Commit eb0ef8ad authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'perf_urgent_for_v6.1_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull perf fixes from Borislav Petkov:

 - Fix an intel PT erratum where CPUs do not support single range output
   for more than 4K

 - Fix a NULL ptr dereference which can happen after an NMI interferes
   with the event enabling dance in amd_pmu_enable_all()

 - Free the events array too when freeing uncore contexts on CPU online,
   thereby fixing a memory leak

 - Improve the pending SIGTRAP check

* tag 'perf_urgent_for_v6.1_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/pt: Fix sampling using single range output
  perf/x86/amd: Fix crash due to race between amd_pmu_enable_all, perf NMI and throttling
  perf/x86/amd/uncore: Fix memory leak for events array
  perf: Improve missing SIGTRAP checking
parents 6a211a75 ce0d998b

arch/x86/events/amd/core.c

+2 −3
Original line number Diff line number Diff line
@@ -861,8 +861,7 @@ static int amd_pmu_handle_irq(struct pt_regs *regs) 
	pmu_enabled = cpuc->enabled;

	cpuc->enabled = 0;



	/* stop everything (includes BRS) */

	amd_pmu_disable_all();

	amd_brs_disable_all();



	/* Drain BRS is in use (could be inactive) */

	if (cpuc->lbr_users)
@@ -873,7 +872,7 @@ static int amd_pmu_handle_irq(struct pt_regs *regs) 


	cpuc->enabled = pmu_enabled;

	if (pmu_enabled)

		amd_pmu_enable_all(0);

		amd_brs_enable_all();



	return amd_pmu_adjust_nmi_window(handled);

}

arch/x86/events/amd/uncore.c

+1 −0
Original line number Diff line number Diff line
@@ -553,6 +553,7 @@ static void uncore_clean_online(void) 


	hlist_for_each_entry_safe(uncore, n, &uncore_unused_list, node) {

		hlist_del(&uncore->node);

		kfree(uncore->events);

		kfree(uncore);

	}

}

arch/x86/events/intel/pt.c

+9 −0
Original line number Diff line number Diff line
@@ -1263,6 +1263,15 @@ static int pt_buffer_try_single(struct pt_buffer *buf, int nr_pages) 
	if (1 << order != nr_pages)

		goto out;



	/*

	 * Some processors cannot always support single range for more than

	 * 4KB - refer errata TGL052, ADL037 and RPL017. Future processors might

	 * also be affected, so for now rather than trying to keep track of

	 * which ones, just disable it for all.

	 */

	if (nr_pages > 1)

		goto out;



	buf->single = true;

	buf->nr_pages = nr_pages;

	ret = 0;

kernel/events/core.c

+19 −6
Original line number Diff line number Diff line
@@ -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);