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| author | Konstantin Khlebnikov | 2019-07-12 06:00:07 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2019-07-12 20:05:47 +0200 |
| commit | 1e426fe28261b03f297992e89da3320b42816f4e (patch) | |
| tree | 7b44fe31e28a4dc64053652cca031326935f4b92 /Documentation/filesystems | |
| parent | proc: use down_read_killable mmap_sem for /proc/pid/map_files (diff) | |
| download | kernel-qcow2-linux-1e426fe28261b03f297992e89da3320b42816f4e.tar.gz kernel-qcow2-linux-1e426fe28261b03f297992e89da3320b42816f4e.tar.xz kernel-qcow2-linux-1e426fe28261b03f297992e89da3320b42816f4e.zip | |
mm: use down_read_killable for locking mmap_sem in access_remote_vm
This function is used by ptrace and proc files like /proc/pid/cmdline and
/proc/pid/environ.
Access_remote_vm never returns error codes, all errors are ignored and
only size of successfully read data is returned. So, if current task was
killed we'll simply return 0 (bytes read).
Mmap_sem could be locked for a long time or forever if something goes
wrong. Using a killable lock permits cleanup of stuck tasks and
simplifies investigation.
Link: http://lkml.kernel.org/r/156007494202.3335.16782303099589302087.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems')
0 files changed, 0 insertions, 0 deletions