Andreas Schwab
045836fcce
+ check (CVE-2026-0861, bsc#1256766, BZ #33796) +- nss-dns-getnetbyaddr.patch: resolv: Fix NSS DNS backend for getnetbyaddr + (CVE-2026-0915, bsc#1256822, BZ #33802) +- nptl-optimize-trylock.patch: nptl: Optimize trylock for high cache + contention workloads (bsc#1256436, BZ #33704) +- wordexp-wrde-reuse.patch: posix: Reset wordexp_t fields with WRDE_REUSE + (CVE-2025-15281, bsc#1257005, BZ #33814)
51 lines
1.7 KiB
Diff
51 lines
1.7 KiB
Diff
From d861635092a5ad3499baf18b2ff955b778734a0e Mon Sep 17 00:00:00 2001
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From: Sunil K Pandey <sunil.k.pandey@intel.com>
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Date: Tue, 9 Dec 2025 08:57:44 -0800
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Subject: [PATCH] nptl: Optimize trylock for high cache contention workloads
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(BZ #33704)
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Check lock availability before acquisition to reduce cache line
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bouncing. Significantly improves trylock throughput on multi-core
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systems under heavy contention.
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Tested on x86_64.
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Fixes BZ #33704.
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Co-authored-by: Alex M Wells <alex.m.wells@intel.com>
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Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
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(cherry picked from commit 63716823dbad9482e09972907ae98e9cb00f9b86)
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---
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nptl/pthread_mutex_trylock.c | 8 ++++++--
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1 file changed, 6 insertions(+), 2 deletions(-)
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diff --git a/nptl/pthread_mutex_trylock.c b/nptl/pthread_mutex_trylock.c
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index 720c103f3f..6cf47403dd 100644
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--- a/nptl/pthread_mutex_trylock.c
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+++ b/nptl/pthread_mutex_trylock.c
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@@ -48,7 +48,8 @@ ___pthread_mutex_trylock (pthread_mutex_t *mutex)
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return 0;
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}
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- if (lll_trylock (mutex->__data.__lock) == 0)
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+ if (atomic_load_relaxed (&(mutex->__data.__lock)) == 0
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+ && lll_trylock (mutex->__data.__lock) == 0)
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{
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/* Record the ownership. */
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mutex->__data.__owner = id;
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@@ -71,7 +72,10 @@ ___pthread_mutex_trylock (pthread_mutex_t *mutex)
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/*FALL THROUGH*/
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case PTHREAD_MUTEX_ADAPTIVE_NP:
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case PTHREAD_MUTEX_ERRORCHECK_NP:
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- if (lll_trylock (mutex->__data.__lock) != 0)
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+ /* Mutex type is already loaded, lock check overhead should
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+ be minimal. */
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+ if (atomic_load_relaxed (&(mutex->__data.__lock)) != 0
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+ || lll_trylock (mutex->__data.__lock) != 0)
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break;
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/* Record the ownership. */
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--
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2.52.0
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