diff options
Diffstat (limited to 'mm/mprotect.c')
| -rw-r--r-- | mm/mprotect.c | 63 |
1 files changed, 42 insertions, 21 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 0af22ab59ea8..92fc6f3fa512 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -330,28 +330,34 @@ uffd_wp_protect_file(struct vm_area_struct *vma, unsigned long cp_flags) /* * If wr-protecting the range for file-backed, populate pgtable for the case * when pgtable is empty but page cache exists. When {pte|pmd|...}_alloc() - * failed it means no memory, we don't have a better option but stop. + * failed we treat it the same way as pgtable allocation failures during + * page faults by kicking OOM and returning error. */ #define change_pmd_prepare(vma, pmd, cp_flags) \ - do { \ + ({ \ + long err = 0; \ if (unlikely(uffd_wp_protect_file(vma, cp_flags))) { \ - if (WARN_ON_ONCE(pte_alloc(vma->vm_mm, pmd))) \ - break; \ + if (pte_alloc(vma->vm_mm, pmd)) \ + err = -ENOMEM; \ } \ - } while (0) + err; \ + }) + /* * This is the general pud/p4d/pgd version of change_pmd_prepare(). We need to * have separate change_pmd_prepare() because pte_alloc() returns 0 on success, * while {pmd|pud|p4d}_alloc() returns the valid pointer on success. */ #define change_prepare(vma, high, low, addr, cp_flags) \ - do { \ + ({ \ + long err = 0; \ if (unlikely(uffd_wp_protect_file(vma, cp_flags))) { \ low##_t *p = low##_alloc(vma->vm_mm, high, addr); \ - if (WARN_ON_ONCE(p == NULL)) \ - break; \ + if (p == NULL) \ + err = -ENOMEM; \ } \ - } while (0) + err; \ + }) static inline long change_pmd_range(struct mmu_gather *tlb, struct vm_area_struct *vma, pud_t *pud, unsigned long addr, @@ -367,11 +373,15 @@ static inline long change_pmd_range(struct mmu_gather *tlb, pmd = pmd_offset(pud, addr); do { - long this_pages; + long ret; next = pmd_addr_end(addr, end); - change_pmd_prepare(vma, pmd, cp_flags); + ret = change_pmd_prepare(vma, pmd, cp_flags); + if (ret) { + pages = ret; + break; + } /* * Automatic NUMA balancing walks the tables with mmap_lock * held for read. It's possible a parallel update to occur @@ -401,7 +411,11 @@ static inline long change_pmd_range(struct mmu_gather *tlb, * cleared; make sure pmd populated if * necessary, then fall-through to pte level. */ - change_pmd_prepare(vma, pmd, cp_flags); + ret = change_pmd_prepare(vma, pmd, cp_flags); + if (ret) { + pages = ret; + break; + } } else { /* * change_huge_pmd() does not defer TLB flushes, @@ -422,9 +436,8 @@ static inline long change_pmd_range(struct mmu_gather *tlb, } /* fall through, the trans huge pmd just split */ } - this_pages = change_pte_range(tlb, vma, pmd, addr, next, - newprot, cp_flags); - pages += this_pages; + pages += change_pte_range(tlb, vma, pmd, addr, next, + newprot, cp_flags); next: cond_resched(); } while (pmd++, addr = next, addr != end); @@ -443,12 +456,14 @@ static inline long change_pud_range(struct mmu_gather *tlb, { pud_t *pud; unsigned long next; - long pages = 0; + long pages = 0, ret; pud = pud_offset(p4d, addr); do { next = pud_addr_end(addr, end); - change_prepare(vma, pud, pmd, addr, cp_flags); + ret = change_prepare(vma, pud, pmd, addr, cp_flags); + if (ret) + return ret; if (pud_none_or_clear_bad(pud)) continue; pages += change_pmd_range(tlb, vma, pud, addr, next, newprot, @@ -464,12 +479,14 @@ static inline long change_p4d_range(struct mmu_gather *tlb, { p4d_t *p4d; unsigned long next; - long pages = 0; + long pages = 0, ret; p4d = p4d_offset(pgd, addr); do { next = p4d_addr_end(addr, end); - change_prepare(vma, p4d, pud, addr, cp_flags); + ret = change_prepare(vma, p4d, pud, addr, cp_flags); + if (ret) + return ret; if (p4d_none_or_clear_bad(p4d)) continue; pages += change_pud_range(tlb, vma, p4d, addr, next, newprot, @@ -486,14 +503,18 @@ static long change_protection_range(struct mmu_gather *tlb, struct mm_struct *mm = vma->vm_mm; pgd_t *pgd; unsigned long next; - long pages = 0; + long pages = 0, ret; BUG_ON(addr >= end); pgd = pgd_offset(mm, addr); tlb_start_vma(tlb, vma); do { next = pgd_addr_end(addr, end); - change_prepare(vma, pgd, p4d, addr, cp_flags); + ret = change_prepare(vma, pgd, p4d, addr, cp_flags); + if (ret) { + pages = ret; + break; + } if (pgd_none_or_clear_bad(pgd)) continue; pages += change_p4d_range(tlb, vma, pgd, addr, next, newprot, |