diff options
Diffstat (limited to '')
| -rw-r--r-- | mm/mprotect.c | 389 |
1 files changed, 298 insertions, 91 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 311c0dadf71c..668bfaa6ed2a 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -28,24 +28,66 @@ #include <linux/ksm.h> #include <linux/uaccess.h> #include <linux/mm_inline.h> -#include <asm/pgtable.h> +#include <linux/pgtable.h> +#include <linux/sched/sysctl.h> +#include <linux/userfaultfd_k.h> +#include <linux/memory-tiers.h> #include <asm/cacheflush.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> +#include <asm/tlb.h> #include "internal.h" -static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, - unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable, int prot_numa) +static inline bool can_change_pte_writable(struct vm_area_struct *vma, + unsigned long addr, pte_t pte) +{ + struct page *page; + + VM_BUG_ON(!(vma->vm_flags & VM_WRITE) || pte_write(pte)); + + if (pte_protnone(pte) || !pte_dirty(pte)) + return false; + + /* Do we need write faults for softdirty tracking? */ + if (vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte)) + return false; + + /* Do we need write faults for uffd-wp tracking? */ + if (userfaultfd_pte_wp(vma, pte)) + return false; + + if (!(vma->vm_flags & VM_SHARED)) { + /* + * We can only special-case on exclusive anonymous pages, + * because we know that our write-fault handler similarly would + * map them writable without any additional checks while holding + * the PT lock. + */ + page = vm_normal_page(vma, addr, pte); + if (!page || !PageAnon(page) || !PageAnonExclusive(page)) + return false; + } + + return true; +} + +static unsigned long change_pte_range(struct mmu_gather *tlb, + struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, + unsigned long end, pgprot_t newprot, unsigned long cp_flags) { pte_t *pte, oldpte; spinlock_t *ptl; unsigned long pages = 0; int target_node = NUMA_NO_NODE; + bool prot_numa = cp_flags & MM_CP_PROT_NUMA; + bool uffd_wp = cp_flags & MM_CP_UFFD_WP; + bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; + + tlb_change_page_size(tlb, PAGE_SIZE); /* - * Can be called with only the mmap_sem for reading by + * Can be called with only the mmap_lock for reading by * prot_numa so we must check the pmd isn't constantly * changing from under us from pmd_none to pmd_trans_huge * and/or the other way around. @@ -55,7 +97,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, /* * The pmd points to a regular pte so the pmd can't change - * from under us even if the mmap_sem is only hold for + * from under us even if the mmap_lock is only hold for * reading. */ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); @@ -79,18 +121,20 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, */ if (prot_numa) { struct page *page; + int nid; + bool toptier; /* Avoid TLB flush if possible */ if (pte_protnone(oldpte)) continue; page = vm_normal_page(vma, addr, oldpte); - if (!page || PageKsm(page)) + if (!page || is_zone_device_page(page) || PageKsm(page)) continue; /* Also skip shared copy-on-write pages */ if (is_cow_mapping(vma->vm_flags) && - page_mapcount(page) != 1) + page_count(page) != 1) continue; /* @@ -98,15 +142,29 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, * it cannot move them all from MIGRATE_ASYNC * context. */ - if (page_is_file_cache(page) && PageDirty(page)) + if (page_is_file_lru(page) && PageDirty(page)) continue; /* * Don't mess with PTEs if page is already on the node * a single-threaded process is running on. */ - if (target_node == page_to_nid(page)) + nid = page_to_nid(page); + if (target_node == nid) + continue; + toptier = node_is_toptier(nid); + + /* + * Skip scanning top tier node if normal numa + * balancing is disabled + */ + if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && + toptier) continue; + if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING && + !toptier) + xchg_page_access_time(page, + jiffies_to_msecs(jiffies)); } oldpte = ptep_modify_prot_start(vma, addr, pte); @@ -114,45 +172,114 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, if (preserve_write) ptent = pte_mk_savedwrite(ptent); - /* Avoid taking write faults for known dirty pages */ - if (dirty_accountable && pte_dirty(ptent) && - (pte_soft_dirty(ptent) || - !