diff options
Diffstat (limited to 'fs/proc/task_mmu.c')
| -rw-r--r-- | fs/proc/task_mmu.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 92a91e7816d8..01d4eb0e6bd1 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1143,6 +1143,24 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, count = -EINTR; goto out_mm; } + /* + * Avoid to modify vma->vm_flags + * without locked ops while the + * coredump reads the vm_flags. + */ + if (!mmget_still_valid(mm)) { + /* + * Silently return "count" + * like if get_task_mm() + * failed. FIXME: should this + * function have returned + * -ESRCH if get_task_mm() + * failed like if + * get_proc_task() fails? + */ + up_write(&mm->mmap_sem); + goto out_mm; + } for (vma = mm->mmap; vma; vma = vma->vm_next) { vma->vm_flags &= ~VM_SOFTDIRTY; vma_set_page_prot(vma); @@ -1151,7 +1169,8 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, break; } - mmu_notifier_range_init(&range, mm, 0, -1UL); + mmu_notifier_range_init(&range, MMU_NOTIFY_SOFT_DIRTY, + 0, NULL, mm, 0, -1UL); mmu_notifier_invalidate_range_start(&range); } walk_page_range(0, mm->highest_vm_end, &clear_refs_walk); |