On Tue, Apr 09, 2019 at 11:31:50PM +0200, Rasmus Villemoes wrote: > On 09/04/2019 22.42, Yury Norov wrote: > > From: Yury Norov <[email protected]> > > > > cpumask_parse() finds first occurrence of either \n or \0 by calling > > strchr() and strlen(). We can do it better with a single call of > > strchrnul(). > > > > Signed-off-by: Yury Norov <[email protected]> > > --- > > include/linux/cpumask.h | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h > > index 147bdec42215..2b87f35c586c 100644 > > --- a/include/linux/cpumask.h > > +++ b/include/linux/cpumask.h > > @@ -633,8 +633,7 @@ static inline int cpumask_parselist_user(const char > > __user *buf, int len, > > */ > > static inline int cpumask_parse(const char *buf, struct cpumask *dstp) > > { > > - char *nl = strchr(buf, '\n'); > > - unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); > > + unsigned int len = (unsigned int)(strchrnul(buf, '\n') - buf); > > ack, but please drop the cast. "len = strchrnul(buf, '\n') - buf;"
Indeed. See below. Thanks, Yury Subject: [PATCH] cpumask: fix double string traverse in cpumask_parse From: Yury Norov <[email protected]> cpumask_parse() finds first occurrence of either \n or \0 by calling strchr() and strlen(). We can do it better with a single call of strchrnul(). Signed-off-by: Yury Norov <[email protected]> Acked-by: Rasmus Villemoes <[email protected]> --- include/linux/cpumask.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 147bdec42215..2b87f35c586c 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -633,8 +633,7 @@ static inline int cpumask_parselist_user(const char __user *buf, int len, */ static inline int cpumask_parse(const char *buf, struct cpumask *dstp) { - char *nl = strchr(buf, '\n'); - unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); + unsigned int len = strchrnul(buf, '\n') - buf; return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); } -- 2.17.1
