Re: [PATCH v2 1/4] lib: move strtobool to kstrtobool
From: Kees Cook
Date: Thu Feb 04 2016 - 17:50:14 EST
On Thu, Feb 4, 2016 at 2:43 PM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Thu, Feb 4, 2016 at 11:00 PM, Kees Cook <keescook@xxxxxxxxxxxx> 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 <keescook@xxxxxxxxxxxx>
>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>
> One minor below.
Thanks!
>
>> ---
>> 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);
>
> We already are using long lines here, perhaps do the same?
I went back and forth on that, and decided that between checkpatch
yelling at me, and trying to be an agent of less entropy, I wrapped
the definition. I am fine either way, though.
-Kees
>
>>
>> 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)
>> +{
>> + 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);
>> +
>> #define kstrto_from_user(f, g, type) \
>> int f(const char __user *s, size_t count, unsigned int base, type *res) \
>> { \
>> @@ -345,3 +379,4 @@ kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
>> kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
>> kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
>> kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
>> +kstrto_from_user(kstrtobool_from_user, kstrtobool, bool);
>> 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
>> --
>> 2.6.3
>>
>
>
>
> --
> With Best Regards,
> Andy Shevchenko
--
Kees Cook
Chrome OS & Brillo Security