From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757042AbcBEUuh (ORCPT ); Fri, 5 Feb 2016 15:50:37 -0500 Received: from mail-ig0-f178.google.com ([209.85.213.178]:34982 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754999AbcBEUud (ORCPT ); Fri, 5 Feb 2016 15:50:33 -0500 MIME-Version: 1.0 In-Reply-To: <8737t8ni8w.fsf@rasmusvillemoes.dk> References: <1454619643-14444-1-git-send-email-keescook@chromium.org> <1454619643-14444-2-git-send-email-keescook@chromium.org> <8737t8ni8w.fsf@rasmusvillemoes.dk> Date: Fri, 5 Feb 2016 12:50:31 -0800 X-Google-Sender-Auth: Uar0x4AmYljocUzAiyNCg-_n7lg Message-ID: Subject: Re: [PATCH v2 1/4] lib: move strtobool to kstrtobool From: Kees Cook To: Rasmus Villemoes Cc: Andrew Morton , Joe Perches , Andy Shevchenko , Daniel Borkmann , Amitkumar Karwar , Nishant Sarmukadam , Kalle Valo , Steve French , Michael Ellerman , Heiko Carstens , Martin Schwidefsky , "x86@kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-s390@vger.kernel.org" , linux-wireless , Network Development , linux-cifs@vger.kernel.org, LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 4, 2016 at 3:55 PM, Rasmus Villemoes wrote: > On Thu, Feb 04 2016, Kees Cook wrote: > >> Create the kstrtobool_from_user helper and moves strtobool logic into >> the new kstrtobool (matching all the other kstrto* functions). Provides >> an inline wrapper for existing strtobool callers. >> >> Signed-off-by: Kees Cook >> --- >> include/linux/kernel.h | 3 +++ >> include/linux/string.h | 6 +++++- >> lib/kstrtox.c | 35 +++++++++++++++++++++++++++++++++++ >> lib/string.c | 29 ----------------------------- >> 4 files changed, 43 insertions(+), 30 deletions(-) >> >> diff --git a/include/linux/kernel.h b/include/linux/kernel.h >> index f31638c6e873..cdc25f47a23f 100644 >> --- a/include/linux/kernel.h >> +++ b/include/linux/kernel.h >> @@ -357,6 +357,7 @@ int __must_check kstrtou16(const char *s, unsigned int base, u16 *res); >> int __must_check kstrtos16(const char *s, unsigned int base, s16 *res); >> int __must_check kstrtou8(const char *s, unsigned int base, u8 *res); >> int __must_check kstrtos8(const char *s, unsigned int base, s8 *res); >> +int __must_check kstrtobool(const char *s, unsigned int base, bool *res); >> >> int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res); >> int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res); >> @@ -368,6 +369,8 @@ int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigne >> int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res); >> int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res); >> int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res); >> +int __must_check kstrtobool_from_user(const char __user *s, size_t count, >> + unsigned int base, bool *res); >> >> static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res) >> { >> diff --git a/include/linux/string.h b/include/linux/string.h >> index 9eebc66d957a..d2fb21b1081d 100644 >> --- a/include/linux/string.h >> +++ b/include/linux/string.h >> @@ -128,7 +128,11 @@ extern char **argv_split(gfp_t gfp, const char *str, int *argcp); >> extern void argv_free(char **argv); >> >> extern bool sysfs_streq(const char *s1, const char *s2); >> -extern int strtobool(const char *s, bool *res); >> +extern int kstrtobool(const char *s, unsigned int base, bool *res); >> +static inline int strtobool(const char *s, bool *res) >> +{ >> + return kstrtobool(s, 0, res); >> +} >> >> #ifdef CONFIG_BINARY_PRINTF >> int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args); >> diff --git a/lib/kstrtox.c b/lib/kstrtox.c >> index 94be244e8441..e18f088704d7 100644 >> --- a/lib/kstrtox.c >> +++ b/lib/kstrtox.c >> @@ -321,6 +321,40 @@ int kstrtos8(const char *s, unsigned int base, s8 *res) >> } >> EXPORT_SYMBOL(kstrtos8); >> >> +/** >> + * kstrtobool - convert common user inputs into boolean values >> + * @s: input string >> + * @base: ignored >> + * @res: result >> + * >> + * This routine returns 0 iff the first character is one of 'Yy1Nn0'. >> + * Otherwise it will return -EINVAL. Value pointed to by res is >> + * updated upon finding a match. >> + */ >> +int kstrtobool(const char *s, unsigned int base, bool *res) >> +{ > > Being able to create the kstrtobool_from_user with a single macro > invocation is convenient, but I don't think that justifies the ugliness > of having an unused parameter. People reading this code or trying to use > the interface will wonder what it's doing there, and it will generate > slightly larger code for all the users of strtobool. > > So I'd just make a separate explicit definition of kstrtobool_from_user > (the stack buffer sizing doesn't apply to the strings we want to parse > anyway, though 11 is of course plenty). Okay, thanks. So many things were bothering me, but I feared code duplication would be seen as worse. I'm much happier to drop the unused argument. :) I'll send a v3 with all the changes. -Kees -- Kees Cook Chrome OS & Brillo Security