[GIT PULL] perf fixes

From: Ingo Molnar
Date: Sun Mar 21 2021 - 06:57:57 EST


Linus,

Please pull the latest perf/urgent git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2021-03-21

# HEAD: 2dc0572f2cef87425147658698dce2600b799bd3 perf/x86/intel: Fix unchecked MSR access error caused by VLBR_EVENT

Boundary condition fixes for bugs unearthed by the perf fuzzer.

Thanks,

Ingo

------------------>
Kan Liang (2):
perf/x86/intel: Fix a crash caused by zero PEBS status
perf/x86/intel: Fix unchecked MSR access error caused by VLBR_EVENT


arch/x86/events/intel/core.c | 3 +++
arch/x86/events/intel/ds.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 7bbb5bb98d8c..37ce38403cb8 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3659,6 +3659,9 @@ static int intel_pmu_hw_config(struct perf_event *event)
return ret;

if (event->attr.precise_ip) {
+ if ((event->attr.config & INTEL_ARCH_EVENT_MASK) == INTEL_FIXED_VLBR_EVENT)
+ return -EINVAL;
+
if (!(event->attr.freq || (event->attr.wakeup_events && !event->attr.watermark))) {
event->hw.flags |= PERF_X86_EVENT_AUTO_RELOAD;
if (!(event->attr.sample_type &
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 7ebae1826403..d32b302719fe 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2010,7 +2010,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs, struct perf_sample_d
*/
if (!pebs_status && cpuc->pebs_enabled &&
!(cpuc->pebs_enabled & (cpuc->pebs_enabled-1)))
- pebs_status = cpuc->pebs_enabled;
+ pebs_status = p->status = cpuc->pebs_enabled;

bit = find_first_bit((unsigned long *)&pebs_status,
x86_pmu.max_pebs_events);