Date: Mon, 23 Oct 2023 17:23:28 GMT From: Mateusz Guzik <mjg@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: c35f527ed115 - main - sx: unset td_wantedlock around going to sleep Message-ID: <202310231723.39NHNSn8063744@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by mjg: URL: https://cgit.FreeBSD.org/src/commit/?id=c35f527ed115b792463d30c7d3c8904e435caead commit c35f527ed115b792463d30c7d3c8904e435caead Author: Mateusz Guzik <mjg@FreeBSD.org> AuthorDate: 2023-10-23 17:22:12 +0000 Commit: Mateusz Guzik <mjg@FreeBSD.org> CommitDate: 2023-10-23 17:22:12 +0000 sx: unset td_wantedlock around going to sleep Otherwise it can crash in sleepq_wait_sig -> sleepq_catch_signals -> sig_ast_checksusp -> thread_suspend_check due to a mutex acquire. Reported by: pho Sponsored by: Rubicon Communications, LLC ("Netgate") --- sys/kern/kern_sx.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/sys/kern/kern_sx.c b/sys/kern/kern_sx.c index bc8a1214689f..455ae165e328 100644 --- a/sys/kern/kern_sx.c +++ b/sys/kern/kern_sx.c @@ -854,10 +854,17 @@ retry_sleepq: sleepq_add(&sx->lock_object, NULL, sx->lock_object.lo_name, SLEEPQ_SX | ((opts & SX_INTERRUPTIBLE) ? SLEEPQ_INTERRUPTIBLE : 0), SQ_EXCLUSIVE_QUEUE); + /* + * Hack: this can land in thread_suspend_check which will + * conditionally take a mutex, tripping over an assert if a + * lock we are waiting for is set. + */ + THREAD_CONTENTION_DONE(&sx->lock_object); if (!(opts & SX_INTERRUPTIBLE)) sleepq_wait(&sx->lock_object, 0); else error = sleepq_wait_sig(&sx->lock_object, 0); + THREAD_CONTENTION_DONE(&sx->lock_object); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&sx->lock_object); sleep_cnt++; @@ -1209,10 +1216,17 @@ retry_sleepq: sleepq_add(&sx->lock_object, NULL, sx->lock_object.lo_name, SLEEPQ_SX | ((opts & SX_INTERRUPTIBLE) ? SLEEPQ_INTERRUPTIBLE : 0), SQ_SHARED_QUEUE); + /* + * Hack: this can land in thread_suspend_check which will + * conditionally take a mutex, tripping over an assert if a + * lock we are waiting for is set. + */ + THREAD_CONTENTION_DONE(&sx->lock_object); if (!(opts & SX_INTERRUPTIBLE)) sleepq_wait(&sx->lock_object, 0); else error = sleepq_wait_sig(&sx->lock_object, 0); + THREAD_CONTENDS_ON_LOCK(&sx->lock_object); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&sx->lock_object); sleep_cnt++;
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202310231723.39NHNSn8063744>