDB
+ /* All of the following assume the allocation lock is held. */
+
+ /* The client asserts that unallocated pages in the heap are never */
+ /* written. */
+
+ /* Initialize virtual dirty bit implementation. */
+ GC_INNER GC_bool GC_dirty_init(void)
+ {
+ GC_VERBOSE_LOG_PRINTF("Initializing DEFAULT_VDB...\n");
+ /* GC_dirty_pages and GC_grungy_pages are already cleared. */
+ return TRUE;
+ }
+#endif /* DEFAULT_VDB */
+
+#ifndef GC_DISABLE_INCREMENTAL
+# if !defined(THREADS) || defined(HAVE_LOCKFREE_AO_OR)
+# define async_set_pht_entry_from_index(db, index) \
+ set_pht_entry_from_index_concurrent(db, index)
+# elif defined(AO_HAVE_test_and_set_acquire)
+ /* We need to lock around the bitmap update (in the write fault */
+ /* handler or GC_dirty) in order to avoid the risk of losing a bit. */
+ /* We do this with a test-and-set spin lock if possible. */
+ GC_INNER volatile AO_TS_t GC_fault_handler_lock = AO_TS_INITIALIZER;
+
+ static void async_set_pht_entry_from_index(volatile page_hash_table db,
+ size_t index)
+ {
+ GC_acquire_dirty_lock();
+ set_pht_entry_from_index(db, index);
+ GC_release_dirty_lock();
+ }
+# else
+# error No test_and_set operation: Introduces a race.
+# endif /* THREADS && !AO_HAVE_test_and_set_acquire */
+#endif /* !GC_DISABLE_INCREMENTAL */
+
+#ifdef MPROTECT_VDB
+ /*
+ * This implementation maintains dirty bits itself by catching write
+ * faults and keeping track of them. We assume nobody else catches
+ * SIGBUS or SIGSEGV. We assume no write faults occur in system calls.
+ * This means that clients must ensure that system calls don't write
+ * to the write-protected heap. Probably the best way to do this is to
+ * ensure that system calls write at most to pointer-free objects in the
+ * heap, and do even that only if we are on a platform on which those
+ * are not protected.
+ * We assume the page size is a multiple of HBLKSIZE.
+ * We prefer them to be the same. We avoid protecting pointer-free
+ * objects only if they are the same.
+ */
+# ifdef DARWIN
+ /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
+ decrease the likelihood of some of the problems described below. */
+# include <mach/vm_map.h>
+ STATIC mach_port_t GC_task_self = 0;
+# define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \
+ if (vm_protect(GC_task_self, (vm_address_t)(addr), (vm_size_t)(len), \
+ FALSE, VM_PROT_READ \
+ | ((allow_write) ? VM_PROT_WRITE : 0) \
+ | (GC_pages_executable ? VM_PROT_EXECUTE : 0)) \
+ == KERN_SUCCESS) {} else ABORT(C_msg_prefix \
+ "vm_protect() failed")
+
+# elif !defined(USE_WINALLOC)
+# include <sys/mman.h>
+# include <signal.h>
+# if !defined(CYGWIN32) && !defined(HAIKU)
+# include <sys/syscall.h>
+# endif
+
+# define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \
+ if (mprotect((caddr_t)(addr), (size_t)(len), \
+ PROT_READ | ((allow_write) ? PROT_WRITE : 0) \
+ | (GC_pages_executable ? PROT_EXEC : 0)) >= 0) { \
+ } else if (GC_pages_executable) { \
+ ABORT_ON_REMAP_FAIL(C_msg_prefix \
+ "mprotect vdb executable pages", \
+ addr, len); \
+ } else ABORT_ON_REMAP_FAIL(C_msg_prefix "mprotect vdb", addr, len)
+# undef IGNORE_PAGES_EXECUTABLE
+
+# else /* USE_WINALLOC */
+# ifndef MSWINCE
+# include <signal.h>
+# endif
+
+ static DWORD protect_junk;
+# define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \
+ if (VirtualProtect(addr, len, \
+ GC_pages_executable ? \
+ ((allow_write) ? PAGE_EXECUTE_READWRITE : \
+ PAGE_EXECUTE_READ) : \
+ (allow_write) ? PAGE_READWRITE : \
+ PAGE_READONLY, \
+ &protect_junk)) { \
+ } else ABORT_ARG1(C_msg_prefix "VirtualProtect failed", \
+ ": errcode= 0x%X", (unsigned)GetLastError())
+# endif /* USE_WINALLOC */
+
+# define PROTECT(addr, len) PROTECT_INNER(addr, len, FALSE, "")
+# define UNPROTECT(addr, len) PROTECT_INNER(addr, len, TRUE, "un-")
+
+# if defined(MSWIN32)
+ typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_HNDLR_PTR;
+# undef SIG_DFL
+# define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER)((signed_word)-1)
+# elif defined(MSWINCE)
+ typedef LONG (WINAPI *SIG_HNDLR_PTR)(struct _EXCEPTION_POINTERS *);
+# undef SIG_DFL
+# define SIG_DFL (SIG_HNDLR_PTR) (-1)
+# elif defined(DARWIN)
+ typedef void (* SIG_HNDLR_PTR)();
+# else
+ typedef void (* SIG_HNDLR_PTR)(int, siginfo_t *, void *);
+ typedef void (* PLAIN_HNDLR_PTR)(int);
+# endif
+
+#ifndef DARWIN
+ STATIC SIG_HNDLR_PTR GC_old_segv_handler = 0;
+ /* Also old MSWIN32 ACCESS_VIOLATION filter */
+# if defined(FREEBSD) || defined(HPUX) || defined(HURD) || defined(LINUX)
+ STATIC SIG_HNDLR_PTR GC_old_bus_handler = 0;
+# ifndef LINUX
+ STATIC GC_bool GC_old_bus_handler_used_si = FALSE;
+# endif
+# endif
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ STATIC GC_bool GC_old_segv_handler_used_si = FALSE;
+# endif /* !MSWIN32 */
+#endif /* !DARWIN */
+
+#ifdef THREADS
+ /* This function is used only by the fault handler. Potential data */
+ /* race between this function and GC_install_header, GC_remove_header */
+ /* should not be harmful because the added or removed header should */
+ /* be already unprotected. */
+ GC_ATTR_NO_SANITIZE_THREAD
+ static GC_bool is_header_found_async(void *addr)
+ {
+# ifdef HASH_TL
+ hdr *result;
+ GET_HDR((ptr_t)addr, result);
+ return result != NULL;
+# else
+ return HDR_INNER(addr) != NULL;
+# endif
+ }
+#else
+# define is_header_found_async(addr) (HDR(addr) != NULL)
+#endif /* !THREADS */
+
+#ifndef DARWIN
+
+# if !defined(MSWIN32) && !defined(MSWINCE)
+# include <errno.h>
+# if defined(FREEBSD) || defined(HURD) || defined(HPUX)
+# define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
+# else
+# define SIG_OK (sig == SIGSEGV)
+ /* Catch SIGSEGV but ignore SIGBUS. */
+# endif
+# if defined(FREEBSD)
+# ifndef SEGV_ACCERR
+# define SEGV_ACCERR 2
+# endif
+# if defined(AARCH64) || defined(ARM32) || defined(MIPS) \
+ || __FreeBSD__ >= 7
+# define CODE_OK (si -> si_code == SEGV_ACCERR)
+# elif defined(POWERPC)
+# define AIM /* Pretend that we're AIM. */
+# include <machine/trap.h>
+# define CODE_OK (si -> si_code == EXC_DSI \
+ || si -> si_code == SEGV_ACCERR)
+# else
+# define CODE_OK (si -> si_code == BUS_PAGE_FAULT \
+ || si -> si_code == SEGV_ACCERR)
+# endif
+# elif defined(OSF1)
+# define CODE_OK (si -> si_code == 2 /* experimentally determined */)
+# elif defined(IRIX5)
+# define CODE_OK (si -> si_code == EACCES)
+# elif defined(CYGWIN32) || defined(HAIKU) || defined(HURD)
+# define CODE_OK TRUE
+# elif defined(LINUX)
+# define CODE_OK TRUE
+ /* Empirically c.trapno == 14, on IA32, but is that useful? */
+ /* Should probably consider alignment issues on other */
+ /* architectures. */
+# elif defined(HPUX)
+# define CODE_OK (si -> si_code == SEGV_ACCERR \
+ || si -> si_code == BUS_ADRERR \
+ || si -> si_code == BUS_UNKNOWN \
+ || si -> si_code == SEGV_UNKNOWN \
+ || si -> si_code == BUS_OBJERR)
+# elif defined(SUNOS5SIGS)
+# define CODE_OK (si -> si_code == SEGV_ACCERR)
+# endif
+# ifndef NO_GETCONTEXT
+# include <ucontext.h>
+# endif
+ STATIC void GC_write_fault_handler(int sig, siginfo_t *si, void *raw_sc)
+# else
+# define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode \
+ == STATUS_ACCESS_VIOLATION)
+# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] \
+ == 1) /* Write fault */
+ STATIC LONG WINAPI GC_write_fault_handler(
+ struct _EXCEPTION_POINTERS *exc_info)
+# endif /* MSWIN32 || MSWINCE */
+ {
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ char *addr = (char *)si->si_addr;
+# else
+ char * addr = (char *) (exc_info -> ExceptionRecord
+ -> ExceptionInformation[1]);
+# endif
+
+ if (SIG_OK && CODE_OK) {
+ struct hblk * h = (struct hblk *)((word)addr
+ & ~(word)(GC_page_size-1));
+ GC_bool in_allocd_block;
+ size_t i;
+
+ GC_ASSERT(GC_page_size != 0);
+# ifdef CHECKSUMS
+ GC_record_fault(h);
+# endif
+# ifdef SUNOS5SIGS
+ /* Address is only within the correct physical page. */
+ in_allocd_block = FALSE;
+ for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
+ if (is_header_found_async(&h[i])) {
+ in_allocd_block = TRUE;
+ break;
+ }
+ }
+# else
+ in_allocd_block = is_header_found_async(addr);
+# endif
+ if (!in_allocd_block) {
+ /* FIXME - We should make sure that we invoke the */
+ /* old handler with the appropriate calling */
+ /* sequence, which often depends on SA_SIGINFO. */
+
+ /* Heap blocks now begin and end on page boundaries */
+ SIG_HNDLR_PTR old_handler;
+
+# if defined(MSWIN32) || defined(MSWINCE)
+ old_handler = GC_old_segv_handler;
+# else
+ GC_bool used_si;
+
+# if defined(FREEBSD) || defined(HURD) || defined(HPUX)
+ if (sig == SIGBUS) {
+ old_handler = GC_old_bus_handler;
+ used_si = GC_old_bus_handler_used_si;
+ } else
+# endif
+ /* else */ {
+ old_handler = GC_old_segv_handler;
+ used_si = GC_old_segv_handler_used_si;
+ }
+# endif
+
+ if (old_handler == (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ ABORT_ARG1("Unexpected bus error or segmentation fault",
+ " at %p", (void *)addr);
+# else
+ return(EXCEPTION_CONTINUE_SEARCH);
+# endif
+ } else {
+ /*
+ * FIXME: This code should probably check if the
+ * old signal handler used the traditional style and
+ * if so call it using that style.
