[PATCH] fortify: Avoid shadowing previous locals

From: Qian Cai
Date: Mon Oct 25 2021 - 14:37:57 EST


__compiletime_strlen macro expansion will shadow p_size and p_len local
variables. Just rename those in __compiletime_strlen.

Signed-off-by: Qian Cai <quic_qiancai@xxxxxxxxxxx>
---
include/linux/fortify-string.h | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index fdb0a74c9ca2..155c622e4f24 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -10,18 +10,18 @@ void __read_overflow(void) __compiletime_error("detected read beyond size of obj
void __read_overflow2(void) __compiletime_error("detected read beyond size of object (2nd parameter)");
void __write_overflow(void) __compiletime_error("detected write beyond size of object (1st parameter)");

-#define __compiletime_strlen(p) \
-({ \
- unsigned char *__p = (unsigned char *)(p); \
- size_t ret = (size_t)-1; \
- size_t p_size = __builtin_object_size(p, 1); \
- if (p_size != (size_t)-1) { \
- size_t p_len = p_size - 1; \
- if (__builtin_constant_p(__p[p_len]) && \
- __p[p_len] == '\0') \
- ret = __builtin_strlen(__p); \
- } \
- ret; \
+#define __compiletime_strlen(ptr) \
+({ \
+ unsigned char *__ptr = (unsigned char *)(ptr); \
+ size_t ret = (size_t)-1; \
+ size_t ptr_size = __builtin_object_size(ptr, 1); \
+ if (ptr_size != (size_t)-1) { \
+ size_t ptr_len = ptr_size - 1; \
+ if (__builtin_constant_p(__ptr[ptr_len]) && \
+ __ptr[ptr_len] == '\0') \
+ ret = __builtin_strlen(__ptr); \
+ } \
+ ret; \
})

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
--
2.30.2