diff options
Diffstat (limited to 'Build/source/libs/luajit/LuaJIT-2.0.3/src/lj_mcode.c')
-rw-r--r-- | Build/source/libs/luajit/LuaJIT-2.0.3/src/lj_mcode.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/Build/source/libs/luajit/LuaJIT-2.0.3/src/lj_mcode.c b/Build/source/libs/luajit/LuaJIT-2.0.3/src/lj_mcode.c new file mode 100644 index 00000000000..5a732960772 --- /dev/null +++ b/Build/source/libs/luajit/LuaJIT-2.0.3/src/lj_mcode.c @@ -0,0 +1,373 @@ +/* +** Machine code management. +** Copyright (C) 2005-2014 Mike Pall. See Copyright Notice in luajit.h +*/ + +#define lj_mcode_c +#define LUA_CORE + +#include "lj_obj.h" +#if LJ_HASJIT +#include "lj_gc.h" +#include "lj_err.h" +#include "lj_jit.h" +#include "lj_mcode.h" +#include "lj_trace.h" +#include "lj_dispatch.h" +#endif +#if LJ_HASJIT || LJ_HASFFI +#include "lj_vm.h" +#endif + +/* -- OS-specific functions ----------------------------------------------- */ + +#if LJ_HASJIT || LJ_HASFFI + +/* Define this if you want to run LuaJIT with Valgrind. */ +#ifdef LUAJIT_USE_VALGRIND +#include <valgrind/valgrind.h> +#endif + +#if LJ_TARGET_IOS +void sys_icache_invalidate(void *start, size_t len); +#endif + +/* Synchronize data/instruction cache. */ +void lj_mcode_sync(void *start, void *end) +{ +#ifdef LUAJIT_USE_VALGRIND + VALGRIND_DISCARD_TRANSLATIONS(start, (char *)end-(char *)start); +#endif +#if LJ_TARGET_X86ORX64 + UNUSED(start); UNUSED(end); +#elif LJ_TARGET_IOS + sys_icache_invalidate(start, (char *)end-(char *)start); +#elif LJ_TARGET_PPC + lj_vm_cachesync(start, end); +#elif defined(__GNUC__) + __clear_cache(start, end); +#else +#error "Missing builtin to flush instruction cache" +#endif +} + +#endif + +#if LJ_HASJIT + +#if LJ_TARGET_WINDOWS + +#define WIN32_LEAN_AND_MEAN +#include <windows.h> + +#define MCPROT_RW PAGE_READWRITE +#define MCPROT_RX PAGE_EXECUTE_READ +#define MCPROT_RWX PAGE_EXECUTE_READWRITE + +static void *mcode_alloc_at(jit_State *J, uintptr_t hint, size_t sz, DWORD prot) +{ + void *p = VirtualAlloc((void *)hint, sz, + MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN, prot); + if (!p && !hint) + lj_trace_err(J, LJ_TRERR_MCODEAL); + return p; +} + +static void mcode_free(jit_State *J, void *p, size_t sz) +{ + UNUSED(J); UNUSED(sz); + VirtualFree(p, 0, MEM_RELEASE); +} + +static int mcode_setprot(void *p, size_t sz, DWORD prot) +{ + DWORD oprot; + return !VirtualProtect(p, sz, prot, &oprot); +} + +#elif LJ_TARGET_POSIX + +#include <sys/mman.h> + +#ifndef MAP_ANONYMOUS +#define MAP_ANONYMOUS MAP_ANON +#endif + +#define MCPROT_RW (PROT_READ|PROT_WRITE) +#define MCPROT_RX (PROT_READ|PROT_EXEC) +#define MCPROT_RWX (PROT_READ|PROT_WRITE|PROT_EXEC) + +static void *mcode_alloc_at(jit_State *J, uintptr_t hint, size_t sz, int prot) +{ + void *p = mmap((void *)hint, sz, prot, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); + if (p == MAP_FAILED) { + if (!hint) lj_trace_err(J, LJ_TRERR_MCODEAL); + p = NULL; + } + return p; +} + +static void mcode_free(jit_State *J, void *p, size_t sz) +{ + UNUSED(J); + munmap(p, sz); +} + +static int mcode_setprot(void *p, size_t sz, int prot) +{ + return mprotect(p, sz, prot); +} + +#elif LJ_64 + +#error "Missing OS support for explicit placement of executable memory" + +#else + +/* Fallback allocator. This will fail if memory is not executable by default. */ +#define LUAJIT_UNPROTECT_MCODE +#define MCPROT_RW 0 +#define MCPROT_RX 0 +#define MCPROT_RWX 0 + +static void *mcode_alloc_at(jit_State *J, uintptr_t hint, size_t