From: Paolo Bonzini Date: Mon, 16 Oct 2023 22:48:58 +0000 (-0400) Subject: x86/microcode/amd: Fix snprintf() format string warning in W=1 build X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2e9064faccd1a5b9de8c6f4b23d9f4948901cbe9;p=linux.git x86/microcode/amd: Fix snprintf() format string warning in W=1 build Building with GCC 11.x results in the following warning: arch/x86/kernel/cpu/microcode/amd.c: In function ‘find_blobs_in_containers’: arch/x86/kernel/cpu/microcode/amd.c:504:58: error: ‘h.bin’ directive output may be truncated writing 5 bytes into a region of size between 1 and 7 [-Werror=format-truncation=] arch/x86/kernel/cpu/microcode/amd.c:503:17: note: ‘snprintf’ output between 35 and 41 bytes into a destination of size 36 The issue is that GCC does not know that the family can only be a byte (it ultimately comes from CPUID). Suggest the right size to the compiler by marking the argument as char-size ("hh"). While at it, instead of using the slightly more obscure precision specifier use the width with zero padding (over 23000 occurrences in kernel sources, vs 500 for the idiom using the precision). Reported-by: kernel test robot Signed-off-by: Paolo Bonzini Signed-off-by: Ingo Molnar Signed-off-by: Borislav Petkov (AMD) Closes: https://lore.kernel.org/oe-kbuild-all/202308252255.2HPJ6x5Q-lkp@intel.com/ Link: https://lore.kernel.org/r/20231016224858.2829248-1-pbonzini@redhat.com --- diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index bbd1dc38ea031..b4eea8a1f68a2 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -501,7 +501,7 @@ static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family) if (family >= 0x15) snprintf(fw_name, sizeof(fw_name), - "amd-ucode/microcode_amd_fam%.2xh.bin", family); + "amd-ucode/microcode_amd_fam%02hhxh.bin", family); if (firmware_request_builtin(&fw, fw_name)) { cp->size = fw.size;