When map_address is NULL, computing map_address+offset is technically
undefined behavior, and triggers Clang/LLVM warning when using
-fsanitize=pointer-overflow.
Fix this by using uintptr_t to perform computations.
Signed-off-by: Shahriar "Nafi" Rouf <n...@google.com>
---
libelf/elf_begin.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/libelf/elf_begin.c b/libelf/elf_begin.c
index fe8c640a..da495bef 100644
--- a/libelf/elf_begin.c
+++ b/libelf/elf_begin.c
@@ -445,15 +445,15 @@ file_read_elf (int fildes, void *map_address, unsigned
char *e_ident,
{
/* This pointer might not be directly usable if the alignment is
not sufficient for the architecture. */
- Elf64_Ehdr *ehdr = (Elf64_Ehdr *) ((char *) map_address + offset);
+ uintptr_t ehdr = (uintptr_t) map_address + offset;
/* This is a 64-bit binary. */
if (map_address != NULL && e_ident[EI_DATA] == MY_ELFDATA
&& (ALLOW_UNALIGNED
- || (((uintptr_t) ehdr) & (__alignof__ (Elf64_Ehdr) - 1)) == 0))
+ || (ehdr & (__alignof__ (Elf64_Ehdr) - 1)) == 0))
{
/* We can use the mmapped memory. */
- elf->state.elf64.ehdr = ehdr;
+ elf->state.elf64.ehdr = (Elf64_Ehdr *) ehdr;
}
else
{
@@ -486,7 +486,7 @@ file_read_elf (int fildes, void *map_address, unsigned char
*e_ident,
if (map_address != NULL && e_ident[EI_DATA] == MY_ELFDATA
&& cmd != ELF_C_READ_MMAP /* We need a copy to be able to write. */
&& (ALLOW_UNALIGNED
- || ((((uintptr_t) ehdr + e_shoff)
+ || (((ehdr + e_shoff)
& (__alignof__ (Elf64_Shdr) - 1)) == 0)))
{
if (unlikely (scncnt > 0 && e_shoff >= maxsize)
@@ -496,7 +496,7 @@ file_read_elf (int fildes, void *map_address, unsigned char
*e_ident,
if (scncnt > 0)
elf->state.elf64.shdr
- = (Elf64_Shdr *) ((char *) ehdr + e_shoff);
+ = (Elf64_Shdr *) (ehdr + e_shoff);
for (size_t cnt = 0; cnt < scncnt; ++cnt)
{
--
2.42.0.869.gea05f2083d-goog
