[PATCH] x86: microcode: avoid -Wformat warning with clang-15

From: Arnd Bergmann
Date: Fri Apr 05 2024 - 16:49:31 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

Older versions of clang show a warning for amd.c after a fix for a gcc
warning:

arch/x86/kernel/cpu/microcode/amd.c:478:47: error: format specifies type 'unsigned char' but the argument has type 'u16' (aka 'unsigned short') [-Werror,-Wformat]
"amd-ucode/microcode_amd_fam%02hhxh.bin", family);
~~~~~~ ^~~~~~
%02hx

In clang-16 and higher, this warning is disabled by default, but clang-15 is
still supported, and it's trivial to avoid by adapting the types according
to the range of the passed data and the format string.

Fixes: 2e9064faccd1 ("x86/microcode/amd: Fix snprintf() format string warning in W=1 build")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/x86/kernel/cpu/microcode/amd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 13b45b9c806d..620f0af713ca 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -465,7 +465,7 @@ static bool early_apply_microcode(u32 cpuid_1_eax, u32 old_rev, void *ucode, siz
return !__apply_microcode_amd(mc);
}

-static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family)
+static bool get_builtin_microcode(struct cpio_data *cp, u8 family)
{
char fw_name[36] = "amd-ucode/microcode_amd.bin";
struct firmware fw;
--
2.39.2