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Merge "Unlink the tombstone proto file before linking the temporary fd."

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Treehugger Robot 2021-02-08 19:23:44 +00:00 • committed by Gerrit Code Review
commit 4abe7c4165
1 changed files with 22 additions and 27 deletions
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49
debuggerd/tombstoned/tombstoned.cpp
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@ -408,12 +408,21 @@ static void crash_request_cb(evutil_socket_t sockfd, short ev, void* arg) {
}
}
static bool link_fd(borrowed_fd fd, borrowed_fd dirfd, const std::string& path) {
std::string fd_path = StringPrintf("/proc/self/fd/%d", fd.get());
static bool rename_tombstone_fd(borrowed_fd fd, borrowed_fd dirfd, const std::string& path) {
// Always try to unlink the tombstone file.
// linkat doesn't let us replace a file, so we need to unlink before linking
// our results onto disk, and if we fail for some reason, we should delete
// stale tombstones to avoid confusing inconsistency.
int rc = unlinkat(dirfd.get(), path.c_str(), 0);
if (rc != 0 && errno != ENOENT) {
PLOG(ERROR) << "failed to unlink tombstone at " << path;
return false;
}
int rc = linkat(AT_FDCWD, fd_path.c_str(), dirfd.get(), path.c_str(), AT_SYMLINK_FOLLOW);
std::string fd_path = StringPrintf("/proc/self/fd/%d", fd.get());
rc = linkat(AT_FDCWD, fd_path.c_str(), dirfd.get(), path.c_str(), AT_SYMLINK_FOLLOW);
if (rc != 0) {
PLOG(ERROR) << "failed to link file descriptor";
PLOG(ERROR) << "failed to link tombstone at " << path;
return false;
}
return true;
@ -446,36 +455,22 @@ static void crash_completed(borrowed_fd sockfd, std::unique_ptr<Crash> crash) {
CrashArtifactPaths paths = queue->get_next_artifact_paths();
// Always try to unlink the tombstone file.
// linkat doesn't let us replace a file, so we need to unlink before linking
// our results onto disk, and if we fail for some reason, we should delete
// stale tombstones to avoid confusing inconsistency.
rc = unlinkat(queue->dir_fd().get(), paths.text.c_str(), 0);
if (rc != 0 && errno != ENOENT) {
PLOG(ERROR) << "failed to unlink tombstone at " << paths.text;
return;
}
if (crash->output.text.fd != -1) {
if (!link_fd(crash->output.text.fd, queue->dir_fd(), paths.text)) {
LOG(ERROR) << "failed to link tombstone";
if (rename_tombstone_fd(crash->output.text.fd, queue->dir_fd(), paths.text)) {
if (crash->crash_type == kDebuggerdJavaBacktrace) {
LOG(ERROR) << "Traces for pid " << crash->crash_pid << " written to: " << paths.text;
} else {
if (crash->crash_type == kDebuggerdJavaBacktrace) {
LOG(ERROR) << "Traces for pid " << crash->crash_pid << " written to: " << paths.text;
} else {
// NOTE: Several tools parse this log message to figure out where the
// tombstone associated with a given native crash was written. Any changes
// to this message must be carefully considered.
LOG(ERROR) << "Tombstone written to: " << paths.text;
}
// NOTE: Several tools parse this log message to figure out where the
// tombstone associated with a given native crash was written. Any changes
// to this message must be carefully considered.
LOG(ERROR) << "Tombstone written to: " << paths.text;
}
}
if (crash->output.proto && crash->output.proto->fd != -1) {
if (!paths.proto) {
LOG(ERROR) << "missing path for proto tombstone";
} else if (!link_fd(crash->output.proto->fd, queue->dir_fd(), *paths.proto)) {
LOG(ERROR) << "failed to link proto tombstone";
} else {
rename_tombstone_fd(crash->output.proto->fd, queue->dir_fd(), *paths.proto);
}
}