[tor-commits] [tor/maint-0.4.2] err/log: Stop closing stderr and stdout during shutdown
nickm at torproject.org
nickm at torproject.org
Mon Jun 29 16:59:29 UTC 2020
commit c8242e4c0ae838121ed00d5a38cf0dae052e9d13
Author: teor <teor at torproject.org>
Date: Wed Feb 12 12:47:15 2020 +1000
err/log: Stop closing stderr and stdout during shutdown
Closing these file descriptors can hide sanitiser logs.
Fixes bug 33087; bugfix on 0.4.1.6.
---
changes/bug33087 | 4 ++++
src/lib/err/torerr.c | 31 ++-----------------------------
src/lib/err/torerr.h | 1 -
src/lib/err/torerr_sys.c | 5 +----
src/lib/log/log.c | 36 +++---------------------------------
src/lib/log/log.h | 1 -
src/lib/log/util_bug.c | 4 +---
7 files changed, 11 insertions(+), 71 deletions(-)
diff --git a/changes/bug33087 b/changes/bug33087
new file mode 100644
index 000000000..7acf72a83
--- /dev/null
+++ b/changes/bug33087
@@ -0,0 +1,4 @@
+ o Minor bugfixes (logging):
+ - Stop closing stderr and stdout during shutdown. Closing these file
+ descriptors can hide sanitiser logs.
+ Fixes bug 33087; bugfix on 0.4.1.6.
diff --git a/src/lib/err/torerr.c b/src/lib/err/torerr.c
index b7e32a3e2..5095c28ba 100644
--- a/src/lib/err/torerr.c
+++ b/src/lib/err/torerr.c
@@ -150,32 +150,6 @@ tor_log_reset_sigsafe_err_fds(void)
tor_log_set_sigsafe_err_fds(fds, 1);
}
-/**
- * Close the list of fds that get errors from inside a signal handler or
- * other emergency condition. These fds are shared with the logging code:
- * closing them flushes the log buffers, and prevents any further logging.
- *
- * This function closes stderr, so it should only be called immediately before
- * process shutdown.
- */
-void
-tor_log_close_sigsafe_err_fds(void)
-{
- int n_fds, i;
- const int *fds = NULL;
-
- n_fds = tor_log_get_sigsafe_err_fds(&fds);
- for (i = 0; i < n_fds; ++i) {
- /* tor_log_close_sigsafe_err_fds_on_error() is called on error and on
- * shutdown, so we can't log or take any useful action if close()
- * fails. */
- (void)close(fds[i]);
- }
-
- /* Don't even try logging, we've closed all the log fds. */
- tor_log_set_sigsafe_err_fds(NULL, 0);
-}
-
/**
* Set the granularity (in ms) to use when reporting fatal errors outside
* the logging system.
@@ -217,13 +191,12 @@ tor_raw_assertion_failed_msg_(const char *file, int line, const char *expr,
/**
* Call the abort() function to kill the current process with a fatal
- * error. But first, close the raw error file descriptors, so error messages
- * are written before process termination.
+ * error. This is a separate function, so that log users don't have to include
+ * the header for abort().
**/
void
tor_raw_abort_(void)
{
- tor_log_close_sigsafe_err_fds();
abort();
}
diff --git a/src/lib/err/torerr.h b/src/lib/err/torerr.h
index 0e839cb1b..a1822d9c9 100644
--- a/src/lib/err/torerr.h
+++ b/src/lib/err/torerr.h
@@ -40,7 +40,6 @@ void tor_log_err_sigsafe(const char *m, ...);
int tor_log_get_sigsafe_err_fds(const int **out);
void tor_log_set_sigsafe_err_fds(const int *fds, int n);
void tor_log_reset_sigsafe_err_fds(void);
-void tor_log_close_sigsafe_err_fds(void);
void tor_log_sigsafe_err_set_granularity(int ms);
void tor_raw_abort_(void) ATTR_NORETURN;
diff --git a/src/lib/err/torerr_sys.c b/src/lib/err/torerr_sys.c
index a14c46f94..6a51a45a4 100644
--- a/src/lib/err/torerr_sys.c
+++ b/src/lib/err/torerr_sys.c
@@ -27,11 +27,8 @@ subsys_torerr_initialize(void)
static void
subsys_torerr_shutdown(void)
{
- /* Stop handling signals with backtraces, then close the logs. */
+ /* Stop handling signals with backtraces. */
clean_up_backtrace_handler();
- /* We can't log any log messages after this point: we've closed all the log
- * fds, including stdio. */
- tor_log_close_sigsafe_err_fds();
}
const subsys_fns_t sys_torerr = {
diff --git a/src/lib/log/log.c b/src/lib/log/log.c
index ec7c2fa24..69624e9ca 100644
--- a/src/lib/log/log.c
+++ b/src/lib/log/log.c
@@ -668,12 +668,8 @@ tor_log_update_sigsafe_err_fds(void)
/* log_fds and err_fds contain matching entries: log_fds are the fds used by
* the log module, and err_fds are the fds used by the err module.
