From: Greg Kroah-Hartman gregkh@linuxfoundation.org
From: Rob Herring robh@kernel.org
commit 7bb8bc6eb550116c504fb25af8678b9d7ca2abc5 upstream.
Commit 0fdf1bb75953 ("arm64: perf: Avoid PMXEV* indirection") changed armv8pmu_read_evcntr() to return a u32 instead of u64. The result is silent truncation of the event counter when using 64-bit counters. Given the offending commit appears to have passed thru several folks, it seems likely this was a bad rebase after v8.5 PMU 64-bit counters landed.
Cc: Alexandru Elisei alexandru.elisei@arm.com Cc: Julien Thierry julien.thierry.kdev@gmail.com Cc: Mark Rutland mark.rutland@arm.com Cc: Will Deacon will@kernel.org Cc: Catalin Marinas catalin.marinas@arm.com Cc: Peter Zijlstra peterz@infradead.org Cc: Ingo Molnar mingo@redhat.com Cc: Arnaldo Carvalho de Melo acme@kernel.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: stable@vger.kernel.org Fixes: 0fdf1bb75953 ("arm64: perf: Avoid PMXEV* indirection") Signed-off-by: Rob Herring robh@kernel.org Acked-by: Mark Rutland mark.rutland@arm.com Reviewed-by: Alexandru Elisei alexandru.elisei@arm.com Link: https://lore.kernel.org/r/20210310004412.1450128-1-robh@kernel.org Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/kernel/perf_event.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/perf_event.c +++ b/arch/arm64/kernel/perf_event.c @@ -460,7 +460,7 @@ static inline int armv8pmu_counter_has_o return pmnc & BIT(ARMV8_IDX_TO_COUNTER(idx)); }
-static inline u32 armv8pmu_read_evcntr(int idx) +static inline u64 armv8pmu_read_evcntr(int idx) { u32 counter = ARMV8_IDX_TO_COUNTER(idx);