[PATCH 1/1] x86/mm: kaslr: fix -Wformat-security warning

From: Nicolas Iooss
Date: Sat Aug 06 2016 - 16:27:33 EST


debug_putstr() is used to output strings without using printf-like
formatting but debug_putstr(v) is defined as early_printk(v) in
arch/x86/lib/kaslr.c. This makes clang reports the following warning
when building with -Wformat-security:

arch/x86/lib/kaslr.c:57:15: warning: format string is not a string
literal (potentially insecure) [-Wformat-security]
debug_putstr(purpose);
^~~~~~~

Fix this by using "%s" in early_printk().

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
---
arch/x86/lib/kaslr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/lib/kaslr.c b/arch/x86/lib/kaslr.c
index f7dfeda83e5c..121f59c6ee54 100644
--- a/arch/x86/lib/kaslr.c
+++ b/arch/x86/lib/kaslr.c
@@ -19,7 +19,7 @@
#include <asm/cpufeature.h>
#include <asm/setup.h>

-#define debug_putstr(v) early_printk(v)
+#define debug_putstr(v) early_printk("%s", v)
#define has_cpuflag(f) boot_cpu_has(f)
#define get_boot_seed() kaslr_offset()
#endif
--
2.9.2