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++;
+ }
+}
void MaybeReexec() {
if (!flags()->allow_reexec) return;
// ourselves.
Dl_info info;
CHECK(dladdr((void*)((uptr)__asan_init), &info));
- const char *dyld_insert_libraries = GetEnv(kDyldInsertLibraries);
+ char *dyld_insert_libraries =
+ const_cast<char*>(GetEnv(kDyldInsertLibraries));
+ sptr old_env_len = dyld_insert_libraries ?
+ internal_strlen(dyld_insert_libraries) : 0;
+ sptr fname_len = internal_strlen(info.dli_fname);
if (!dyld_insert_libraries ||
!REAL(strstr)(dyld_insert_libraries, info.dli_fname)) {
// DYLD_INSERT_LIBRARIES is not set or does not contain the runtime
char program_name[1024];
uint32_t buf_size = sizeof(program_name);
_NSGetExecutablePath(program_name, &buf_size);
- // Ok to use setenv() since the wrappers don't depend on the value of
- // asan_inited.
+ 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.
- uptr old_env_len = internal_strlen(dyld_insert_libraries);
- uptr fname_len = internal_strlen(info.dli_fname);
- LowLevelAllocator allocator_for_env;
- char *new_env =
- (char*)allocator_for_env.Allocate(old_env_len + fname_len + 2);
+ 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.
}
if (flags()->verbosity >= 1) {
Report("exec()-ing the program with\n");
- Report("%s=%s\n", kDyldInsertLibraries, info.dli_fname);
+ Report("%s=%s\n", kDyldInsertLibraries, new_env);
Report("to enable ASan wrappers.\n");
Report("Set ASAN_OPTIONS=allow_reexec=0 to disable this.\n");
}
execv(program_name, *_NSGetArgv());
+ } else {
+ // DYLD_INSERT_LIBRARIES is set and contains the runtime library.
+ if (old_env_len == fname_len) {
+ // It's just the runtime library name - fine to unset the variable.
+ LeakyResetEnv(kDyldInsertLibraries, NULL);
+ } else {
+ sptr 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 (piece_start - dyld_insert_libraries > old_env_len) break;
+ uptr piece_len = piece_end - piece_start;
+
+ // If the current piece isn't the runtime library name, append it to new_env.
+ if ((piece_len != fname_len) ||
+ (internal_strncmp(piece_start, info.dli_fname, fname_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);
+ }
+ // Move on to the next piece.
+ new_env_pos += piece_len;
+ 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().
+ LeakyResetEnv(kDyldInsertLibraries, new_env);
+ }
}
}