[RFC 5/6] xen/console: Add noreturn attribute to panic function

[Julien Grall <julien.grall@linaro.org>]

Panic function will never return. Without this attribute, gcc may output
warnings in call function.

Cc: Keir Fraser <keir@xen.org>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
---
 xen/drivers/char/console.c | 4 +++-
 xen/include/xen/lib.h      | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index f83c92e..229d48a 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -1049,7 +1049,7 @@ __initcall(debugtrace_init);
  * **************************************************************
  */
 
-void panic(const char *fmt, ...)
+void __attribute__((noreturn)) panic(const char *fmt, ...)
 {
     va_list args;
     unsigned long flags;
@@ -1092,6 +1092,8 @@ void panic(const char *fmt, ...)
         watchdog_disable();
         machine_restart(5000);
     }
+
+    while ( 1 );
 }
 
 void __bug(char *file, int line)
diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 5b258fd..9c3a242 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -88,7 +88,7 @@ extern void printk(const char *format, ...)
 extern void guest_printk(const struct domain *d, const char *format, ...)
     __attribute__ ((format (printf, 2, 3)));
 extern void panic(const char *format, ...)
-    __attribute__ ((format (printf, 1, 2)));
+    __attribute__ ((format (printf, 1, 2))) __attribute__ ((noreturn));
 extern long vm_assist(struct domain *, unsigned int, unsigned int);
 extern int __printk_ratelimit(int ratelimit_ms, int ratelimit_burst);
 extern int printk_ratelimit(void);
-- 
1.8.3.1