(vma->vm_flags & VM_SOFTDIRTY))) { - ptent = pte_mkwrite(ptent); + if (uffd_wp) { + ptent = pte_wrprotect(ptent); + ptent = pte_mkuffd_wp(ptent); + } else if (uffd_wp_resolve) { + ptent = pte_clear_uffd_wp(ptent); } + + /* + * In some writable, shared mappings, we might want + * to catch actual write access -- see + * vma_wants_writenotify(). + * + * In all writable, private mappings, we have to + * properly handle COW. + * + * In both cases, we can sometimes still change PTEs + * writable and avoid the write-fault handler, for + * example, if a PTE is already dirty and no other + * COW or special handling is required. + */ + if ((cp_flags & MM_CP_TRY_CHANGE_WRITABLE) && + !pte_write(ptent) && + can_change_pte_writable(vma, addr, ptent)) + ptent = pte_mkwrite(ptent); + ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent); + if (pte_needs_flush(oldpte, ptent)) + tlb_flush_pte_range(tlb, addr, PAGE_SIZE); pages++; - } else if (IS_ENABLED(CONFIG_MIGRATION)) { + } else if (is_swap_pte(oldpte)) { swp_entry_t entry = pte_to_swp_entry(oldpte); + pte_t newpte; + + if (is_writable_migration_entry(entry)) { + struct page *page = pfn_swap_entry_to_page(entry); - if (is_write_migration_entry(entry)) { - pte_t newpte; /* * A protection check is difficult so * just be safe and disable write */ - make_migration_entry_read(&entry); + if (PageAnon(page)) + entry = make_readable_exclusive_migration_entry( + swp_offset(entry)); + else + entry = make_readable_migration_entry(swp_offset(entry)); newpte = swp_entry_to_pte(entry); if (pte_swp_soft_dirty(oldpte)) newpte = pte_swp_mksoft_dirty(newpte); - set_pte_at(vma->vm_mm, addr, pte, newpte); - - pages++; - } - - if (is_write_device_private_entry(entry)) { - pte_t newpte; - + if (pte_swp_uffd_wp(oldpte)) + newpte = pte_swp_mkuffd_wp(newpte); + } else if (is_writable_device_private_entry(entry)) { /* * We do not preserve soft-dirtiness. See * copy_one_pte() for explanation. */ - make_device_private_entry_read(&entry); + entry = make_readable_device_private_entry( + swp_offset(entry)); newpte = swp_entry_to_pte(entry); - set_pte_at(vma->vm_mm, addr, pte, newpte); + if (pte_swp_uffd_wp(oldpte)) + newpte = pte_swp_mkuffd_wp(newpte); + } else if (is_writable_device_exclusive_entry(entry)) { + entry = make_readable_device_exclusive_entry( + swp_offset(entry)); + newpte = swp_entry_to_pte(entry); + if (pte_swp_soft_dirty(oldpte)) + newpte = pte_swp_mksoft_dirty(newpte); + if (pte_swp_uffd_wp(oldpte)) + newpte = pte_swp_mkuffd_wp(newpte); + } else if (pte_marker_entry_uffd_wp(entry)) { + /* + * If this is uffd-wp pte marker and we'd like + * to unprotect it, drop it; the next page + * fault will trigger without uffd trapping. + */ + if (uffd_wp_resolve) { + pte_clear(vma->vm_mm, addr, pte); + pages++; + } + continue; + } else { + newpte = oldpte; + } + if (uffd_wp) + newpte = pte_swp_mkuffd_wp(newpte); + else if (uffd_wp_resolve) + newpte = pte_swp_clear_uffd_wp(newpte); + + if (!pte_same(oldpte, newpte)) { + set_pte_at(vma->vm_mm, addr, pte, newpte); + pages++; + } + } else { + /* It must be an none page, or what else?.. */ + WARN_ON_ONCE(!pte_none(oldpte)); +#ifdef CONFIG_PTE_MARKER_UFFD_WP + if (unlikely(uffd_wp && !vma_is_anonymous(vma))) { + /* + * For file-backed mem, we need to be able to + * wr-protect a none pte, because even if the + * pte is none, the page/swap cache could + * exist. Doing that by install a marker. + */ + set_pte_at(vma->vm_mm, addr, pte, + make_pte_marker(PTE_MARKER_UFFD_WP)); pages++; } +#endif } } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); @@ -186,9 +313,42 @@ static inline int pmd_none_or_clear_bad_unless_trans_huge(pmd_t *pmd) return 0; } -static inline unsigned long