Messages in this thread Patch in this message | | | From | Colin Ian King <> | Subject | [PATCH][next] perf/x86/amd: fix potential integer overflow on shift of a int | Date | Fri, 2 Dec 2022 13:51:49 +0000 |
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The left shift of int 32 bit integer constant 1 is evaluated using 32 bit arithmetic and then passed as a 64 bit function argument. In the case where i is 32 or more this can lead to an overflow. Avoid this by shifting using the BIT_ULL macro instead.
Fixes: 471af006a747 ("perf/x86/amd: Constrain Large Increment per Cycle events") Signed-off-by: Colin Ian King <colin.i.king@gmail.com> --- arch/x86/events/amd/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index d6f3703e4119..4386b10682ce 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -1387,7 +1387,7 @@ static int __init amd_core_pmu_init(void) * numbered counter following it. */ for (i = 0; i < x86_pmu.num_counters - 1; i += 2) - even_ctr_mask |= 1 << i; + even_ctr_mask |= BIT_ULL(i); pair_constraint = (struct event_constraint) __EVENT_CONSTRAINT(0, even_ctr_mask, 0, -- 2.38.1
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