+ */
+# if defined(MSWIN32) || defined(MSWINCE)
+ return((*old_handler)(exc_info));
+# else
+ if (used_si)
+ ((SIG_HNDLR_PTR)old_handler) (sig, si, raw_sc);
+ else
+ /* FIXME: should pass nonstandard args as well. */
+ ((PLAIN_HNDLR_PTR)(signed_word)old_handler)(sig);
+ return;
+# endif
+ }
+ }
+ UNPROTECT(h, GC_page_size);
+ /* We need to make sure that no collection occurs between */
+ /* the UNPROTECT and the setting of the dirty bit. Otherwise */
+ /* a write by a third thread might go unnoticed. Reversing */
+ /* the order is just as bad, since we would end up unprotecting */
+ /* a page in a GC cycle during which it's not marked. */
+ /* Currently we do this by disabling the thread stopping */
+ /* signals while this handler is running. An alternative might */
+ /* be to record the fact that we're about to unprotect, or */
+ /* have just unprotected a page in the GC's thread structure, */
+ /* and then to have the thread stopping code set the dirty */
+ /* flag, if necessary. */
+ for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
+ word index = PHT_HASH(h+i);
+
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ /* The write may not take place before dirty bits are read. */
+ /* But then we'll fault again ... */
+# if defined(MSWIN32) || defined(MSWINCE)
+ return(EXCEPTION_CONTINUE_EXECUTION);
+# else
+ return;
+# endif
+ }
+# if defined(MSWIN32) || defined(MSWINCE)
+ return EXCEPTION_CONTINUE_SEARCH;
+# else
+ ABORT_ARG1("Unexpected bus error or segmentation fault",
+ " at %p", (void *)addr);
+# endif
+ }
+
+# if defined(GC_WIN32_THREADS) && !defined(CYGWIN32)
+ GC_INNER void GC_set_write_fault_handler(void)
+ {
+ SetUnhandledExceptionFilter(GC_write_fault_handler);
+ }
+# endif
+
+# ifdef SOFT_VDB
+ static GC_bool soft_dirty_init(void);
+# endif
+
+ GC_INNER GC_bool GC_dirty_init(void)
+ {
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ struct sigaction act, oldact;
+# endif
+
+# ifdef COUNT_PROTECTED_REGIONS
+ GC_ASSERT(GC_page_size != 0);
+ if ((signed_word)(GC_heapsize / (word)GC_page_size)
+ >= ((signed_word)GC_UNMAPPED_REGIONS_SOFT_LIMIT
+ - GC_num_unmapped_regions) * 2) {
+ GC_COND_LOG_PRINTF("Cannot turn on GC incremental mode"
+ " as heap contains too many pages\n");
+ return FALSE;
+ }
+# endif
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ act.sa_flags = SA_RESTART | SA_SIGINFO;
+ act.sa_sigaction = GC_write_fault_handler;
+ (void)sigemptyset(&act.sa_mask);
+# if defined(THREADS) && !defined(GC_OPENBSD_UTHREADS) \
+ && !defined(GC_WIN32_THREADS) && !defined(NACL)
+ /* Arrange to postpone the signal while we are in a write fault */
+ /* handler. This effectively makes the handler atomic w.r.t. */
+ /* stopping the world for GC. */
+ (void)sigaddset(&act.sa_mask, GC_get_suspend_signal());
+# endif
+# endif /* !MSWIN32 */
+ GC_VERBOSE_LOG_PRINTF(
+ "Initializing mprotect virtual dirty bit implementation\n");
+ if (GC_page_size % HBLKSIZE != 0) {
+ ABORT("Page size not multiple of HBLKSIZE");
+ }
+# ifdef GWW_VDB
+ if (GC_gww_dirty_init()) {
+ GC_COND_LOG_PRINTF("Using GetWriteWatch()\n");
+ return TRUE;
+ }
+# elif defined(SOFT_VDB)
+ if (soft_dirty_init()) {
+ GC_COND_LOG_PRINTF("Using soft-dirty bit feature\n");
+ return TRUE;
+ }
+# endif
+# ifdef MSWIN32
+ GC_old_segv_handler = SetUnhandledExceptionFilter(
+ GC_write_fault_handler);
+ if (GC_old_segv_handler != NULL) {
+ GC_COND_LOG_PRINTF("Replaced other UnhandledExceptionFilter\n");
+ } else {
+ GC_old_segv_handler = SIG_DFL;
+ }
+# elif defined(MSWINCE)
+ /* MPROTECT_VDB is unsupported for WinCE at present. */
+ /* FIXME: implement it (if possible). */
+# else
+ /* act.sa_restorer is deprecated and should not be initialized. */
+# if defined(GC_IRIX_THREADS)
+ sigaction(SIGSEGV, 0, &oldact);
+ sigaction(SIGSEGV, &act, 0);
+# else
+ {
+ int res = sigaction(SIGSEGV, &act, &oldact);
+ if (res != 0) ABORT("Sigaction failed");
+ }
+# endif
+ if (oldact.sa_flags & SA_SIGINFO) {
+ GC_old_segv_handler = oldact.sa_sigaction;
+ GC_old_segv_handler_used_si = TRUE;
+ } else {
+ GC_old_segv_handler = (SIG_HNDLR_PTR)(signed_word)oldact.sa_handler;
+ GC_old_segv_handler_used_si = FALSE;
+ }
+ if (GC_old_segv_handler == (SIG_HNDLR_PTR)(signed_word)SIG_IGN) {
+ WARN("Previously ignored segmentation violation!?\n", 0);
+ GC_old_segv_handler = (SIG_HNDLR_PTR)(signed_word)SIG_DFL;
+ }
+ if (GC_old_segv_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
+ GC_VERBOSE_LOG_PRINTF("Replaced other SIGSEGV handler\n");
+ }
+# if defined(HPUX) || defined(LINUX) || defined(HURD) \
+ || (defined(FREEBSD) && defined(SUNOS5SIGS))
+ sigaction(SIGBUS, &act, &oldact);
+ if ((oldact.sa_flags & SA_SIGINFO) != 0) {
+ GC_old_bus_handler = oldact.sa_sigaction;
+# if !defined(LINUX)
+ GC_old_bus_handler_used_si = TRUE;
+# endif
+ } else {
+ GC_old_bus_handler = (SIG_HNDLR_PTR)(signed_word)oldact.sa_handler;
+ }
+ if (GC_old_bus_handler == (SIG_HNDLR_PTR)(signed_word)SIG_IGN) {
+ WARN("Previously ignored bus error!?\n", 0);
+# if !defined(LINUX)
+ GC_old_bus_handler = (SIG_HNDLR_PTR)(signed_word)SIG_DFL;
+# else
+ /* GC_old_bus_handler is not used by GC_write_fault_handler. */
+# endif
+ } else if (GC_old_bus_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
+ GC_VERBOSE_LOG_PRINTF("Replaced other SIGBUS handler\n");
+ }
+# endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */
+# endif /* !MSWIN32 && !MSWINCE */
+# if defined(CPPCHECK) && defined(ADDRESS_SANITIZER)
+ GC_noop1((word)&__asan_default_options);
+# endif
+ return TRUE;
+ }
+#endif /* !DARWIN */
+
+GC_API int GC_CALL GC_incremental_protection_needs(void)
+{
+ GC_ASSERT(GC_is_initialized);
+# if defined(GWW_VDB) || defined(SOFT_VDB)
+ /* Only if the incremental mode is already switched on. */
+ if (GC_GWW_AVAILABLE())
+ return GC_PROTECTS_NONE;
+# endif
+ if (GC_page_size == HBLKSIZE) {
+ return GC_PROTECTS_POINTER_HEAP;
+ } else {
+ return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
+ }
+}
+#define HAVE_INCREMENTAL_PROTECTION_NEEDS
+
+#define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
+#define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
+
+STATIC void GC_protect_heap(void)
+{
+ unsigned i;
+ GC_bool protect_all =
+ (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
+
+ GC_ASSERT(GC_page_size != 0);
+ for (i = 0; i < GC_n_heap_sects; i++) {
+ ptr_t start = GC_heap_sects[i].hs_start;
+ size_t len = GC_heap_sects[i].hs_bytes;
+
+ if (protect_all) {
+ PROTECT(start, len);
+ } else {
+ struct hblk * current;
+ struct hblk * current_start; /* Start of block to be protected. */
+ struct hblk * limit;
+
+ GC_ASSERT(PAGE_ALIGNED(len));
+ GC_ASSERT(PAGE_ALIGNED(start));
+ current_start = current = (struct hblk *)start;
+ limit = (struct hblk *)(start + len);
+ while ((word)current < (word)limit) {
+ hdr * hhdr;
+ word nhblks;
+ GC_bool is_ptrfree;
+
+ GC_ASSERT(PAGE_ALIGNED(current));
+ GET_HDR(current, hhdr);
+ if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
+ /* This can happen only if we're at the beginning of a */
+ /* heap segment, and a block spans heap segments. */
+ /* We will handle that block as part of the preceding */
+ /* segment. */
+ GC_ASSERT(current_start == current);
+ current_start = ++current;
+ continue;
+ }
+ if (HBLK_IS_FREE(hhdr)) {
+ GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
+ nhblks = divHBLKSZ(hhdr -> hb_sz);
+ is_ptrfree = TRUE; /* dirty on alloc */
+ } else {
+ nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
+ is_ptrfree = IS_PTRFREE(hhdr);
+ }
+ if (is_ptrfree) {
+ if ((word)current_start < (word)current) {
+ PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
+ }
+ current_start = (current += nhblks);
+ } else {
+ current += nhblks;
+ }
+ }
+ if ((word)current_start < (word)current) {
+ PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
+ }
+ }
+ }
+}
+
+# if defined(CAN_HANDLE_FORK) && defined(DARWIN) && defined(THREADS) \
+ || defined(COUNT_PROTECTED_REGIONS)
+ /* Remove protection for the entire heap not updating GC_dirty_pages. */
+ STATIC void GC_unprotect_all_heap(void)
+ {
+ unsigned i;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ GC_ASSERT(GC_auto_incremental);
+ for (i = 0; i < GC_n_heap_sects; i++) {
+ UNPROTECT(GC_heap_sects[i].hs_start, GC_heap_sects[i].hs_bytes);
+ }
+ }
