[v1] selftests/bpf: Add F_SETFL for fcntl

[PATCH bpf-next] selftests/bpf: Add F_SETFL for fcntl

Posted by Geliang Tang 1 month ago

From: Geliang Tang <tanggeliang@kylinos.cn>

Incorrect arguments are passed to fcntl() in test_sockmap.c when invoking
it to set file status flags. If O_NONBLOCK is used as 2nd argument and
passed into fcntl, -EINVAL will be returned (See do_fcntl() in fs/fcntl.c).
The correct approach is to use F_SETFL as 2nd argument, and O_NONBLOCK as
3rd one.

Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 tools/testing/selftests/bpf/test_sockmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index 024a0faafb3b..34d6a1e6f664 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 		struct timeval timeout;
 		fd_set w;
 
-		fcntl(fd, fd_flags);
+		fcntl(fd, F_SETFL, fd_flags);
 		/* Account for pop bytes noting each iteration of apply will
 		 * call msg_pop_data helper so we need to account for this
 		 * by calculating the number of apply iterations. Note user
-- 
2.40.1

Re: [PATCH bpf-next] selftests/bpf: Add F_SETFL for fcntl

Posted by Jakub Sitnicki 1 month ago

Hi Geliang,

On Wed, Apr 03, 2024 at 04:32 PM +08, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
>
> Incorrect arguments are passed to fcntl() in test_sockmap.c when invoking
> it to set file status flags. If O_NONBLOCK is used as 2nd argument and
> passed into fcntl, -EINVAL will be returned (See do_fcntl() in fs/fcntl.c).
> The correct approach is to use F_SETFL as 2nd argument, and O_NONBLOCK as
> 3rd one.
>
> Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> ---
>  tools/testing/selftests/bpf/test_sockmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
> index 024a0faafb3b..34d6a1e6f664 100644
> --- a/tools/testing/selftests/bpf/test_sockmap.c
> +++ b/tools/testing/selftests/bpf/test_sockmap.c
> @@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
>  		struct timeval timeout;
>  		fd_set w;
>  
> -		fcntl(fd, fd_flags);
> +		fcntl(fd, F_SETFL, fd_flags);
>  		/* Account for pop bytes noting each iteration of apply will
>  		 * call msg_pop_data helper so we need to account for this
>  		 * by calculating the number of apply iterations. Note user

Good catch. But we also need to figure out why some tests failing with
this patch applied and fix them in one go:

# 6/ 7  sockmap::txmsg test skb:FAIL
#21/ 7 sockhash::txmsg test skb:FAIL
#36/ 7 sockhash:ktls:txmsg test skb:FAIL
Pass: 42 Fail: 3

I'm seeing this error message when running `test_sockmap`:

detected skb data error with skb ingress update @iov[0]:0 "00 00 00 00" != "PASS"
data verify msg failed: Unknown error -5
rx thread exited with err 1.

I'd also:
- add an error check for fnctl, so we don't regress,
- get rid of fd_flags, pass O_NONBLOCK flag directly to fnctl.

Thanks,
-jkbs

Re: [PATCH bpf-next] selftests/bpf: Add F_SETFL for fcntl

Posted by John Fastabend 1 month ago

Jakub Sitnicki wrote:
> Hi Geliang,
> 
> On Wed, Apr 03, 2024 at 04:32 PM +08, Geliang Tang wrote:
> > From: Geliang Tang <tanggeliang@kylinos.cn>
> >
> > Incorrect arguments are passed to fcntl() in test_sockmap.c when invoking
> > it to set file status flags. If O_NONBLOCK is used as 2nd argument and
> > passed into fcntl, -EINVAL will be returned (See do_fcntl() in fs/fcntl.c).
> > The correct approach is to use F_SETFL as 2nd argument, and O_NONBLOCK as
> > 3rd one.
> >
> > Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > ---
> >  tools/testing/selftests/bpf/test_sockmap.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
> > index 024a0faafb3b..34d6a1e6f664 100644
> > --- a/tools/testing/selftests/bpf/test_sockmap.c
> > +++ b/tools/testing/selftests/bpf/test_sockmap.c
> > @@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
> >  		struct timeval timeout;
> >  		fd_set w;
> >  
> > -		fcntl(fd, fd_flags);
> > +		fcntl(fd, F_SETFL, fd_flags);
> >  		/* Account for pop bytes noting each iteration of apply will
> >  		 * call msg_pop_data helper so we need to account for this
> >  		 * by calculating the number of apply iterations. Note user
> 
> Good catch. But we also need to figure out why some tests failing with
> this patch applied and fix them in one go:
> 
> # 6/ 7  sockmap::txmsg test skb:FAIL
> #21/ 7 sockhash::txmsg test skb:FAIL
> #36/ 7 sockhash:ktls:txmsg test skb:FAIL
> Pass: 42 Fail: 3
> 
> I'm seeing this error message when running `test_sockmap`:
> 
> detected skb data error with skb ingress update @iov[0]:0 "00 00 00 00" != "PASS"
> data verify msg failed: Unknown error -5
> rx thread exited with err 1.

