diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 4ec3717003d5..884871427a94 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -9306,14 +9306,27 @@ static int __perf_event_overflow(struct perf_event *event, } if (event->attr.sigtrap) { - /* - * Should not be able to return to user space without processing - * pending_sigtrap (kernel events can overflow multiple times). - */ - WARN_ON_ONCE(event->pending_sigtrap && event->attr.exclude_kernel); + unsigned int pending_id = 1; + + if (regs) + pending_id = hash32_ptr((void *)instruction_pointer(regs)) ?: 1; if (!event->pending_sigtrap) { - event->pending_sigtrap = 1; + event->pending_sigtrap = pending_id; local_inc(&event->ctx->nr_pending); + } else if (event->attr.exclude_kernel) { + /* + * Should not be able to return to user space without + * consuming pending_sigtrap; with exceptions: + * + * 1. Where !exclude_kernel, events can overflow again + * in the kernel without returning to user space. + * + * 2. Events that can overflow again before the IRQ- + * work without user space progress (e.g. hrtimer). + * To approximate progress (with false negatives), + * check 32-bit hash of the current IP. + */ + WARN_ON_ONCE(event->pending_sigtrap != pending_id); } event->pending_addr = data->addr; irq_work_queue(&event->pending_irq); |