Commit fbf7b0e4 authored Dec 02, 2022 by Colin Ian King Committed by Greg Kroah-Hartman Feb 06, 2023

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



commit 08245672cdc6505550d1a5020603b0a8d4a6dcc7 upstream.

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>
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


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f571e340

arch/x86/events/amd/core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -969,7 +969,7 @@ 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,