diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 303869f4855f..6f121a034cef 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -410,6 +410,7 @@ static int kvmppc_memslot_page_merge(struct kvm *kvm, ret = H_STATE; break; } + vma_start_write(vma); /* Copy vm_flags to avoid partial modifications in ksm_madvise */ vm_flags = vma->vm_flags; ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 65bf92615772..b739aa508877 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -632,6 +632,7 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx, mmap_write_lock(mm); for_each_vma(vmi, vma) { if (vma->vm_userfaultfd_ctx.ctx == release_new_ctx) { + vma_start_write(vma); vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS); @@ -667,6 +668,7 @@ int dup_userfaultfd(struct vm_area_struct *vma, struct list_head *fcs) octx = vma->vm_userfaultfd_ctx.ctx; if (!octx || !(octx->features & UFFD_FEATURE_EVENT_FORK)) { + vma_start_write(vma); vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS); return 0; @@ -748,6 +750,7 @@ void mremap_userfaultfd_prep(struct vm_area_struct *vma, atomic_inc(&ctx->mmap_changing); } else { /* Drop uffd context if remap feature not enabled */ + vma_start_write(vma); vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS); } @@ -906,6 +909,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file) prev = vma; } + vma_start_write(vma); userfaultfd_set_vm_flags(vma, new_flags); vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; } @@ -1474,6 +1478,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, * the next vma was merged into the current one and * the current one has not been updated yet. */ + vma_start_write(vma); userfaultfd_set_vm_flags(vma, new_flags); vma->vm_userfaultfd_ctx.ctx = ctx; @@ -1662,6 +1667,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, * the next vma was merged into the current one and * the current one has not been updated yet. */ + vma_start_write(vma); userfaultfd_set_vm_flags(vma, new_flags); vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; diff --git a/include/linux/mm.h b/include/linux/mm.h index 54e1b27a65cb..9acb8a04116d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -779,18 +779,22 @@ static inline void vm_flags_init(struct vm_area_struct *vma, ACCESS_PRIVATE(vma, __vm_flags) = flags; } -/* Use when VMA is part of the VMA tree and modifications need coordination */ +/* + * Use when VMA is part of the VMA tree and modifications need coordination + * Note: vm_flags_reset and vm_flags_reset_once do not lock the vma and + * it should be locked explicitly beforehand. + */ static inline void vm_flags_reset(struct vm_area_struct *vma, vm_flags_t flags) { - vma_start_write(vma); + vma_assert_write_locked(vma); vm_flags_init(vma, flags); } static inline void vm_flags_reset_once(struct vm_area_struct *vma, vm_flags_t flags) { - vma_start_write(vma); + vma_assert_write_locked(vma); WRITE_ONCE(ACCESS_PRIVATE(vma, __vm_flags), flags); } diff --git a/mm/madvise.c b/mm/madvise.c index 105c17011a2c..21b5de11c329 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -180,9 +180,8 @@ static int madvise_update_vma(struct vm_area_struct *vma, } success: - /* - * vm_flags is protected by the mmap_lock held in write mode. - */ + /* vm_flags is protected by the mmap_lock held in write mode. */ + vma_start_write(vma); vm_flags_reset(vma, new_flags); if (!vma->vm_file) { error = replace_anon_vma_name(vma, anon_name); diff --git a/mm/mlock.c b/mm/mlock.c index 827df077a5eb..580f1d39f454 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -381,6 +381,7 @@ static void mlock_vma_pages_range(struct vm_area_struct *vma, */ if (newflags & VM_LOCKED) newflags |= VM_IO; + vma_start_write(vma); vm_flags_reset_once(vma, newflags); lru_add_drain(); @@ -454,9 +455,9 @@ success: * It's okay if try_to_unmap_one unmaps a page just after we * set VM_LOCKED, populate_vma_page_range will bring it back. */ - if ((newflags & VM_LOCKED) && (oldflags & VM_LOCKED)) { /* No work to do, and mlocking twice would be wrong */ + vma_start_write(vma); vm_flags_reset(vma, newflags); } else { mlock_vma_pages_range(vma, start, end, newflags); diff --git a/mm/mprotect.c b/mm/mprotect.c index 3a04999e8353..45a87f0ce625 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -631,6 +631,7 @@ success: * vm_flags and vm_page_prot are protected by the mmap_lock * held in write mode. */ + vma_start_write(vma); vm_flags_reset(vma, newflags); /* * We want to check manually if we can change individual PTEs writable