Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar: "Two fixes on the kernel side: fix an over-eager condition that failed larger perf ring-buffer sizes, plus fix crashes in the Intel BTS code for a corner case, found by fuzzing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Fix impossible ring-buffer sizes warning perf/x86: Add check_period PMU callback

Linus Torvalds committed 7 years ago

Commit dd6f29d2 parents c5f1ac5 528871b6 files · +59 −3Browse files

Unified · Split

6 files

arch/x86/events/core.c +14 −0
arch/x86/events/intel/core.c +9 −0
arch/x86/events/perf_event.h +14 −2
include/linux/perf_event.h +5 −0
kernel/events/core.c +16 −0
kernel/events/ring_buffer.c +1 −1

arch/x86/events/core.c+14−0

@@ -2278,6 +2278,19 @@ void perf_check_microcode(void) · 2277 unmodified lines
2278	x86_pmu.check_microcode();	2278	x86_pmu.check_microcode();
2279	}	2279	}
2280		2280
		2281	static int x86_pmu_check_period(struct perf_event *event, u64 value)
		2282	{
		2283	if (x86_pmu.check_period && x86_pmu.check_period(event, value))
		2284	return -EINVAL;
		2285
		2286	if (value && x86_pmu.limit_period) {
		2287	if (x86_pmu.limit_period(event, value) > value)
		2288	return -EINVAL;
		2289	}
		2290
		2291	return 0;
		2292	}
		2293
2281	static struct pmu pmu = {	2294	static struct pmu pmu = {
2282	.pmu_enable = x86_pmu_enable,	2295	.pmu_enable = x86_pmu_enable,
2283	.pmu_disable = x86_pmu_disable,	2296	.pmu_disable = x86_pmu_disable,
@@ -2302,6 +2315,7 @@ static struct pmu pmu = { · 18 unmodified lines
2302	.event_idx = x86_pmu_event_idx,	2315	.event_idx = x86_pmu_event_idx,
2303	.sched_task = x86_pmu_sched_task,	2316	.sched_task = x86_pmu_sched_task,
2304	.task_ctx_size = sizeof(struct x86_perf_task_context),	2317	.task_ctx_size = sizeof(struct x86_perf_task_context),
		2318	.check_period = x86_pmu_check_period,
2305	};	2319	};
2306		2320
2307	void arch_perf_update_userpage(struct perf_event *event,	2321	void arch_perf_update_userpage(struct perf_event *event,

arch/x86/events/intel/core.c+9−0

 	intel_pmu_lbr_sched_task(ctx, sched_in);
 }
+static int intel_pmu_check_period(struct perf_event *event, u64 value)
+{
+	return intel_pmu_has_bts_period(event, value) ? -EINVAL : 0;
+}
 PMU_FORMAT_ATTR(offcore_rsp, "config1:0-63");
 PMU_FORMAT_ATTR(ldlat, "config1:0-15");
 	.cpu_starting		= intel_pmu_cpu_starting,
 	.cpu_dying		= intel_pmu_cpu_dying,
 	.cpu_dead		= intel_pmu_cpu_dead,
+	.check_period		= intel_pmu_check_period,
 };
 static struct attribute *intel_pmu_attrs[];
 	.guest_get_msrs		= intel_guest_get_msrs,
 	.sched_task		= intel_pmu_sched_task,
+	.check_period		= intel_pmu_check_period,
 };
 static __init void intel_clovertown_quirk(void)

arch/x86/events/perf_event.h+14−2

 	 * Intel host/guest support (KVM)
 	 */
 	struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr);
+	/*
+	 * Check period value for PERF_EVENT_IOC_PERIOD ioctl.
+	 */
+	int (*check_period) (struct perf_event *event, u64 period);
 };
 struct x86_perf_task_context {
 #ifdef CONFIG_CPU_SUP_INTEL
-static inline bool intel_pmu_has_bts(struct perf_event *event)
+static inline bool intel_pmu_has_bts_period(struct perf_event *event, u64 period)
 {
 	struct hw_perf_event *hwc = &event->hw;
 	unsigned int hw_event, bts_event;
 	hw_event = hwc->config & INTEL_ARCH_EVENT_MASK;
 	bts_event = x86_pmu.event_map(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
-	return hw_event == bts_event && hwc->sample_period == 1;
+	return hw_event == bts_event && period == 1;
+}
+static inline bool intel_pmu_has_bts(struct perf_event *event)
+{
+	struct hw_perf_event *hwc = &event->hw;
+	return intel_pmu_has_bts_period(event, hwc->sample_period);
 }
 int intel_pmu_save_and_restart(struct perf_event *event);

include/linux/perf_event.h+5−0

 	 * Filter events for PMU-specific reasons.
 	 */
 	int (*filter_match)		(struct perf_event *event); /* optional */
+	/*
+	 * Check period value for PERF_EVENT_IOC_PERIOD ioctl.
+	 */
+	int (*check_period)		(struct perf_event *event, u64 value); /* optional */
 };
 enum perf_addr_filter_action_t {

kernel/events/core.c+16−0

 	}
 }
+static int perf_event_check_period(struct perf_event *event, u64 value)
+{
+	return event->pmu->check_period(event, value);
+}
 static int perf_event_period(struct perf_event *event, u64 __user *arg)
 {
 	u64 value;
 	if (event->attr.freq && value > sysctl_perf_event_sample_rate)
 		return -EINVAL;
+	if (perf_event_check_period(event, value))
+		return -EINVAL;
 	event_function_call(event, __perf_event_period, &value);
 	return 0;
 	return 0;
 }
+static int perf_event_nop_int(struct perf_event *event, u64 value)
+{
+	return 0;
+}
 static DEFINE_PER_CPU(unsigned int, nop_txn_flags);
 static void perf_pmu_start_txn(struct pmu *pmu, unsigned int flags)
 		pmu->pmu_disable = perf_pmu_nop_void;
 	}
+	if (!pmu->check_period)
+		pmu->check_period = perf_event_nop_int;
 	if (!pmu->event_idx)
 		pmu->event_idx = perf_event_idx_default;

kernel/events/ring_buffer.c+1−1

@@ -734,7 +734,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) · 733 unmodified lines
734	size = sizeof(struct ring_buffer);	734	size = sizeof(struct ring_buffer);
735	size += nr_pages * sizeof(void *);	735	size += nr_pages * sizeof(void *);
736		736
737	if (order_base_2(size) >= MAX_ORDER)	737	if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
738	goto fail;	738	goto fail;
739		739
740	rb = kzalloc(size, GFP_KERNEL);	740	rb = kzalloc(size, GFP_KERNEL);