[v2,09/13] contrib/elf2dmp: Use rol64() to decode

Commit Message

Akihiko Odaki March 5, 2024, 7:36 a.m. UTC

rol64() is roubust against too large shift values and fixes UBSan
warnings.

Signed-off-by: Akihiko Odaki <[e-mail]>
Reviewed-by: Peter Maydell <[e-mail]>
---
 contrib/elf2dmp/main.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Patch

diff --git a/contrib/elf2dmp/main.c b/contrib/elf2dmp/main.c
index 25cf0fdff724..20547fd8f819 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;
     }