Messages in this thread | | | Date | Wed, 27 Mar 2024 14:40:25 +0800 | Subject | Re: [kvm-unit-tests Patch v3 02/11] x86: pmu: Enlarge cnt[] length to 64 in check_counters_many() | From | "Mi, Dapeng" <> |
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On 3/26/2024 5:41 AM, Jim Mattson wrote: > On Tue, Jan 2, 2024 at 7:09 PM Dapeng Mi <dapeng1.mi@linux.intel.com> wrote: >> Considering there are already 8 GP counters and 4 fixed counters on >> latest Intel processors, like Sapphire Rapids. The original cnt[] array >> length 10 is definitely not enough to cover all supported PMU counters on these >> new processors even through currently KVM only supports 3 fixed counters >> at most. This would cause out of bound memory access and may trigger >> false alarm on PMU counter validation >> >> It's probably more and more GP and fixed counters are introduced in the >> future and then directly extends the cnt[] array length to 64 once and >> for all. >> >> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> >> --- >> x86/pmu.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/x86/pmu.c b/x86/pmu.c >> index 0def28695c70..a13b8a8398c6 100644 >> --- a/x86/pmu.c >> +++ b/x86/pmu.c >> @@ -254,7 +254,7 @@ static void check_fixed_counters(void) >> >> static void check_counters_many(void) >> { >> - pmu_counter_t cnt[10]; >> + pmu_counter_t cnt[64]; > I think 48 should be sufficient, based on the layout of > IA32_PERF_GLOBAL_CTRL and IA32_PERF_GLOBAL_STATUS. > > In any event, let's bump this up! > > Reviewed-by: Jim Mattson <jmattson@google.com>
Yeah, would shrink to 48.
Thanks Jim. I'm glad you have time to review this patchset. Not sure if you have time to review other patches?
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