Replace vma_start_write() with vma_start_write_killable() when process_vma_walk_lock() is used with PGWALK_WRLOCK option. Adjust its direct and indirect users to check for a possible error and handle it. Ensure users handle EINTR correctly and do not ignore it.
Signed-off-by: Suren Baghdasaryan <[email protected]> --- arch/s390/kvm/kvm-s390.c | 2 +- fs/proc/task_mmu.c | 5 ++++- mm/mempolicy.c | 14 +++++++++++--- mm/pagewalk.c | 20 ++++++++++++++------ mm/vma.c | 22 ++++++++++++++-------- mm/vma.h | 6 ++++++ 6 files changed, 50 insertions(+), 19 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 7a175d86cef0..337e4f7db63a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2948,7 +2948,7 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) } /* must be called without kvm->lock */ r = kvm_s390_handle_pv(kvm, &args); - if (copy_to_user(argp, &args, sizeof(args))) { + if (r != -EINTR && copy_to_user(argp, &args, sizeof(args))) { r = -EFAULT; break; } diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index e091931d7ca1..1238a2988eb6 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1797,6 +1797,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, struct clear_refs_private cp = { .type = type, }; + int err; if (mmap_write_lock_killable(mm)) { count = -EINTR; @@ -1824,7 +1825,9 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, 0, mm, 0, -1UL); mmu_notifier_invalidate_range_start(&range); } - walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); + err = walk_page_range(mm, 0, -1, &clear_refs_walk_ops, &cp); + if (err < 0) + count = err; if (type == CLEAR_REFS_SOFT_DIRTY) { mmu_notifier_invalidate_range_end(&range); flush_tlb_mm(mm); diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 90939f5bde02..3c8b3dfc9c56 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -988,6 +988,8 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end, &queue_pages_lock_vma_walk_ops : &queue_pages_walk_ops; err = walk_page_range(mm, start, end, ops, &qp); + if (err == -EINTR) + return err; if (!qp.first) /* whole range in hole */ @@ -1309,9 +1311,14 @@ static long migrate_to_node(struct mm_struct *mm, int source, int dest, flags | MPOL_MF_DISCONTIG_OK, &pagelist); mmap_read_unlock(mm); + if (nr_failed == -EINTR) + err = nr_failed; + if (!list_empty(&pagelist)) { - err = migrate_pages(&pagelist, alloc_migration_target, NULL, - (unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL); + if (!err) + err = migrate_pages(&pagelist, alloc_migration_target, + NULL, (unsigned long)&mtc, + MIGRATE_SYNC, MR_SYSCALL, NULL); if (err) putback_movable_pages(&pagelist); } @@ -1611,7 +1618,8 @@ static long do_mbind(unsigned long start, unsigned long len, MR_MEMPOLICY_MBIND, NULL); } - if (nr_failed && (flags & MPOL_MF_STRICT)) + /* Do not mask EINTR */ + if ((err != -EINTR) && (nr_failed && (flags & MPOL_MF_STRICT))) err = -EIO; if (!list_empty(&pagelist)) putback_movable_pages(&pagelist); diff --git a/mm/pagewalk.c b/mm/pagewalk.c index a94c401ab2cf..dc9f7a7709c6 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -425,14 +425,13 @@ static inline void process_mm_walk_lock(struct mm_struct *mm, mmap_assert_write_locked(mm); } -static inline void process_vma_walk_lock(struct vm_area_struct *vma, +static inline int process_vma_walk_lock(struct vm_area_struct *vma, enum page_walk_lock walk_lock) { #ifdef CONFIG_PER_VMA_LOCK switch (walk_lock) { case PGWALK_WRLOCK: - vma_start_write(vma); - break; + return