change_pmd_range(struct vm_area_struct *vma, - pud_t *pud, unsigned long addr, unsigned long end, - pgprot_t newprot, int dirty_accountable, int prot_numa) +/* Return true if we're uffd wr-protecting file-backed memory, or false */ +static inline bool +uffd_wp_protect_file(struct vm_area_struct *vma, unsigned long cp_flags) +{ + return (cp_flags & MM_CP_UFFD_WP) && !vma_is_anonymous(vma); +} + +/* + * 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. + */ +#define change_pmd_prepare(vma, pmd, cp_flags) \ + do { \ + if (unlikely(uffd_wp_protect_file(vma, cp_flags))) { \ + if (WARN_ON_ONCE(pte_alloc(vma->vm_mm, pmd))) \ + break; \ + } \ + } while (0) +/* + * 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 { \ + 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; \ + } \ + } while (0) + +static inline unsigned long change_pmd_range(struct mmu_gather *tlb, + struct vm_area_struct *vma, pud_t *pud, unsigned long addr, + unsigned long end, pgprot_t newprot, unsigned long cp_flags) { pmd_t *pmd; unsigned long next; @@ -204,8 +364,9 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, next = pmd_addr_end(addr, end); + change_pmd_prepare(vma, pmd, cp_flags); /* - * Automatic NUMA balancing walks the tables with mmap_sem + * Automatic NUMA balancing walks the tables with mmap_lock * held for read. It's possible a parallel update to occur * between pmd_trans_huge() and a pmd_none_or_clear_bad() * check leading to a false positive and clearing. @@ -225,11 +386,22 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, } if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { - if (next - addr != HPAGE_PMD_SIZE) { + if ((next - addr != HPAGE_PMD_SIZE) || + uffd_wp_protect_file(vma, cp_flags)) { __split_huge_pmd(vma, pmd, addr, false, NULL); + /* + * For file-backed, the pmd could have been + * cleared; make sure pmd populated if + * necessary, then fall-through to pte level. + */ + change_pmd_prepare(vma, pmd, cp_flags); } else { - int nr_ptes = change_huge_pmd(vma, pmd, addr, - newprot, prot_numa); + /* + * change_huge_pmd() does not defer TLB flushes, + * so no need to propagate the tlb argument. + */ + int nr_ptes = change_huge_pmd(tlb, vma, pmd, + addr, newprot, cp_flags); if (nr_ptes) { if (nr_ptes == HPAGE_PMD_NR) { @@ -243,8 +415,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, } /* fall through, the trans huge pmd just split */ } - this_pages = change_pte_range(vma, pmd, addr, next, newprot, - dirty_accountable, prot_numa); + this_pages = change_pte_range(tlb, vma, pmd, addr, next, + newprot, cp_flags); pages += this_pages; next: cond_resched(); @@ -258,9 +430,9 @@ next: return pages; } -static inline unsigned long change_pud_range(struct vm_area_struct *vma, - p4d_t *p4d, unsigned long addr, unsigned long end, - pgprot_t newprot, int dirty_accountable, int prot_numa) +static inline unsigned long change_pud_range(struct mmu_gather *tlb, + struct vm_area_struct *vma, p4d_t *p4d, unsigned long addr, + unsigned long end, pgprot_t newprot, unsigned long cp_flags) { pud_t *pud; unsigned long next; @@ -269,18 +441,19 @@ static inline unsigned long change_pud_range(struct vm_area_struct *vma, pud = pud_offset(p4d, addr); do { next = pud_addr_end(addr, end); + change_prepare(vma, pud, pmd, addr, cp_flags); if (pud_none_or_clear_bad(pud)) continue; - pages += change_pmd_range(vma, pud, addr, next, newprot, - dirty_accountable, prot_numa); + pages += change_pmd_range(tlb, vma, pud, addr, next, newprot, + cp_flags); } while (pud++, addr = next, addr != end); return pages; } -static inline unsigned long change_p4d_range(struct vm_area_struct *vma, - pgd_t *pgd, unsigned long addr, unsigned long end, - pgprot_t newprot, int dirty_accountable, int prot_numa) +static inline unsigned long change_p4d_range(struct mmu_gather *tlb, + struct vm_area_struct *vma, pgd_t *pgd, unsigned long addr, + unsigned long end, pgprot_t newprot, unsigned long cp_flags) { p4d_t *p4d; unsigned long next; @@ -289,55 +462,57 @@ static inline unsigned long