From 2e9064faccd1a5b9de8c6f4b23d9f4948901cbe9 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 16 Oct 2023 18:48:58 -0400 Subject: [PATCH] x86/microcode/amd: Fix snprintf() format string warning in W=1 build MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- 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 bbd1dc38ea0316..b4eea8a1f68a2d 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;