+# endif /* CAN_HANDLE_FORK && DARWIN && THREADS || COUNT_PROTECTED_REGIONS */
+
+# ifdef COUNT_PROTECTED_REGIONS
+ GC_INNER void GC_handle_protected_regions_limit(void)
+ {
+ GC_ASSERT(GC_page_size != 0);
+ /* To prevent exceeding the limit of vm.max_map_count, the most */
+ /* trivial (though highly restrictive) way is to turn off the */
+ /* incremental collection mode (based on mprotect) once the */
+ /* number of pages in the heap reaches that limit. */
+ if (GC_auto_incremental && !GC_GWW_AVAILABLE()
+ && (signed_word)(GC_heapsize / (word)GC_page_size)
+ >= ((signed_word)GC_UNMAPPED_REGIONS_SOFT_LIMIT
+ - GC_num_unmapped_regions) * 2) {
+ GC_unprotect_all_heap();
+# ifdef DARWIN
+ GC_task_self = 0;
+# endif
+ GC_incremental = FALSE;
+ WARN("GC incremental mode is turned off"
+ " to prevent hitting VM maps limit\n", 0);
+ }
+ }
+# endif /* COUNT_PROTECTED_REGIONS */
+
+#endif /* MPROTECT_VDB */
+
+#if !defined(THREADS) && (defined(PROC_VDB) || defined(SOFT_VDB))
+ static pid_t saved_proc_pid; /* pid used to compose /proc file names */
+#endif
+
+#ifdef PROC_VDB
+/* This implementation assumes a Solaris 2.X like /proc */
+/* pseudo-file-system from which we can read page modified bits. This */
+/* facility is far from optimal (e.g. we would like to get the info for */
+/* only some of the address space), but it avoids intercepting system */
+/* calls. */
+
+# include <errno.h>
+# include <sys/types.h>
+# include <sys/signal.h>
+# include <sys/syscall.h>
+# include <sys/stat.h>
+
+# ifdef GC_NO_SYS_FAULT_H
+ /* This exists only to check PROC_VDB code compilation (on Linux). */
+# define PG_MODIFIED 1
+ struct prpageheader {
+ int dummy[2]; /* pr_tstamp */
+ unsigned long pr_nmap;
+ unsigned long pr_npage;
+ };
+ struct prasmap {
+ char *pr_vaddr;
+ size_t pr_npage;
+ char dummy1[64+8]; /* pr_mapname, pr_offset */
+ unsigned pr_mflags;
+ unsigned pr_pagesize;
+ int dummy2[2];
+ };
+# else
+# include <sys/fault.h>
+# include <sys/procfs.h>
+# endif
+
+# define INITIAL_BUF_SZ 16384
+ STATIC size_t GC_proc_buf_size = INITIAL_BUF_SZ;
+ STATIC char *GC_proc_buf = NULL;
+ STATIC int GC_proc_fd = -1;
+
+ static GC_bool proc_dirty_open_files(void)
+ {
+ char buf[40];
+ pid_t pid = getpid();
+
+ (void)snprintf(buf, sizeof(buf), "/proc/%ld/pagedata", (long)pid);
+ buf[sizeof(buf) - 1] = '\0';
+ GC_proc_fd = open(buf, O_RDONLY);
+ if (-1 == GC_proc_fd) {
+ WARN("/proc open failed; cannot enable GC incremental mode\n", 0);
+ return FALSE;
+ }
+ if (syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC) == -1)
+ WARN("Could not set FD_CLOEXEC for /proc\n", 0);
+# ifndef THREADS
+ saved_proc_pid = pid; /* updated on success only */
+# endif
+ return TRUE;
+ }
+
+# ifdef CAN_HANDLE_FORK
+ GC_INNER void GC_dirty_update_child(void)
+ {
+ if (-1 == GC_proc_fd)
+ return; /* GC incremental mode is off */
+
+ close(GC_proc_fd);
+ if (!proc_dirty_open_files())
+ GC_incremental = FALSE; /* should be safe to turn it off */
+ }
+# endif /* CAN_HANDLE_FORK */
+
+GC_INNER GC_bool GC_dirty_init(void)
+{
+ if (GC_bytes_allocd != 0 || GC_bytes_allocd_before_gc != 0) {
+ memset(GC_written_pages, 0xff, sizeof(page_hash_table));
+ GC_VERBOSE_LOG_PRINTF(
+ "Allocated %lu bytes: all pages may have been written\n",
+ (unsigned long)(GC_bytes_allocd + GC_bytes_allocd_before_gc));
+ }
+ if (!proc_dirty_open_files())
+ return FALSE;
+ GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
+ if (GC_proc_buf == NULL)
+ ABORT("Insufficient space for /proc read");
+ return TRUE;
+}
+
+GC_INLINE void GC_proc_read_dirty(GC_bool output_unneeded)
+{
+ int nmaps;
+ char * bufp = GC_proc_buf;
+ int i;
+
+# ifndef THREADS
+ /* If the current pid differs from the saved one, then we are in */
+ /* the forked (child) process, the current /proc file should be */
+ /* closed, the new one should be opened with the updated path. */
+ /* Note, this is not needed for multi-threaded case because */
+ /* fork_child_proc() reopens the file right after fork. */
+ if (getpid() != saved_proc_pid
+ && (-1 == GC_proc_fd /* no need to retry */
+ || (close(GC_proc_fd), !proc_dirty_open_files()))) {
+ /* Failed to reopen the file. Punt! */
+ if (!output_unneeded)
+ memset(GC_grungy_pages, 0xff, sizeof(page_hash_table));
+ memset(GC_written_pages, 0xff, sizeof(page_hash_table));
+ return;
+ }
+# endif
+
+ BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
+ if (PROC_READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
+ /* Retry with larger buffer. */
+ size_t new_size = 2 * GC_proc_buf_size;
+ char *new_buf;
+
+ WARN("/proc read failed: GC_proc_buf_size= %" WARN_PRIuPTR "\n",
+ GC_proc_buf_size);
+ new_buf = GC_scratch_alloc(new_size);
+ if (new_buf != 0) {
+ GC_scratch_recycle_no_gww(bufp, GC_proc_buf_size);
+ GC_proc_buf = bufp = new_buf;
+ GC_proc_buf_size = new_size;
+ }
+ if (PROC_READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
+ WARN("Insufficient space for /proc read\n", 0);
+ /* Punt: */
+ if (!output_unneeded)
+ memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
+ memset(GC_written_pages, 0xff, sizeof(page_hash_table));
+ return;
+ }
+ }
+
+ /* Copy dirty bits into GC_grungy_pages */
+ nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("Proc VDB read: pr_nmap= %u, pr_npage= %lu\n",
+ nmaps, ((struct prpageheader *)bufp)->pr_npage);
+# endif
+# if defined(GC_NO_SYS_FAULT_H) && defined(CPPCHECK)
+ GC_noop1(((struct prpageheader *)bufp)->dummy[0]);
+# endif
+ bufp += sizeof(struct prpageheader);
+ for (i = 0; i < nmaps; i++) {
+ struct prasmap * map = (struct prasmap *)bufp;
+ ptr_t vaddr = (ptr_t)(map -> pr_vaddr);
+ unsigned long npages = map -> pr_npage;
+ unsigned pagesize = map -> pr_pagesize;
+ ptr_t limit;
+
+# if defined(GC_NO_SYS_FAULT_H) && defined(CPPCHECK)
+ GC_noop1(map->dummy1[0] + map->dummy2[0]);
+# endif
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf(
+ "pr_vaddr= %p, npage= %lu, mflags= 0x%x, pagesize= 0x%x\n",
+ (void *)vaddr, npages, map->pr_mflags, pagesize);
+# endif
+
+ bufp += sizeof(struct prasmap);
+ limit = vaddr + pagesize * npages;
+ for (; (word)vaddr < (word)limit; vaddr += pagesize) {
+ if ((*bufp++) & PG_MODIFIED) {
+ struct hblk * h;
+ ptr_t next_vaddr = vaddr + pagesize;
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("dirty page at: %p\n", (void *)vaddr);
+# endif
+ for (h = (struct hblk *)vaddr;
+ (word)h < (word)next_vaddr; h++) {
+ word index = PHT_HASH(h);
+
+ set_pht_entry_from_index(GC_grungy_pages, index);
+ }
+ }
+ }
+ bufp = (char *)(((word)bufp + (sizeof(long)-1))
+ & ~(word)(sizeof(long)-1));
+ }
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("Proc VDB read done\n");
+# endif
+
+ /* Update GC_written_pages (even if output_unneeded). */
+ GC_or_pages(GC_written_pages, GC_grungy_pages);
+}
+
+#endif /* PROC_VDB */
+
+#ifdef SOFT_VDB
+# ifndef VDB_BUF_SZ
+# define VDB_BUF_SZ 16384
+# endif
+
+ static int open_proc_fd(pid_t pid, const char *proc_filename, int mode)
+ {
+ int f;
+ char buf[40];
+
+ (void)snprintf(buf, sizeof(buf), "/proc/%ld/%s", (long)pid,
+ proc_filename);
+ buf[sizeof(buf) - 1] = '\0';
+ f = open(buf, mode);
+ if (-1 == f) {
+ WARN("/proc/self/%s open failed; cannot enable GC incremental mode\n",
+ proc_filename);
+ } else if (fcntl(f, F_SETFD, FD_CLOEXEC) == -1) {
+ WARN("Could not set FD_CLOEXEC for /proc\n", 0);
+ }
+ return f;
+ }
+
+# include <stdint.h> /* for uint64_t */
+
+ typedef uint64_t pagemap_elem_t;
+
+ static pagemap_elem_t *soft_vdb_buf;
+ static int pagemap_fd;
+
+ static GC_bool soft_dirty_open_files(void)
+ {
+ pid_t pid = getpid();
+
+ clear_refs_fd = open_proc_fd(pid, "clear_refs", O_WRONLY);
+ if (-1 == clear_refs_fd)
+ return FALSE;
+ pagemap_fd = open_proc_fd(pid, "pagemap", O_RDONLY);
+ if (-1 == pagemap_fd) {
+ close(clear_refs_fd);
+ clear_refs_fd = -1;
+ return FALSE;
+ }
+# ifndef THREADS
+ saved_proc_pid = pid; /* updated on success only */
+# endif
+ return TRUE;
+ }
+
+# ifdef CAN_HANDLE_FORK
+ GC_INNER void GC_dirty_update_child(void)
+ {
+ if (-1 == clear_refs_fd)
+ return; /* GC incremental mode is off */
+
+ close(clear_refs_fd);
+ close(pagemap_fd);
+ if (!soft_dirty_open_files())
+ GC_incremental = FALSE;
+ }
+# endif /* CAN_HANDLE_FORK */
+
+ /* Clear soft-dirty bits from the task's PTEs. */
+ static void clear_soft_dirty_bits(void)
