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perf/x86/amd: fix potential integer overflow on shift of a int 

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: 471af006a7 ("perf/x86/amd: Constrain Large Increment per Cycle events")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Kim Phillips <kim.phillips@amd.com>
Link: https://lore.kernel.org/r/20221202135149.1797974-1-colin.i.king@gmail.com
This commit is contained in:
Colin Ian King 2022-12-02 13:51:49 +00:00 committed by Peter Zijlstra
parent f841b682ba
commit 08245672cd
1 changed files with 1 additions and 1 deletions
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2
arch/x86/events/amd/core.c
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@ -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,