* [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
@ 2024-09-22 16:47 Dipendra Khadka
2024-09-23 9:40 ` Ming-Hung Tsai
2024-09-23 13:26 ` Mikulas Patocka
0 siblings, 2 replies; 7+ messages in thread
From: Dipendra Khadka @ 2024-09-22 16:47 UTC (permalink / raw)
To: agk, snitzer, mpatocka; +Cc: Dipendra Khadka, dm-devel, linux-kernel
Smatch reported following:
'''
drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
'''
Since, the only negative value that is returned by sscanf is -1.
Returning -ENVAL when sscanf returns -1.
Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
---
drivers/md/dm-cache-target.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 17f0fab1e254..c35d65e310d6 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
* Try and parse form (ii) first.
*/
r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
- if (r < 0)
- return r;
+ if (r == -1)
+ return -EINVAL;
if (r == 2) {
result->begin = to_cblock(b);
@@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
* That didn't work, try form (i).
*/
r = sscanf(str, "%llu%c", &b, &dummy);
- if (r < 0)
- return r;
+ if (r == -1)
+ return -EINVAL;
if (r == 1) {
result->begin = to_cblock(b);
--
2.43.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
2024-09-22 16:47 [PATCH] Return error code for failure input for sscanf in parse_cblock_range() Dipendra Khadka
@ 2024-09-23 9:40 ` Ming-Hung Tsai
2024-09-23 15:09 ` Mikulas Patocka
2024-09-23 13:26 ` Mikulas Patocka
1 sibling, 1 reply; 7+ messages in thread
From: Ming-Hung Tsai @ 2024-09-23 9:40 UTC (permalink / raw)
To: Dipendra Khadka; +Cc: agk, snitzer, mpatocka, dm-devel, linux-kernel
On Mon, Sep 23, 2024 at 12:47 AM Dipendra Khadka <kdipendra88@gmail.com> wrote:
>
> Smatch reported following:
> '''
> drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> '''
>
> Since, the only negative value that is returned by sscanf is -1.
> Returning -ENVAL when sscanf returns -1.
>
> Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> ---
> drivers/md/dm-cache-target.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> index 17f0fab1e254..c35d65e310d6 100644
> --- a/drivers/md/dm-cache-target.c
> +++ b/drivers/md/dm-cache-target.c
> @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> * Try and parse form (ii) first.
> */
> r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> - if (r < 0)
> - return r;
> + if (r == -1)
> + return -EINVAL;
>
> if (r == 2) {
> result->begin = to_cblock(b);
> @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> * That didn't work, try form (i).
> */
> r = sscanf(str, "%llu%c", &b, &dummy);
> - if (r < 0)
> - return r;
> + if (r == -1)
> + return -EINVAL;
>
> if (r == 1) {
> result->begin = to_cblock(b);
Could you please clarify how to reproduce unexpected results? From
what I observe, the kernel's sscanf doesn't return -1 on an empty
input. Even if a negative value other than -EINVAL is returned, it is
handled by the callers.
Hank
> --
> 2.43.0
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
2024-09-22 16:47 [PATCH] Return error code for failure input for sscanf in parse_cblock_range() Dipendra Khadka
2024-09-23 9:40 ` Ming-Hung Tsai
@ 2024-09-23 13:26 ` Mikulas Patocka
1 sibling, 0 replies; 7+ messages in thread
From: Mikulas Patocka @ 2024-09-23 13:26 UTC (permalink / raw)
To: Dipendra Khadka; +Cc: agk, snitzer, dm-devel, linux-kernel
Hi
I skimmed through the sscanf source code and it seems that it can't return
a negative value at all.
I think, this should be:
r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
if (r != 2)
return -EINVAL;
Mikulas
On Sun, 22 Sep 2024, Dipendra Khadka wrote:
> Smatch reported following:
> '''
> drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> '''
>
> Since, the only negative value that is returned by sscanf is -1.
> Returning -ENVAL when sscanf returns -1.
>
> Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> ---
> drivers/md/dm-cache-target.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> index 17f0fab1e254..c35d65e310d6 100644
> --- a/drivers/md/dm-cache-target.c
> +++ b/drivers/md/dm-cache-target.c
> @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> * Try and parse form (ii) first.