+ {
+ ssize_t res = write(clear_refs_fd, "4\n", 2);
+
+ if (res != 2)
+ ABORT_ARG1("Failed to write to /proc/self/clear_refs",
+ ": errno= %d", res < 0 ? errno : 0);
+ }
+
+ /* The bit 55 of the 64-bit qword of pagemap file is the soft-dirty one. */
+# define PM_SOFTDIRTY_MASK ((pagemap_elem_t)1 << 55)
+
+ static GC_bool detect_soft_dirty_supported(ptr_t vaddr)
+ {
+ off_t fpos;
+ pagemap_elem_t buf[1];
+
+ GC_ASSERT(GC_page_size != 0);
+ *vaddr = 1; /* make it dirty */
+ fpos = (off_t)((word)vaddr / GC_page_size * sizeof(pagemap_elem_t));
+
+ for (;;) {
+ /* Read the relevant PTE from the pagemap file. */
+ if (lseek(pagemap_fd, fpos, SEEK_SET) == (off_t)(-1))
+ return FALSE;
+ if (PROC_READ(pagemap_fd, buf, sizeof(buf)) != (int)sizeof(buf))
+ return FALSE;
+
+ /* Is the soft-dirty bit unset? */
+ if ((buf[0] & PM_SOFTDIRTY_MASK) == 0) return FALSE;
+
+ if (0 == *vaddr) break;
+ /* Retry to check that writing to clear_refs works as expected. */
+ /* This malfunction of the soft-dirty bits implementation is */
+ /* observed on some Linux kernels on Power9 (e.g. in Fedora 36). */
+ clear_soft_dirty_bits();
+ *vaddr = 0;
+ }
+ return TRUE; /* success */
+ }
+
+# ifndef NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK
+# include <sys/utsname.h>
+# include <string.h> /* for strcmp() */
+
+ /* Ensure the linux (kernel) major/minor version is as given or higher. */
+ static GC_bool ensure_min_linux_ver(int major, int minor) {
+ struct utsname info;
+ int actual_major;
+ int actual_minor = -1;
+
+ if (uname(&info) == -1) {
+ return FALSE; /* uname() failed, should not happen actually. */
+ }
+ if (strcmp(info.sysname, "Linux")) {
+ WARN("Cannot ensure Linux version as running on other OS: %s\n",
+ info.sysname);
+ return FALSE;
+ }
+ actual_major = GC_parse_version(&actual_minor, info.release);
+ return actual_major > major
+ || (actual_major == major && actual_minor >= minor);
+ }
+# endif
+
+# ifdef MPROTECT_VDB
+ static GC_bool soft_dirty_init(void)
+# else
+ GC_INNER GC_bool GC_dirty_init(void)
+# endif
+ {
+# ifdef MPROTECT_VDB
+ char * str = GETENV("GC_USE_GETWRITEWATCH");
+
+# ifdef GC_PREFER_MPROTECT_VDB
+ if (str == NULL || (*str == '0' && *(str + 1) == '\0'))
+ return FALSE; /* the environment variable is unset or set to "0" */
+# else
+ if (str != NULL && *str == '0' && *(str + 1) == '\0')
+ return FALSE; /* the environment variable is set "0" */
+# endif
+# endif
+ GC_ASSERT(NULL == soft_vdb_buf);
+# ifndef NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK
+ if (!ensure_min_linux_ver(3, 18)) {
+ GC_COND_LOG_PRINTF(
+ "Running on old kernel lacking correct soft-dirty bit support\n");
+ return FALSE;
+ }
+# endif
+ if (!soft_dirty_open_files())
+ return FALSE;
+ soft_vdb_buf = (pagemap_elem_t *)GC_scratch_alloc(VDB_BUF_SZ);
+ if (NULL == soft_vdb_buf)
+ ABORT("Insufficient space for /proc pagemap buffer");
+ if (!detect_soft_dirty_supported((ptr_t)soft_vdb_buf)) {
+ GC_COND_LOG_PRINTF("Soft-dirty bit is not supported by kernel\n");
+ /* Release the resources. */
+ GC_scratch_recycle_no_gww(soft_vdb_buf, VDB_BUF_SZ);
+ soft_vdb_buf = NULL;
+ close(clear_refs_fd);
+ clear_refs_fd = -1;
+ close(pagemap_fd);
+ return FALSE;
+ }
+ return TRUE;
+ }
+
+ static off_t pagemap_buf_fpos; /* valid only if pagemap_buf_len > 0 */
+ static size_t pagemap_buf_len;
+
+ /* Read bytes from /proc/self/pagemap at given file position. */
+ /* len - the maximum number of bytes to read; (*pres) - amount of */
+ /* bytes actually read, always bigger than 0 but never exceeds len; */
+ /* next_fpos_hint - the file position of the next bytes block to read */
+ /* ahead if possible (0 means no information provided). */
+ static const pagemap_elem_t *pagemap_buffered_read(size_t *pres,
+ off_t fpos, size_t len,
+ off_t next_fpos_hint)
+ {
+ ssize_t res;
+ size_t ofs;
+
+ GC_ASSERT(len > 0);
+ if (pagemap_buf_fpos <= fpos
+ && fpos < pagemap_buf_fpos + (off_t)pagemap_buf_len) {
+ /* The requested data is already in the buffer. */
+ ofs = (size_t)(fpos - pagemap_buf_fpos);
+ res = (ssize_t)(pagemap_buf_fpos + pagemap_buf_len - fpos);
+ } else {
+ off_t aligned_pos = fpos & ~(off_t)(GC_page_size < VDB_BUF_SZ
+ ? GC_page_size-1 : VDB_BUF_SZ-1);
+
+ for (;;) {
+ size_t count;
+
+ if ((0 == pagemap_buf_len
+ || pagemap_buf_fpos + (off_t)pagemap_buf_len != aligned_pos)
+ && lseek(pagemap_fd, aligned_pos, SEEK_SET) == (off_t)(-1))
+ ABORT_ARG2("Failed to lseek /proc/self/pagemap",
+ ": offset= %lu, errno= %d", (unsigned long)fpos, errno);
+
+ /* How much to read at once? */
+ ofs = (size_t)(fpos - aligned_pos);
+ GC_ASSERT(ofs < VDB_BUF_SZ);
+ if (next_fpos_hint > aligned_pos
+ && next_fpos_hint - aligned_pos < VDB_BUF_SZ) {
+ count = VDB_BUF_SZ;
+ } else {
+ count = len + ofs;
+ if (count > VDB_BUF_SZ)
+ count = VDB_BUF_SZ;
+ }
+
+ GC_ASSERT(count % sizeof(pagemap_elem_t) == 0);
+ res = PROC_READ(pagemap_fd, soft_vdb_buf, count);
+ if (res > (ssize_t)ofs)
+ break;
+ if (res <= 0)
+ ABORT_ARG1("Failed to read /proc/self/pagemap",
+ ": errno= %d", res < 0 ? errno : 0);
+ /* Retry (once) w/o page-alignment. */
+ aligned_pos = fpos;
+ }
+
+ /* Save the buffer (file window) position and size. */
+ pagemap_buf_fpos = aligned_pos;
+ pagemap_buf_len = (size_t)res;
+ res -= (ssize_t)ofs;
+ }
+
+ GC_ASSERT(ofs % sizeof(pagemap_elem_t) == 0);
+ *pres = (size_t)res < len ? (size_t)res : len;
+ return &soft_vdb_buf[ofs / sizeof(pagemap_elem_t)];
+ }
+
+ static void soft_set_grungy_pages(ptr_t start, ptr_t limit,
+ ptr_t next_start_hint)
+ {
+ word vaddr = (word)start & ~(word)(GC_page_size-1);
+ off_t next_fpos_hint;
+
+ GC_ASSERT(modHBLKSZ((word)start) == 0);
+ GC_ASSERT(GC_page_size != 0);
+ next_fpos_hint = (off_t)((word)next_start_hint / GC_page_size
+ * sizeof(pagemap_elem_t));
+ while (vaddr < (word)limit) {
+ size_t res;
+ word limit_buf;
+ const pagemap_elem_t *bufp = pagemap_buffered_read(&res,
+ (off_t)(vaddr / GC_page_size * sizeof(pagemap_elem_t)),
+ (size_t)(((word)limit - vaddr + GC_page_size-1) / GC_page_size
+ * sizeof(pagemap_elem_t)),
+ next_fpos_hint);
+
+ if (res % sizeof(pagemap_elem_t) != 0) {
+ /* Punt: */
+ memset(GC_grungy_pages, 0xff, sizeof(page_hash_table));
+ WARN("Incomplete read of pagemap, not multiple of entry size\n", 0);
+ break;
+ }
+
+ limit_buf = vaddr + (res / sizeof(pagemap_elem_t)) * GC_page_size;
+ for (; vaddr < limit_buf; vaddr += GC_page_size, bufp++)
+ if ((*bufp & PM_SOFTDIRTY_MASK) != 0) {
+ struct hblk * h;
+ word next_vaddr = vaddr + GC_page_size;
+
+ if (EXPECT(next_vaddr > (word)limit, FALSE))
+ next_vaddr = (word)limit;
+ /* If the bit is set, the respective PTE was written to */
+ /* since clearing the soft-dirty bits. */
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("dirty page at: %p\n", (void *)vaddr);
+# endif
+ h = (struct hblk *)vaddr;
+ if (EXPECT(vaddr < (word)start, FALSE))
+ h = (struct hblk *)start;
+ for (; (word)h < next_vaddr; h++) {
+ word index = PHT_HASH(h);
+ set_pht_entry_from_index(GC_grungy_pages, index);
+ }
+ }
+ /* Read the next portion of pagemap file if incomplete. */
+ }
+ }
+
+ GC_INLINE void GC_soft_read_dirty(GC_bool output_unneeded)
+ {
+# ifndef THREADS
+ /* Similar as for GC_proc_read_dirty. */
+ if (getpid() != saved_proc_pid
+ && (-1 == clear_refs_fd /* no need to retry */
+ || (close(clear_refs_fd), close(pagemap_fd),
+ !soft_dirty_open_files()))) {
+ /* Failed to reopen the files. */
+ if (!output_unneeded) {
+ /* Punt: */
+ memset(GC_grungy_pages, 0xff, sizeof(page_hash_table));
+# ifdef CHECKSUMS
+ memset(GC_written_pages, 0xff, sizeof(page_hash_table));
+# endif
+ }
+ return;
+ }
+# endif
+
+ if (!output_unneeded) {
+ word i;
+
+ BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
+ pagemap_buf_len = 0; /* invalidate soft_vdb_buf */
+
+ for (i = 0; i != GC_n_heap_sects; ++i) {
+ ptr_t start = GC_heap_sects[i].hs_start;
+
+ soft_set_grungy_pages(start, start + GC_heap_sects[i].hs_bytes,
+ i < GC_n_heap_sects-1 ?
+ GC_heap_sects[i+1].hs_start : NULL);
+ }
+# ifdef CHECKSUMS
+ GC_or_pages(GC_written_pages, GC_grungy_pages);
+# endif
+
+# ifndef NO_VDB_FOR_STATIC_ROOTS
+ for (i = 0; (int)i < n_root_sets; ++i) {
+ soft_set_grungy_pages((ptr_t)HBLKPTR(GC_static_roots[i].r_start),
+ GC_static_roots[i].r_end,
+ (int)i < n_root_sets-1 ?
