| Message ID | 20210728161535.421-1-Dd_nirvana@sjtu.edu.cn |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [v2] lib: sbi: Fix bug in strncmp function | expand |
Hi Dong, On Thu, Jul 29, 2021 at 12:23 AM Dong Du <Dd_nirvana@sjtu.edu.cn> wrote: > > No need to compare characters when the count turns to 0. > Fix the issue in sbi_strncmp. > > Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> > --- > lib/sbi/sbi_string.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/lib/sbi/sbi_string.c b/lib/sbi/sbi_string.c > index 7805ba4..c87bce9 100644 > --- a/lib/sbi/sbi_string.c > +++ b/lib/sbi/sbi_string.c > @@ -33,6 +33,10 @@ int sbi_strncmp(const char *a, const char *b, size_t count) > for (; count > 0 && *a == *b && *a != '\0'; a++, b++, count--) > ; > > + /* No difference till the end */ > + if (!count) > + return 0; > + > return *a - *b; > } > Your original patch is also needed: "strncmp should return 0 when the count is 0" Regards, Bin
On Aug 05 2021, Bin Meng wrote: > Hi Dong, > > On Thu, Jul 29, 2021 at 12:23 AM Dong Du <Dd_nirvana@sjtu.edu.cn> wrote: >> >> No need to compare characters when the count turns to 0. >> Fix the issue in sbi_strncmp. >> >> Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> >> --- >> lib/sbi/sbi_string.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/lib/sbi/sbi_string.c b/lib/sbi/sbi_string.c >> index 7805ba4..c87bce9 100644 >> --- a/lib/sbi/sbi_string.c >> +++ b/lib/sbi/sbi_string.c >> @@ -33,6 +33,10 @@ int sbi_strncmp(const char *a, const char *b, size_t count) >> for (; count > 0 && *a == *b && *a != '\0'; a++, b++, count--) >> ; >> >> + /* No difference till the end */ >> + if (!count) >> + return 0; >> + >> return *a - *b; >> } >> > > Your original patch is also needed: "strncmp should return 0 when the > count is 0" Which this patch duly implements. Andreas.
On Thu, Aug 5, 2021 at 4:46 PM Andreas Schwab <schwab@linux-m68k.org> wrote: > > On Aug 05 2021, Bin Meng wrote: > > > Hi Dong, > > > > On Thu, Jul 29, 2021 at 12:23 AM Dong Du <Dd_nirvana@sjtu.edu.cn> wrote: > >> > >> No need to compare characters when the count turns to 0. > >> Fix the issue in sbi_strncmp. > >> > >> Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> > >> --- > >> lib/sbi/sbi_string.c | 4 ++++ > >> 1 file changed, 4 insertions(+) > >> > >> diff --git a/lib/sbi/sbi_string.c b/lib/sbi/sbi_string.c > >> index 7805ba4..c87bce9 100644 > >> --- a/lib/sbi/sbi_string.c > >> +++ b/lib/sbi/sbi_string.c > >> @@ -33,6 +33,10 @@ int sbi_strncmp(const char *a, const char *b, size_t count) > >> for (; count > 0 && *a == *b && *a != '\0'; a++, b++, count--) > >> ; > >> > >> + /* No difference till the end */ > >> + if (!count) > >> + return 0; > >> + > >> return *a - *b; > >> } > >> > > > > Your original patch is also needed: "strncmp should return 0 when the > > count is 0" > > Which this patch duly implements. Ah, yes. Maybe we should update the comment to make it clear. Anyway: Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
On Thu, Aug 5, 2021 at 2:49 PM Bin Meng <bmeng.cn@gmail.com> wrote: > > On Thu, Aug 5, 2021 at 4:46 PM Andreas Schwab <schwab@linux-m68k.org> wrote: > > > > On Aug 05 2021, Bin Meng wrote: > > > > > Hi Dong, > > > > > > On Thu, Jul 29, 2021 at 12:23 AM Dong Du <Dd_nirvana@sjtu.edu.cn> wrote: > > >> > > >> No need to compare characters when the count turns to 0. > > >> Fix the issue in sbi_strncmp. > > >> > > >> Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> > > >> --- > > >> lib/sbi/sbi_string.c | 4 ++++ > > >> 1 file changed, 4 insertions(+) > > >> > > >> diff --git a/lib/sbi/sbi_string.c b/lib/sbi/sbi_string.c > > >> index 7805ba4..c87bce9 100644 > > >> --- a/lib/sbi/sbi_string.c > > >> +++ b/lib/sbi/sbi_string.c > > >> @@ -33,6 +33,10 @@ int sbi_strncmp(const char *a, const char *b, size_t count) > > >> for (; count > 0 && *a == *b && *a != '\0'; a++, b++, count--) > > >> ; > > >> > > >> + /* No difference till the end */ > > >> + if (!count) > > >> + return 0; > > >> + > > >> return *a - *b; > > >> } > > >> > > > > > > Your original patch is also needed: "strncmp should return 0 when the > > > count is 0" > > > > Which this patch duly implements. > > Ah, yes. Maybe we should update the comment to make it clear. > > Anyway: > Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Looks good to me. Reviewed-by: Anup Patel <anup.patel@wdc.com> Applied this patch to the riscv/opensbi repo. Thanks, Anup > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi
diff --git a/lib/sbi/sbi_string.c b/lib/sbi/sbi_string.c index 7805ba4..c87bce9 100644 --- a/lib/sbi/sbi_string.c +++ b/lib/sbi/sbi_string.c @@ -33,6 +33,10 @@ int sbi_strncmp(const char *a, const char *b, size_t count) for (; count > 0 && *a == *b && *a != '\0'; a++, b++, count--) ; + /* No difference till the end */ + if (!count) + return 0; + return *a - *b; }
No need to compare characters when the count turns to 0. Fix the issue in sbi_strncmp. Signed-off-by: Dong Du <Dd_nirvana@sjtu.edu.cn> --- lib/sbi/sbi_string.c | 4 ++++ 1 file changed, 4 insertions(+)