diff options
Diffstat (limited to 'contrib/compiler-rt/lib/asan/asan_mac.cc')
| -rw-r--r-- | contrib/compiler-rt/lib/asan/asan_mac.cc | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/asan/asan_mac.cc b/contrib/compiler-rt/lib/asan/asan_mac.cc new file mode 100644 index 000000000000..b35368617dca --- /dev/null +++ b/contrib/compiler-rt/lib/asan/asan_mac.cc @@ -0,0 +1,436 @@ +//===-- asan_mac.cc -------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file is a part of AddressSanitizer, an address sanity checker. +// +// Mac-specific details. +//===----------------------------------------------------------------------===// + +#include "sanitizer_common/sanitizer_platform.h" +#if SANITIZER_MAC + +#include "asan_interceptors.h" +#include "asan_internal.h" +#include "asan_mapping.h" +#include "asan_stack.h" +#include "asan_thread.h" +#include "sanitizer_common/sanitizer_atomic.h" +#include "sanitizer_common/sanitizer_libc.h" +#include "sanitizer_common/sanitizer_mac.h" + +#include <crt_externs.h> // for _NSGetArgv +#include <dlfcn.h> // for dladdr() +#include <mach-o/dyld.h> +#include <mach-o/loader.h> +#include <sys/mman.h> +#include <sys/resource.h> +#include <sys/sysctl.h> +#include <sys/ucontext.h> +#include <fcntl.h> +#include <pthread.h> +#include <stdlib.h> // for free() +#include <unistd.h> +#include <libkern/OSAtomic.h> + +namespace __asan { + +void GetPcSpBp(void *context, uptr *pc, uptr *sp, uptr *bp) { + ucontext_t *ucontext = (ucontext_t*)context; +# if SANITIZER_WORDSIZE == 64 + *pc = ucontext->uc_mcontext->__ss.__rip; + *bp = ucontext->uc_mcontext->__ss.__rbp; + *sp = ucontext->uc_mcontext->__ss.__rsp; +# else + *pc = ucontext->uc_mcontext->__ss.__eip; + *bp = ucontext->uc_mcontext->__ss.__ebp; + *sp = ucontext->uc_mcontext->__ss.__esp; +# endif // SANITIZER_WORDSIZE +} + + +bool PlatformHasDifferentMemcpyAndMemmove() { + // On OS X 10.7 memcpy() and memmove() are both resolved + // into memmove$VARIANT$sse42. + // See also http://code.google.com/p/address-sanitizer/issues/detail?id=34. + // TODO(glider): need to check dynamically that memcpy() and memmove() are + // actually the same function. + return GetMacosVersion() == MACOS_VERSION_SNOW_LEOPARD; +} + +extern "C" +void __asan_init(); + +static const char kDyldInsertLibraries[] = "DYLD_INSERT_LIBRARIES"; +LowLevelAllocator allocator_for_env; + +// Change the value of the env var |name|, leaking the original value. +// If |name_value| is NULL, the variable is deleted from the environment, +// otherwise the corresponding "NAME=value" string is replaced with +// |name_value|. +void LeakyResetEnv(const char *name, const char *name_value) { + char ***env_ptr = _NSGetEnviron(); + CHECK(env_ptr); + char **environ = *env_ptr; + CHECK(environ); + uptr name_len = internal_strlen(name); + while (*environ != 0) { + uptr len = internal_strlen(*environ); + if (len > name_len) { + const char *p = *environ; + if (!internal_memcmp(p, name, name_len) && p[name_len] == '=') { + // Match. + if (name_value) { + // Replace the old value with the new one. + *environ = const_cast<char*>(name_value); + } else { + // Shift the subsequent pointers back. + char **del = environ; + do { + del[0] = del[1]; + } while (*del++); + } + } + } + environ++; + } +} + +static bool reexec_disabled = false; + +void DisableReexec() { + reexec_disabled = true; +} + +void MaybeReexec() { + if (reexec_disabled) return; + + // Make sure the dynamic ASan runtime library is preloaded so that the + // wrappers work. If it is not, set DYLD_INSERT_LIBRARIES and re-exec + // ourselves. + Dl_info info; + CHECK(dladdr((void*)((uptr)__asan_init), &info)); + char *dyld_insert_libraries = + const_cast<char*>(GetEnv(kDyldInsertLibraries)); + uptr old_env_len = dyld_insert_libraries ? + internal_strlen(dyld_insert_libraries) : 0; + uptr fname_len = internal_strlen(info.dli_fname); + const char *dylib_name = StripModuleName(info.dli_fname); + uptr dylib_name_len = internal_strlen(dylib_name); + if (!dyld_insert_libraries || + !REAL(strstr)(dyld_insert_libraries, dylib_name)) { + // DYLD_INSERT_LIBRARIES is not set or does not contain the runtime + // library. + char program_name[1024]; + uint32_t buf_size = sizeof(program_name); + _NSGetExecutablePath(program_name, &buf_size); + char *new_env = const_cast<char*>(info.dli_fname); + if (dyld_insert_libraries) { + // Append the runtime dylib name to the existing value of + // DYLD_INSERT_LIBRARIES. + new_env = (char*)allocator_for_env.Allocate(old_env_len + fname_len + 2); + internal_strncpy(new_env, dyld_insert_libraries, old_env_len); + new_env[old_env_len] = ':'; + // Copy fname_len and add a trailing zero. + internal_strncpy(new_env + old_env_len + 1, info.dli_fname, + fname_len + 1); + // Ok to use setenv() since the wrappers don't depend on the value of + // asan_inited. + setenv(kDyldInsertLibraries, new_env, /*overwrite*/1); + } else { + // Set DYLD_INSERT_LIBRARIES equal to the runtime dylib name. + setenv(kDyldInsertLibraries, info.dli_fname, /*overwrite*/0); + } + VReport(1, "exec()-ing the program with\n"); + VReport(1, "%s=%s\n", kDyldInsertLibraries, new_env); + VReport(1, "to enable ASan wrappers.\n"); + execv(program_name, *_NSGetArgv()); + + // We get here only if execv() failed. + Report("ERROR: The process is launched without DYLD_INSERT_LIBRARIES, " + "which is required for ASan to work. ASan tried to set the " + "environment variable and re-execute itself, but execv() failed, " + "possibly because of sandbox restrictions. Make sure to launch the " + "executable with:\n%s=%s\n", kDyldInsertLibraries, new_env); + CHECK("execv failed" && 0); + } + + // DYLD_INSERT_LIBRARIES is set and contains the runtime library. Let's remove + // the dylib from the environment variable, because interceptors are installed + // and we don't want our children to inherit the variable. + + uptr env_name_len = internal_strlen(kDyldInsertLibraries); + // Allocate memory to hold the previous env var name, its value, the '=' + // sign and the '\0' char. + char *new_env = (char*)allocator_for_env.Allocate( + old_env_len + 2 + env_name_len); + CHECK(new_env); + internal_memset(new_env, '\0', old_env_len + 2 + env_name_len); + internal_strncpy(new_env, kDyldInsertLibraries, env_name_len); + new_env[env_name_len] = '='; + char *new_env_pos = new_env + env_name_len + 1; + + // Iterate over colon-separated pieces of |dyld_insert_libraries|. + char *piece_start = dyld_insert_libraries; + char *piece_end = NULL; + char *old_env_end = dyld_insert_libraries + old_env_len; + do { + if (piece_start[0] == ':') piece_start++; + piece_end = REAL(strchr)(piece_start, ':'); + if (!piece_end) piece_end = dyld_insert_libraries + old_env_len; + if ((uptr)(piece_start - dyld_insert_libraries) > old_env_len) break; + uptr piece_len = piece_end - piece_start; + + char *filename_start = + (char *)internal_memrchr(piece_start, '/', piece_len); + uptr filename_len = piece_len; + if (filename_start) { + filename_start += 1; + filename_len = piece_len - (filename_start - piece_start); + } else { + filename_start = piece_start; + } + + // If the current piece isn't the runtime library name, + // append it to new_env. + if ((dylib_name_len != filename_len) || + (internal_memcmp(filename_start, dylib_name, dylib_name_len) != 0)) { + if (new_env_pos != new_env + env_name_len + 