From 1180e732c985ed3c8866d2fd9e02b619848404a0 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 26 Nov 2020 17:21:30 +0100 Subject: mm/gup: Fix the lockless PMD access On architectures where the PTE/PMD is larger than the native word size (i386-PAE for example), READ_ONCE() can do the wrong thing. Use pmdp_get_lockless() just like we use ptep_get_lockless(). Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20221022114424.906110403%40infradead.org --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 4ec3717003d5..b0d38424f3f7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7306,7 +7306,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr) return pud_leaf_size(pud); pmdp = pmd_offset_lockless(pudp, pud, addr); - pmd = READ_ONCE(*pmdp); + pmd = pmdp_get_lockless(pmdp); if (!pmd_present(pmd)) return 0; -- cgit v1.2.3