I have a theory this is a real bug in the SK_SKB_STREAM_PARSER which has an
issue with wakup logic. Maybe we wakeup the poll/select logic before the
data is copied and because the recv() is actually nonblocking now we get
the error.

> 
> I'd also:
> - add an error check for fnctl, so we don't regress,
> - get rid of fd_flags, pass O_NONBLOCK flag directly to fnctl.
> 
> Thanks,
> -jkbs

Re: [PATCH bpf-next] selftests/bpf: Add F_SETFL for fcntl

Posted by Geliang Tang 1 month ago

Hi Jakub,
 
On Wed, 2024-04-03 at 15:29 -0700, John Fastabend wrote:
> Jakub Sitnicki wrote:
> > Hi Geliang,
> > 
> > On Wed, Apr 03, 2024 at 04:32 PM +08, Geliang Tang wrote:
> > > From: Geliang Tang <tanggeliang@kylinos.cn>
> > > 
> > > Incorrect arguments are passed to fcntl() in test_sockmap.c when
> > > invoking
> > > it to set file status flags. If O_NONBLOCK is used as 2nd
> > > argument and
> > > passed into fcntl, -EINVAL will be returned (See do_fcntl() in
> > > fs/fcntl.c).
> > > The correct approach is to use F_SETFL as 2nd argument, and
> > > O_NONBLOCK as
> > > 3rd one.
> > > 
> > > Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> > > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > > ---
> > >  tools/testing/selftests/bpf/test_sockmap.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/tools/testing/selftests/bpf/test_sockmap.c
> > > b/tools/testing/selftests/bpf/test_sockmap.c
> > > index 024a0faafb3b..34d6a1e6f664 100644
> > > --- a/tools/testing/selftests/bpf/test_sockmap.c
> > > +++ b/tools/testing/selftests/bpf/test_sockmap.c
> > > @@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count,
> > > int iov_length, int cnt,
> > >  		struct timeval timeout;
> > >  		fd_set w;
> > >  
> > > -		fcntl(fd, fd_flags);
> > > +		fcntl(fd, F_SETFL, fd_flags);
> > >  		/* Account for pop bytes noting each iteration
> > > of apply will
> > >  		 * call msg_pop_data helper so we need to
> > > account for this
> > >  		 * by calculating the number of apply
> > > iterations. Note user
> > 
> > Good catch. But we also need to figure out why some tests failing
> > with
> > this patch applied and fix them in one go:
> > 
> > # 6/ 7  sockmap::txmsg test skb:FAIL
> > #21/ 7 sockhash::txmsg test skb:FAIL
> > #36/ 7 sockhash:ktls:txmsg test skb:FAIL
> > Pass: 42 Fail: 3

Sorry, I didn't notice these fails in my testing before, they do exist.
I'll try to fix them and sent a v2 soon.

Thanks,
-Geliang

> > 
> > I'm seeing this error message when running `test_sockmap`:
> > 
> > detected skb data error with skb ingress update @iov[0]:0 "00 00 00
> > 00" != "PASS"
> > data verify msg failed: Unknown error -5
> > rx thread exited with err 1.
> 
> I have a theory this is a real bug in the SK_SKB_STREAM_PARSER which
> has an
> issue with wakup logic. Maybe we wakeup the poll/select logic before
> the
> data is copied and because the recv() is actually nonblocking now we
> get
> the error.
> 
> > 
> > I'd also:
> > - add an error check for fnctl, so we don't regress,
> > - get rid of fd_flags, pass O_NONBLOCK flag directly to fnctl.
> > 
> > Thanks,
> > -jkbs
> 
>

