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Diffstat (limited to 'graphics/asymptote/gc/os_dep.c')
-rw-r--r-- | graphics/asymptote/gc/os_dep.c | 5485 |
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 */ |