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 --- mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm') diff --git a/mm/gup.c b/mm/gup.c index fe195d47de74..ff8b22327e16 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2808,7 +2808,7 @@ static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned lo pmdp = pmd_offset_lockless(pudp, pud, addr); do { - pmd_t pmd = READ_ONCE(*pmdp); + pmd_t pmd = pmdp_get_lockless(pmdp); next = pmd_addr_end(addr, end); if (!pmd_present(pmd)) -- cgit v1.2.3