Commit f7018be2 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull perf fixes from Borislav Petkov:

 - Prevent unintentional page sharing by checking whether a page
   reference to a PMU samples page has been acquired properly before
   that

 - Make sure the LBR_SELECT MSR is saved/restored too

 - Reset the LBR_SELECT MSR when resetting the LBR PMU to clear any
   residual data left

* tag 'perf_urgent_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Avoid put_page() when GUP fails
  perf/x86/vlbr: Add c->flags to vlbr event constraints
  perf/x86/lbr: Reset LBR_SELECT during vlbr reset
parents 1654e95e 4716023a

arch/x86/events/intel/core.c

+3 −1
Original line number Diff line number Diff line
@@ -3048,8 +3048,10 @@ intel_vlbr_constraints(struct perf_event *event) 
{

	struct event_constraint *c = &vlbr_constraint;



	if (unlikely(constraint_match(c, event->hw.config)))

	if (unlikely(constraint_match(c, event->hw.config))) {

		event->hw.flags |= c->flags;

		return c;

	}



	return NULL;

}

arch/x86/events/intel/lbr.c

+2 −0
Original line number Diff line number Diff line
@@ -265,6 +265,8 @@ void intel_pmu_lbr_reset(void) 


	cpuc->last_task_ctx = NULL;

	cpuc->last_log_id = 0;

	if (!static_cpu_has(X86_FEATURE_ARCH_LBR) && cpuc->lbr_select)

		wrmsrl(MSR_LBR_SELECT, 0);

}



/*

kernel/events/core.c

+5 −5
Original line number Diff line number Diff line
@@ -7154,7 +7154,6 @@ void perf_output_sample(struct perf_output_handle *handle, 
static u64 perf_virt_to_phys(u64 virt)

{

	u64 phys_addr = 0;

	struct page *p = NULL;



	if (!virt)

		return 0;
@@ -7173,14 +7172,15 @@ static u64 perf_virt_to_phys(u64 virt) 
		 * If failed, leave phys_addr as 0.

		 */

		if (current->mm != NULL) {

			struct page *p;



			pagefault_disable();

			if (get_user_page_fast_only(virt, 0, &p))

			if (get_user_page_fast_only(virt, 0, &p)) {

				phys_addr = page_to_phys(p) + virt % PAGE_SIZE;

				put_page(p);

			}

			pagefault_enable();

		}



		if (p)

			put_page(p);

	}



	return phys_addr;