change_p4d_range(struct vm_area_struct *vma, p4d = p4d_offset(pgd, addr); do { next = p4d_addr_end(addr, end); + change_prepare(vma, p4d, pud, addr, cp_flags); if (p4d_none_or_clear_bad(p4d)) continue; - pages += change_pud_range(vma, p4d, addr, next, newprot, - dirty_accountable, prot_numa); + pages += change_pud_range(tlb, vma, p4d, addr, next, newprot, + cp_flags); } while (p4d++, addr = next, addr != end); return pages; } -static unsigned long change_protection_range(struct vm_area_struct *vma, - unsigned long addr, unsigned long end, pgprot_t newprot, - int dirty_accountable, int prot_numa) +static unsigned long change_protection_range(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long addr, + unsigned long end, pgprot_t newprot, unsigned long cp_flags) { struct mm_struct *mm = vma->vm_mm; pgd_t *pgd; unsigned long next; - unsigned long start = addr; unsigned long pages = 0; BUG_ON(addr >= end); pgd = pgd_offset(mm, addr); - flush_cache_range(vma, addr, end); - inc_tlb_flush_pending(mm); + tlb_start_vma(tlb, vma); do { next = pgd_addr_end(addr, end); + change_prepare(vma, pgd, p4d, addr, cp_flags); if (pgd_none_or_clear_bad(pgd)) continue; - pages += change_p4d_range(vma, pgd, addr, next, newprot, - dirty_accountable, prot_numa); + pages += change_p4d_range(tlb, vma, pgd, addr, next, newprot, + cp_flags); } while (pgd++, addr = next, addr != end); - /* Only flush the TLB if we actually modified any entries: */ - if (pages) - flush_tlb_range(vma, start, end); - dec_tlb_flush_pending(mm); + tlb_end_vma(tlb, vma); return pages; } -unsigned long change_protection(struct vm_area_struct *vma, unsigned long start, +unsigned long change_protection(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, - int dirty_accountable, int prot_numa) + unsigned long cp_flags) { unsigned long pages; + BUG_ON((cp_flags & MM_CP_UFFD_WP_ALL) == MM_CP_UFFD_WP_ALL); + if (is_vm_hugetlb_page(vma)) - pages = hugetlb_change_protection(vma, start, end, newprot); + pages = hugetlb_change_protection(vma, start, end, newprot, + cp_flags); else - pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa); + pages = change_protection_range(tlb, vma, start, end, newprot, + cp_flags); return pages; } @@ -370,16 +545,17 @@ static const struct mm_walk_ops prot_none_walk_ops = { }; int -mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, - unsigned long start, unsigned long end, unsigned long newflags) +mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, + struct vm_area_struct **pprev, unsigned long start, + unsigned long end, unsigned long newflags) { struct mm_struct *mm = vma->vm_mm; unsigned long oldflags = vma->vm_flags; long nrpages = (end - start) >> PAGE_SHIFT; unsigned long charged = 0; + bool try_change_writable; pgoff_t pgoff; int error; - int dirty_accountable = 0; if (newflags == oldflags) { *pprev = vma; @@ -393,7 +569,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, */ if (arch_has_pfn_modify_check() && (vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && - (newflags & (VM_READ|VM_WRITE|VM_EXEC)) == 0) { + (newflags & VM_ACCESS_FLAGS) == 0) { pgprot_t new_pgprot = vm_get_page_prot(newflags); error = walk_page_range(current->mm, start, end, @@ -428,7 +604,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); *pprev = vma_merge(mm, *pprev, start, end, newflags, vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), - vma->vm_userfaultfd_ctx); + vma->vm_userfaultfd_ctx, anon_vma_name(vma)); if (*pprev) { vma = *pprev; VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY); @@ -451,15 +627,24 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, success: /* - * vm_flags and vm_page_prot are protected by the mmap_sem + * vm_flags and vm_page_prot are protected by the mmap_lock * held in write mode. */ vma->vm_flags = newflags; - dirty_accountable = vma_wants_writenotify(vma, vma->vm_page_prot); + /* + * We want to check manually if we can change individual PTEs writable + * if we can't do that automatically for all PTEs in a mapping. For + * private mappings, that's always the case when we have write + * permissions as we properly have to handle COW. + */ + if (vma->vm_flags & VM_SHARED) + try_change_writable = vma_wants_writenotify(vma, vma->vm_page_prot); + else + try_change_writable = !!