3.16.65-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Arnaldo Carvalho de Melo <[email protected]> commit 2f5302533f306d5ee87bd375aef9ca35b91762cb 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 specific case this would only happen if fgets() was buggy, as its man page states that it should read one less byte than the size of the destination buffer, so that it can put the nul byte at the end of it, so it would never copy 255 non-nul chars, as fgets reads into the orig buffer at most 254 non-nul chars and terminates it. But lets just switch to strlcpy to keep the original intent and silence the gcc 8.2 warning. This fixes this warning on an Alpine Linux Edge system with gcc 8.2: In function 'cpu_model', inlined from 'svg_cpu_box' at util/svghelper.c:378:2: util/svghelper.c:337:5: error: 'strncpy' output may be truncated copying 255 bytes from a string of length 255 [-Werror=stringop-truncation] strncpy(cpu_m, &buf[13], 255); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Cc: Adrian Hunter <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Arjan van de Ven <[email protected]> Fixes: f48d55ce7871 ("perf: Add a SVG helper library file") Link: https://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- tools/perf/util/svghelper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/perf/util/svghelper.c +++ b/tools/perf/util/svghelper.c @@ -257,7 +257,7 @@ static char *cpu_model(void) if (file) { while (fgets(buf, 255, file)) { if (strstr(buf, "model name")) { - strncpy(cpu_m, &buf[13], 255); + strlcpy(cpu_m, &buf[13], 255); break; } }
