From: Kan Liang <kan.li...@linux.intel.com>
The perf fuzzer caused skylake machine to crash.
[ 9680.085831] Call Trace:
[ 9680.088301] <IRQ>
[ 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] </IRQ>
The XMM registers can only be collected by hardware events, not
software/probe events.
Add has_non_generic_regs() to check if non-generic registers, e.g. XMM
on X86, are applied for software/probe events. If yes, return
-EOPNOTSUPP.
The generic code define the mask of non-generic registers as 0 if arch
headers haven't overridden it.
Fixes: 878068ea270e ("perf/x86: Support outputting XMM registers")
Reported-by: Vince Weaver <vincent.wea...@maine.edu>
Signed-off-by: Kan Liang <kan.li...@linux.intel.com>
---
Changes since V1:
- Use macro PERF_REG_NON_GENERIC_MASK to replace function
- Avoid unnecessary abbreviations in comments
- Remove unnecessary bracket for return.
arch/x86/include/uapi/asm/perf_regs.h | 3 +++
include/linux/perf_regs.h | 8 ++++++++
kernel/events/core.c | 30 ++++++++++++++++++++++++++++++
3 files changed, 41 insertions(+)
diff --git a/arch/x86/include/uapi/asm/perf_regs.h
b/arch/x86/include/uapi/asm/perf_regs.h
index ac67bbe..3a96971 100644
--- a/arch/x86/include/uapi/asm/perf_regs.h
+++ b/arch/x86/include/uapi/asm/perf_regs.h
@@ -52,4 +52,7 @@ enum perf_event_x86_regs {
/* These include both GPRs and XMMX registers */
PERF_REG_X86_XMM_MAX = PERF_REG_X86_XMM15 + 2,
};
+
+#define PERF_REG_NON_GENERIC_MASK (~((1ULL << PERF_REG_X86_XMM0) - 1))
+
#endif /* _ASM_X86_PERF_REGS_H */
diff --git a/include/linux/perf_regs.h b/include/linux/perf_regs.h
index 4767474..1d794355 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 <asm/perf_regs.h>
+
+#ifndef PERF_REG_NON_GENERIC_MASK
+#define PERF_REG_NON_GENERIC_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_NON_GENERIC_MASK 0
+
static inline u64 perf_reg_value(struct pt_regs *regs, int idx)
{
return 0;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index abbd4b3..4865bdf 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8457,6 +8457,12 @@ static void sw_perf_event_destroy(struct perf_event
*event)
swevent_hlist_put();
}
+static inline bool has_non_generic_regs(struct perf_event *event)
+{
+ return (event->attr.sample_regs_user & PERF_REG_NON_GENERIC_MASK) ||
+ (event->attr.sample_regs_intr & PERF_REG_NON_GENERIC_MASK);
+}
+
static int perf_swevent_init(struct perf_event *event)
{
u64 event_id = event->attr.config;
@@ -8470,6 +8476,10 @@ static int perf_swevent_init(struct perf_event *event)
if (has_branch_stack(event))
return -EOPNOTSUPP;
+ /* Only support generic registers */
+ if (has_non_generic_regs(event))
+ return -EOPNOTSUPP;
+
switch (event_id) {
case PERF_COUNT_SW_CPU_CLOCK:
case PERF_COUNT_SW_TASK_CLOCK:
@@ -8633,6 +8643,10 @@ static int perf_tp_event_init(struct perf_event *event)
if (has_branch_stack(event))
return -EOPNOTSUPP;
+ /* Only support generic registers */
+ if (has_non_generic_regs(event))
+ return -EOPNOTSUPP;
+
err = perf_trace_init(event);
if (err)
return err;
@@ -8722,6 +8736,10 @@ static int perf_kprobe_event_init(struct perf_event
*event)
if (has_branch_stack(event))
return -EOPNOTSUPP;
+ /* Only support generic registers */
+ if (has_non_generic_regs(event))
+ return -EOPNOTSUPP;
+
is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
err = perf_kprobe_init(event, is_retprobe);
if (err)
@@ -8782,6 +8800,10 @@ static int perf_uprobe_event_init(struct perf_event
*event)
if (has_branch_stack(event))
return -EOPNOTSUPP;
+ /* Only support generic registers */
+ if (has_non_generic_regs(event))
+ return -EOPNOTSUPP;
+
is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe);
@@ -9562,6 +9584,10 @@ static int cpu_clock_event_init(struct perf_event *event)
if (has_branch_stack(event))
return -EOPNOTSUPP;
+ /* Only support generic registers */
+ if (has_non_generic_regs(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);
return 0;
@@ -9643,6 +9669,10 @@ static int task_clock_event_init(struct perf_event
*event)
if (has_branch_stack(event))
return -EOPNOTSUPP;
+ /* Only support generic registers */
+ if (has_non_generic_regs(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);
return 0;
--
2.7.4
