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| author | Oleg Nesterov <oleg@redhat.com> | 2015-11-06 16:32:19 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-06 17:50:42 -0800 |
| commit | 2e01fabe67ccaff1d59bda01e60a61f5fb0aa7b6 (patch) | |
| tree | 4db02540f4e0f4f3981965b86ee43cbd88ae517e /include | |
| parent | 4f05028f8d1af782cfd03d09e0a052e9745dc5ad (diff) | |
| download | lwn-2e01fabe67ccaff1d59bda01e60a61f5fb0aa7b6.tar.gz lwn-2e01fabe67ccaff1d59bda01e60a61f5fb0aa7b6.zip | |
signals: kill block_all_signals() and unblock_all_signals()
It is hardly possible to enumerate all problems with block_all_signals()
and unblock_all_signals(). Just for example,
1. block_all_signals(SIGSTOP/etc) simply can't help if the caller is
multithreaded. Another thread can dequeue the signal and force the
group stop.
2. Even is the caller is single-threaded, it will "stop" anyway. It
will not sleep, but it will spin in kernel space until SIGCONT or
SIGKILL.
And a lot more. In short, this interface doesn't work at all, at least
the last 10+ years.
Daniel said:
Yeah the only times I played around with the DRM_LOCK stuff was when
old drivers accidentally deadlocked - my impression is that the entire
DRM_LOCK thing was never really tested properly ;-) Hence I'm all for
purging where this leaks out of the drm subsystem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/drmP.h | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 7 |
2 files changed, 1 insertions, 7 deletions
diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 8b5ce7c5d9bb..f56cdcecc1c9 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -822,7 +822,6 @@ struct drm_device { struct drm_sg_mem *sg; /**< Scatter gather memory */ unsigned int num_crtcs; /**< Number of CRTCs on this device */ - sigset_t sigmask; struct { int context; diff --git a/include/linux/sched.h b/include/linux/sched.h index eeb5066a44fb..923ec1a9b2b4 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1570,9 +1570,7 @@ struct task_struct { unsigned long sas_ss_sp; size_t sas_ss_size; - int (*notifier)(void *priv); - void *notifier_data; - sigset_t *notifier_mask; + struct callback_head *task_works; struct audit_context *audit_context; @@ -2476,9 +2474,6 @@ static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, s return ret; } -extern void block_all_signals(int (*notifier)(void *priv), void *priv, - sigset_t *mask); -extern void unblock_all_signals(void); extern void release_task(struct task_struct * p); extern int send_sig_info(int, struct siginfo *, struct task_struct *); extern int force_sigsegv(int, struct task_struct *); |