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authorLinus Torvalds <torvalds@linux-foundation.org>2021-11-14 09:33:12 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-14 09:33:12 -0800
commitf7018be29253b89175d03284f8f49ac4ffed0472 (patch)
treef8a7c2a66848774e7b421ad506b43a0dda34c8d1 /kernel
parent1654e95ee30a82bec843e73a591f9ea3db8da8db (diff)
parent4716023a8f6a0f4a28047f14dd7ebdc319606b84 (diff)
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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
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f2253ea729a2..523106a506ee 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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;