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| author | Athira Rajeev <atrajeev@linux.vnet.ibm.com> | 2020-07-17 16:38:21 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-22 13:56:41 +0200 |
| commit | bfe3b1945d5e0531103b3d4ab3a367a1a156d99a (patch) | |
| tree | f696c7a6fea2eec0d5ced69c598091823390c921 | |
| parent | powerpc/perf: power10 Performance Monitoring support (diff) | |
| download | linux-bfe3b1945d5e0531103b3d4ab3a367a1a156d99a.tar.xz linux-bfe3b1945d5e0531103b3d4ab3a367a1a156d99a.zip | |
powerpc/perf: Ignore the BHRB kernel address filtering for P10
Commit bb19af816025 ("powerpc/perf: Prevent kernel address leak to
userspace via BHRB buffer") added a check in bhrb_read() to filter
the kernel address from BHRB buffer. This patch modified it to avoid
that check for PowerISA v3.1 based processors, since PowerISA v3.1
allows only MSR[PR]=1 address to be written to BHRB buffer.
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1594996707-3727-10-git-send-email-atrajeev@linux.vnet.ibm.com
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 6bffffa22ee8..e31629fb6e7e 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -470,8 +470,11 @@ static void power_pmu_bhrb_read(struct perf_event *event, struct cpu_hw_events * * addresses at this point. Check the privileges before * exporting it to userspace (avoid exposure of regions * where we could have speculative execution) + * Incase of ISA v3.1, BHRB will capture only user-space + * addresses, hence include a check before filtering code */ - if (is_kernel_addr(addr) && perf_allow_kernel(&event->attr) != 0) + if (!(ppmu->flags & PPMU_ARCH_31) && + is_kernel_addr(addr) && perf_allow_kernel(&event->attr) != 0) continue; /* Branches are read most recent first (ie. mfbhrb 0 is |