Date: Tue, 14 Jul 2026 14:56:25 +0000 From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 49b5356bc3e9 - stable/14 - linux/futex: Don't load a timeout when try-locking a mutex Message-ID: <6a564e19.3e951.4a9c9d0f@gitrepo.freebsd.org>
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The branch stable/14 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=49b5356bc3e97ec42709996814b0e4d8a582eafb commit 49b5356bc3e97ec42709996814b0e4d8a582eafb Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2026-07-07 22:52:56 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2026-07-14 14:08:41 +0000 linux/futex: Don't load a timeout when try-locking a mutex linux_sys_futex() does not copyin a timespec for the timeout if the operation is LINUX_FUTEX_TRYLOCK_PI, presumably because it doesn't make sense to specify a timeout for a try-lock operation. However, this means that we pass a userspace timespec pointer to linux_umtx_abs_timeout_init(). Modify linux_futex_lock_pi() to not initialize the timeout if we're try-locking. Reviewed by: kib, dchagin Reported by: Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.2 from Z.ai MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D58061 (cherry picked from commit 407c7c339adb429efcb6658accd16399031c34ca) --- sys/compat/linux/linux_futex.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/sys/compat/linux/linux_futex.c b/sys/compat/linux/linux_futex.c index 37d0142bae8b..27a6e580cc70 100644 --- a/sys/compat/linux/linux_futex.c +++ b/sys/compat/linux/linux_futex.c @@ -356,7 +356,7 @@ linux_futex(struct thread *td, struct linux_futex_args *args) static int linux_futex_lock_pi(struct thread *td, bool try, struct linux_futex_args *args) { - struct umtx_abs_timeout timo; + struct umtx_abs_timeout timo, *timop; struct linux_emuldata *em; struct umtx_pi *pi, *new_pi; struct thread *td1; @@ -370,8 +370,12 @@ linux_futex_lock_pi(struct thread *td, bool try, struct linux_futex_args *args) &uq->uq_key); if (error != 0) return (error); - if (args->ts != NULL) - linux_umtx_abs_timeout_init(&timo, args); + if (!try && args->ts != NULL) { + timop = &timo; + linux_umtx_abs_timeout_init(timop, args); + } else { + timop = NULL; + } umtxq_lock(&uq->uq_key); pi = umtx_pi_lookup(&uq->uq_key); @@ -546,8 +550,7 @@ linux_futex_lock_pi(struct thread *td, bool try, struct linux_futex_args *args) /* We set the contested bit, sleep. */ error = umtxq_sleep_pi(uq, pi, owner, "futexp", - args->ts == NULL ? NULL : &timo, - (args->flags & FUTEX_SHARED) != 0); + timop, (args->flags & FUTEX_SHARED) != 0); if (error != 0) continue;home | help
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