Do not stuck forever if something wrong. Killable lock allows to cleanup stuck tasks and simplifies investigation. Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Reviewed-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Cyrill Gorcunov <gorcunov@xxxxxxxxx> Reviewed-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> --- fs/proc/task_mmu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 781879a91e3b..78bed6adc62d 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1547,7 +1547,9 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, /* overflow ? */ if (end < start_vaddr || end > end_vaddr) end = end_vaddr; - down_read(&mm->mmap_sem); + ret = down_read_killable(&mm->mmap_sem); + if (ret) + goto out_free; ret = walk_page_range(start_vaddr, end, &pagemap_walk); up_read(&mm->mmap_sem); start_vaddr = end;