sz, int prot) +{ + UNUSED(hint); UNUSED(prot); + return lj_mem_new(J->L, sz); +} + +static void mcode_free(jit_State *J, void *p, size_t sz) +{ + lj_mem_free(J2G(J), p, sz); +} + +#endif + +/* -- MCode area protection ----------------------------------------------- */ + +/* Define this ONLY if the page protection twiddling becomes a bottleneck. */ +#ifdef LUAJIT_UNPROTECT_MCODE + +/* It's generally considered to be a potential security risk to have +** pages with simultaneous write *and* execute access in a process. +** +** Do not even think about using this mode for server processes or +** apps handling untrusted external data (such as a browser). +** +** The security risk is not in LuaJIT itself -- but if an adversary finds +** any *other* flaw in your C application logic, then any RWX memory page +** simplifies writing an exploit considerably. +*/ +#define MCPROT_GEN MCPROT_RWX +#define MCPROT_RUN MCPROT_RWX + +static void mcode_protect(jit_State *J, int prot) +{ + UNUSED(J); UNUSED(prot); +} + +#else + +/* This is the default behaviour and much safer: +** +** Most of the time the memory pages holding machine code are executable, +** but NONE of them is writable. +** +** The current memory area is marked read-write (but NOT executable) only +** during the short time window while the assembler generates machine code. +*/ +#define MCPROT_GEN MCPROT_RW +#define MCPROT_RUN MCPROT_RX + +/* Protection twiddling failed. Probably due to kernel security. */ +static LJ_NOINLINE void mcode_protfail(jit_State *J) +{ + lua_CFunction panic = J2G(J)->panic; + if (panic) { + lua_State *L = J->L; + setstrV(L, L->top++, lj_err_str(L, LJ_ERR_JITPROT)); + panic(L); + } +} + +/* Change protection of MCode area. */ +static void mcode_protect(jit_State *J, int prot) +{ + if (J->mcprot != prot) { + if (LJ_UNLIKELY(mcode_setprot(J->mcarea, J->szmcarea, prot))) + mcode_protfail(J); + J->mcprot = prot; + } +} + +#endif + +/* -- MCode area allocation ----------------------------------------------- */ + +#if LJ_TARGET_X64 +#define mcode_validptr(p) ((p) && (uintptr_t)(p) < (uintptr_t)1<<47) +#else +#define mcode_validptr(p) ((p) && (uintptr_t)(p) < 0xffff0000) +#endif + +#ifdef LJ_TARGET_JUMPRANGE + +/* Get memory within relative jump distance of our code in 64 bit mode. */ +static void *mcode_alloc(jit_State *J, size_t sz) +{ + /* Target an address in the static assembler code (64K aligned). + ** Try addresses within a distance of target-range/2+1MB..target+range/2-1MB. + ** Use half the jump range so every address in the range can reach any other. + */ +#if LJ_TARGET_MIPS + /* Use the middle of the 256MB-aligned region. */ + uintptr_t target = ((uintptr_t)(void *)lj_vm_exit_handler & 0xf0000000u) + + 0x08000000u; +#else + uintptr_t target = (uintptr_t)(void *)lj_vm_exit_handler & ~(uintptr_t)0xffff; +#endif + const uintptr_t range = (1u << (LJ_TARGET_JUMPRANGE-1)) - (1u << 21); + /* First try a contiguous area below the last one. */ + uintptr_t hint = J->mcarea ? (uintptr_t)J->mcarea - sz : 0; + int i; + for (i = 0; i < 32; i++) { /* 32 attempts ought to be enough ... */ + if (mcode_validptr(hint)) { + void *p = mcode_alloc_at(J, hint, sz, MCPROT_GEN); + + if (mcode_validptr(p) && + ((uintptr_t)p + sz - target < range || target - (uintptr_t)p < range)) + return p; + if (p) mcode_free(J, p, sz); /* Free badly placed area. */ + } + /* Next try probing pseudo-random addresses. */ + do { + hint = (0x78fb ^ LJ_PRNG_BITS(J, 15)) << 16; /* 64K aligned. */ + } while (!