On Tue, Apr 09, 2024 at 04:00:54PM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > gcc can warn when a string is too long to fit into the strncpy() > destination buffer, as it is here depending on the function > arguments: > > inlined from 'test_hexdump_prepare_test.constprop' at /home/arnd/arm-soc/lib/test_hexdump.c:116:3: > include/linux/fortify-string.h:108:33: error: '__builtin_strncpy' output truncated copying between 0 and 32 bytes from a string of length 32 [-Werror=stringop-truncation] > 108 | #define __underlying_strncpy __builtin_strncpy > | ^ > include/linux/fortify-string.h:187:16: note: in expansion of macro '__underlying_strncpy' > 187 | return __underlying_strncpy(p, q, size); > | ^~~~~~~~~~~~~~~~~~~~ > > The intention here is to copy exactly 'l' bytes without any padding or > NUL-termination, so the most logical change is to use memcpy(), just as > a previous change adapted the other output from strncpy() to memcpy(). > > Cc: Justin Stitt <justinstitt@xxxxxxxxxx> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> This looks better than the previous strscpy() usage. Acked-by: Justin Stitt <justinstitt@xxxxxxxxxx> > --- > --- > lib/test_hexdump.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/test_hexdump.c b/lib/test_hexdump.c > index b916801f23a8..fe2682bb21e6 100644 > --- a/lib/test_hexdump.c > +++ b/lib/test_hexdump.c > @@ -113,7 +113,7 @@ static void __init test_hexdump_prepare_test(size_t len, int rowsize, > *p++ = ' '; > } while (p < test + rs * 2 + rs / gs + 1); > > - strncpy(p, data_a, l); > + memcpy(p, data_a, l); > p += l; > } > > -- > 2.39.2 >