+ GC_static_roots[i+1].r_start : NULL);
+ }
+# endif
+ }
+
+ clear_soft_dirty_bits();
+ }
+#endif /* SOFT_VDB */
+
+#ifdef PCR_VDB
+
+# include "vd/PCR_VD.h"
+
+# define NPAGES (32*1024) /* 128 MB */
+
+PCR_VD_DB GC_grungy_bits[NPAGES];
+
+STATIC ptr_t GC_vd_base = NULL;
+ /* Address corresponding to GC_grungy_bits[0] */
+ /* HBLKSIZE aligned. */
+
+GC_INNER GC_bool GC_dirty_init(void)
+{
+ /* For the time being, we assume the heap generally grows up */
+ GC_vd_base = GC_heap_sects[0].hs_start;
+ if (GC_vd_base == 0) {
+ ABORT("Bad initial heap segment");
+ }
+ if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
+ != PCR_ERes_okay) {
+ ABORT("Dirty bit initialization failed");
+ }
+ return TRUE;
+}
+#endif /* PCR_VDB */
+
+#ifndef GC_DISABLE_INCREMENTAL
+ GC_INNER GC_bool GC_manual_vdb = FALSE;
+
+ /* Manually mark the page containing p as dirty. Logically, this */
+ /* dirties the entire object. */
+ GC_INNER void GC_dirty_inner(const void *p)
+ {
+ word index = PHT_HASH(p);
+
+# if defined(MPROTECT_VDB)
+ /* Do not update GC_dirty_pages if it should be followed by the */
+ /* page unprotection. */
+ GC_ASSERT(GC_manual_vdb);
+# endif
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+
+ /* Retrieve system dirty bits for the heap to a local buffer (unless */
+ /* output_unneeded). Restore the systems notion of which pages are */
+ /* dirty. We assume that either the world is stopped or it is OK to */
+ /* lose dirty bits while it's happening (as in GC_enable_incremental).*/
+ GC_INNER void GC_read_dirty(GC_bool output_unneeded)
+ {
+ if (GC_manual_vdb
+# if defined(MPROTECT_VDB)
+ || !GC_GWW_AVAILABLE()
+# endif
+ ) {
+ if (!output_unneeded)
+ BCOPY((/* no volatile */ void *)GC_dirty_pages, GC_grungy_pages,
+ sizeof(GC_dirty_pages));
+ BZERO((/* no volatile */ void *)GC_dirty_pages,
+ sizeof(GC_dirty_pages));
+# ifdef MPROTECT_VDB
+ if (!GC_manual_vdb)
+ GC_protect_heap();
+# endif
+ return;
+ }
+
+# ifdef GWW_VDB
+ GC_gww_read_dirty(output_unneeded);
+# elif defined(PROC_VDB)
+ GC_proc_read_dirty(output_unneeded);
+# elif defined(SOFT_VDB)
+ GC_soft_read_dirty(output_unneeded);
+# elif defined(PCR_VDB)
+ /* lazily enable dirty bits on newly added heap sects */
+ {
+ static int onhs = 0;
+ int nhs = GC_n_heap_sects;
+ for (; onhs < nhs; onhs++) {
+ PCR_VD_WriteProtectEnable(
+ GC_heap_sects[onhs].hs_start,
+ GC_heap_sects[onhs].hs_bytes);
+ }
+ }
+ if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
+ != PCR_ERes_okay) {
+ ABORT("Dirty bit read failed");
+ }
+# endif
+ }
+
+# if !defined(NO_VDB_FOR_STATIC_ROOTS) && !defined(PROC_VDB)
+ GC_INNER GC_bool GC_is_vdb_for_static_roots(void)
+ {
+ if (GC_manual_vdb) return FALSE;
+# if defined(MPROTECT_VDB)
+ /* Currently used only in conjunction with SOFT_VDB. */
+ return GC_GWW_AVAILABLE();
+# else
+ GC_ASSERT(GC_incremental);
+ return TRUE;
+# endif
+ }
+# endif
+
+ /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
+ /* If the actual page size is different, this returns TRUE if any */
+ /* of the pages overlapping h are dirty. This routine may err on the */
+ /* side of labeling pages as dirty (and this implementation does). */
+ GC_INNER GC_bool GC_page_was_dirty(struct hblk *h)
+ {
+ word index;
+
+# ifdef PCR_VDB
+ if (!GC_manual_vdb) {
+ if ((word)h < (word)GC_vd_base
+ || (word)h >= (word)(GC_vd_base + NPAGES * HBLKSIZE)) {
+ return TRUE;
+ }
+ return GC_grungy_bits[h-(struct hblk*)GC_vd_base] & PCR_VD_DB_dirtyBit;
+ }
+# elif defined(DEFAULT_VDB)
+ if (!GC_manual_vdb)
+ return TRUE;
+# elif defined(PROC_VDB)
+ /* Unless manual VDB is on, the bitmap covers all process memory. */
+ if (GC_manual_vdb)
+# endif
+ {
+ if (NULL == HDR(h))
+ return TRUE;
+ }
+ index = PHT_HASH(h);
+ return get_pht_entry_from_index(GC_grungy_pages, index);
+ }
+
+# if defined(CHECKSUMS) || defined(PROC_VDB)
+ /* Could any valid GC heap pointer ever have been written to this page? */
+ GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk *h)
+ {
+# if defined(GWW_VDB) || defined(PROC_VDB) || defined(SOFT_VDB)
+ word index;
+
+# ifdef MPROTECT_VDB
+ if (!GC_GWW_AVAILABLE())
+ return TRUE;
+# endif
+# if defined(PROC_VDB)
+ if (GC_manual_vdb)
+# endif
+ {
+ if (NULL == HDR(h))
+ return TRUE;
+ }
+ index = PHT_HASH(h);
+ return get_pht_entry_from_index(GC_written_pages, index);
+# else
+ /* TODO: implement me for MANUAL_VDB. */
+ (void)h;
+ return TRUE;
+# endif
+ }
+# endif /* CHECKSUMS || PROC_VDB */
+
+ /* We expect block h to be written shortly. Ensure that all pages */
+ /* containing any part of the n hblks starting at h are no longer */
+ /* protected. If is_ptrfree is false, also ensure that they will */
+ /* subsequently appear to be dirty. Not allowed to call GC_printf */
+ /* (and the friends) here, see Win32 GC_stop_world for the details. */
+ GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
+ GC_bool is_ptrfree)
+ {
+# ifdef PCR_VDB
+ (void)is_ptrfree;
+ if (!GC_auto_incremental)
+ return;
+ PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
+ PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
+# elif defined(MPROTECT_VDB)
+ struct hblk * h_trunc; /* Truncated to page boundary */
+ struct hblk * h_end; /* Page boundary following block end */
+ struct hblk * current;
+
+ if (!GC_auto_incremental || GC_GWW_AVAILABLE())
+ return;
+ GC_ASSERT(GC_page_size != 0);
+ h_trunc = (struct hblk *)((word)h & ~(word)(GC_page_size-1));
+ h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size - 1)
+ & ~(word)(GC_page_size - 1));
+ /* Note that we cannot examine GC_dirty_pages to check */
+ /* whether the page at h_trunc has already been marked */
+ /* dirty as there could be a hash collision. */
+ for (current = h_trunc; (word)current < (word)h_end; ++current) {
+ word index = PHT_HASH(current);
+
+ if (!is_ptrfree || (word)current < (word)h
+ || (word)current >= (word)(h + nblocks)) {
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ }
+ UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
+# else
+ /* Ignore write hints. They don't help us here. */
+ (void)h; (void)nblocks; (void)is_ptrfree;
+# endif
+ }
+#endif /* !GC_DISABLE_INCREMENTAL */
+
+#if defined(MPROTECT_VDB) && defined(DARWIN)
+/* The following sources were used as a "reference" for this exception
+ handling code:
+ 1. Apple's mach/xnu documentation
+ 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
+ omnigroup's macosx-dev list.
+ www.omnigroup.com/mailman/archive/macosx-dev/2000-June/014178.html
+ 3. macosx-nat.c from Apple's GDB source code.
+*/
+
+/* The bug that caused all this trouble should now be fixed. This should
+ eventually be removed if all goes well. */
+
+/* #define BROKEN_EXCEPTION_HANDLING */
+
+#include <mach/mach.h>
+#include <mach/mach_error.h>
+#include <mach/exception.h>
+#include <mach/task.h>
+
+EXTERN_C_BEGIN
+
+/* Some of the following prototypes are missing in any header, although */
+/* they are documented. Some are in mach/exc.h file. */
+extern boolean_t
+exc_server(mach_msg_header_t *, mach_msg_header_t *);
+
+extern kern_return_t
+exception_raise(mach_port_t, mach_port_t, mach_port_t, exception_type_t,
+ exception_data_t, mach_msg_type_number_t);
+
+extern kern_return_t
+exception_raise_state(mach_port_t, mach_port_t, mach_port_t, exception_type_t,
+ exception_data_t, mach_msg_type_number_t,
+ thread_state_flavor_t*, thread_state_t,
+ mach_msg_type_number_t, thread_state_t,
+ mach_msg_type_number_t*);
+
+extern kern_return_t
+exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
+ exception_type_t, exception_data_t,
+ mach_msg_type_number_t, thread_state_flavor_t*,
+ thread_state_t, mach_msg_type_number_t,
+ thread_state_t, mach_msg_type_number_t*);
+
+GC_API_OSCALL kern_return_t
+catch_exception_raise(mach_port_t exception_port, mach_port_t thread,
+ mach_port_t task, exception_type_t exception,
+ exception_data_t code,
+ mach_msg_type_number_t code_count);
+
+GC_API_OSCALL kern_return_t
+catch_exception_raise_state(mach_port_name_t exception_port,
+ int exception, exception_data_t code,
+ mach_msg_type_number_t codeCnt, int flavor,
+ thread_state_t old_state, int old_stateCnt,
+ thread_state_t new_state, int new_stateCnt);
+
+GC_API_OSCALL kern_return_t
+catch_exception_raise_state_identity(mach_port_name_t exception_port,
+ mach_port_t thread, mach_port_t task, int exception,
+ exception_data_t code, mach_msg_type_number_t codeCnt,
+ int flavor, thread_state_t old_state, int old_stateCnt,
+ thread_state_t new_state, int new_stateCnt);
+
+EXTERN_C_END
+
+/* These should never be called, but just in case... */
+GC_API_OSCALL kern_return_t
+catch_exception_raise_state(mach_port_name_t exception_port GC_ATTR_UNUSED,
+ int exception GC_ATTR_UNUSED, exception_data_t code GC_ATTR_UNUSED,
+ mach_msg_type_number_t codeCnt GC_ATTR_UNUSED, int flavor GC_ATTR_UNUSED,
+ thread_state_t old_state GC_ATTR_UNUSED, int old_stateCnt GC_ATTR_UNUSED,
+ thread_state_t new_state GC_ATTR_UNUSED, int new_stateCnt GC_ATTR_UNUSED)
+{
+ ABORT_RET("Unexpected catch_exception_raise_state invocation");
+ return(KERN_INVALID_ARGUMENT);
+}
+
+GC_API_OSCALL kern_return_t
+catch_exception_raise_state_identity(
+ mach_port_name_t exception_port GC_ATTR_UNUSED,
+ mach_port_t thread GC_ATTR_UNUSED, mach_port_t task GC_ATTR_UNUSED,
+ int exception GC_ATTR_UNUSED, exception_data_t code GC_ATTR_UNUSED,
+ mach_msg_type_number_t codeCnt GC_ATTR_UNUSED, int flavor GC_ATTR_UNUSED,
+ thread_state_t old_state GC_ATTR_UNUSED, int old_stateCnt GC_ATTR_UNUSED,
+ thread_state_t new_state GC_ATTR_UNUSED, int new_stateCnt GC_ATTR_UNUSED)
+{
+ ABORT_RET("Unexpected catch_exception_raise_state_identity invocation");
+ return(KERN_INVALID_ARGUMENT);
+}
+
+#define MAX_EXCEPTION_PORTS 16
+
+static struct {
+ mach_msg_type_number_t count;
+ exception_mask_t masks[MAX_EXCEPTION_PORTS];
+ exception_handler_t ports[MAX_EXCEPTION_PORTS];
+ exception_behavior_t behaviors[MAX_EXCEPTION_PORTS];
+ thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
