From e0d61779d3fe56bf139c6e4c8381d9dd3eddc1f0 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 17 Mar 2016 14:22:50 -0700 Subject: [PATCH] lib: move strtobool() to kstrtobool() commit ef951599074ba4fad2d0efa0a977129b41e6d203 upstream. Create the kstrtobool_from_user() helper and move 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 Cc: Joe Perches Cc: Andy Shevchenko Cc: Rasmus Villemoes Cc: Daniel Borkmann Cc: Amitkumar Karwar Cc: Nishant Sarmukadam Cc: Kalle Valo Cc: Steve French Cc: Michael Ellerman Cc: Heiko Carstens Cc: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/kernel.h | 2 ++ include/linux/string.h | 6 ++++- lib/kstrtox.c | 50 ++++++++++++++++++++++++++++++++++++++++++ lib/string.c | 29 ------------------------ 4 files changed, 57 insertions(+), 30 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index e571e592e53a..50220cab738c 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -356,6 +356,7 @@ 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, 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); @@ -367,6 +368,7 @@ 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, 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 9ef7795e65e4..aa30789b0f65 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -127,7 +127,11 @@ 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, bool *res); +static inline int strtobool(const char *s, bool *res) +{ + return kstrtobool(s, 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..e8ba4a013e82 100644 --- a/lib/kstrtox.c +++ b/lib/kstrtox.c @@ -321,6 +321,56 @@ int kstrtos8(const char *s, unsigned int base, s8 *res) } EXPORT_SYMBOL(kstrtos8); +/** + * kstrtobool - convert common user inputs into boolean values + * @s: input string + * @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, bool *res) +{ + if (!s) + return -EINVAL; + + switch (s[0]) { + case 'y': + case 'Y': + case '1': + *res = true; + return 0; + case 'n': + case 'N': + case '0': + *res = false; + return 0; + default: + break; + } + + return -EINVAL; +} +EXPORT_SYMBOL(kstrtobool); + +/* + * Since "base" would be a nonsense argument, this open-codes the + * _from_user helper instead of using the helper macro below. + */ +int kstrtobool_from_user(const char __user *s, size_t count, bool *res) +{ + /* Longest string needed to differentiate, newline, terminator */ + char buf[4]; + + count = min(count, sizeof(buf) - 1); + if (copy_from_user(buf, s, count)) + return -EFAULT; + buf[count] = '\0'; + return kstrtobool(buf, res); +} +EXPORT_SYMBOL(kstrtobool_from_user); + #define kstrto_from_user(f, g, type) \ int f(const char __user *s, size_t count, unsigned int base, type *res) \ { \ diff --git a/lib/string.c b/lib/string.c index 0323c0d5629a..1a90db9bc6e1 100644 --- a/lib/string.c +++ b/lib/string.c @@ -630,35 +630,6 @@ bool sysfs_streq(const char *s1, const char *s2) } EXPORT_SYMBOL(sysfs_streq); -/** - * strtobool - convert common user inputs into boolean values - * @s: input string - * @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 strtobool(const char *s, bool *res) -{ - switch (s[0]) { - case 'y': - case 'Y': - case '1': - *res = true; - break; - case 'n': - case 'N': - case '0': - *res = false; - break; - default: - return -EINVAL; - } - return 0; -} -EXPORT_SYMBOL(strtobool); - #ifndef __HAVE_ARCH_MEMSET /** * memset - Fill a region of memory with the given value -- 2.34.1