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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-14 09:33:12 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-14 09:33:12 -0800 |
| commit | f7018be29253b89175d03284f8f49ac4ffed0472 (patch) | |
| tree | f8a7c2a66848774e7b421ad506b43a0dda34c8d1 /kernel | |
| parent | 1654e95ee30a82bec843e73a591f9ea3db8da8db (diff) | |
| parent | 4716023a8f6a0f4a28047f14dd7ebdc319606b84 (diff) | |
| download | linux-stable-f7018be29253b89175d03284f8f49ac4ffed0472.tar.gz linux-stable-f7018be29253b89175d03284f8f49ac4ffed0472.tar.bz2 linux-stable-f7018be29253b89175d03284f8f49ac4ffed0472.zip | |
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.c | 10 |
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; |