diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-08 09:43:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-08 09:43:34 -0800
commit9e8ed26e6062e4f585fe831fba362eb567648881 (patch)
parent410ef736a77b584e1c54a3784ee56ca63114ce11 (diff)
parent6767df245f4736d0cf0c6fb7cf9cf94b27414245 (diff)
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fix from Will Deacon: "Fix pte_same() to avoid getting stuck on write fault. This single arm64 fix is a revert of 747a70e60b72 ("arm64: Fix copy-on-write referencing in HugeTLB"), not because that patch was wrong, but because it was broken by aa57157be69f ("arm64: Ensure VM_WRITE|VM_SHARED ptes are clean by default") which we merged in -rc6. We spotted the issue in Android (AOSP), where one of the JIT threads gets stuck on a write fault during boot because the faulting pte is marked as PTE_DIRTY | PTE_WRITE | PTE_RDONLY and the fault handler decides that there's nothing to do thanks to pte_same() masking out PTE_RDONLY. Thanks to John Stultz for reporting this and testing this so quickly, and to Steve Capper for confirming that the HugeTLB tests continue to pass" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Do not mask out PTE_RDONLY in pte_same()
1 files changed, 0 insertions, 17 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 8330810f699e..565aa45ef134 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -283,23 +283,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
set_pte(ptep, pte);
-static inline int pte_same(pte_t pte_a, pte_t pte_b)
- pteval_t lhs, rhs;
- lhs = pte_val(pte_a);
- rhs = pte_val(pte_b);
- if (pte_present(pte_a))
- lhs &= ~PTE_RDONLY;
- if (pte_present(pte_b))
- rhs &= ~PTE_RDONLY;
- return (lhs == rhs);
* Huge pte definitions.