> */
> r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> - if (r < 0)
> - return r;
> + if (r == -1)
> + return -EINVAL;
>
> if (r == 2) {
> result->begin = to_cblock(b);
> @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> * That didn't work, try form (i).
> */
> r = sscanf(str, "%llu%c", &b, &dummy);
> - if (r < 0)
> - return r;
> + if (r == -1)
> + return -EINVAL;
>
> if (r == 1) {
> result->begin = to_cblock(b);
> --
> 2.43.0
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
2024-09-23 9:40 ` Ming-Hung Tsai
@ 2024-09-23 15:09 ` Mikulas Patocka
2024-09-23 15:35 ` Dipendra Khadka
0 siblings, 1 reply; 7+ messages in thread
From: Mikulas Patocka @ 2024-09-23 15:09 UTC (permalink / raw)
To: Ming-Hung Tsai; +Cc: Dipendra Khadka, agk, snitzer, dm-devel, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2080 bytes --]
On Mon, 23 Sep 2024, Ming-Hung Tsai wrote:
> On Mon, Sep 23, 2024 at 12:47 AM Dipendra Khadka <kdipendra88@gmail.com> wrote:
> >
> > Smatch reported following:
> > '''
> > drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> > drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> > '''
> >
> > Since, the only negative value that is returned by sscanf is -1.
> > Returning -ENVAL when sscanf returns -1.
> >
> > Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> > ---
> > drivers/md/dm-cache-target.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> > index 17f0fab1e254..c35d65e310d6 100644
> > --- a/drivers/md/dm-cache-target.c
> > +++ b/drivers/md/dm-cache-target.c
> > @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > * Try and parse form (ii) first.
> > */
> > r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> > - if (r < 0)
> > - return r;
> > + if (r == -1)
> > + return -EINVAL;
> >
> > if (r == 2) {
> > result->begin = to_cblock(b);
> > @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > * That didn't work, try form (i).
> > */
> > r = sscanf(str, "%llu%c", &b, &dummy);
> > - if (r < 0)
> > - return r;
> > + if (r == -1)
> > + return -EINVAL;
> >
> > if (r == 1) {
> > result->begin = to_cblock(b);
>
>
> Could you please clarify how to reproduce unexpected results? From
> what I observe, the kernel's sscanf doesn't return -1 on an empty
> input. Even if a negative value other than -EINVAL is returned, it is
> handled by the callers.
>
> Hank
I applied the patch, but I deleted the conditions "if (r == -1) return
-EINVAL;"
sscanf in the kernel doesn't return negative numbers.
Mikulas
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
2024-09-23 15:09 ` Mikulas Patocka
@ 2024-09-23 15:35 ` Dipendra Khadka
2024-09-23 15:59 ` Mikulas Patocka
0 siblings, 1 reply; 7+ messages in thread
From: Dipendra Khadka @ 2024-09-23 15:35 UTC (permalink / raw)
To: Mikulas Patocka; +Cc: Ming-Hung Tsai, agk, snitzer, dm-devel, linux-kernel
Hi,
On Mon, 23 Sept 2024 at 20:55, Mikulas Patocka <mpatocka@redhat.com> wrote:
>
>
>
> On Mon, 23 Sep 2024, Ming-Hung Tsai wrote:
>
> > On Mon, Sep 23, 2024 at 12:47 AM Dipendra Khadka <kdipendra88@gmail.com> wrote:
> > >
> > > Smatch reported following:
> > > '''
> > > drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> > > drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> > > '''
> > >
> > > Since, the only negative value that is returned by sscanf is -1.
> > > Returning -ENVAL when sscanf returns -1.
> > >
> > > Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> > > ---
> > > drivers/md/dm-cache-target.c | 8 ++++----
> > > 1 file changed, 4 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> > > index 17f0fab1e254..c35d65e310d6 100644
> > > --- a/drivers/md/dm-cache-target.c
> > > +++ b/drivers/md/dm-cache-target.c
> > > @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > > * Try and parse form (ii) first.
