diff options
| author | Konstantin Khlebnikov <[email protected]> | 2019-07-11 21:00:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2019-07-12 11:05:47 -0700 |
| commit | c46038017fbdcac627b670c9d4176f1d0c2f5fa3 (patch) | |
| tree | 5529fe8c15d395da61cba375ed13a35ff544ce34 | |
| parent | ad80b932c57d85fd6377f97f359b025baf179a87 (diff) | |
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
Do not remain stuck forever if something goes wrong. Using a killable
lock permits cleanup of stuck tasks and simplifies investigation.
Replace the only unkillable mmap_sem lock in clear_refs_write().
Link: http://lkml.kernel.org/r/156007493826.3335.5424884725467456239.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <[email protected]>
Reviewed-by: Roman Gushchin <[email protected]>
Reviewed-by: Cyrill Gorcunov <[email protected]>
Reviewed-by: Kirill Tkhai <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michal Koutný <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | fs/proc/task_mmu.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 78bed6adc62d..7f84d1477b5b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1140,7 +1140,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, goto out_mm; } - down_read(&mm->mmap_sem); + if (down_read_killable(&mm->mmap_sem)) { + count = -EINTR; + goto out_mm; + } tlb_gather_mmu(&tlb, mm, 0, -1); if (type == CLEAR_REFS_SOFT_DIRTY) { for (vma = mm->mmap; vma; vma = vma->vm_next) { |