From: Arnaldo Carvalho de Melo acme@redhat.com
commit 4d0f16d059ddb91424480d88473f7392f24aebdc upstream.
The strncpy() function may leave the destination string buffer unterminated, better use strlcpy() that we have a __weak fallback implementation for systems without it.
In this case we are actually setting the null byte at the right place, but since we pass the buffer size as the limit to strncpy() and not it minus one, gcc ends up warning us about that, see below. So, lets just switch to the shorter form provided by strlcpy().
This fixes this warning on an Alpine Linux Edge system with gcc 8.2:
ui/tui/helpline.c: In function 'tui_helpline__push': ui/tui/helpline.c:27:2: error: 'strncpy' specified bound 512 equals destination size [-Werror=stringop-truncation] strncpy(ui_helpline__current, msg, sz)[sz - 1] = '\0'; ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors
Cc: Adrian Hunter adrian.hunter@intel.com Cc: Jiri Olsa jolsa@kernel.org Cc: Namhyung Kim namhyung@kernel.org Fixes: e6e904687949 ("perf ui: Introduce struct ui_helpline") Link: https://lkml.kernel.org/n/tip-d1wz0hjjsh19xbalw69qpytj@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/perf/ui/tui/helpline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/perf/ui/tui/helpline.c +++ b/tools/perf/ui/tui/helpline.c @@ -23,7 +23,7 @@ static void tui_helpline__push(const cha SLsmg_set_color(0); SLsmg_write_nstring((char *)msg, SLtt_Screen_Cols); SLsmg_refresh(); - strncpy(ui_helpline__current, msg, sz)[sz - 1] = '\0'; + strlcpy(ui_helpline__current, msg, sz); }
static int tui_helpline__show(const char *format, va_list ap)