1) { + new_env_pos[0] = ':'; + new_env_pos++; + } + internal_strncpy(new_env_pos, piece_start, piece_len); + new_env_pos += piece_len; + } + // Move on to the next piece. + piece_start = piece_end; + } while (piece_start < old_env_end); + + // Can't use setenv() here, because it requires the allocator to be + // initialized. + // FIXME: instead of filtering DYLD_INSERT_LIBRARIES here, do it in + // a separate function called after InitializeAllocator(). + if (new_env_pos == new_env + env_name_len + 1) new_env = NULL; + LeakyResetEnv(kDyldInsertLibraries, new_env); +} + +// No-op. Mac does not support static linkage anyway. +void *AsanDoesNotSupportStaticLinkage() { + return 0; +} + +// No-op. Mac does not support static linkage anyway. +void AsanCheckDynamicRTPrereqs() {} + +// No-op. Mac does not support static linkage anyway. +void AsanCheckIncompatibleRT() {} + +void AsanPlatformThreadInit() { +} + +void ReadContextStack(void *context, uptr *stack, uptr *ssize) { + UNIMPLEMENTED(); +} + +// Support for the following functions from libdispatch on Mac OS: +// dispatch_async_f() +// dispatch_async() +// dispatch_sync_f() +// dispatch_sync() +// dispatch_after_f() +// dispatch_after() +// dispatch_group_async_f() +// dispatch_group_async() +// TODO(glider): libdispatch API contains other functions that we don't support +// yet. +// +// dispatch_sync() and dispatch_sync_f() are synchronous, although chances are +// they can cause jobs to run on a thread different from the current one. +// TODO(glider): if so, we need a test for this (otherwise we should remove +// them). +// +// The following functions use dispatch_barrier_async_f() (which isn't a library +// function but is exported) and are thus supported: +// dispatch_source_set_cancel_handler_f() +// dispatch_source_set_cancel_handler() +// dispatch_source_set_event_handler_f() +// dispatch_source_set_event_handler() +// +// The reference manual for Grand Central Dispatch is available at +// http://developer.apple.com/library/mac/#documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html +// The implementation details are at +// http://libdispatch.macosforge.org/trac/browser/trunk/src/queue.c + +typedef void* dispatch_group_t; +typedef void* dispatch_queue_t; +typedef void* dispatch_source_t; +typedef u64 dispatch_time_t; +typedef void (*dispatch_function_t)(void *block); +typedef void* (*worker_t)(void *block); + +// A wrapper for the ObjC blocks used to support libdispatch. +typedef struct { + void *block; + dispatch_function_t func; + u32 parent_tid; +} asan_block_context_t; + +ALWAYS_INLINE +void asan_register_worker_thread(int parent_tid, StackTrace *stack) { + AsanThread *t = GetCurrentThread(); + if (!t) { + t = AsanThread::Create(/* start_routine */ nullptr, /* arg */ nullptr, + parent_tid, stack, /* detached */ true); + t->Init(); + asanThreadRegistry().StartThread(t->tid(), 0, 0); + SetCurrentThread(t); + } +} + +// For use by only those functions that allocated the context via +// alloc_asan_context(). +extern "C" +void asan_dispatch_call_block_and_release(void *block) { + GET_STACK_TRACE_THREAD; + asan_block_context_t *context = (asan_block_context_t*)block; + VReport(2, + "asan_dispatch_call_block_and_release(): " + "context: %p, pthread_self: %p\n", + block, pthread_self()); + asan_register_worker_thread(context->parent_tid, &stack); + // Call the original dispatcher for the block. + context->func(context->block); + asan_free(context, &stack, FROM_MALLOC); +} + +} // namespace __asan + +using namespace __asan; // NOLINT + +// Wrap |ctxt| and |func| into an asan_block_context_t. +// The caller retains control of the allocated context. +extern "C" +asan_block_context_t *alloc_asan_context(void *ctxt, dispatch_function_t