+} GC_old_exc_ports;
+
+STATIC struct ports_s {
+ void (*volatile os_callback[3])(void);
+ mach_port_t exception;
+# if defined(THREADS)
+ mach_port_t reply;
+# endif
+} GC_ports = {
+ {
+ /* This is to prevent stripping these routines as dead. */
+ (void (*)(void))catch_exception_raise,
+ (void (*)(void))catch_exception_raise_state,
+ (void (*)(void))catch_exception_raise_state_identity
+ },
+# ifdef THREADS
+ 0, /* for 'exception' */
+# endif
+ 0
+};
+
+typedef struct {
+ mach_msg_header_t head;
+} GC_msg_t;
+
+typedef enum {
+ GC_MP_NORMAL,
+ GC_MP_DISCARDING,
+ GC_MP_STOPPED
+} GC_mprotect_state_t;
+
+#ifdef THREADS
+ /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field, but it */
+ /* is not documented. Use the source and see if they should be OK. */
+# define ID_STOP 1
+# define ID_RESUME 2
+
+ /* This value is only used on the reply port. */
+# define ID_ACK 3
+
+ STATIC GC_mprotect_state_t GC_mprotect_state = GC_MP_NORMAL;
+
+ /* The following should ONLY be called when the world is stopped. */
+ STATIC void GC_mprotect_thread_notify(mach_msg_id_t id)
+ {
+ struct buf_s {
+ GC_msg_t msg;
+ mach_msg_trailer_t trailer;
+ } buf;
+ mach_msg_return_t r;
+
+ /* remote, local */
+ buf.msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0);
+ buf.msg.head.msgh_size = sizeof(buf.msg);
+ buf.msg.head.msgh_remote_port = GC_ports.exception;
+ buf.msg.head.msgh_local_port = MACH_PORT_NULL;
+ buf.msg.head.msgh_id = id;
+
+ r = mach_msg(&buf.msg.head, MACH_SEND_MSG | MACH_RCV_MSG | MACH_RCV_LARGE,
+ sizeof(buf.msg), sizeof(buf), GC_ports.reply,
+ MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+ if (r != MACH_MSG_SUCCESS)
+ ABORT("mach_msg failed in GC_mprotect_thread_notify");
+ if (buf.msg.head.msgh_id != ID_ACK)
+ ABORT("Invalid ack in GC_mprotect_thread_notify");
+ }
+
+ /* Should only be called by the mprotect thread */
+ STATIC void GC_mprotect_thread_reply(void)
+ {
+ GC_msg_t msg;
+ mach_msg_return_t r;
+ /* remote, local */
+
+ msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0);
+ msg.head.msgh_size = sizeof(msg);
+ msg.head.msgh_remote_port = GC_ports.reply;
+ msg.head.msgh_local_port = MACH_PORT_NULL;
+ msg.head.msgh_id = ID_ACK;
+
+ r = mach_msg(&msg.head, MACH_SEND_MSG, sizeof(msg), 0, MACH_PORT_NULL,
+ MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+ if (r != MACH_MSG_SUCCESS)
+ ABORT("mach_msg failed in GC_mprotect_thread_reply");
+ }
+
+ GC_INNER void GC_mprotect_stop(void)
+ {
+ GC_mprotect_thread_notify(ID_STOP);
+ }
+
+ GC_INNER void GC_mprotect_resume(void)
+ {
+ GC_mprotect_thread_notify(ID_RESUME);
+ }
+
+# ifdef CAN_HANDLE_FORK
+ GC_INNER void GC_dirty_update_child(void)
+ {
+ GC_ASSERT(I_HOLD_LOCK());
+ if (0 == GC_task_self) return; /* GC incremental mode is off */
+
+ GC_ASSERT(GC_mprotect_state == GC_MP_NORMAL);
+ GC_task_self = mach_task_self(); /* needed by UNPROTECT() */
+ GC_unprotect_all_heap();
+
+ /* Restore the old task exception ports. */
+ /* TODO: Should we do it in fork_prepare/parent_proc? */
+ if (GC_old_exc_ports.count > 0) {
+ /* TODO: Should we check GC_old_exc_ports.count<=1? */
+ if (task_set_exception_ports(GC_task_self, GC_old_exc_ports.masks[0],
+ GC_old_exc_ports.ports[0], GC_old_exc_ports.behaviors[0],
+ GC_old_exc_ports.flavors[0]) != KERN_SUCCESS)
+ ABORT("task_set_exception_ports failed (in child)");
+ }
+
+ /* TODO: Re-enable incremental mode in child. */
+ GC_task_self = 0;
+ GC_incremental = FALSE;
+ }
+# endif /* CAN_HANDLE_FORK */
+
+#else
+ /* The compiler should optimize away any GC_mprotect_state computations */
+# define GC_mprotect_state GC_MP_NORMAL
+#endif /* !THREADS */
+
+struct mp_reply_s {
+ mach_msg_header_t head;
+ char data[256];
+};
+
+struct mp_msg_s {
+ mach_msg_header_t head;
+ mach_msg_body_t msgh_body;
+ char data[1024];
+};
+
+STATIC void *GC_mprotect_thread(void *arg)
+{
+ mach_msg_return_t r;
+ /* These two structures contain some private kernel data. We don't */
+ /* need to access any of it so we don't bother defining a proper */
+ /* struct. The correct definitions are in the xnu source code. */
+ struct mp_reply_s reply;
+ struct mp_msg_s msg;
+ mach_msg_id_t id;
+
+ if ((word)arg == GC_WORD_MAX) return 0; /* to prevent a compiler warning */
+# if defined(CPPCHECK)
+ reply.data[0] = 0; /* to prevent "field unused" warnings */
+ msg.data[0] = 0;
+# endif
+
+# if defined(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID)
+ (void)pthread_setname_np("GC-mprotect");
+# endif
+# if defined(THREADS) && !defined(GC_NO_THREADS_DISCOVERY)
+ GC_darwin_register_mach_handler_thread(mach_thread_self());
+# endif
+
+ for (;;) {
+ r = mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE |
+ (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT
+ : 0), 0, sizeof(msg), GC_ports.exception,
+ GC_mprotect_state == GC_MP_DISCARDING ? 0
+ : MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+ id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
+
+# if defined(THREADS)
+ if (GC_mprotect_state == GC_MP_DISCARDING) {
+ if (r == MACH_RCV_TIMED_OUT) {
+ GC_mprotect_state = GC_MP_STOPPED;
+ GC_mprotect_thread_reply();
+ continue;
+ }
+ if (r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
+ ABORT("Out of order mprotect thread request");
+ }
+# endif /* THREADS */
+
+ if (r != MACH_MSG_SUCCESS) {
+ ABORT_ARG2("mach_msg failed",
+ ": errcode= %d (%s)", (int)r, mach_error_string(r));
+ }
+
+ switch (id) {
+# if defined(THREADS)
+ case ID_STOP:
+ if (GC_mprotect_state != GC_MP_NORMAL)
+ ABORT("Called mprotect_stop when state wasn't normal");
+ GC_mprotect_state = GC_MP_DISCARDING;
+ break;
+ case ID_RESUME:
+ if (GC_mprotect_state != GC_MP_STOPPED)
+ ABORT("Called mprotect_resume when state wasn't stopped");
+ GC_mprotect_state = GC_MP_NORMAL;
+ GC_mprotect_thread_reply();
+ break;
+# endif /* THREADS */
+ default:
+ /* Handle the message (calls catch_exception_raise) */
+ if (!exc_server(&msg.head, &reply.head))
+ ABORT("exc_server failed");
+ /* Send the reply */
+ r = mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0,
+ MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE,
+ MACH_PORT_NULL);
+ if (r != MACH_MSG_SUCCESS) {
+ /* This will fail if the thread dies, but the thread */
+ /* shouldn't die... */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ GC_err_printf("mach_msg failed with %d %s while sending "
+ "exc reply\n", (int)r, mach_error_string(r));
+# else
+ ABORT("mach_msg failed while sending exception reply");
+# endif
+ }
+ } /* switch */
+ } /* for */
+}
+
+/* All this SIGBUS code shouldn't be necessary. All protection faults should
+ be going through the mach exception handler. However, it seems a SIGBUS is
+ occasionally sent for some unknown reason. Even more odd, it seems to be
+ meaningless and safe to ignore. */
+#ifdef BROKEN_EXCEPTION_HANDLING
+
+ /* Updates to this aren't atomic, but the SIGBUS'es seem pretty rare. */
+ /* Even if this doesn't get updated property, it isn't really a problem. */
+ STATIC int GC_sigbus_count = 0;
+
+ STATIC void GC_darwin_sigbus(int num, siginfo_t *sip, void *context)
+ {
+ if (num != SIGBUS)
+ ABORT("Got a non-sigbus signal in the sigbus handler");
+
+ /* Ugh... some seem safe to ignore, but too many in a row probably means
+ trouble. GC_sigbus_count is reset for each mach exception that is
+ handled */
+ if (GC_sigbus_count >= 8) {
+ ABORT("Got more than 8 SIGBUSs in a row!");
+ } else {
+ GC_sigbus_count++;
+ WARN("Ignoring SIGBUS\n", 0);
+ }
+ }
+#endif /* BROKEN_EXCEPTION_HANDLING */
+
+GC_INNER GC_bool GC_dirty_init(void)
+{
+ kern_return_t r;
+ mach_port_t me;
+ pthread_t thread;
+ pthread_attr_t attr;
+ exception_mask_t mask;
+
+# if defined(CAN_HANDLE_FORK) && !defined(THREADS)
+ if (GC_handle_fork) {
+ /* To both support GC incremental mode and GC functions usage in */
+ /* the forked child, pthread_atfork should be used to install */
+ /* handlers that switch off GC_incremental in the child */
+ /* gracefully (unprotecting all pages and clearing */
+ /* GC_mach_handler_thread). For now, we just disable incremental */
+ /* mode if fork() handling is requested by the client. */
+ WARN("Can't turn on GC incremental mode as fork()"
+ " handling requested\n", 0);
+ return FALSE;
+ }
+# endif
+
+ GC_VERBOSE_LOG_PRINTF("Initializing mach/darwin mprotect"
+ " virtual dirty bit implementation\n");
+# ifdef BROKEN_EXCEPTION_HANDLING
+ WARN("Enabling workarounds for various darwin "
+ "exception handling bugs\n", 0);
+# endif
+ if (GC_page_size % HBLKSIZE != 0) {
+ ABORT("Page size not multiple of HBLKSIZE");
+ }
+
+ GC_task_self = me = mach_task_self();
+ GC_ASSERT(me != 0);
+
+ r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.exception);
+ /* TODO: WARN and return FALSE in case of a failure. */
+ if (r != KERN_SUCCESS)
+ ABORT("mach_port_allocate failed (exception port)");
+
+ r = mach_port_insert_right(me, GC_ports.exception, GC_ports.exception,
+ MACH_MSG_TYPE_MAKE_SEND);
+ if (r != KERN_SUCCESS)
+ ABORT("mach_port_insert_right failed (exception port)");
+
+# if defined(THREADS)
+ r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.reply);
+ if(r != KERN_SUCCESS)
+ ABORT("mach_port_allocate failed (reply port)");
+# endif
+
+ /* The exceptions we want to catch. */
+ mask = EXC_MASK_BAD_ACCESS;
+ r = task_get_exception_ports(me, mask, GC_old_exc_ports.masks,
+ &GC_old_exc_ports.count, GC_old_exc_ports.ports,
+ GC_old_exc_ports.behaviors,
+ GC_old_exc_ports.flavors);
+ if (r != KERN_SUCCESS)
+ ABORT("task_get_exception_ports failed");
+
+ r = task_set_exception_ports(me, mask, GC_ports.exception, EXCEPTION_DEFAULT,
+ GC_MACH_THREAD_STATE);
+ if (r != KERN_SUCCESS)
+ ABORT("task_set_exception_ports failed");
+
+ if (pthread_attr_init(&attr) != 0)
+ ABORT("pthread_attr_init failed");
+ if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0)
+ ABORT("pthread_attr_setdetachedstate failed");
+ /* This will call the real pthread function, not our wrapper. */
