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authorLinus Torvalds <torvalds@linux-foundation.org>2024-07-16 17:13:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-07-16 17:13:31 -0700
commit576a997c6315ee482519e7cc080f341b07638808 (patch)
tree625cff628b8db0638ed496f560d38eda0375cacb /kernel/events/core.c
parent4a996d90b9e046c6d59845acf00a54d464c34ff3 (diff)
parentfa0c1c9d283b37fdb7fc1dcccbb88fc8f48a4aa4 (diff)
Merge tag 'perf-core-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar: - Intel PT support enhancements & fixes - Fix leaked SIGTRAP events - Improve and fix the Intel uncore driver - Add support for Intel HBM and CXL uncore counters - Add Intel Lake and Arrow Lake support - AMD uncore driver fixes - Make SIGTRAP and __perf_pending_irq() work on RT - Micro-optimizations - Misc cleanups and fixes * tag 'perf-core-2024-07-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) perf/x86/intel: Add a distinct name for Granite Rapids perf/x86/intel/ds: Fix non 0 retire latency on Raptorlake perf/x86/intel: Hide Topdown metrics events if the feature is not enumerated perf/x86/intel/uncore: Fix the bits of the CHA extended umask for SPR perf: Split __perf_pending_irq() out of perf_pending_irq() perf: Don't disable preemption in perf_pending_task(). perf: Move swevent_htable::recursion into task_struct. perf: Shrink the size of the recursion counter. perf: Enqueue SIGTRAP always via task_work. task_work: Add TWA_NMI_CURRENT as an additional notify mode. perf: Move irq_work_queue() where the event is prepared. perf: Fix event leak upon exec and file release perf: Fix event leak upon exit task_work: Introduce task_work_cancel() again task_work: s/task_work_cancel()/task_work_cancel_func()/ perf/x86/amd/uncore: Fix DF and UMC domain identification perf/x86/amd/uncore: Avoid PMU registration if counters are unavailable perf/x86/intel: Support Perfmon MSRs aliasing perf/x86/intel: Support PERFEVTSEL extension perf/x86: Add config_mask to represent EVENTSEL bitmask ...
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r--kernel/events/core.c125
1 files changed, 75 insertions, 50 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8f908f077935..ab6c4c942f79 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2283,21 +2283,6 @@ event_sched_out(struct perf_event *event, struct perf_event_context *ctx)
state = PERF_EVENT_STATE_OFF;
}
- if (event->pending_sigtrap) {
- bool dec = true;
-
- event->pending_sigtrap = 0;
- if (state != PERF_EVENT_STATE_OFF &&
- !event->pending_work) {
- event->pending_work = 1;
- dec = false;
- WARN_ON_ONCE(!atomic_long_inc_not_zero(&event->refcount));
- task_work_add(current, &event->pending_task, TWA_RESUME);
- }
- if (dec)
- local_dec(&event->ctx->nr_pending);
- }
-
perf_event_set_state(event, state);
if (!is_software_event(event))
@@ -2466,7 +2451,7 @@ static void __perf_event_disable(struct perf_event *event,
* hold the top-level event's child_mutex, so any descendant that
* goes to exit will block in perf_event_exit_event().
*
- * When called from perf_pending_irq it's OK because event->ctx
+ * When called from perf_pending_disable it's OK because event->ctx
* is the current context on this CPU and preemption is disabled,
* hence we can't get into perf_event_task_sched_out for this context.
*/
@@ -2506,7 +2491,7 @@ EXPORT_SYMBOL_GPL(perf_event_disable);
void perf_event_disable_inatomic(struct perf_event *event)
{
event->pending_disable = 1;
- irq_work_queue(&event->pending_irq);
+ irq_work_queue(&event->pending_disable_irq);
}
#define MAX_INTERRUPTS (~0ULL)
@@ -5206,9 +5191,35 @@ static bool exclusive_event_installable(struct perf_event *event,
static void perf_addr_filters_splice(struct perf_event *event,
struct list_head *head);
+static void perf_pending_task_sync(struct perf_event *event)
+{
+ struct callback_head *head = &event->pending_task;
+
+ if (!event->pending_work)
+ return;
+ /*
+ * If the task is queued to the current task's queue, we
+ * obviously can't wait for it to complete. Simply cancel it.
