From fbcde5ea4613bc04c174e9adcca9f6eb5e308d79 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 17 Dec 2024 18:12:03 +0100 Subject: [PATCH] x86: Avoid integer truncation with large cache sizes (bug 32470) Some hypervisors report 1 TiB L3 cache size. This results in some variables incorrectly getting zeroed, causing crashes in memcpy/memmove because invariants are violated. (cherry picked from commit 61c3450db96dce96ad2b24b4f0b548e6a46d68e5) --- NEWS | 1 + sysdeps/x86/dl-cacheinfo.h | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/NEWS b/NEWS index 30a3eaaf47d..32cba994c93 100644 --- a/NEWS +++ b/NEWS @@ -106,6 +106,7 @@ The following bugs are resolved with this release: [32052] Name space violation in fortify wrappers [32137] libio: Attempt wide backup free only for non-legacy code [32231] elf: Change ldconfig auxcache magic number + [32470] x86: Avoid integer truncation with large cache sizes Version 2.36 diff --git a/sysdeps/x86/dl-cacheinfo.h b/sysdeps/x86/dl-cacheinfo.h index d95c1efa2c2..72ee1788e3a 100644 --- a/sysdeps/x86/dl-cacheinfo.h +++ b/sysdeps/x86/dl-cacheinfo.h @@ -901,12 +901,12 @@ dl_init_cacheinfo (struct cpu_features *cpu_features) #if HAVE_TUNABLES /* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8. */ - unsigned int minimum_rep_movsb_threshold; + unsigned long int minimum_rep_movsb_threshold; #endif /* NB: The default REP MOVSB threshold is 4096 * (VEC_SIZE / 16) for VEC_SIZE == 64 or 32. For VEC_SIZE == 16, the default REP MOVSB threshold is 2048 * (VEC_SIZE / 16). */ - unsigned int rep_movsb_threshold; + unsigned long int rep_movsb_threshold; if (CPU_FEATURE_USABLE_P (cpu_features, AVX512F) && !CPU_FEATURE_PREFERRED_P (cpu_features, Prefer_No_AVX512)) { -- 2.47.2