diff options
| author | Palmer Dabbelt <palmer@rivosinc.com> | 2022-09-28 15:18:07 +0200 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-10-13 20:18:39 +0200 |
| commit | 5a5294fbe0200d1327f0e089135dad77b45aa2ee (patch) | |
| tree | 538d6e3f66215967336ee80b5088d3799fd938e7 /drivers/perf | |
| parent | riscv: vdso: fix NULL deference in vdso_join_timens() when vfork (diff) | |
| download | linux-5a5294fbe0200d1327f0e089135dad77b45aa2ee.tar.xz linux-5a5294fbe0200d1327f0e089135dad77b45aa2ee.zip | |
RISC-V: Re-enable counter access from userspace
These counters were part of the ISA when we froze the uABI, removing
them breaks userspace.
Link: https://lore.kernel.org/all/YxEhC%2FmDW1lFt36J@aurel32.net/
Fixes: e9991434596f ("RISC-V: Add perf platform driver based on SBI PMU extension")
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220928131807.30386-1-palmer@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'drivers/perf')
| -rw-r--r-- | drivers/perf/riscv_pmu_sbi.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c index 15e5a47be7d5..3852c18362f5 100644 --- a/drivers/perf/riscv_pmu_sbi.c +++ b/drivers/perf/riscv_pmu_sbi.c @@ -652,8 +652,11 @@ static int pmu_sbi_starting_cpu(unsigned int cpu, struct hlist_node *node) struct riscv_pmu *pmu = hlist_entry_safe(node, struct riscv_pmu, node); struct cpu_hw_events *cpu_hw_evt = this_cpu_ptr(pmu->hw_events); - /* Enable the access for TIME csr only from the user mode now */ - csr_write(CSR_SCOUNTEREN, 0x2); + /* + * Enable the access for CYCLE, TIME, and INSTRET CSRs from userspace, + * as is necessary to maintain uABI compatibility. + */ + csr_write(CSR_SCOUNTEREN, 0x7); /* Stop all the counters so that they can be enabled from perf */ pmu_sbi_stop_all(pmu); |