(hint + sz < range)); + hint = target + hint - (range>>1); + } + lj_trace_err(J, LJ_TRERR_MCODEAL); /* Give up. OS probably ignores hints? */ + return NULL; +} + +#else + +/* All memory addresses are reachable by relative jumps. */ +#define mcode_alloc(J, sz) mcode_alloc_at((J), 0, (sz), MCPROT_GEN) + +#endif + +/* -- MCode area management ----------------------------------------------- */ + +/* Linked list of MCode areas. */ +typedef struct MCLink { + MCode *next; /* Next area. */ + size_t size; /* Size of current area. */ +} MCLink; + +/* Allocate a new MCode area. */ +static void mcode_allocarea(jit_State *J) +{ + MCode *oldarea = J->mcarea; + size_t sz = (size_t)J->param[JIT_P_sizemcode] << 10; + sz = (sz + LJ_PAGESIZE-1) & ~(size_t)(LJ_PAGESIZE - 1); + J->mcarea = (MCode *)mcode_alloc(J, sz); + J->szmcarea = sz; + J->mcprot = MCPROT_GEN; + J->mctop = (MCode *)((char *)J->mcarea + J->szmcarea); + J->mcbot = (MCode *)((char *)J->mcarea + sizeof(MCLink)); + ((MCLink *)J->mcarea)->next = oldarea; + ((MCLink *)J->mcarea)->size = sz; + J->szallmcarea += sz; +} + +/* Free all MCode areas. */ +void lj_mcode_free(jit_State *J) +{ + MCode *mc = J->mcarea; + J->mcarea = NULL; + J->szallmcarea = 0; + while (mc) { + MCode *next = ((MCLink *)mc)->next; + mcode_free(J, mc, ((MCLink *)mc)->size); + mc = next; + } +} + +/* -- MCode transactions -------------------------------------------------- */ + +/* Reserve the remainder of the current MCode area. */ +MCode *lj_mcode_reserve(jit_State *J, MCode **lim) +{ + if (!J->mcarea) + mcode_allocarea(J); + else + mcode_protect(J, MCPROT_GEN); + *lim = J->mcbot; + return J->mctop; +} + +/* Commit the top part of the current MCode area. */ +void lj_mcode_commit(jit_State *J, MCode *top) +{ + J->mctop = top; + mcode_protect(J, MCPROT_RUN); +} + +/* Abort the reservation. */ +void lj_mcode_abort(jit_State *J) +{ + if (J->mcarea) + mcode_protect(J, MCPROT_RUN); +} + +/* Set/reset protection to allow patching of MCode areas. */ +MCode *lj_mcode_patch(jit_State *J, MCode *ptr, int finish) +{ +#ifdef LUAJIT_UNPROTECT_MCODE + UNUSED(J); UNUSED(ptr); UNUSED(finish); + return NULL; +#else + if (finish) { + if (J->mcarea == ptr) + mcode_protect(J, MCPROT_RUN); + else if (LJ_UNLIKELY(mcode_setprot(ptr, ((MCLink *)ptr)->size, MCPROT_RUN))) + mcode_protfail(J); + return NULL; + } else { + MCode *mc = J->mcarea; + /* Try current area first to use the protection cache. */ + if (ptr >= mc && ptr < (MCode *)((char *)mc + J->szmcarea)) { + mcode_protect(J, MCPROT_GEN); + return mc; + } + /* Otherwise search through the list of MCode areas. */ + for (;;) { + mc = ((MCLink *)mc)->next; + lua_assert(mc != NULL); + if (ptr >= mc && ptr < (MCode *)((char *)mc + ((MCLink *)mc)->size)) { + if (LJ_UNLIKELY(mcode_setprot(mc, ((MCLink *)mc)->size, MCPROT_GEN))) + mcode_protfail(J); + return mc; + } + } + } +#endif +} + +/* Limit of MCode reservation reached. */ +void lj_mcode_limiterr(jit_State *J, size_t need) +{ + size_t sizemcode, maxmcode; + lj_mcode_abort(J); + sizemcode = (size_t)J->param[JIT_P_sizemcode] << 10; + sizemcode = (sizemcode + LJ_PAGESIZE-1) & ~(size_t)(LJ_PAGESIZE - 1); + maxmcode = (size_t)J->param[JIT_P_maxmcode] << 10; + if ((size_t)need > sizemcode) + lj_trace_err(J, LJ_TRERR_MCODEOV); /* Too long for any area. */ + if (J->szallmcarea + sizemcode > maxmcode) + lj_trace_err(J, LJ_TRERR_MCODEAL); + mcode_allocarea(J); + lj_trace_err(J, LJ_TRERR_MCODELM); /* Retry with new area. */ +} + +#endif |