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-rw-r--r--include/linux/signal.h1
-rw-r--r--kernel/signal.c29
2 files changed, 25 insertions, 5 deletions
diff --git a/include/linux/signal.h b/include/linux/signal.h
index fcd2b14b193..ba009c16727 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -243,6 +243,7 @@ extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig,
siginfo_t *info);
extern long do_sigpending(void __user *, unsigned long);
extern int sigprocmask(int, sigset_t *, sigset_t *);
+extern void set_current_blocked(const sigset_t *);
extern int show_unhandled_signals;
struct pt_regs;
diff --git a/kernel/signal.c b/kernel/signal.c
index e8308e3238c..8aa3a2e226a 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2299,6 +2299,29 @@ long do_no_restart_syscall(struct restart_block *param)
return -EINTR;
}
+/**
+ * set_current_blocked - change current->blocked mask
+ * @newset: new mask
+ *
+ * It is wrong to change ->blocked directly, this helper should be used
+ * to ensure the process can't miss a shared signal we are going to block.
+ */
+void set_current_blocked(const sigset_t *newset)
+{
+ struct task_struct *tsk = current;
+
+ spin_lock_irq(&tsk->sighand->siglock);
+ if (signal_pending(tsk) && !thread_group_empty(tsk)) {
+ sigset_t newblocked;
+ /* A set of now blocked but previously unblocked signals. */
+ signandsets(&newblocked, newset, &current->blocked);
+ retarget_shared_pending(tsk, &newblocked);
+ }
+ tsk->blocked = *newset;
+ recalc_sigpending();
+ spin_unlock_irq(&tsk->sighand->siglock);
+}
+
/*
* This is also useful for kernel threads that want to temporarily
* (or permanently) block certain signals.
@@ -2330,11 +2353,7 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
return -EINVAL;
}
- spin_lock_irq(&tsk->sighand->siglock);
- tsk->blocked = newset;
- recalc_sigpending();
- spin_unlock_irq(&tsk->sighand->siglock);
-
+ set_current_blocked(&newset);
return 0;
}