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memtest: use {READ,WRITE}_ONCE in memory scanning

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memtest failed to find bad memory when compiled with clang.  So use
{WRITE,READ}_ONCE to access memory to avoid compiler over optimization.

Link: https://lkml.kernel.org/r/20240312080422.691222-1-qiang4.zhang@intel.com
Signed-off-by: Qiang Zhang <qiang4.zhang@intel.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Qiang Zhang 2024-03-12 16:04:23 +08:00 committed by Andrew Morton
parent cd197c3a20
commit 82634d7e24
1 changed files with 2 additions and 2 deletions
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4
mm/memtest.c
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@ -51,10 +51,10 @@ static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size
last_bad = 0; last_bad = 0;
for (p = start; p < end; p++) for (p = start; p < end; p++)
*p = pattern; WRITE_ONCE(*p, pattern);
for (p = start; p < end; p++, start_phys_aligned += incr) { for (p = start; p < end; p++, start_phys_aligned += incr) {
if (*p == pattern) if (READ_ONCE(*p) == pattern)
continue; continue;
if (start_phys_aligned == last_bad + incr) { if (start_phys_aligned == last_bad + incr) {
last_bad += incr; last_bad += incr;