vma_start_write_killable(vma); case PGWALK_WRLOCK_VERIFY: vma_assert_write_locked(vma); break; @@ -444,6 +443,7 @@ static inline void process_vma_walk_lock(struct vm_area_struct *vma, break; } #endif + return 0; } /* @@ -487,7 +487,9 @@ int walk_page_range_mm_unsafe(struct mm_struct *mm, unsigned long start, if (ops->pte_hole) err = ops->pte_hole(start, next, -1, &walk); } else { /* inside vma */ - process_vma_walk_lock(vma, ops->walk_lock); + err = process_vma_walk_lock(vma, ops->walk_lock); + if (err) + break; walk.vma = vma; next = min(end, vma->vm_end); vma = find_vma(mm, vma->vm_end); @@ -704,6 +706,7 @@ int walk_page_range_vma_unsafe(struct vm_area_struct *vma, unsigned long start, .vma = vma, .private = private, }; + int err; if (start >= end || !walk.mm) return -EINVAL; @@ -711,7 +714,9 @@ int walk_page_range_vma_unsafe(struct vm_area_struct *vma, unsigned long start, return -EINVAL; process_mm_walk_lock(walk.mm, ops->walk_lock); - process_vma_walk_lock(vma, ops->walk_lock); + err = process_vma_walk_lock(vma, ops->walk_lock); + if (err) + return err; return __walk_page_range(start, end, &walk); } @@ -734,6 +739,7 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, .vma = vma, .private = private, }; + int err; if (!walk.mm) return -EINVAL; @@ -741,7 +747,9 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, return -EINVAL; process_mm_walk_lock(walk.mm, ops->walk_lock); - process_vma_walk_lock(vma, ops->walk_lock); + err = process_vma_walk_lock(vma, ops->walk_lock); + if (err) + return err; return __walk_page_range(vma->vm_start, vma->vm_end, &walk); } diff --git a/mm/vma.c b/mm/vma.c index 9f2664f1d078..46bbad6e64a4 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -998,14 +998,18 @@ static __must_check struct vm_area_struct *vma_merge_existing_range( if (anon_dup) unlink_anon_vmas(anon_dup); - /* - * This means we have failed to clone anon_vma's correctly, but no - * actual changes to VMAs have occurred, so no harm no foul - if the - * user doesn't want this reported and instead just wants to give up on - * the merge, allow it. - */ - if (!vmg->give_up_on_oom) - vmg->state = VMA_MERGE_ERROR_NOMEM; + if (err == -EINTR) { + vmg->state = VMA_MERGE_ERROR_INTR; + } else { + /* + * This means we have failed to clone anon_vma's correctly, + * but no actual changes to VMAs have occurred, so no harm no + * foul - if the user doesn't want this reported and instead + * just wants to give up on the merge, allow it. + */ + if (!vmg->give_up_on_oom) + vmg->state = VMA_MERGE_ERROR_NOMEM; + } return NULL; } @@ -1681,6 +1685,8 @@ static struct vm_area_struct *vma_modify(struct vma_merge_struct *vmg) merged = vma_merge_existing_range(vmg); if (merged) return merged; + if (vmg_intr(vmg)) + return ERR_PTR(-EINTR); if (vmg_nomem(vmg)) return ERR_PTR(-ENOMEM); diff --git a/mm/vma.h b/mm/vma.h index eba388c61ef4..fe4560f81f4f 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -56,6 +56,7 @@ struct vma_munmap_struct { enum vma_merge_state { VMA_MERGE_START, VMA_MERGE_ERROR_NOMEM, + VMA_MERGE_ERROR_INTR, VMA_MERGE_NOMERGE, VMA_MERGE_SUCCESS, }; @@ -226,6 +227,11 @@ static inline bool vmg_nomem(struct vma_merge_struct *vmg) return vmg->state == VMA_MERGE_ERROR_NOMEM; } +static inline bool vmg_intr(struct vma_merge_struct *vmg) +{ + return vmg->state == VMA_MERGE_ERROR_INTR; +} + /* Assumes addr >= vma->vm_start. */ static inline pgoff_t vma_pgoff_offset(struct vm_area_struct *vma, unsigned long addr) -- 2.53.0.414.gf7e9f6c205-goog