func, + BufferedStackTrace *stack) { + asan_block_context_t *asan_ctxt = + (asan_block_context_t*) asan_malloc(sizeof(asan_block_context_t), stack); + asan_ctxt->block = ctxt; + asan_ctxt->func = func; + asan_ctxt->parent_tid = GetCurrentTidOrInvalid(); + return asan_ctxt; +} + +// Define interceptor for dispatch_*_f function with the three most common +// parameters: dispatch_queue_t, context, dispatch_function_t. +#define INTERCEPT_DISPATCH_X_F_3(dispatch_x_f) \ + INTERCEPTOR(void, dispatch_x_f, dispatch_queue_t dq, void *ctxt, \ + dispatch_function_t func) { \ + GET_STACK_TRACE_THREAD; \ + asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); \ + if (Verbosity() >= 2) { \ + Report(#dispatch_x_f "(): context: %p, pthread_self: %p\n", \ + asan_ctxt, pthread_self()); \ + PRINT_CURRENT_STACK(); \ + } \ + return REAL(dispatch_x_f)(dq, (void*)asan_ctxt, \ + asan_dispatch_call_block_and_release); \ + } + +INTERCEPT_DISPATCH_X_F_3(dispatch_async_f) +INTERCEPT_DISPATCH_X_F_3(dispatch_sync_f) +INTERCEPT_DISPATCH_X_F_3(dispatch_barrier_async_f) + +INTERCEPTOR(void, dispatch_after_f, dispatch_time_t when, + dispatch_queue_t dq, void *ctxt, + dispatch_function_t func) { + GET_STACK_TRACE_THREAD; + asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); + if (Verbosity() >= 2) { + Report("dispatch_after_f: %p\n", asan_ctxt); + PRINT_CURRENT_STACK(); + } + return REAL(dispatch_after_f)(when, dq, (void*)asan_ctxt, + asan_dispatch_call_block_and_release); +} + +INTERCEPTOR(void, dispatch_group_async_f, dispatch_group_t group, + dispatch_queue_t dq, void *ctxt, + dispatch_function_t func) { + GET_STACK_TRACE_THREAD; + asan_block_context_t *asan_ctxt = alloc_asan_context(ctxt, func, &stack); + if (Verbosity() >= 2) { + Report("dispatch_group_async_f(): context: %p, pthread_self: %p\n", + asan_ctxt, pthread_self()); + PRINT_CURRENT_STACK(); + } + REAL(dispatch_group_async_f)(group, dq, (void*)asan_ctxt, + asan_dispatch_call_block_and_release); +} + +#if !defined(MISSING_BLOCKS_SUPPORT) +extern "C" { +void dispatch_async(dispatch_queue_t dq, void(^work)(void)); +void dispatch_group_async(dispatch_group_t dg, dispatch_queue_t dq, + void(^work)(void)); +void dispatch_after(dispatch_time_t when, dispatch_queue_t queue, + void(^work)(void)); +void dispatch_source_set_cancel_handler(dispatch_source_t ds, + void(^work)(void)); +void dispatch_source_set_event_handler(dispatch_source_t ds, void(^work)(void)); +} + +#define GET_ASAN_BLOCK(work) \ + void (^asan_block)(void); \ + int parent_tid = GetCurrentTidOrInvalid(); \ + asan_block = ^(void) { \ + GET_STACK_TRACE_THREAD; \ + asan_register_worker_thread(parent_tid, &stack); \ + work(); \ + } + +INTERCEPTOR(void, dispatch_async, + dispatch_queue_t dq, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_async)(dq, asan_block); +} + +INTERCEPTOR(void, dispatch_group_async, + dispatch_group_t dg, dispatch_queue_t dq, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_group_async)(dg, dq, asan_block); +} + +INTERCEPTOR(void, dispatch_after, + dispatch_time_t when, dispatch_queue_t queue, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_after)(when, queue, asan_block); +} + +INTERCEPTOR(void, dispatch_source_set_cancel_handler, + dispatch_source_t ds, void(^work)(void)) { + if (!work) { + REAL(dispatch_source_set_cancel_handler)(ds, work); + return; + } + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_source_set_cancel_handler)(ds, asan_block); +} + +INTERCEPTOR(void, dispatch_source_set_event_handler, + dispatch_source_t ds, void(^work)(void)) { + ENABLE_FRAME_POINTER; + GET_ASAN_BLOCK(work); + REAL(dispatch_source_set_event_handler)(ds, asan_block); +} +#endif + +#endif // SANITIZER_MAC |