From: Colin Ian King <colin.i.king@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H . Peter Anvin" <hpa@zytor.com>,
Kim Phillips <kim.phillips@amd.com>,
linux-perf-users@vger.kernel.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] perf/x86/amd: fix potential integer overflow on shift of a int
Date: Fri, 2 Dec 2022 13:51:49 +0000 [thread overview]
Message-ID: <20221202135149.1797974-1-colin.i.king@gmail.com> (raw)
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
next reply other threads:[~2022-12-02 13:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-02 13:51 Colin Ian King [this message]
2022-12-02 17:36 ` [PATCH][next] perf/x86/amd: fix potential integer overflow on shift of a int Ian Rogers
2022-12-02 19:10 ` Kim Phillips
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