The patch titled
signals: simplify sig_ignored() pathes
has been removed from the -mm tree. Its filename was
signals-simplify-sig_ignored-pathes.patch
This patch was dropped because an updated version will be merged
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: signals: simplify sig_ignored() pathes
From: Oleg Nesterov <oleg@xxxxxxxxxx>
The code which checks for ignored signals is a bit overcomplicated because
tracehook_consider_ignored_signal() wants the "handler" arg. Can't we
kill it? It is not used even with utrace, and even if it will be used
later it is OK to read ->sighand again in the slow path.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/tracehook.h | 5 +----
kernel/signal.c | 35 ++++++++++++-----------------------
2 files changed, 13 insertions(+), 27 deletions(-)
diff -puN include/linux/tracehook.h~signals-simplify-sig_ignored-pathes include/linux/tracehook.h
--- a/include/linux/tracehook.h~signals-simplify-sig_ignored-pathes
+++ a/include/linux/tracehook.h
@@ -388,17 +388,14 @@ static inline void tracehook_signal_hand
* tracehook_consider_ignored_signal - suppress short-circuit of ignored signal
* @task: task receiving the signal
* @sig: signal number being sent
- * @handler: %SIG_IGN or %SIG_DFL
*
* Return zero iff tracing doesn't care to examine this ignored signal,
* so it can short-circuit normal delivery and never even get queued.
- * Either @handler is %SIG_DFL and @sig's default is ignore, or it's %SIG_IGN.
*
* Called with @task->sighand->siglock held.
*/
static inline int tracehook_consider_ignored_signal(struct task_struct *task,
- int sig,
- void __user *handler)
+ int sig)
{
return (task_ptrace(task) & PT_PTRACED) != 0;
}
diff -puN kernel/signal.c~signals-simplify-sig_ignored-pathes kernel/signal.c
--- a/kernel/signal.c~signals-simplify-sig_ignored-pathes
+++ a/kernel/signal.c
@@ -41,44 +41,33 @@
static struct kmem_cache *sigqueue_cachep;
-static void __user *sig_handler(struct task_struct *t, int sig)
+static int sig_task_ignored(struct task_struct *t, int sig)
{
void __user *h = t->sighand->action[sig - 1].sa.sa_handler;
- /* drop SIGKILL early to not confuse wait_xxx_killable/etc */
- if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && h == SIG_DFL)
- h = SIG_IGN;
-
- return h;
-}
-
-static int sig_handler_ignored(void __user *handler, int sig)
-{
- /* Is it explicitly or implicitly ignored? */
- return handler == SIG_IGN ||
- (handler == SIG_DFL && sig_kernel_ignore(sig));
+ if (h == SIG_DFL) {
+ /* init drops SIGKILL early to not confuse xxx_killable/etc */
+ return sig_kernel_ignore(sig) ||
+ unlikely(t->signal->flags & SIGNAL_UNKILLABLE);
+ }
+ return h == SIG_IGN;
}
static int sig_ignored(struct task_struct *t, int sig)
{
- void __user *handler;
-
/*
* Blocked signals are never ignored, since the
* signal handler may change by the time it is
* unblocked.
*/
- if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
- return 0;
-
- handler = sig_handler(t, sig);
- if (!sig_handler_ignored(handler, sig))
+ if (sigismember(&t->blocked, sig) ||
+ sigismember(&t->real_blocked, sig) ||
+ !sig_task_ignored(t, sig))
return 0;
-
/*
* Tracers may want to know about even ignored signals.
*/
- return !tracehook_consider_ignored_signal(t, sig, handler);
+ return !tracehook_consider_ignored_signal(t, sig);
}
/*
@@ -2356,7 +2345,7 @@ int do_sigaction(int sig, struct k_sigac
* (for example, SIGCHLD), shall cause the pending signal to
* be discarded, whether or not it is blocked"
*/
- if (sig_handler_ignored(sig_handler(t, sig), sig)) {
+ if (sig_task_ignored(t, sig)) {
sigemptyset(&mask);
sigaddset(&mask, sig);
rm_from_queue_full(&mask, &t->signal->shared_pending);
_
Patches currently in -mm which might be from oleg@xxxxxxxxxx are
origin.patch
forkc-cleanup-for-copy_sighand.patch
do_wait-wakeup-optimization.patch
signals-simplify-sig_ignored-pathes.patch
workqueues-kill-cpu_singlethread_map-use-get_cpu_mask-instead.patch
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