- * For stdio logs, the log_fd and err_fd values are identical,
- * and the err module closes the fd on shutdown.
- * For file logs, the err_fd is a dup() of the log_fd,
- * and the log and err modules both close their respective fds on shutdown.
- * (Once all fds representing a file are closed, the underlying file is
- * closed.)
+ * For stdio logs, the log_fd and err_fd values are identical.
+ * For file logs, the err_fd is a dup() of the log_fd.
*/
int log_fds[TOR_SIGSAFE_LOG_MAX_FDS];
int err_fds[TOR_SIGSAFE_LOG_MAX_FDS];
@@ -704,12 +700,10 @@ tor_log_update_sigsafe_err_fds(void)
log_fds[n_fds] = lf->fd;
if (lf->needs_close) {
/* File log fds are duplicated, because close_log() closes the log
- * module's fd, and tor_log_close_sigsafe_err_fds() closes the err
* module's fd. Both refer to the same file. */
err_fds[n_fds] = dup(lf->fd);
} else {
- /* stdio log fds are not closed by the log module.
- * tor_log_close_sigsafe_err_fds() closes stdio logs. */
+ /* stdio log fds are not closed by the log module. */
err_fds[n_fds] = lf->fd;
}
n_fds++;
@@ -838,30 +832,6 @@ logs_free_all(void)
* log mutex. */
}
-/** Close signal-safe log files.
- * Closing the log files makes the process and OS flush log buffers.
- *
- * This function is safe to call from a signal handler. It should only be
- * called when shutting down the log or err modules. It is currenly called
- * by the err module, when terminating the process on an abnormal condition.
- */
-void
-logs_close_sigsafe(void)
-{
- logfile_t *victim, *next;
- /* We can't LOCK_LOGS() in a signal handler, because it may call
- * signal-unsafe functions. And we can't deallocate memory, either. */
- next = logfiles;
- logfiles = NULL;
- while (next) {
- victim = next;
- next = next->next;
- if (victim->needs_close) {
- close_log_sigsafe(victim);
- }
- }
-}
-
/** Remove and free the log entry <b>victim</b> from the linked-list
* logfiles (it is probably present, but it might not be due to thread
* racing issues). After this function is called, the caller shouldn't
diff --git a/src/lib/log/log.h b/src/lib/log/log.h
index 4291418eb..c4a27782c 100644
--- a/src/lib/log/log.h
+++ b/src/lib/log/log.h
@@ -173,7 +173,6 @@ void logs_set_domain_logging(int enabled);
int get_min_log_level(void);
void switch_logs_debug(void);
void logs_free_all(void);
-void logs_close_sigsafe(void);
void add_temp_log(int min_severity);
void close_temp_logs(void);
void rollback_log_changes(void);
diff --git a/src/lib/log/util_bug.c b/src/lib/log/util_bug.c
index 0e99be35a..640fe050e 100644
--- a/src/lib/log/util_bug.c
+++ b/src/lib/log/util_bug.c
@@ -163,8 +163,7 @@ tor_bug_occurred_(const char *fname, unsigned int line,
/**
* Call the tor_raw_abort_() function to close raw logs, then kill the current
- * process with a fatal error. But first, close the file-based log file
- * descriptors, so error messages are written before process termination.
+ * process with a fatal error.
*
* (This is a separate function so that we declare it in util_bug.h without
* including torerr.h in all the users of util_bug.h)
@@ -172,7 +171,6 @@ tor_bug_occurred_(const char *fname, unsigned int line,
void
tor_abort_(void)
{
- logs_close_sigsafe();
tor_raw_abort_();
}
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