diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 24 |
1 files changed, 11 insertions, 13 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 52ee273afeec..430eaf82da49 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -34,6 +34,7 @@ #include <linux/hugetlb.h> #include <asm/bug.h> +#include <asm/cmpxchg.h> #include <asm/cpufeature.h> #include <asm/exception.h> #include <asm/debug-monitors.h> @@ -197,8 +198,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address, pte_t *ptep, pte_t entry, int dirty) { - pteval_t old_pteval; - unsigned int tmp; + pteval_t old_pteval, pteval; if (pte_same(*ptep, entry)) return 0; @@ -208,7 +208,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma, /* set PTE_RDONLY if actual read-only or clean PTE */ if (!pte_write(entry) || !pte_sw_dirty(entry)) - pte_val(entry) |= PTE_RDONLY; + entry = pte_set_rdonly(entry); /* * Setting the flags must be done atomically to avoid racing with the @@ -217,16 +217,14 @@ int ptep_set_access_flags(struct vm_area_struct *vma, * (calculated as: a & b == ~(~a | ~b)). */ pte_val(entry) ^= PTE_RDONLY; - asm volatile("// ptep_set_access_flags\n" - " prfm pstl1strm, %2\n" - "1: ldxr %0, %2\n" - " eor %0, %0, %3 // negate PTE_RDONLY in *ptep\n" - " orr %0, %0, %4 // set flags\n" - " eor %0, %0, %3 // negate final PTE_RDONLY\n" - " stxr %w1, %0, %2\n" - " cbnz %w1, 1b\n" - : "=&r" (old_pteval), "=&r" (tmp), "+Q" (pte_val(*ptep)) - : "L" (PTE_RDONLY), "r" (pte_val(entry))); + pteval = READ_ONCE(pte_val(*ptep)); + do { + old_pteval = pteval; + pteval ^= PTE_RDONLY; + pteval |= pte_val(entry); + pteval ^= PTE_RDONLY; + pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval); + } while (pteval != old_pteval); flush_tlb_fix_spurious_fault(vma, address); return 1; |