Projects
Mega:24.03:SP1:Everything
glibc
_service:tar_scm:0002-linux-Use-rseq-area-uncon...
Sign Up
Log In
Username
Password
Overview
Repositories
Revisions
Requests
Users
Attributes
Meta
File _service:tar_scm:0002-linux-Use-rseq-area-unconditionally-in-sched_getcpu-.patch of Package glibc
From 5753cda1ca0749002c4718122a9b6d5177087b7b Mon Sep 17 00:00:00 2001 From: Florian Weimer <fweimer@redhat.com> Date: Fri, 15 Mar 2024 19:08:24 +0100 Subject: [PATCH 02/26] linux: Use rseq area unconditionally in sched_getcpu (bug 31479) Originally, nptl/descr.h included <sys/rseq.h>, but we removed that in commit 2c6b4b272e6b4d07303af25709051c3e96288f2d ("nptl: Unconditionally use a 32-byte rseq area"). After that, it was not ensured that the RSEQ_SIG macro was defined during sched_getcpu.c compilation that provided a definition. This commit always checks the rseq area for CPU number information before using the other approaches. This adds an unnecessary (but well-predictable) branch on architectures which do not define RSEQ_SIG, but its cost is small compared to the system call. Most architectures that have vDSO acceleration for getcpu also have rseq support. Fixes: 2c6b4b272e6b4d07303af25709051c3e96288f2d Fixes: 1d350aa06091211863e41169729cee1bca39f72f Reviewed-by: Arjun Shankar <arjun@redhat.com> (cherry picked from commit 7a76f218677d149d8b7875b336722108239f7ee9) --- sysdeps/unix/sysv/linux/sched_getcpu.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/sysdeps/unix/sysv/linux/sched_getcpu.c b/sysdeps/unix/sysv/linux/sched_getcpu.c index 4457d714bc..22700ef846 100644 --- a/sysdeps/unix/sysv/linux/sched_getcpu.c +++ b/sysdeps/unix/sysv/linux/sched_getcpu.c @@ -33,17 +33,9 @@ vsyscall_sched_getcpu (void) return r == -1 ? r : cpu; } -#ifdef RSEQ_SIG int sched_getcpu (void) { int cpu_id = THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id); return __glibc_likely (cpu_id >= 0) ? cpu_id : vsyscall_sched_getcpu (); } -#else /* RSEQ_SIG */ -int -sched_getcpu (void) -{ - return vsyscall_sched_getcpu (); -} -#endif /* RSEQ_SIG */ -- 2.33.0
Locations
Projects
Search
Status Monitor
Help
Open Build Service
OBS Manuals
API Documentation
OBS Portal
Reporting a Bug
Contact
Mailing List
Forums
Chat (IRC)
Twitter
Open Build Service (OBS)
is an
openSUSE project
.
浙ICP备2022010568号-2