+ if (GC_inner_pthread_create(&thread, &attr, GC_mprotect_thread, NULL) != 0)
+ ABORT("pthread_create failed");
+ (void)pthread_attr_destroy(&attr);
+
+ /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ {
+ struct sigaction sa, oldsa;
+ sa.sa_handler = (SIG_HNDLR_PTR)GC_darwin_sigbus;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART|SA_SIGINFO;
+ /* sa.sa_restorer is deprecated and should not be initialized. */
+ if (sigaction(SIGBUS, &sa, &oldsa) < 0)
+ ABORT("sigaction failed");
+ if (oldsa.sa_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) {
+ GC_VERBOSE_LOG_PRINTF("Replaced other SIGBUS handler\n");
+ }
+ }
+# endif /* BROKEN_EXCEPTION_HANDLING */
+# if defined(CPPCHECK)
+ GC_noop1((word)GC_ports.os_callback[0]);
+# endif
+ return TRUE;
+}
+
+/* The source code for Apple's GDB was used as a reference for the */
+/* exception forwarding code. This code is similar to be GDB code only */
+/* because there is only one way to do it. */
+STATIC kern_return_t GC_forward_exception(mach_port_t thread, mach_port_t task,
+ exception_type_t exception,
+ exception_data_t data,
+ mach_msg_type_number_t data_count)
+{
+ unsigned int i;
+ kern_return_t r;
+ mach_port_t port;
+ exception_behavior_t behavior;
+ thread_state_flavor_t flavor;
+
+ thread_state_data_t thread_state;
+ mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
+
+ for (i = 0; i < GC_old_exc_ports.count; i++) {
+ if ((GC_old_exc_ports.masks[i] & ((exception_mask_t)1 << exception)) != 0)
+ break;
+ }
+ if (i == GC_old_exc_ports.count)
+ ABORT("No handler for exception!");
+
+ port = GC_old_exc_ports.ports[i];
+ behavior = GC_old_exc_ports.behaviors[i];
+ flavor = GC_old_exc_ports.flavors[i];
+
+ if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) {
+ r = thread_get_state(thread, flavor, thread_state, &thread_state_count);
+ if (r != KERN_SUCCESS)
+ ABORT("thread_get_state failed in forward_exception");
+ }
+
+ switch (behavior) {
+ case EXCEPTION_STATE:
+ r = exception_raise_state(port, thread, task, exception, data,
+ data_count, &flavor, thread_state,
+ thread_state_count, thread_state,
+ &thread_state_count);
+ break;
+ case EXCEPTION_STATE_IDENTITY:
+ r = exception_raise_state_identity(port, thread, task, exception, data,
+ data_count, &flavor, thread_state,
+ thread_state_count, thread_state,
+ &thread_state_count);
+ break;
+ /* case EXCEPTION_DEFAULT: */ /* default signal handlers */
+ default: /* user-supplied signal handlers */
+ r = exception_raise(port, thread, task, exception, data, data_count);
+ }
+
+ if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) {
+ r = thread_set_state(thread, flavor, thread_state, thread_state_count);
+ if (r != KERN_SUCCESS)
+ ABORT("thread_set_state failed in forward_exception");
+ }
+ return r;
+}
+
+#define FWD() GC_forward_exception(thread, task, exception, code, code_count)
+
+#ifdef ARM32
+# define DARWIN_EXC_STATE ARM_EXCEPTION_STATE
+# define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE_COUNT
+# define DARWIN_EXC_STATE_T arm_exception_state_t
+# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(far)
+#elif defined(AARCH64)
+# define DARWIN_EXC_STATE ARM_EXCEPTION_STATE64
+# define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE64_COUNT
+# define DARWIN_EXC_STATE_T arm_exception_state64_t
+# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(far)
+#elif defined(POWERPC)
+# if CPP_WORDSZ == 32
+# define DARWIN_EXC_STATE PPC_EXCEPTION_STATE
+# define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE_COUNT
+# define DARWIN_EXC_STATE_T ppc_exception_state_t
+# else
+# define DARWIN_EXC_STATE PPC_EXCEPTION_STATE64
+# define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE64_COUNT
+# define DARWIN_EXC_STATE_T ppc_exception_state64_t
+# endif
+# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(dar)
+#elif defined(I386) || defined(X86_64)
+# if CPP_WORDSZ == 32
+# if defined(i386_EXCEPTION_STATE_COUNT) \
+ && !defined(x86_EXCEPTION_STATE32_COUNT)
+ /* Use old naming convention for 32-bit x86. */
+# define DARWIN_EXC_STATE i386_EXCEPTION_STATE
+# define DARWIN_EXC_STATE_COUNT i386_EXCEPTION_STATE_COUNT
+# define DARWIN_EXC_STATE_T i386_exception_state_t
+# else
+# define DARWIN_EXC_STATE x86_EXCEPTION_STATE32
+# define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE32_COUNT
+# define DARWIN_EXC_STATE_T x86_exception_state32_t
+# endif
+# else
+# define DARWIN_EXC_STATE x86_EXCEPTION_STATE64
+# define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE64_COUNT
+# define DARWIN_EXC_STATE_T x86_exception_state64_t
+# endif
+# define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(faultvaddr)
+#elif !defined(CPPCHECK)
+# error FIXME for non-arm/ppc/x86 darwin
+#endif
+
+/* This violates the namespace rules but there isn't anything that can */
+/* be done about it. The exception handling stuff is hard coded to */
+/* call this. catch_exception_raise, catch_exception_raise_state and */
+/* and catch_exception_raise_state_identity are called from OS. */
+GC_API_OSCALL kern_return_t
+catch_exception_raise(mach_port_t exception_port GC_ATTR_UNUSED,
+ mach_port_t thread, mach_port_t task GC_ATTR_UNUSED,
+ exception_type_t exception, exception_data_t code,
+ mach_msg_type_number_t code_count GC_ATTR_UNUSED)
+{
+ kern_return_t r;
+ char *addr;
+ thread_state_flavor_t flavor = DARWIN_EXC_STATE;
+ mach_msg_type_number_t exc_state_count = DARWIN_EXC_STATE_COUNT;
+ DARWIN_EXC_STATE_T exc_state;
+
+ if (exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
+# ifdef DEBUG_EXCEPTION_HANDLING
+ /* We aren't interested, pass it on to the old handler */
+ GC_log_printf("Exception: 0x%x Code: 0x%x 0x%x in catch...\n",
+ exception, code_count > 0 ? code[0] : -1,
+ code_count > 1 ? code[1] : -1);
+# endif
+ return FWD();
+ }
+
+ r = thread_get_state(thread, flavor, (natural_t*)&exc_state,
+ &exc_state_count);
+ if (r != KERN_SUCCESS) {
+ /* The thread is supposed to be suspended while the exception */
+ /* handler is called. This shouldn't fail. */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ GC_err_printf("thread_get_state failed in catch_exception_raise\n");
+ return KERN_SUCCESS;
+# else
+ ABORT("thread_get_state failed in catch_exception_raise");
+# endif
+ }
+
+ /* This is the address that caused the fault */
+ addr = (char*) exc_state.DARWIN_EXC_STATE_DAR;
+ if (!is_header_found_async(addr)) {
+ /* Ugh... just like the SIGBUS problem above, it seems we get */
+ /* a bogus KERN_PROTECTION_FAILURE every once and a while. We wait */
+ /* till we get a bunch in a row before doing anything about it. */
+ /* If a "real" fault ever occurs it'll just keep faulting over and */
+ /* over and we'll hit the limit pretty quickly. */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ static char *last_fault;
+ static int last_fault_count;
+
+ if (addr != last_fault) {
+ last_fault = addr;
+ last_fault_count = 0;
+ }
+ if (++last_fault_count < 32) {
+ if (last_fault_count == 1)
+ WARN("Ignoring KERN_PROTECTION_FAILURE at %p\n", addr);
+ return KERN_SUCCESS;
+ }
+
+ GC_err_printf("Unexpected KERN_PROTECTION_FAILURE at %p; aborting...\n",
+ (void *)addr);
+ /* Can't pass it along to the signal handler because that is */
+ /* ignoring SIGBUS signals. We also shouldn't call ABORT here as */
+ /* signals don't always work too well from the exception handler. */
+ EXIT();
+# else /* BROKEN_EXCEPTION_HANDLING */
+ /* Pass it along to the next exception handler
+ (which should call SIGBUS/SIGSEGV) */
+ return FWD();
+# endif /* !BROKEN_EXCEPTION_HANDLING */
+ }
+
+# ifdef BROKEN_EXCEPTION_HANDLING
+ /* Reset the number of consecutive SIGBUSs */
+ GC_sigbus_count = 0;
+# endif
+
+ GC_ASSERT(GC_page_size != 0);
+ if (GC_mprotect_state == GC_MP_NORMAL) { /* common case */
+ struct hblk * h = (struct hblk *)((word)addr & ~(word)(GC_page_size-1));
+ size_t i;
+
+# ifdef CHECKSUMS
+ GC_record_fault(h);
+# endif
+ UNPROTECT(h, GC_page_size);
+ for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
+ word index = PHT_HASH(h+i);
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ } else if (GC_mprotect_state == GC_MP_DISCARDING) {
+ /* Lie to the thread for now. No sense UNPROTECT()ing the memory
+ when we're just going to PROTECT() it again later. The thread
+ will just fault again once it resumes */
+ } else {
+ /* Shouldn't happen, i don't think */
+ GC_err_printf("KERN_PROTECTION_FAILURE while world is stopped\n");
+ return FWD();
+ }
+ return KERN_SUCCESS;
+}
+#undef FWD
+
+#ifndef NO_DESC_CATCH_EXCEPTION_RAISE
+ /* These symbols should have REFERENCED_DYNAMICALLY (0x10) bit set to */
+ /* let strip know they are not to be stripped. */
+ __asm__(".desc _catch_exception_raise, 0x10");
+ __asm__(".desc _catch_exception_raise_state, 0x10");
+ __asm__(".desc _catch_exception_raise_state_identity, 0x10");
+#endif
+
+#endif /* DARWIN && MPROTECT_VDB */
+
+#ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
+ GC_API int GC_CALL GC_incremental_protection_needs(void)
+ {
+ GC_ASSERT(GC_is_initialized);
+ return GC_PROTECTS_NONE;
+ }
+#endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
+
+#ifdef ECOS
+ /* Undo sbrk() redirection. */
+# undef sbrk
+#endif
+
+/* If value is non-zero then allocate executable memory. */
+GC_API void GC_CALL GC_set_pages_executable(int value)
+{
+ GC_ASSERT(!GC_is_initialized);
+ /* Even if IGNORE_PAGES_EXECUTABLE is defined, GC_pages_executable is */
+ /* touched here to prevent a compiler warning. */
+ GC_pages_executable = (GC_bool)(value != 0);
+}
+
+/* Returns non-zero if the GC-allocated memory is executable. */
+/* GC_get_pages_executable is defined after all the places */
+/* where GC_get_pages_executable is undefined. */
+GC_API int GC_CALL GC_get_pages_executable(void)
+{
+# ifdef IGNORE_PAGES_EXECUTABLE
+ return 1; /* Always allocate executable memory. */
+# else
+ return (int)GC_pages_executable;
+# endif
+}
+
