Merge branch 'next' into for-linus

Prepare first round of input updates for 3.20.

1 files changed, 14 insertions, 0 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index d09dc5c32c6..4d8d6f906de 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -33,6 +33,7 @@ static int pause_on_oops;
 static int pause_on_oops_flag;
 static DEFINE_SPINLOCK(pause_on_oops_lock);
 static bool crash_kexec_post_notifiers;
+int panic_on_warn __read_mostly;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
@@ -244,6 +245,7 @@ static const struct tnt tnts[] = {
  *  'I' - Working around severe firmware bug.
  *  'O' - Out-of-tree module has been loaded.
  *  'E' - Unsigned module has been loaded.
+ *  'L' - A soft lockup has previously occurred.
  *
  *	The string is overwritten by the next call to print_tainted().
  */
@@ -427,6 +429,17 @@ static void warn_slowpath_common(const char *file, int line, void *caller,
 	if (args)
 		vprintk(args->fmt, args->args);
 
+	if (panic_on_warn) {
+		/*
+		 * This thread may hit another WARN() in the panic path.
+		 * Resetting this prevents additional WARN() from panicking the
+		 * system on this thread.  Other threads are blocked by the
+		 * panic_mutex in panic().
+		 */
+		panic_on_warn = 0;
+		panic("panic_on_warn set ...\n");
+	}
+
 	print_modules();
 	dump_stack();
 	print_oops_end_marker();
@@ -484,6 +497,7 @@ EXPORT_SYMBOL(__stack_chk_fail);
 
 core_param(panic, panic_timeout, int, 0644);
 core_param(pause_on_oops, pause_on_oops, int, 0644);
+core_param(panic_on_warn, panic_on_warn, int, 0644);
 
 static int __init setup_crash_kexec_post_notifiers(char *s)
 {