arm_pmu: Fix write counter error in ARMv7 big-endian mode
hulk inclusion category: bugfix bugzilla: 51829 CVE: NA -------------------------------- Commit 3a95200d ("arm_pmu: Change API to support 64bit counter values") changes the input "value" type from 32-bit to 64-bit, which introduces the following problem: ARMv7 PMU counters is 32-bit width, in big-endian mode, write counter uses high 32-bit, which writes an incorrect value. Before: Performance counter stats for 'ls': 2.22 msec task-clock # 0.675 CPUs utilized 0 context-switches # 0.000 K/sec 0 cpu-migrations # 0.000 K/sec 49 page-faults # 0.022 M/sec 2150476593 cycles # 966.663 GHz 2148588788 instructions # 1.00 insn per cycle 2147745484 branches # 965435.074 M/sec 2147508540 branch-misses # 99.99% of all branches None of the above hw event counters are correct. After: Performance counter stats for 'ls': 2.09 msec task-clock # 0.681 CPUs utilized 0 context-switches # 0.000 K/sec 0 cpu-migrations # 0.000 K/sec 46 page-faults # 0.022 M/sec 2807301 cycles # 1.344 GHz 1060159 instructions # 0.38 insn per cycle 250496 branches # 119.914 M/sec 23192 branch-misses # 9.26% of all branches Solution: "value" is forcibly converted to 32-bit type before being written to PMU register. Fixes: 3a95200d ("arm_pmu: Change API to support 64bit counter values") Signed-off-by: NYang Jihong <yangjihong1@huawei.com> Reviewed-by: NKuohai Xu <xukuohai@huawei.com> Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
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