+ */
+ if (task_work_cancel(current, head)) {
+ event->pending_work = 0;
+ local_dec(&event->ctx->nr_pending);
+ return;
+ }
+
+ /*
+ * All accesses related to the event are within the same RCU section in
+ * perf_pending_task(). The RCU grace period before the event is freed
+ * will make sure all those accesses are complete by then.
+ */
+ rcuwait_wait_event(&event->pending_work_wait, !event->pending_work, TASK_UNINTERRUPTIBLE);
+}
+
static void _free_event(struct perf_event *event)
{
irq_work_sync(&event->pending_irq);
+ irq_work_sync(&event->pending_disable_irq);
+ perf_pending_task_sync(event);
unaccount_event(event);
@@ -6509,6 +6520,8 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
return -EINVAL;
nr_pages = vma_size / PAGE_SIZE;
+ if (nr_pages > INT_MAX)
+ return -ENOMEM;
mutex_lock(&event->mmap_mutex);
ret = -EINVAL;
@@ -6750,7 +6763,7 @@ static void perf_sigtrap(struct perf_event *event)
/*
* Deliver the pending work in-event-context or follow the context.
*/
-static void __perf_pending_irq(struct perf_event *event)
+static void __perf_pending_disable(struct perf_event *event)
{
int cpu = READ_ONCE(event->oncpu);
@@ -6765,11 +6778,6 @@ static void __perf_pending_irq(struct perf_event *event)
* Yay, we hit home and are in the context of the event.
*/
if (cpu == smp_processor_id()) {
- if (event->pending_sigtrap) {
- event->pending_sigtrap = 0;
- perf_sigtrap(event);
- local_dec(&event->ctx->nr_pending);
- }
if (event->pending_disable) {
event->pending_disable = 0;
perf_event_disable_local(event);
@@ -6793,11 +6801,26 @@ static void __perf_pending_irq(struct perf_event *event)
* irq_work_queue(); // FAILS
*
* irq_work_run()
- * perf_pending_irq()
+ * perf_pending_disable()
*
* But the event runs on CPU-B and wants disabling there.
*/
- irq_work_queue_on(&event->pending_irq, cpu);
+ irq_work_queue_on(&event->pending_disable_irq, cpu);
+}
+
+static void perf_pending_disable(struct irq_work *entry)
+{
+ struct perf_event *event = container_of(entry, struct perf_event, pending_disable_irq);
+ int rctx;
+
+ /*
+ * If we 'fail' here, that's OK, it means recursion is already disabled
+ * and we won't recurse 'further'.
+ */
+ rctx = perf_swevent_get_recursion_context();
+ __perf_pending_disable(event);
+ if (rctx >= 0)
+ perf_swevent_put_recursion_context(rctx);
}
static void perf_pending_irq(struct irq_work *entry)
@@ -6820,8 +6843,6 @@ static void perf_pending_irq(struct irq_work *entry)
perf_event_wakeup(event);
}
- __perf_pending_irq(event);
-
if (rctx >= 0)
perf_swevent_put_recursion_context(rctx);
}
@@ -6832,23 +6853,27 @@ static void perf_pending_task(struct callback_head *head)
int rctx;
/*
+ * All accesses to the event must belong to the same implicit RCU read-side
+ * critical section as the ->pending_work reset. See comment in
+ * perf_pending_task_sync().
+ */
+ rcu_read_lock();
+ /*
* If we 'fail' here, that's OK, it means recursion is already disabled
* and we won't recurse 'further'.