+/* Call stack save code for debugging. Should probably be in */
+/* mach_dep.c, but that requires reorganization. */
+
+/* I suspect the following works for most *nix x86 variants, so */
+/* long as the frame pointer is explicitly stored. In the case of gcc, */
+/* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
+#if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
+# include <features.h>
+
+ struct frame {
+ struct frame *fr_savfp;
+ long fr_savpc;
+# if NARGS > 0
+ long fr_arg[NARGS]; /* All the arguments go here. */
+# endif
+ };
+#endif
+
+#if defined(SPARC)
+# if defined(LINUX)
+# include <features.h>
+
+# if defined(SAVE_CALL_CHAIN)
+ struct frame {
+ long fr_local[8];
+ long fr_arg[6];
+ struct frame *fr_savfp;
+ long fr_savpc;
+# ifndef __arch64__
+ char *fr_stret;
+# endif
+ long fr_argd[6];
+ long fr_argx[0];
+ };
+# endif
+# elif defined (DRSNX)
+# include <sys/sparc/frame.h>
+# elif defined(OPENBSD)
+# include <frame.h>
+# elif defined(FREEBSD) || defined(NETBSD)
+# include <machine/frame.h>
+# else
+# include <sys/frame.h>
+# endif
+# if NARGS > 6
+# error We only know how to get the first 6 arguments
+# endif
+#endif /* SPARC */
+
+#ifdef NEED_CALLINFO
+/* Fill in the pc and argument information for up to NFRAMES of my */
+/* callers. Ignore my frame and my callers frame. */
+
+#ifdef LINUX
+# include <unistd.h>
+#endif
+
+#endif /* NEED_CALLINFO */
+
+#if defined(GC_HAVE_BUILTIN_BACKTRACE)
+# ifdef _MSC_VER
+# include "private/msvc_dbg.h"
+# else
+# include <execinfo.h>
+# endif
+#endif
+
+#ifdef SAVE_CALL_CHAIN
+
+#if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
+ && defined(GC_HAVE_BUILTIN_BACKTRACE)
+
+#ifdef REDIRECT_MALLOC
+ /* Deal with possible malloc calls in backtrace by omitting */
+ /* the infinitely recursing backtrace. */
+# ifdef THREADS
+ __thread /* If your compiler doesn't understand this */
+ /* you could use something like pthread_getspecific. */
+# endif
+ GC_bool GC_in_save_callers = FALSE;
+
+# if defined(THREADS) && defined(DBG_HDRS_ALL)
+# include "private/dbg_mlc.h"
+
+ /* A dummy version of GC_save_callers() which does not call */
+ /* backtrace(). */
+ GC_INNER void GC_save_callers_no_unlock(struct callinfo info[NFRAMES])
+ {
+ GC_ASSERT(I_HOLD_LOCK());
+ info[0].ci_pc = (word)(&GC_save_callers_no_unlock);
+ BZERO(&info[1], sizeof(void *) * (NFRAMES - 1));
+ }
+# endif
+#endif /* REDIRECT_MALLOC */
+
+GC_INNER void GC_save_callers(struct callinfo info[NFRAMES])
+{
+ void * tmp_info[NFRAMES + 1];
+ int npcs, i;
+
+ GC_ASSERT(I_HOLD_LOCK());
+ /* backtrace may call dl_iterate_phdr which is also */
+ /* used by GC_register_dynamic_libraries, and */
+ /* dl_iterate_phdr is not guaranteed to be reentrant. */
+
+ GC_STATIC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
+# ifdef REDIRECT_MALLOC
+ if (GC_in_save_callers) {
+ info[0].ci_pc = (word)(&GC_save_callers);
+ for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0;
+ return;
+ }
+ GC_in_save_callers = TRUE;
+ /* backtrace() might call a redirected malloc. */
+ UNLOCK();
+ npcs = backtrace((void **)tmp_info, NFRAMES + 1);
+ LOCK();
+# else
+ npcs = backtrace((void **)tmp_info, NFRAMES + 1);
+# endif
+ /* We retrieve NFRAMES+1 pc values, but discard the first one, since */
+ /* it points to our own frame. */
+ i = 0;
+ if (npcs > 1) {
+ i = npcs - 1;
+ BCOPY(&tmp_info[1], info, (unsigned)i * sizeof(void *));
+ }
+ for (; i < NFRAMES; ++i) info[i].ci_pc = 0;
+# ifdef REDIRECT_MALLOC
+ GC_in_save_callers = FALSE;
+# endif
+}
+
+#else /* No builtin backtrace; do it ourselves */
+
+#if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC)
+# define FR_SAVFP fr_fp
+# define FR_SAVPC fr_pc
+#else
+# define FR_SAVFP fr_savfp
+# define FR_SAVPC fr_savpc
+#endif
+
+#if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
+# define BIAS 2047
+#else
+# define BIAS 0
+#endif
+
+GC_INNER void GC_save_callers(struct callinfo info[NFRAMES])
+{
+ struct frame *frame;
+ struct frame *fp;
+ int nframes = 0;
+# ifdef I386
+ /* We assume this is turned on only with gcc as the compiler. */
+ asm("movl %%ebp,%0" : "=r"(frame));
+ fp = frame;
+# else
+ frame = (struct frame *)GC_save_regs_in_stack();
+ fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
+#endif
+
+ for (; !((word)fp HOTTER_THAN (word)frame)
+# ifndef THREADS
+ && !((word)GC_stackbottom HOTTER_THAN (word)fp)
+# elif defined(STACK_GROWS_UP)
+ && fp != NULL
+# endif
+ && nframes < NFRAMES;
+ fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
+# if NARGS > 0
+ int i;
+# endif
+
+ info[nframes].ci_pc = fp->FR_SAVPC;
+# if NARGS > 0
+ for (i = 0; i < NARGS; i++) {
+ info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
+ }
+# endif /* NARGS > 0 */
+ }
+ if (nframes < NFRAMES) info[nframes].ci_pc = 0;
+}
+
+#endif /* No builtin backtrace */
+
+#endif /* SAVE_CALL_CHAIN */
+
+#ifdef NEED_CALLINFO
+
+/* Print info to stderr. We do NOT hold the allocation lock */
+GC_INNER void GC_print_callers(struct callinfo info[NFRAMES])
+{
+ int i;
+ static int reentry_count = 0;
+ DCL_LOCK_STATE;
+
+ /* FIXME: This should probably use a different lock, so that we */
+ /* become callable with or without the allocation lock. */
+ LOCK();
+ ++reentry_count;
+ UNLOCK();
+
+# if NFRAMES == 1
+ GC_err_printf("\tCaller at allocation:\n");
+# else
+ GC_err_printf("\tCall chain at allocation:\n");
+# endif
+ for (i = 0; i < NFRAMES; i++) {
+# if defined(LINUX) && !defined(SMALL_CONFIG)
+ GC_bool stop = FALSE;
+# endif
+
+ if (0 == info[i].ci_pc)
+ break;
+# if NARGS > 0
+ {
+ int j;
+
+ GC_err_printf("\t\targs: ");
+ for (j = 0; j < NARGS; j++) {
+ if (j != 0) GC_err_printf(", ");
+ GC_err_printf("%d (0x%X)", ~(info[i].ci_arg[j]),
+ ~(info[i].ci_arg[j]));
+ }
+ GC_err_printf("\n");
+ }
+# endif
+ if (reentry_count > 1) {
+ /* We were called during an allocation during */
+ /* a previous GC_print_callers call; punt. */
+ GC_err_printf("\t\t##PC##= 0x%lx\n",
+ (unsigned long)info[i].ci_pc);
+ continue;
+ }
+ {
+ char buf[40];
+ char *name;
+# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
+ && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
+ char **sym_name =
+ backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
+ if (sym_name != NULL) {
+ name = sym_name[0];
+ } else
+# endif
+ /* else */ {
+ (void)snprintf(buf, sizeof(buf), "##PC##= 0x%lx",
+ (unsigned long)info[i].ci_pc);
+ buf[sizeof(buf) - 1] = '\0';
+ name = buf;
+ }
+# if defined(LINUX) && !defined(SMALL_CONFIG)
+ /* Try for a line number. */
+ do {
+ FILE *pipe;
+# define EXE_SZ 100
+ static char exe_name[EXE_SZ];
+# define CMD_SZ 200
+ char cmd_buf[CMD_SZ];
+# define RESULT_SZ 200
+ static char result_buf[RESULT_SZ];
+ size_t result_len;
+ char *old_preload;
+# define PRELOAD_SZ 200
+ char preload_buf[PRELOAD_SZ];
+ static GC_bool found_exe_name = FALSE;
+ static GC_bool will_fail = FALSE;
+
+ /* Try to get it via a hairy and expensive scheme. */
+ /* First we get the name of the executable: */
+ if (will_fail)
+ break;
+ if (!found_exe_name) {
+ int ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
+
+ if (ret_code < 0 || ret_code >= EXE_SZ
+ || exe_name[0] != '/') {
+ will_fail = TRUE; /* Don't try again. */
+ break;
+ }
+ exe_name[ret_code] = '\0';
+ found_exe_name = TRUE;
+ }
+ /* Then we use popen to start addr2line -e <exe> <addr> */
+ /* There are faster ways to do this, but hopefully this */
+ /* isn't time critical. */
+ (void)snprintf(cmd_buf, sizeof(cmd_buf),
+ "/usr/bin/addr2line -f -e %s 0x%lx",
+ exe_name, (unsigned long)info[i].ci_pc);
+ cmd_buf[sizeof(cmd_buf) - 1] = '\0';
+ old_preload = GETENV("LD_PRELOAD");
+ if (0 != old_preload) {
+ size_t old_len = strlen(old_preload);
+ if (old_len >= PRELOAD_SZ) {
+ will_fail = TRUE;
+ break;
+ }
+ BCOPY(old_preload, preload_buf, old_len + 1);
+ unsetenv ("LD_PRELOAD");
+ }
+ pipe = popen(cmd_buf, "r");
+ if (0 != old_preload
+ && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) {
+ WARN("Failed to reset LD_PRELOAD\n", 0);
+ }
+ if (NULL == pipe) {
+ will_fail = TRUE;
+ break;
+ }
+ result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe);
+ (void)pclose(pipe);
+ if (0 == result_len) {
+ will_fail = TRUE;
+ break;
+ }
+ if (result_buf[result_len - 1] == '\n') --result_len;
+ result_buf[result_len] = 0;
+ if (result_buf[0] == '?'
+ || (result_buf[result_len-2] == ':'
+ && result_buf[result_len-1] == '0'))
+ break;
+ /* Get rid of embedded newline, if any. Test for "main" */
+ {
+ char * nl = strchr(result_buf, '\n');
+ if (nl != NULL
+ && (word)nl < (word)(result_buf + result_len)) {
+ *nl = ':';
+ }
+ if (strncmp(result_buf, "main",
+ nl != NULL
+ ? (size_t)((word)nl /* a cppcheck workaround */
+ - COVERT_DATAFLOW(result_buf))
+ : result_len) == 0) {
+ stop = TRUE;
+ }
+ }
+ if (result_len < RESULT_SZ - 25) {
+ /* Add in hex address */
+ (void)snprintf(&result_buf[result_len],
+ sizeof(result_buf) - result_len,
+ " [0x%lx]", (unsigned long)info[i].ci_pc);
+ result_buf[sizeof(result_buf) - 1] = '\0';
+ }
+# if defined(CPPCHECK)
+ GC_noop1((unsigned char)name[0]);
+ /* name computed previously is discarded */
+# endif
+ name = result_buf;
+ } while (0);
+# endif /* LINUX */
+ GC_err_printf("\t\t%s\n", name);
+# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
+ && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
+ if (sym_name != NULL)
+ free(sym_name); /* May call GC_[debug_]free; that's OK */
+# endif
+ }
+# if defined(LINUX) && !defined(SMALL_CONFIG)
+ if (stop)
+ break;
+# endif
+ }
+ LOCK();
+ --reentry_count;
+ UNLOCK();
+}
+
+#endif /* NEED_CALLINFO */
+
+#if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
+ /* Dump /proc/self/maps to GC_stderr, to enable looking up names for */
+ /* addresses in FIND_LEAK output. */
+ void GC_print_address_map(void)
+ {
+ const char *maps = GC_get_maps();
+
+ GC_err_printf("---------- Begin address map ----------\n");
+ GC_err_puts(maps);
+ GC_err_printf("---------- End address map ----------\n");
+ }
+#endif /* LINUX && ELF */