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-rw-r--r--drivers/block/drbd/drbd_main.c2
-rw-r--r--fs/cifs/connect.c2
-rw-r--r--include/linux/signal.h15
-rw-r--r--kernel/signal.c5
4 files changed, 22 insertions, 2 deletions
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 9bd4ddd12b25..5b248763a672 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -322,6 +322,8 @@ static int drbd_thread_setup(void *arg)
thi->name[0],
resource->name);
+ allow_kernel_signal(DRBD_SIGKILL);
+ allow_kernel_signal(SIGXCPU);
restart:
retval = thi->function(thi);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a15a6e738eb5..1795e80cbdf7 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1113,7 +1113,7 @@ cifs_demultiplex_thread(void *p)
mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
set_freezable();
- allow_signal(SIGKILL);
+ allow_kernel_signal(SIGKILL);
while (server->tcpStatus != CifsExiting) {
if (try_to_freeze())
continue;
diff --git a/include/linux/signal.h b/include/linux/signal.h
index b5d99482d3fe..1a5f88316b08 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -282,6 +282,9 @@ extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
extern void exit_signals(struct task_struct *tsk);
extern void kernel_sigaction(int, __sighandler_t);
+#define SIG_KTHREAD ((__force __sighandler_t)2)
+#define SIG_KTHREAD_KERNEL ((__force __sighandler_t)3)
+
static inline void allow_signal(int sig)
{
/*
@@ -289,7 +292,17 @@ static inline void allow_signal(int sig)
* know it'll be handled, so that they don't get converted to
* SIGKILL or just silently dropped.
*/
- kernel_sigaction(sig, (__force __sighandler_t)2);
+ kernel_sigaction(sig, SIG_KTHREAD);
+}
+
+static inline void allow_kernel_signal(int sig)
+{
+ /*
+ * Kernel threads handle their own signals. Let the signal code
+ * know signals sent by the kernel will be handled, so that they
+ * don't get silently dropped.
+ */
+ kernel_sigaction(sig, SIG_KTHREAD_KERNEL);
}
static inline void disallow_signal(int sig)
diff --git a/kernel/signal.c b/kernel/signal.c
index e667be6907d7..534fec266a33 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -90,6 +90,11 @@ static bool sig_task_ignored(struct task_struct *t, int sig, bool force)
handler == SIG_DFL && !(force && sig_kernel_only(sig)))
return true;
+ /* Only allow kernel generated signals to this kthread */
+ if (unlikely((t->flags & PF_KTHREAD) &&
+ (handler == SIG_KTHREAD_KERNEL) && !force))
+ return true;
+
return sig_handler_ignored(handler, sig);
}