diff mbox series

[v4,14/19] contrib/elf2dmp: Use rol64() to decode

Message ID 20240307-elf2dmp-v4-14-4f324ad4d99d@daynix.com
State New
Headers show
Series contrib/elf2dmp: Improve robustness | expand

Commit Message

Akihiko Odaki March 7, 2024, 10:20 a.m. UTC 
rol64() is roubust against too large shift values and fixes UBSan
warnings.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 contrib/elf2dmp/main.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Comments

Philippe Mathieu-Daudé March 7, 2024, 10:29 a.m. UTC | #1 
On 7/3/24 11:20, Akihiko Odaki wrote:
> rol64() is roubust against too large shift values and fixes UBSan
> warnings.
> 
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   contrib/elf2dmp/main.c | 8 ++------
>   1 file changed, 2 insertions(+), 6 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff mbox series

Patch

diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
index 32dc8bac6a30..d046a72ae67f 100644
--- a/contrib/elf2dmp/main.c
+++ b/contrib/elf2dmp/main.c
@@ -6,6 +6,7 @@ 
  */
 
 #include "qemu/osdep.h"
+#include "qemu/bitops.h"
 
 #include "err.h"
 #include "addrspace.h"
@@ -47,11 +48,6 @@  static const uint64_t SharedUserData = 0xfffff78000000000;
     s ? printf(#s" = 0x%016"PRIx64"\n", s) :\
     eprintf("Failed to resolve "#s"\n"), s)
 
-static uint64_t rol(uint64_t x, uint64_t y)
-{
-    return (x << y) | (x >> (64 - y));
-}
-
 /*
  * Decoding algorithm can be found in Volatility project
  */
@@ -64,7 +60,7 @@  static void kdbg_decode(uint64_t *dst, uint64_t *src, size_t size,
         uint64_t block;
 
         block = src[i];
-        block = rol(block ^ kwn, (uint8_t)kwn);
+        block = rol64(block ^ kwn, kwn);
         block = __builtin_bswap64(block ^ kdbe) ^ kwa;
         dst[i] = block;
     }