(vma->vm_flags & VM_WRITE); vma_set_page_prot(vma); - change_protection(vma, start, end, vma->vm_page_prot, - dirty_accountable, 0); + change_protection(tlb, vma, start, end, vma->vm_page_prot, + try_change_writable ? MM_CP_TRY_CHANGE_WRITABLE : 0); /* * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major @@ -488,10 +673,12 @@ static int do_mprotect_pkey(unsigned long start, size_t len, { unsigned long nstart, end, tmp, reqprot; struct vm_area_struct *vma, *prev; - int error = -EINVAL; + int error; const int grows = prot & (PROT_GROWSDOWN|PROT_GROWSUP); const bool rier = (current->personality & READ_IMPLIES_EXEC) && (prot & PROT_READ); + struct mmu_gather tlb; + MA_STATE(mas, ¤t->mm->mm_mt, 0, 0); start = untagged_addr(start); @@ -512,7 +699,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len, reqprot = prot; - if (down_write_killable(¤t->mm->mmap_sem)) + if (mmap_write_lock_killable(current->mm)) return -EINTR; /* @@ -523,11 +710,12 @@ static int do_mprotect_pkey(unsigned long start, size_t len, if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey)) goto out; - vma = find_vma(current->mm, start); + mas_set(&mas, start); + vma = mas_find(&mas, ULONG_MAX); error = -ENOMEM; if (!vma) goto out; - prev = vma->vm_prev; + if (unlikely(grows & PROT_GROWSDOWN)) { if (vma->vm_start >= end) goto out; @@ -545,9 +733,13 @@ static int do_mprotect_pkey(unsigned long start, size_t len, goto out; } } + if (start > vma->vm_start) prev = vma; + else + prev = mas_prev(&mas, 0); + tlb_gather_mmu(&tlb, current->mm); for (nstart = start ; ; ) { unsigned long mask_off_old_flags; unsigned long newflags; @@ -572,37 +764,52 @@ static int do_mprotect_pkey(unsigned long start, size_t len, newflags |= (vma->vm_flags & ~mask_off_old_flags); /* newflags >> 4 shift VM_MAY% in place of VM_% */ - if ((newflags & ~(newflags >> 4)) & (VM_READ | VM_WRITE | VM_EXEC)) { + if ((newflags & ~(newflags >> 4)) & VM_ACCESS_FLAGS) { error = -EACCES; - goto out; + break; + } + + /* Allow architectures to sanity-check the new flags */ + if (!arch_validate_flags(newflags)) { + error = -EINVAL; + break; } error = security_file_mprotect(vma, reqprot, prot); if (error) - goto out; + break; tmp = vma->vm_end; if (tmp > end) tmp = end; - error = mprotect_fixup(vma, &prev, nstart, tmp, newflags); + + if (vma->vm_ops && vma->vm_ops->mprotect) { + error = vma->vm_ops->mprotect(vma, nstart, tmp, newflags); + if (error) + break; + } + + error = mprotect_fixup(&tlb, vma, &prev, nstart, tmp, newflags); if (error) - goto out; + break; + nstart = tmp; if (nstart < prev->vm_end) nstart = prev->vm_end; if (nstart >= end) - goto out; + break; - vma = prev->vm_next; + vma = find_vma(current->mm, prev->vm_end); if (!vma || vma->vm_start != nstart) { error = -ENOMEM; - goto out; + break; } prot = reqprot; } + tlb_finish_mmu(&tlb); out: - up_write(¤t->mm->mmap_sem); + mmap_write_unlock(current->mm); return error; } @@ -632,7 +839,7 @@ SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) if (init_val & ~PKEY_ACCESS_MASK) return -EINVAL; - down_write(¤t->mm->mmap_sem); + mmap_write_lock(current->mm); pkey = mm_pkey_alloc(current->mm); ret = -ENOSPC; @@ -646,7 +853,7 @@ SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val) } ret = pkey; out: - up_write(¤t->mm->mmap_sem); + mmap_write_unlock(current->mm); return ret; } @@ -654,12 +861,12 @@ SYSCALL_DEFINE1(pkey_free, int, pkey) { int ret; - down_write(¤t->mm->mmap_sem); + mmap_write_lock(current->mm); ret = mm_pkey_free(current->mm, pkey); - up_write(¤t->mm->mmap_sem); + mmap_write_unlock(current->mm); /* - * We could provie warnings or errors if any VMA still + * We could provide warnings or errors if any VMA still * has the pkey set here. */ return ret; |