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authorMark Rutland <mark.rutland@arm.com>2018-09-05 17:38:57 +0100
committerWill Deacon <will.deacon@arm.com>2018-09-06 18:01:13 +0100
commitfac880c7d074fdfca874114b5c47b36aa034e4ee (patch)
tree6124d50861d475863156199d14fe89d00fba0b6f
parent57361846b52bc686112da6ca5368d11210796804 (diff)
arm64: fix erroneous warnings in page freeing functions
In pmd_free_pte_page() and pud_free_pmd_page() we try to warn if they hit a present non-table entry. In both cases we'll warn for non-present entries, as the VM_WARN_ON() only checks the entry is not a table entry. This has been observed to result in warnings when booting a v4.19-rc2 kernel under qemu. Fix this by bailing out earlier for non-present entries. Fixes: ec28bb9c9b0826d7 ("arm64: Implement page table free interfaces") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
-rw-r--r--arch/arm64/mm/mmu.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 65f86271f02b..8080c9f489c3 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -985,8 +985,9 @@ int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr)
pmd = READ_ONCE(*pmdp);
- /* No-op for empty entry and WARN_ON for valid entry */
- if (!pmd_present(pmd) || !pmd_table(pmd)) {
+ if (!pmd_present(pmd))
+ return 1;
+ if (!pmd_table(pmd)) {
VM_WARN_ON(!pmd_table(pmd));
return 1;
}
@@ -1007,8 +1008,9 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
pud = READ_ONCE(*pudp);
- /* No-op for empty entry and WARN_ON for valid entry */
- if (!pud_present(pud) || !pud_table(pud)) {
+ if (!pud_present(pud))
+ return 1;
+ if (!pud_table(pud)) {
VM_WARN_ON(!pud_table(pud));
return 1;
}