> > > */
> > > r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> > > - if (r < 0)
> > > - return r;
> > > + if (r == -1)
> > > + return -EINVAL;
> > >
> > > if (r == 2) {
> > > result->begin = to_cblock(b);
> > > @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > > * That didn't work, try form (i).
> > > */
> > > r = sscanf(str, "%llu%c", &b, &dummy);
> > > - if (r < 0)
> > > - return r;
> > > + if (r == -1)
> > > + return -EINVAL;
> > >
> > > if (r == 1) {
> > > result->begin = to_cblock(b);
> >
> >
> > Could you please clarify how to reproduce unexpected results? From
> > what I observe, the kernel's sscanf doesn't return -1 on an empty
> > input. Even if a negative value other than -EINVAL is returned, it is
> > handled by the callers.
> >
> > Hank
>
> I applied the patch, but I deleted the conditions "if (r == -1) return
> -EINVAL;"
>
> sscanf in the kernel doesn't return negative numbers.
>
Do I have to send v2 with
if (r != 2)
return -EINVAL;
or what should I do now?
> Mikulas
Best Regards,
Dipendra
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
2024-09-23 15:35 ` Dipendra Khadka
@ 2024-09-23 15:59 ` Mikulas Patocka
2024-09-23 16:05 ` Dipendra Khadka
0 siblings, 1 reply; 7+ messages in thread
From: Mikulas Patocka @ 2024-09-23 15:59 UTC (permalink / raw)
To: Dipendra Khadka; +Cc: Ming-Hung Tsai, agk, snitzer, dm-devel, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2675 bytes --]
On Mon, 23 Sep 2024, Dipendra Khadka wrote:
> Hi,
>
> On Mon, 23 Sept 2024 at 20:55, Mikulas Patocka <mpatocka@redhat.com> wrote:
> >
> >
> >
> > On Mon, 23 Sep 2024, Ming-Hung Tsai wrote:
> >
> > > On Mon, Sep 23, 2024 at 12:47 AM Dipendra Khadka <kdipendra88@gmail.com> wrote:
> > > >
> > > > Smatch reported following:
> > > > '''
> > > > drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> > > > drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> > > > '''
> > > >
> > > > Since, the only negative value that is returned by sscanf is -1.
> > > > Returning -ENVAL when sscanf returns -1.
> > > >
> > > > Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> > > > ---
> > > > drivers/md/dm-cache-target.c | 8 ++++----
> > > > 1 file changed, 4 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> > > > index 17f0fab1e254..c35d65e310d6 100644
> > > > --- a/drivers/md/dm-cache-target.c
> > > > +++ b/drivers/md/dm-cache-target.c
> > > > @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > > > * Try and parse form (ii) first.
> > > > */
> > > > r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> > > > - if (r < 0)
> > > > - return r;
> > > > + if (r == -1)
> > > > + return -EINVAL;
> > > >
> > > > if (r == 2) {
> > > > result->begin = to_cblock(b);
> > > > @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > > > * That didn't work, try form (i).
> > > > */
> > > > r = sscanf(str, "%llu%c", &b, &dummy);
> > > > - if (r < 0)
> > > > - return r;
> > > > + if (r == -1)
> > > > + return -EINVAL;
> > > >
> > > > if (r == 1) {
> > > > result->begin = to_cblock(b);
> > >
> > >
> > > Could you please clarify how to reproduce unexpected results? From
> > > what I observe, the kernel's sscanf doesn't return -1 on an empty
> > > input. Even if a negative value other than -EINVAL is returned, it is
> > > handled by the callers.
> > >
> > > Hank
> >
> > I applied the patch, but I deleted the conditions "if (r == -1) return
> > -EINVAL;"
> >
> > sscanf in the kernel doesn't return negative numbers.
> >
>
> Do I have to send v2 with
> if (r != 2)
> return -EINVAL;
>
> or what should I do now?
> > Mikulas
>
> Best Regards,
> Dipendra
You can do nothing :)
I fixed the patch and I'll send it to Linus in this merge window.
