From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/12075 Path: news.gmane.org!.POSTED!not-for-mail From: Bobby Bingham Newsgroups: gmane.linux.lib.musl.general Subject: [PATCH] save/restore errno around pthread_atfork handlers Date: Fri, 10 Nov 2017 14:58:29 -0600 Message-ID: <20171110205829.18319-1-koorogi@koorogi.info> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org X-Trace: blaine.gmane.org 1510347534 17093 195.159.176.226 (10 Nov 2017 20:58:54 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 10 Nov 2017 20:58:54 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-12091-gllmg-musl=m.gmane.org@lists.openwall.com Fri Nov 10 21:58:49 2017 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1eDGNx-00049r-UW for gllmg-musl@m.gmane.org; Fri, 10 Nov 2017 21:58:46 +0100 Original-Received: (qmail 28116 invoked by uid 550); 10 Nov 2017 20:58:50 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 28070 invoked from network); 10 Nov 2017 20:58:49 -0000 X-Mailer: git-send-email 2.15.0 Xref: news.gmane.org gmane.linux.lib.musl.general:12075 Archived-At: If the syscall fails, errno must be preserved for the caller. There's no guarantee that the handlers registered with pthread_atfork won't clobber errno. --- src/process/fork.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/process/fork.c b/src/process/fork.c index b96f0024..6602eafc 100644 --- a/src/process/fork.c +++ b/src/process/fork.c @@ -15,6 +15,7 @@ pid_t fork(void) { pid_t ret; sigset_t set; + int olderr; __fork_handler(-1); __block_all_sigs(&set); #ifdef SYS_fork @@ -30,6 +31,10 @@ pid_t fork(void) libc.threads_minus_1 = 0; } __restore_sigs(&set); + + olderr = errno; __fork_handler(!ret); + errno = olderr; + return ret; } -- 2.15.0