diff options
Diffstat (limited to 'lib/asan/asan_mac.cc')
| -rw-r--r-- | lib/asan/asan_mac.cc | 197 |
1 files changed, 5 insertions, 192 deletions
diff --git a/lib/asan/asan_mac.cc b/lib/asan/asan_mac.cc index 3e028378df28..f00d98f8e5e6 100644 --- a/lib/asan/asan_mac.cc +++ b/lib/asan/asan_mac.cc @@ -24,26 +24,17 @@ #include "sanitizer_common/sanitizer_libc.h" #include "sanitizer_common/sanitizer_mac.h" -#if !SANITIZER_IOS -#include <crt_externs.h> // for _NSGetArgv and _NSGetEnviron -#else -extern "C" { - extern char ***_NSGetArgv(void); -} -#endif - -#include <dlfcn.h> // for dladdr() +#include <fcntl.h> +#include <libkern/OSAtomic.h> #include <mach-o/dyld.h> #include <mach-o/loader.h> +#include <pthread.h> +#include <stdlib.h> // for free() #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 { @@ -52,187 +43,12 @@ void InitializePlatformInterceptors() {} 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. + // See also https://github.com/google/sanitizers/issues/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 = GetEnviron(); - uptr name_len = internal_strlen(name); - while (*env != 0) { - uptr len = internal_strlen(*env); - if (len > name_len) { - const char *p = *env; - if (!internal_memcmp(p, name, name_len) && p[name_len] == '=') { - // Match. - if (name_value) { - // Replace the old value with the new one. - *env = const_cast<char*>(name_value); - } else { - // Shift the subsequent pointers back. - char **del = env; - do { - del[0] = del[1]; - } while (*del++); - } - } - } - env++; - } -} - -static bool reexec_disabled = false; - -void DisableReexec() { - reexec_disabled = true; -} - -bool DyldNeedsEnvVariable() { -// If running on OS X 10.11+ or iOS 9.0+, dyld will interpose even if -// DYLD_INSERT_LIBRARIES is not set. - -#if SANITIZER_IOSSIM - // GetMacosVersion will not work for the simulator, whose kernel version - // is tied to the host. Use a weak linking hack for the simulator. - // This API was introduced in the same version of the OS as the dyld - // optimization. - - // Check for presence of a symbol that is available on OS X 10.11+, iOS 9.0+. - return (dlsym(RTLD_NEXT, "mach_memory_info") == nullptr); -#else - return (GetMacosVersion() <= MACOS_VERSION_YOSEMITE); -#endif -} - -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); - - bool lib_is_in_env = - dyld_insert_libraries && REAL(strstr)(dyld_insert_libraries, dylib_name); - if (DyldNeedsEnvVariable() && !lib_is_in_env) { - // 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); - } - - if (!lib_is_in_env) - return; - - // 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; @@ -244,9 +60,6 @@ void AsanCheckDynamicRTPrereqs() {} // No-op. Mac does not support static linkage anyway. void AsanCheckIncompatibleRT() {} -void AsanPlatformThreadInit() { -} - void ReadContextStack(void *context, uptr *stack, uptr *ssize) { UNIMPLEMENTED(); } |