/openbmc/linux/arch/powerpc/perf/ |
H A D | power9-pmu.c | 3202e35e Fri May 10 21:42:17 CDT 2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com> powerpc/perf: Fix MMCRA corruption by bhrb_filter
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> 3202e35e Fri May 10 21:42:17 CDT 2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com> powerpc/perf: Fix MMCRA corruption by bhrb_filter 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>
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H A D | power8-pmu.c | 3202e35e Fri May 10 21:42:17 CDT 2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com> powerpc/perf: Fix MMCRA corruption by bhrb_filter
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> 3202e35e Fri May 10 21:42:17 CDT 2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com> powerpc/perf: Fix MMCRA corruption by bhrb_filter 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>
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H A D | core-book3s.c | 3202e35e Fri May 10 21:42:17 CDT 2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com> powerpc/perf: Fix MMCRA corruption by bhrb_filter
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> 3202e35e Fri May 10 21:42:17 CDT 2019 Ravi Bangoria <ravi.bangoria@linux.ibm.com> powerpc/perf: Fix MMCRA corruption by bhrb_filter 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>
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