From e321d02db87af7840da29ef833a2a71fc0eab198 Mon Sep 17 00:00:00 2001
From: Kan Liang
Date: Tue, 28 May 2019 15:08:30 -0700
Subject: perf/x86: Disable extended registers for non-supported PMUs
The perf fuzzer caused Skylake machine to crash:
[ 9680.085831] Call Trace:
[ 9680.088301]
[ 9680.090363] perf_output_sample_regs+0x43/0xa0
[ 9680.094928] perf_output_sample+0x3aa/0x7a0
[ 9680.099181] perf_event_output_forward+0x53/0x80
[ 9680.103917] __perf_event_overflow+0x52/0xf0
[ 9680.108266] ? perf_trace_run_bpf_submit+0xc0/0xc0
[ 9680.113108] perf_swevent_hrtimer+0xe2/0x150
[ 9680.117475] ? check_preempt_wakeup+0x181/0x230
[ 9680.122091] ? check_preempt_curr+0x62/0x90
[ 9680.126361] ? ttwu_do_wakeup+0x19/0x140
[ 9680.130355] ? try_to_wake_up+0x54/0x460
[ 9680.134366] ? reweight_entity+0x15b/0x1a0
[ 9680.138559] ? __queue_work+0x103/0x3f0
[ 9680.142472] ? update_dl_rq_load_avg+0x1cd/0x270
[ 9680.147194] ? timerqueue_del+0x1e/0x40
[ 9680.151092] ? __remove_hrtimer+0x35/0x70
[ 9680.155191] __hrtimer_run_queues+0x100/0x280
[ 9680.159658] hrtimer_interrupt+0x100/0x220
[ 9680.163835] smp_apic_timer_interrupt+0x6a/0x140
[ 9680.168555] apic_timer_interrupt+0xf/0x20
[ 9680.172756]
The XMM registers can only be collected by PEBS hardware events on the
platforms with PEBS baseline support, e.g. Icelake, not software/probe
events.
Add capabilities flag PERF_PMU_CAP_EXTENDED_REGS to indicate the PMU
which support extended registers. For X86, the extended registers are
XMM registers.
Add has_extended_regs() to check if extended registers are applied.
The generic code define the mask of extended registers as 0 if arch
headers haven't overridden it.
Originally-by: Peter Zijlstra (Intel)
Reported-by: Vince Weaver
Signed-off-by: Kan Liang
Signed-off-by: Peter Zijlstra (Intel)
Cc: Alexander Shishkin
Cc: Arnaldo Carvalho de Melo
Cc: Jiri Olsa
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Stephane Eranian
Cc: Thomas Gleixner
Fixes: 878068ea270e ("perf/x86: Support outputting XMM registers")
Link: https://lkml.kernel.org/r/1559081314-9714-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar
---
include/linux/perf_event.h | 1 +
include/linux/perf_regs.h | 8 ++++++++
2 files changed, 9 insertions(+)
(limited to 'include')
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 0ab99c7b652d..2bca72f3028b 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -241,6 +241,7 @@ struct perf_event;
#define PERF_PMU_CAP_NO_INTERRUPT 0x01
#define PERF_PMU_CAP_NO_NMI 0x02
#define PERF_PMU_CAP_AUX_NO_SG 0x04
+#define PERF_PMU_CAP_EXTENDED_REGS 0x08
#define PERF_PMU_CAP_EXCLUSIVE 0x10
#define PERF_PMU_CAP_ITRACE 0x20
#define PERF_PMU_CAP_HETEROGENEOUS_CPUS 0x40
diff --git a/include/linux/perf_regs.h b/include/linux/perf_regs.h
index 476747456bca..2d12e97d5e7b 100644
--- a/include/linux/perf_regs.h
+++ b/include/linux/perf_regs.h
@@ -11,6 +11,11 @@ struct perf_regs {
#ifdef CONFIG_HAVE_PERF_REGS
#include
+
+#ifndef PERF_REG_EXTENDED_MASK
+#define PERF_REG_EXTENDED_MASK 0
+#endif
+
u64 perf_reg_value(struct pt_regs *regs, int idx);
int perf_reg_validate(u64 mask);
u64 perf_reg_abi(struct task_struct *task);
@@ -18,6 +23,9 @@ void perf_get_regs_user(struct perf_regs *regs_user,
struct pt_regs *regs,
struct pt_regs *regs_user_copy);
#else
+
+#define PERF_REG_EXTENDED_MASK 0
+
static inline u64 perf_reg_value(struct pt_regs *regs, int idx)
{
return 0;
--
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