From 82715a0f332843d3a1830d7ebc9ac7c99a00c880 Mon Sep 17 00:00:00 2001 From: Athira Rajeev Date: Wed, 26 Aug 2020 02:40:29 -0400 Subject: powerpc/perf: Fix reading of MSR[HV/PR] bits in trace-imc IMC trace-mode uses MSR[HV/PR] bits to set the cpumode for the instruction pointer captured in each sample. The bits are fetched from the third double word of the trace record. Reading third double word from IMC trace record should use be64_to_cpu() along with READ_ONCE inorder to fetch correct MSR[HV/PR] bits. Patch addresses this change. Currently we are using PERF_RECORD_MISC_HYPERVISOR as cpumode if MSR HV is 1 and PR is 0 which means the address is from host counter. But using PERF_RECORD_MISC_HYPERVISOR for host counter data will fail to resolve the address -> symbol during "perf report" because perf tools side uses PERF_RECORD_MISC_KERNEL to represent the host counter data. Therefore, fix the trace imc sample data to use PERF_RECORD_MISC_KERNEL as cpumode for host kernel information. Fixes: 77ca3951cc37 ("powerpc/perf: Add kernel support for new MSR[HV PR] bits in trace-imc") Signed-off-by: Athira Rajeev Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1598424029-1662-1-git-send-email-atrajeev@linux.vnet.ibm.com --- arch/powerpc/perf/imc-pmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/perf') diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index a45d694a5d5d..62d0b54086f8 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -1289,7 +1289,7 @@ static int trace_imc_prepare_sample(struct trace_imc_data *mem, header->misc = 0; if (cpu_has_feature(CPU_FTR_ARCH_31)) { - switch (IMC_TRACE_RECORD_VAL_HVPR(mem->val)) { + switch (IMC_TRACE_RECORD_VAL_HVPR(be64_to_cpu(READ_ONCE(mem->val)))) { case 0:/* when MSR HV and PR not set in the trace-record */ header->misc |= PERF_RECORD_MISC_GUEST_KERNEL; break; @@ -1297,7 +1297,7 @@ static int trace_imc_prepare_sample(struct trace_imc_data *mem, header->misc |= PERF_RECORD_MISC_GUEST_USER; break; case 2: /* MSR HV is 1 and PR is 0 */ - header->misc |= PERF_RECORD_MISC_HYPERVISOR; + header->misc |= PERF_RECORD_MISC_KERNEL; break; case 3: /* MSR HV is 1 and PR is 1 */ header->misc |= PERF_RECORD_MISC_USER; -- cgit v1.2.3