musl: update to 1.1.20.

This commit is contained in:
Adrian Pistol 2018-10-04 14:25:29 +02:00 committed by Enno Boland
parent d1e4ef306e
commit 4fd58e8395
2 changed files with 56 additions and 2 deletions

View File

@ -0,0 +1,54 @@
From 0db393d3a77bb9f300a356c6a5484fc2dddb161d Mon Sep 17 00:00:00 2001
From: Kaarle Ritvanen <kaarle.ritvanen@datakunkku.fi>
Date: Tue, 18 Sep 2018 10:03:27 +0300
Subject: fix race condition in file locking
The condition occurs when
- thread #1 is holding the lock
- thread #2 is waiting for it on __futexwait
- thread #1 is about to release the lock and performs a_swap
- thread #3 enters the __lockfile function and manages to grab the lock
before thread #1 calls __wake, resetting the MAYBE_WAITERS flag
- thread #1 calls __wake
- thread #2 wakes up but goes again to __futexwait as the lock is
held by thread #3
- thread #3 releases the lock but does not call __wake as the
MAYBE_WAITERS flag is not set
This condition results in thread #2 not being woken up. This patch fixes
the problem by making the woken up thread ensure that the flag is
properly set before going to sleep again.
Mainainer's note: This fixes a regression introduced in commit
c21f750727515602a9e84f2a190ee8a0a2aeb2a1.
---
src/stdio/__lockfile.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git src/stdio/__lockfile.c.orig src/stdio/__lockfile.c
index 2ff75d8a..0dcb2a42 100644
--- src/stdio/__lockfile.c.orig
+++ src/stdio/__lockfile.c
@@ -8,13 +8,13 @@ int __lockfile(FILE *f)
int owner = f->lock, tid = __pthread_self()->tid;
if ((owner & ~MAYBE_WAITERS) == tid)
return 0;
- for (;;) {
- owner = a_cas(&f->lock, 0, tid);
- if (!owner) return 1;
- if (a_cas(&f->lock, owner, owner|MAYBE_WAITERS)==owner) break;
+ owner = a_cas(&f->lock, 0, tid);
+ if (!owner) return 1;
+ while ((owner = a_cas(&f->lock, 0, tid|MAYBE_WAITERS))) {
+ if ((owner & MAYBE_WAITERS) ||
+ a_cas(&f->lock, owner, owner|MAYBE_WAITERS)==owner)
+ __futexwait(&f->lock, owner|MAYBE_WAITERS, 1);
}
- while ((owner = a_cas(&f->lock, 0, tid|MAYBE_WAITERS)))
- __futexwait(&f->lock, owner, 1);
return 1;
}
--
cgit v1.2.1

View File

@ -1,6 +1,6 @@
# Template file for 'musl'.
pkgname=musl
version=1.1.19
version=1.1.20
revision=1
build_style=gnu-configure
configure_args="--prefix=/usr --disable-gcc-wrapper"
@ -11,7 +11,7 @@ maintainer="Juan RP <xtraeme@voidlinux.eu>"
license="MIT"
homepage="http://www.musl-libc.org/"
distfiles="http://www.musl-libc.org/releases/musl-${version}.tar.gz"
checksum=db59a8578226b98373f5b27e61f0dd29ad2456f4aa9cec587ba8c24508e4c1d9
checksum=44be8771d0e6c6b5f82dd15662eb2957c9a3173a19a8b49966ac0542bbd40d61
nostrip_files="libc.so"
shlib_provides="libc.so"