From: Tony Luck <tony.luck@xxxxxxxxx> [ Upstream commit 7ccddc4613db446dc3cbb69a3763ba60ec651d13 ] The kbuild test robot reported this warning: arch/x86/kernel/cpu/mce/dev-mcelog.c: In function 'dev_mcelog_init_device': arch/x86/kernel/cpu/mce/dev-mcelog.c:346:2: warning: 'strncpy' output \ truncated before terminating nul copying 12 bytes from a string of the \ same length [-Wstringop-truncation] This is accurate, but I don't care that the trailing NUL character isn't copied. The string being copied is just a magic number signature so that crash dump tools can be sure they are decoding the right blob of memory. Use memcpy() instead of strncpy(). Fixes: d8ecca4043f2 ("x86/mce/dev-mcelog: Dynamically allocate space for machine check records") Reported-by: kbuild test robot <lkp@xxxxxxxxx> Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20200527182808.27737-1-tony.luck@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/kernel/cpu/mce/dev-mcelog.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mce/dev-mcelog.c b/arch/x86/kernel/cpu/mce/dev-mcelog.c index d089567a9ce8..bcb379b2fd42 100644 --- a/arch/x86/kernel/cpu/mce/dev-mcelog.c +++ b/arch/x86/kernel/cpu/mce/dev-mcelog.c @@ -343,7 +343,7 @@ static __init int dev_mcelog_init_device(void) if (!mcelog) return -ENOMEM; - strncpy(mcelog->signature, MCE_LOG_SIGNATURE, sizeof(mcelog->signature)); + memcpy(mcelog->signature, MCE_LOG_SIGNATURE, sizeof(mcelog->signature)); mcelog->len = mce_log_len; mcelog->recordlen = sizeof(struct mce); -- 2.25.1