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| author | Mark Rutland <mark.rutland@arm.com> | 2018-09-05 18:38:57 +0200 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-09-06 19:01:13 +0200 |
| commit | fac880c7d074fdfca874114b5c47b36aa034e4ee (patch) | |
| tree | 6124d50861d475863156199d14fe89d00fba0b6f /arch | |
| parent | Linux 4.19-rc2 (diff) | |
| download | linux-fac880c7d074fdfca874114b5c47b36aa034e4ee.tar.xz linux-fac880c7d074fdfca874114b5c47b36aa034e4ee.zip | |
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/mm/mmu.c | 10 |
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; } |