Mikulas
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] Return error code for failure input for sscanf in parse_cblock_range()
2024-09-23 15:59 ` Mikulas Patocka
@ 2024-09-23 16:05 ` Dipendra Khadka
0 siblings, 0 replies; 7+ messages in thread
From: Dipendra Khadka @ 2024-09-23 16:05 UTC (permalink / raw)
To: Mikulas Patocka; +Cc: Ming-Hung Tsai, agk, snitzer, dm-devel, linux-kernel
On Mon, 23 Sept 2024 at 21:45, Mikulas Patocka <mpatocka@redhat.com> wrote:
>
>
>
> On Mon, 23 Sep 2024, Dipendra Khadka wrote:
>
> > Hi,
> >
> > On Mon, 23 Sept 2024 at 20:55, Mikulas Patocka <mpatocka@redhat.com> wrote:
> > >
> > >
> > >
> > > On Mon, 23 Sep 2024, Ming-Hung Tsai wrote:
> > >
> > > > On Mon, Sep 23, 2024 at 12:47 AM Dipendra Khadka <kdipendra88@gmail.com> wrote:
> > > > >
> > > > > Smatch reported following:
> > > > > '''
> > > > > drivers/md/dm-cache-target.c:3204 parse_cblock_range() warn: sscanf doesn't return error codes
> > > > > drivers/md/dm-cache-target.c:3217 parse_cblock_range() warn: sscanf doesn't return error codes
> > > > > '''
> > > > >
> > > > > Since, the only negative value that is returned by sscanf is -1.
> > > > > Returning -ENVAL when sscanf returns -1.
> > > > >
> > > > > Signed-off-by: Dipendra Khadka <kdipendra88@gmail.com>
> > > > > ---
> > > > > drivers/md/dm-cache-target.c | 8 ++++----
> > > > > 1 file changed, 4 insertions(+), 4 deletions(-)
> > > > >
> > > > > diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
> > > > > index 17f0fab1e254..c35d65e310d6 100644
> > > > > --- a/drivers/md/dm-cache-target.c
> > > > > +++ b/drivers/md/dm-cache-target.c
> > > > > @@ -3200,8 +3200,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > > > > * Try and parse form (ii) first.
> > > > > */
> > > > > r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
> > > > > - if (r < 0)
> > > > > - return r;
> > > > > + if (r == -1)
> > > > > + return -EINVAL;
> > > > >
> > > > > if (r == 2) {
> > > > > result->begin = to_cblock(b);
> > > > > @@ -3213,8 +3213,8 @@ static int parse_cblock_range(struct cache *cache, const char *str,
> > > > > * That didn't work, try form (i).
> > > > > */
> > > > > r = sscanf(str, "%llu%c", &b, &dummy);
> > > > > - if (r < 0)
> > > > > - return r;
> > > > > + if (r == -1)
> > > > > + return -EINVAL;
> > > > >
> > > > > if (r == 1) {
> > > > > result->begin = to_cblock(b);
> > > >
> > > >
> > > > Could you please clarify how to reproduce unexpected results? From
> > > > what I observe, the kernel's sscanf doesn't return -1 on an empty
> > > > input. Even if a negative value other than -EINVAL is returned, it is
> > > > handled by the callers.
> > > >
> > > > Hank
> > >
> > > I applied the patch, but I deleted the conditions "if (r == -1) return
> > > -EINVAL;"
> > >
> > > sscanf in the kernel doesn't return negative numbers.
> > >
> >
> > Do I have to send v2 with
> > if (r != 2)
> > return -EINVAL;
> >
> > or what should I do now?
> > > Mikulas
> >
> > Best Regards,
> > Dipendra
>
> You can do nothing :)
>
> I fixed the patch and I'll send it to Linus in this merge window.
>
Oh, ok. Thank you for your time.
> Mikulas
Best Regards,
Dipendra.
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2024-09-23 16:06 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2024-09-22 16:47 [PATCH] Return error code for failure input for sscanf in parse_cblock_range() Dipendra Khadka
2024-09-23 9:40 ` Ming-Hung Tsai
2024-09-23 15:09 ` Mikulas Patocka
2024-09-23 15:35 ` Dipendra Khadka
2024-09-23 15:59 ` Mikulas Patocka
2024-09-23 16:05 ` Dipendra Khadka
2024-09-23 13:26 ` Mikulas Patocka
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