Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751827AbbLKSuZ (ORCPT ); Fri, 11 Dec 2015 13:50:25 -0500 Received: from mail-ig0-f173.google.com ([209.85.213.173]:38550 "EHLO mail-ig0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751187AbbLKSuX convert rfc822-to-8bit (ORCPT ); Fri, 11 Dec 2015 13:50:23 -0500 MIME-Version: 1.0 In-Reply-To: References: <1449697404-21076-1-git-send-email-keescook@chromium.org> <1449697404-21076-3-git-send-email-keescook@chromium.org> Date: Fri, 11 Dec 2015 10:50:22 -0800 X-Google-Sender-Auth: 6t6YZbKxaLyAPhmauLGIa7120io Message-ID: Subject: Re: [PATCH v3 2/8] lib: add "on" and "off" to strtobool From: Kees Cook To: Andy Shevchenko Cc: "linux-kernel@vger.kernel.org" , Rasmus Villemoes , Daniel Borkmann , Ingo Molnar , Andy Lutomirski , "H. Peter Anvin" , Michael Ellerman , Mathias Krause , Thomas Gleixner , "x86@kernel.org" , Arnd Bergmann , PaX Team , Emese Revfy , "kernel-hardening@lists.openwall.com" , linux-arch Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2919 Lines: 99 On Fri, Dec 11, 2015 at 9:00 AM, Andy Shevchenko wrote: > On Wed, Dec 9, 2015 at 11:43 PM, Kees Cook wrote: >> Several places in the kernel expect to use "on" and "off" for their >> boolean signifiers, so add them to strtobool. >> >> Signed-off-by: Kees Cook >> Cc: Rasmus Villemoes >> Cc: Daniel Borkmann >> --- >> lib/string.c | 21 ++++++++++++++++++++- >> 1 file changed, 20 insertions(+), 1 deletion(-) >> >> diff --git a/lib/string.c b/lib/string.c >> index 0323c0d5629a..d7550432f91c 100644 >> --- a/lib/string.c >> +++ b/lib/string.c >> @@ -635,12 +635,16 @@ EXPORT_SYMBOL(sysfs_streq); >> * @s: input string >> * @res: result >> * >> - * This routine returns 0 iff the first character is one of 'Yy1Nn0'. >> + * This routine returns 0 iff the first character is one of 'Yy1Nn0', or >> + * 'Oo' when the second character is one of 'fFnN' (for "on" and "off"). > > Maybe > > …or [Oo][FfNn] for "off" and "on"… Sure! That's more readable. >> * Otherwise it will return -EINVAL. Value pointed to by res is >> * updated upon finding a match. >> */ >> int strtobool(const char *s, bool *res) >> { > >> + if (!s) >> + return -EINVAL; >> + > > This change I think is better to do separately. Do we have even need for it? I'm happy to separate it, sure. I added it here because several of the __setup and param callers do a check for !NULL input, and it made this cleaner. Also it seems sensible to do this check anyway. >> switch (s[0]) { >> case 'y': >> case 'Y': >> @@ -652,6 +656,21 @@ int strtobool(const char *s, bool *res) >> case '0': >> *res = false; >> break; >> + case 'o': >> + case 'O': >> + switch (s[1]) { >> + case 'n': >> + case 'N': >> + *res = true; >> + break; >> + case 'f': >> + case 'F': >> + *res = false; >> + break; > > >> + default: >> + return -EINVAL; >> + } >> + break; >> default: >> return -EINVAL; > > Maybe in both cases > default: > break; > } > … > } > return -EINVAL; I went back and forth on this. To switch to the fall-back being EINVAL meant I had to change all the other "breaks" into "return 0", and it just looked ugly to me. If that is preferred, though, I'm happy to do it. Thanks! -Kees -- Kees Cook Chrome OS & Brillo Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/