This is very theoretical compile failure:
ELF_ST_TYPE(st_info = A)
Cast will bind first and st_info will stop being lvalue:
error: lvalue required as left operand of assignment
Given that the only use of this macro is
ELF_ST_TYPE(sym->st_info)
where st_info is "unsigned char" I've decided to remove cast especially
given that companion macro ELF_ST_BIND doesn't use cast.
Signed-off-by: Alexey Dobriyan <[email protected]>
---
include/uapi/linux/elf.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -134,7 +134,7 @@ typedef __s64 Elf64_Sxword;
#define STT_TLS 6
#define ELF_ST_BIND(x) ((x) >> 4)
-#define ELF_ST_TYPE(x) (((unsigned int) x) & 0xf)
+#define ELF_ST_TYPE(x) ((x) & 0xf)
#define ELF32_ST_BIND(x) ELF_ST_BIND(x)
#define ELF32_ST_TYPE(x) ELF_ST_TYPE(x)
#define ELF64_ST_BIND(x) ELF_ST_BIND(x)
On Fri, Apr 29, 2022 at 10:25:23AM -0700, Kees Cook wrote:
> Please keep Eric & I CCed on ELF changes; there's a MAINTAINERS entry
> now...
Hah!
I honestly searched for 'ELF' before sending and didn't find anything.
On Fri, Apr 29, 2022 at 05:50:03PM +0300, Alexey Dobriyan wrote:
> This is very theoretical compile failure:
>
> ELF_ST_TYPE(st_info = A)
>
> Cast will bind first and st_info will stop being lvalue:
>
> error: lvalue required as left operand of assignment
>
> Given that the only use of this macro is
>
> ELF_ST_TYPE(sym->st_info)
>
> where st_info is "unsigned char" I've decided to remove cast especially
> given that companion macro ELF_ST_BIND doesn't use cast.
>
> Signed-off-by: Alexey Dobriyan <[email protected]>
> ---
>
> include/uapi/linux/elf.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
It looks like akpm already pulled this, so:
Acked-by: Kees Cook <[email protected]>
Please keep Eric & I CCed on ELF changes; there's a MAINTAINERS entry
now...
-Kees
--
Kees Cook