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authorRavi Bangoria <ravi.bangoria@linux.ibm.com>2019-05-11 05:42:17 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2019-05-22 14:38:20 +0300
commit3202e35ec1c8fc19cea24253ff83edf702a60a02 (patch)
tree07a2f0939c84526a9bc367cccb2b958c7e8b8550 /arch/powerpc/perf
parentb59bd3527fe3c1939340df558d7f9d568fc9f882 (diff)
downloadlinux-3202e35ec1c8fc19cea24253ff83edf702a60a02.tar.xz
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>
Diffstat (limited to 'arch/powerpc/perf')
-rw-r--r--arch/powerpc/perf/core-book3s.c6
-rw-r--r--arch/powerpc/perf/power8-pmu.c3
-rw-r--r--arch/powerpc/perf/power9-pmu.c3
3 files changed, 10 insertions, 2 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index a66fb9c01c9e..2c21ff896e2c 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -1850,6 +1850,7 @@ static int power_pmu_event_init(struct perf_event *event)
int n;
int err;
struct cpu_hw_events *cpuhw;
+ u64 bhrb_filter;
if (!ppmu)
return -ENOENT;
@@ -1955,13 +1956,14 @@ static int power_pmu_event_init(struct perf_event *event)
err = power_check_constraints(cpuhw, events, cflags, n + 1);
if (has_branch_stack(event)) {
- cpuhw->bhrb_filter = ppmu->bhrb_filter_map(
+ bhrb_filter = ppmu->bhrb_filter_map(
event->attr.branch_sample_type);
- if (cpuhw->bhrb_filter == -1) {
+ if (bhrb_filter == -1) {
put_cpu_var(cpu_hw_events);
return -EOPNOTSUPP;
}
+ cpuhw->bhrb_filter = bhrb_filter;
}
put_cpu_var(cpu_hw_events);
diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c
index bcc3409a06de..c0eb3e2329f0 100644
--- a/arch/powerpc/perf/power8-pmu.c
+++ b/arch/powerpc/perf/power8-pmu.c
@@ -29,6 +29,7 @@ enum {
#define POWER8_MMCRA_IFM1 0x0000000040000000UL
#define POWER8_MMCRA_IFM2 0x0000000080000000UL
#define POWER8_MMCRA_IFM3 0x00000000C0000000UL
+#define POWER8_MMCRA_BHRB_MASK 0x00000000C0000000UL
/*
* Raw event encoding for PowerISA v2.07 (Power8):
@@ -243,6 +244,8 @@ static u64 power8_bhrb_filter_map(u64 branch_sample_type)
static void power8_config_bhrb(u64 pmu_bhrb_filter)
{
+ pmu_bhrb_filter &= POWER8_MMCRA_BHRB_MASK;
+
/* Enable BHRB filter in PMU */
mtspr(SPRN_MMCRA, (mfspr(SPRN_MMCRA) | pmu_bhrb_filter));
}
diff --git a/arch/powerpc/perf/power9-pmu.c b/arch/powerpc/perf/power9-pmu.c
index 3a31ac6f4805..e19c492bd6ec 100644
--- a/arch/powerpc/perf/power9-pmu.c
+++ b/arch/powerpc/perf/power9-pmu.c
@@ -92,6 +92,7 @@ enum {
#define POWER9_MMCRA_IFM1 0x0000000040000000UL
#define POWER9_MMCRA_IFM2 0x0000000080000000UL
#define POWER9_MMCRA_IFM3 0x00000000C0000000UL
+#define POWER9_MMCRA_BHRB_MASK 0x00000000C0000000UL
/* Nasty Power9 specific hack */
#define PVR_POWER9_CUMULUS 0x00002000
@@ -300,6 +301,8 @@ static u64 power9_bhrb_filter_map(u64 branch_sample_type)
static void power9_config_bhrb(u64 pmu_bhrb_filter)
{
+ pmu_bhrb_filter &= POWER9_MMCRA_BHRB_MASK;
+
/* Enable BHRB filter in PMU */
mtspr(SPRN_MMCRA, (mfspr(SPRN_MMCRA) | pmu_bhrb_filter));
}