*/
- preempt_disable_notrace();
rctx = perf_swevent_get_recursion_context();
if (event->pending_work) {
event->pending_work = 0;
perf_sigtrap(event);
local_dec(&event->ctx->nr_pending);
+ rcuwait_wake_up(&event->pending_work_wait);
}
+ rcu_read_unlock();
if (rctx >= 0)
perf_swevent_put_recursion_context(rctx);
- preempt_enable_notrace();
-
- put_event(event);
}
#ifdef CONFIG_GUEST_PERF_EVENTS
@@ -9706,16 +9731,26 @@ static int __perf_event_overflow(struct perf_event *event,
*/
bool valid_sample = sample_is_allowed(event, regs);
unsigned int pending_id = 1;
+ enum task_work_notify_mode notify_mode;
if (regs)
pending_id = hash32_ptr((void *)instruction_pointer(regs)) ?: 1;
- if (!event->pending_sigtrap) {
- event->pending_sigtrap = pending_id;
+
+ notify_mode = in_nmi() ? TWA_NMI_CURRENT : TWA_RESUME;
+
+ if (!event->pending_work &&
+ !task_work_add(current, &event->pending_task, notify_mode)) {
+ event->pending_work = pending_id;
local_inc(&event->ctx->nr_pending);
+
+ event->pending_addr = 0;
+ if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))
+ event->pending_addr = data->addr;
+
} else if (event->attr.exclude_kernel && valid_sample) {
/*
* Should not be able to return to user space without
- * consuming pending_sigtrap; with exceptions:
+ * consuming pending_work; with exceptions:
*
* 1. Where !exclude_kernel, events can overflow again
* in the kernel without returning to user space.
@@ -9725,13 +9760,8 @@ static int __perf_event_overflow(struct perf_event *event,
* To approximate progress (with false negatives),
* check 32-bit hash of the current IP.
*/
- WARN_ON_ONCE(event->pending_sigtrap != pending_id);
+ WARN_ON_ONCE(event->pending_work != pending_id);
}
-
- event->pending_addr = 0;
- if (valid_sample && (data->sample_flags & PERF_SAMPLE_ADDR))
- event->pending_addr = data->addr;
- irq_work_queue(&event->pending_irq);
}
READ_ONCE(event->overflow_handler)(event, data, regs);
@@ -9759,11 +9789,7 @@ struct swevent_htable {
struct swevent_hlist *swevent_hlist;
struct mutex hlist_mutex;
int hlist_refcount;
-
- /* Recursion avoidance in each contexts */
- int recursion[PERF_NR_CONTEXTS];
};
-
static DEFINE_PER_CPU(struct swevent_htable, swevent_htable);
/*
@@ -9961,17 +9987,13 @@ DEFINE_PER_CPU(struct pt_regs, __perf_regs[4]);
int perf_swevent_get_recursion_context(void)
{
- struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
-
- return get_recursion_context(swhash->recursion);
+ return get_recursion_context(current->perf_recursion);
}
EXPORT_SYMBOL_GPL(perf_swevent_get_recursion_context);
void perf_swevent_put_recursion_context(int rctx)
{
- struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
-
- put_recursion_context(swhash->recursion, rctx);
+ put_recursion_context(current->perf_recursion, rctx);
}
void ___perf_sw_event(u32 event_id, u64 nr, struct pt_regs *regs, u64 addr)
@@ -11961,7 +11983,9 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
init_waitqueue_head(&event->waitq);
init_irq_work(&event->pending_irq, perf_pending_irq);
+ event->pending_disable_irq = IRQ_WORK_INIT_HARD(perf_pending_disable);
init_task_work(&event->pending_task, perf_pending_task);
+ rcuwait_init(&event->pending_work_wait);
mutex_init(&event->mmap_mutex);
raw_spin_lock_init(&event->addr_filters.lock);
@@ -13637,6 +13661,7 @@ int perf_event_init_task(struct task_struct *child, u64 clone_flags)
{
int ret;
+ memset(child->perf_recursion, 0, sizeof(child->perf_recursion));
child->perf_event_ctxp = NULL;
mutex_init(&child->perf_event_mutex);
INIT_LIST_HEAD(&child->perf_event_list);