xen/arm: check string format for early_printk

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/xen/include/asm-arm/early_printk.h b/xen/include/asm-arm/early_printk.h
index b72fce7a21582d6ead82fd5cb1ba23bfe363cad4..03ead23a0b0b1433a5d6cecb45bb014cd30bae3f 100644 (file)
--- a/xen/include/asm-arm/early_printk.h
+++ b/xen/include/asm-arm/early_printk.h
@@ -14,13 +14,19 @@
 
 #ifdef EARLY_PRINTK
 
-void early_printk(const char *fmt, ...);
-void early_panic(const char *fmt, ...) __attribute__((noreturn));
+void early_printk(const char *fmt, ...)
+    __attribute__((format (printf, 1, 2)));
+void early_panic(const char *fmt, ...) __attribute__((noreturn))
+    __attribute__((format (printf, 1, 2)));
 
 #else
 
-static inline void early_printk(const char *fmt, ...) {}
-static inline void  __attribute__((noreturn)) early_panic(const char *fmt, ...) {while(1);}
+static inline void early_printk(const char *fmt, ...)
+    __attribute__((format (printf, 1, 2)))
+{}
+static inline void  __attribute__((noreturn)) early_panic(const char *fmt, ...)
+    __attribute__((format (printf, 1, 2)))
+{while(1);}
 
 #endif