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authorLinus Torvalds <torvalds@linux-foundation.org>2020-12-14 17:13:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-14 17:13:53 -0800
commit1ac0884d5474fea8dc6ceabbd0e870d1bf4b7b42 (patch)
tree5158d582c0f5040a9c8a28fe9051881c5ec7b5eb /kernel/signal.c
parentff6135959a9150ad45cb92ca38da270903a74343 (diff)
parentc6156e1da633f241e132eaea3b676d674376d770 (diff)
Merge tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core entry/exit updates from Thomas Gleixner: "A set of updates for entry/exit handling: - More generalization of entry/exit functionality - The consolidation work to reclaim TIF flags on x86 and also for non-x86 specific TIF flags which are solely relevant for syscall related work and have been moved into their own storage space. The x86 specific part had to be merged in to avoid a major conflict. - The TIF_NOTIFY_SIGNAL work which replaces the inefficient signal delivery mode of task work and results in an impressive performance improvement for io_uring. The non-x86 consolidation of this is going to come seperate via Jens. - The selective syscall redirection facility which provides a clean and efficient way to support the non-Linux syscalls of WINE by catching them at syscall entry and redirecting them to the user space emulation. This can be utilized for other purposes as well and has been designed carefully to avoid overhead for the regular fastpath. This includes the core changes and the x86 support code. - Simplification of the context tracking entry/exit handling for the users of the generic entry code which guarantee the proper ordering and protection. - Preparatory changes to make the generic entry code accomodate S390 specific requirements which are mostly related to their syscall restart mechanism" * tag 'core-entry-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) entry: Add syscall_exit_to_user_mode_work() entry: Add exit_to_user_mode() wrapper entry_Add_enter_from_user_mode_wrapper entry: Rename exit_to_user_mode() entry: Rename enter_from_user_mode() docs: Document Syscall User Dispatch selftests: Add benchmark for syscall user dispatch selftests: Add kselftest for syscall user dispatch entry: Support Syscall User Dispatch on common syscall entry kernel: Implement selective syscall userspace redirection signal: Expose SYS_USER_DISPATCH si_code type x86: vdso: Expose sigreturn address on vdso to the kernel MAINTAINERS: Add entry for common entry code entry: Fix boot for !CONFIG_GENERIC_ENTRY x86: Support HAVE_CONTEXT_TRACKING_OFFSTACK context_tracking: Only define schedule_user() on !HAVE_CONTEXT_TRACKING_OFFSTACK archs sched: Detect call to schedule from critical entry code context_tracking: Don't implement exception_enter/exit() on CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK context_tracking: Introduce HAVE_CONTEXT_TRACKING_OFFSTACK x86: Reclaim unused x86 TI flags ...
Diffstat (limited to 'kernel/signal.c')
-rw-r--r--kernel/signal.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index 26018c59821d..c37170655171 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -984,7 +984,7 @@ static inline bool wants_signal(int sig, struct task_struct *p)
if (task_is_stopped_or_traced(p))
return false;
- return task_curr(p) || !signal_pending(p);
+ return task_curr(p) || !task_sigpending(p);
}
static void complete_signal(int sig, struct task_struct *p, enum pid_type type)
@@ -2550,6 +2550,20 @@ bool get_signal(struct ksignal *ksig)
struct signal_struct *signal = current->signal;
int signr;
+ /*
+ * For non-generic architectures, check for TIF_NOTIFY_SIGNAL so
+ * that the arch handlers don't all have to do it. If we get here
+ * without TIF_SIGPENDING, just exit after running signal work.
+ */
+#ifdef TIF_NOTIFY_SIGNAL
+ if (!IS_ENABLED(CONFIG_GENERIC_ENTRY)) {
+ if (test_thread_flag(TIF_NOTIFY_SIGNAL))
+ tracehook_notify_signal();
+ if (!task_sigpending(current))
+ return false;
+ }
+#endif
+
if (unlikely(uprobe_deny_signal()))
return false;
@@ -2847,7 +2861,7 @@ static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which)
/* Remove the signals this thread can handle. */
sigandsets(&retarget, &retarget, &t->blocked);
- if (!signal_pending(t))
+ if (!task_sigpending(t))
signal_wake_up(t, 0);
if (sigisemptyset(&retarget))
@@ -2881,7 +2895,7 @@ void exit_signals(struct task_struct *tsk)
cgroup_threadgroup_change_end(tsk);
- if (!signal_pending(tsk))
+ if (!task_sigpending(tsk))
goto out;
unblocked = tsk->blocked;
@@ -2925,7 +2939,7 @@ long do_no_restart_syscall(struct restart_block *param)
static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset)
{
- if (signal_pending(tsk) && !thread_group_empty(tsk)) {
+ if (task_sigpending(tsk) && !thread_group_empty(tsk)) {
sigset_t newblocked;
/* A set of now blocked but previously unblocked signals. */
sigandnsets(&newblocked, newset, &current->blocked);

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