From: Atish Patra atishp@rivosinc.com
commit 133a6d1fe7d7ad8393af025c4dde379c0616661f upstream.
Currently, riscv_pmu_event_set_period updates the userpage mapping. However, the caller of riscv_pmu_event_set_period should update the userpage mapping because the counter can not be updated/started from set_period function in counter overflow path.
Invoke the perf_event_update_userpage at the caller so that it doesn't get invoked twice during counter start path.
Fixes: f5bfa23f576f ("RISC-V: Add a perf core library for pmu drivers") Reviewed-by: Anup Patel anup@brainfault.org Signed-off-by: Atish Patra atishp@rivosinc.com Reviewed-by: Guo Ren guoren@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20220711174632.4186047-3-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/perf/riscv_pmu.c | 1 - drivers/perf/riscv_pmu_sbi.c | 1 + 2 files changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/perf/riscv_pmu.c +++ b/drivers/perf/riscv_pmu.c @@ -170,7 +170,6 @@ int riscv_pmu_event_set_period(struct pe left = (max_period >> 1);
local64_set(&hwc->prev_count, (u64)-left); - perf_event_update_userpage(event);
return overflow; } --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -542,6 +542,7 @@ static inline void pmu_sbi_start_overflo sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, idx, 1, flag, init_val, 0, 0); #endif + perf_event_update_userpage(event); } ctr_ovf_mask = ctr_ovf_mask >> 1; idx++;