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author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2019-05-11 08:12:17 +0530 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-09 09:17:17 +0200 |
commit | ca221cf9ab6f30ecbd6280606d6f32253ee8d72b (patch) | |
tree | 91d0bc363b63b7e3ce5641039ae4ca84cad91b0b /README | |
parent | 55a94d81f5363bcf048ba8c14117dba67e4bea7b (diff) | |
download | linux-stable-ca221cf9ab6f30ecbd6280606d6f32253ee8d72b.tar.gz linux-stable-ca221cf9ab6f30ecbd6280606d6f32253ee8d72b.tar.bz2 linux-stable-ca221cf9ab6f30ecbd6280606d6f32253ee8d72b.zip |
powerpc/perf: Fix MMCRA corruption by bhrb_filter
commit 3202e35ec1c8fc19cea24253ff83edf702a60a02 upstream.
Consider a scenario where user creates two events:
1st event:
attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY;
fd = perf_event_open(attr, 0, 1, -1, 0);
This sets cpuhw->bhrb_filter to 0 and returns valid fd.
2nd event:
attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
attr.branch_sample_type = PERF_SAMPLE_BRANCH_CALL;
fd = perf_event_open(attr, 0, 1, -1, 0);
It overrides cpuhw->bhrb_filter to -1 and returns with error.
Now if power_pmu_enable() gets called by any path other than
power_pmu_add(), ppmu->config_bhrb(-1) will set MMCRA to -1.
Fixes: 3925f46bb590 ("powerpc/perf: Enable branch stack sampling framework")
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'README')
0 files changed, 0 insertions, 0 deletions