Author: kib
Date: Sat Jun 17 11:29:59 2017
New Revision: 320052
URL: https://svnweb.freebsd.org/changeset/base/320052
Log:
Do not leak syslog_mutex on cancellation.
Make syslog(3) resilent to cancellation occuring in supported deferred
mode. Code must unlock syslog_mutex on cancel, install the cleanup
handler.
Diagnosed and tested by: eugen
Discussed with: dchagin
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Modified:
head/lib/libc/gen/syslog.c
Modified: head/lib/libc/gen/syslog.c
==============================================================================
--- head/lib/libc/gen/syslog.c Sat Jun 17 11:25:31 2017 (r320051)
+++ head/lib/libc/gen/syslog.c Sat Jun 17 11:29:59 2017 (r320052)
@@ -129,8 +129,8 @@ syslog(int pri, const char *fmt, ...)
va_end(ap);
}
-void
-vsyslog(int pri, const char *fmt, va_list ap)
+static void
+vsyslog1(int pri, const char *fmt, va_list ap)
{
int cnt;
char ch, *p;
@@ -151,13 +151,9 @@ vsyslog(int pri, const char *fmt, va_list ap)
saved_errno = errno;
- THREAD_LOCK();
-
/* Check priority against setlogmask values. */
- if (!(LOG_MASK(LOG_PRI(pri)) & LogMask)) {
- THREAD_UNLOCK();
+ if (!(LOG_MASK(LOG_PRI(pri)) & LogMask))
return;
- }
/* Set default facility if none specified. */
if ((pri & LOG_FACMASK) == 0)
@@ -167,10 +163,8 @@ vsyslog(int pri, const char *fmt, va_list ap)
tbuf_cookie.base = tbuf;
tbuf_cookie.left = sizeof(tbuf);
fp = fwopen(&tbuf_cookie, writehook);
- if (fp == NULL) {
- THREAD_UNLOCK();
+ if (fp == NULL)
return;
- }
/* Build the message. */
(void)time(&now);
@@ -200,7 +194,6 @@ vsyslog(int pri, const char *fmt, va_list ap)
fmt_fp = fwopen(&fmt_cookie, writehook);
if (fmt_fp == NULL) {
fclose(fp);
- THREAD_UNLOCK();
return;
}
@@ -285,10 +278,8 @@ vsyslog(int pri, const char *fmt, va_list ap)
*/
disconnectlog();
connectlog();
- if (send(LogFile, tbuf, cnt, 0) >= 0) {
- THREAD_UNLOCK();
+ if (send(LogFile, tbuf, cnt, 0) >= 0)
return;
- }
/*
* if the resend failed, fall through to
* possible scenario 2
@@ -303,15 +294,11 @@ vsyslog(int pri, const char *fmt, va_list ap)
if (status == CONNPRIV)
break;
_usleep(1);
- if (send(LogFile, tbuf, cnt, 0) >= 0) {
- THREAD_UNLOCK();
+ if (send(LogFile, tbuf, cnt, 0) >= 0)
return;
- }
}
- } else {
- THREAD_UNLOCK();
+ } else
return;
- }
/*
* Output the message to the console; try not to block
@@ -333,10 +320,25 @@ vsyslog(int pri, const char *fmt, va_list ap)
(void)_writev(fd, iov, 2);
(void)_close(fd);
}
+}
+static void
+syslog_cancel_cleanup(void *arg __unused)
+{
+
THREAD_UNLOCK();
}
+void
+vsyslog(int pri, const char *fmt, va_list ap)
+{
+
+ THREAD_LOCK();
+ pthread_cleanup_push(syslog_cancel_cleanup, NULL);
+ vsyslog1(pri, fmt, ap);
+ pthread_cleanup_pop(1);
+}
+
/* Should be called with mutex acquired */
static void
disconnectlog(void)
@@ -423,9 +425,11 @@ openlog_unlocked(const char *ident, int logstat, int l
void
openlog(const char *ident, int logstat, int logfac)
{
+
THREAD_LOCK();
+ pthread_cleanup_push(syslog_cancel_cleanup, NULL);
openlog_unlocked(ident, logstat, logfac);
- THREAD_UNLOCK();
+ pthread_cleanup_pop(1);
}
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