mailing list of musl libc
 help / color / mirror / code / Atom feed
From: Bobby Bingham <koorogi@koorogi.info>
To: musl@lists.openwall.com
Subject: [PATCH] save/restore errno around pthread_atfork handlers
Date: Fri, 10 Nov 2017 14:58:29 -0600	[thread overview]
Message-ID: <20171110205829.18319-1-koorogi@koorogi.info> (raw)

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



             reply	other threads:[~2017-11-10 20:58 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-10 20:58 Bobby Bingham [this message]
2017-11-10 23:31 ` Rich Felker
2017-11-11  0:03   ` Bobby Bingham
2017-11-11  0:16     ` Rich Felker
2017-11-11  0:37       ` Bobby Bingham

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20171110205829.18319-1-koorogi@koorogi.info \
    --to=koorogi@koorogi.info \
    --cc=musl@lists.openwall.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/musl/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).