Re: [PATCH bpf-next] selftests/bpf: Add F_SETFL for fcntl

Posted by John Fastabend 1 month ago

Geliang Tang wrote:
> Hi Jakub,
>  
> On Wed, 2024-04-03 at 15:29 -0700, John Fastabend wrote:
> > Jakub Sitnicki wrote:
> > > Hi Geliang,
> > > 
> > > On Wed, Apr 03, 2024 at 04:32 PM +08, Geliang Tang wrote:
> > > > From: Geliang Tang <tanggeliang@kylinos.cn>
> > > > 
> > > > Incorrect arguments are passed to fcntl() in test_sockmap.c when
> > > > invoking
> > > > it to set file status flags. If O_NONBLOCK is used as 2nd
> > > > argument and
> > > > passed into fcntl, -EINVAL will be returned (See do_fcntl() in
> > > > fs/fcntl.c).
> > > > The correct approach is to use F_SETFL as 2nd argument, and
> > > > O_NONBLOCK as
> > > > 3rd one.
> > > > 
> > > > Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> > > > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > > > ---
> > > >  tools/testing/selftests/bpf/test_sockmap.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/tools/testing/selftests/bpf/test_sockmap.c
> > > > b/tools/testing/selftests/bpf/test_sockmap.c
> > > > index 024a0faafb3b..34d6a1e6f664 100644
> > > > --- a/tools/testing/selftests/bpf/test_sockmap.c
> > > > +++ b/tools/testing/selftests/bpf/test_sockmap.c
> > > > @@ -603,7 +603,7 @@ static int msg_loop(int fd, int iov_count,
> > > > int iov_length, int cnt,
> > > >  		struct timeval timeout;
> > > >  		fd_set w;
> > > >  
> > > > -		fcntl(fd, fd_flags);
> > > > +		fcntl(fd, F_SETFL, fd_flags);
> > > >  		/* Account for pop bytes noting each iteration
> > > > of apply will
> > > >  		 * call msg_pop_data helper so we need to
> > > > account for this
> > > >  		 * by calculating the number of apply
> > > > iterations. Note user
> > > 
> > > Good catch. But we also need to figure out why some tests failing
> > > with
> > > this patch applied and fix them in one go:
> > > 
> > > # 6/ 7  sockmap::txmsg test skb:FAIL
> > > #21/ 7 sockhash::txmsg test skb:FAIL
> > > #36/ 7 sockhash:ktls:txmsg test skb:FAIL
> > > Pass: 42 Fail: 3
> 
> Sorry, I didn't notice these fails in my testing before, they do exist.
> I'll try to fix them and sent a v2 soon.

Not 100% sure but a hint. I would look into where the stream parser
is waking up the sock here. I'm not sure there is an easy fix tbh.
I can help look at this soon as well if you don't beat me to a fix.

Thanks for looking into it.

> 
> Thanks,
> -Geliang

Re: [PATCH bpf-next] selftests/bpf: Add F_SETFL for fcntl

Posted by Geliang Tang 4 weeks ago

On Thu, 2024-04-04 at 21:47 -0700, John Fastabend wrote:
> Geliang Tang wrote:
> > Hi Jakub,
> >  
> > On Wed, 2024-04-03 at 15:29 -0700, John Fastabend wrote:
> > > Jakub Sitnicki wrote:
> > > > Hi Geliang,
> > > > 
> > > > On Wed, Apr 03, 2024 at 04:32 PM +08, Geliang Tang wrote:
> > > > > From: Geliang Tang <tanggeliang@kylinos.cn>
> > > > > 
> > > > > Incorrect arguments are passed to fcntl() in test_sockmap.c
> > > > > when
> > > > > invoking
> > > > > it to set file status flags. If O_NONBLOCK is used as 2nd
> > > > > argument and
> > > > > passed into fcntl, -EINVAL will be returned (See do_fcntl()
> > > > > in
> > > > > fs/fcntl.c).
> > > > > The correct approach is to use F_SETFL as 2nd argument, and
> > > > > O_NONBLOCK as
> > > > > 3rd one.
> > > > > 
> > > > > Fixes: 16962b2404ac ("bpf: sockmap, add selftests")
> > > > > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > > > > ---
> > > > >  tools/testing/selftests/bpf/test_sockmap.c | 2 +-
> > > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > 
> > > > > diff --git a/tools/testing/selftests/bpf/test_sockmap.c
> > > > > b/tools/testing/selftests/bpf/test_sockmap.c
> > > > > index 024a0faafb3b..34d6a1e6f664 100644
> > > > > --- a/tools/testing/selftests/bpf/test_sockmap.c
> > > > > +++ b/tools/testing/selftests/bpf/test_sockmap.c
> > > > > @@ -603,7 +603,7 @@ static int msg_loop(int fd, int
> > > > > iov_count,
> > > > > int iov_length, int cnt,
> > > > >  		struct timeval timeout;
> > > > >  		fd_set w;
> > > > >  
> > > > > -		fcntl(fd, fd_flags);
> > > > > +		fcntl(fd, F_SETFL, fd_flags);
> > > > >  		/* Account for pop bytes noting each
> > > > > iteration
> > > > > of apply will
> > > > >  		 * call msg_pop_data helper so we need to
> > > > > account for this
> > > > >  		 * by calculating the number of apply
> > > > > iterations. Note user
> > > > 
> > > > Good catch. But we also need to figure out why some tests
> > > > failing
> > > > with
> > > > this patch applied and fix them in one go:
> > > > 
> > > > # 6/ 7  sockmap::txmsg test skb:FAIL
> > > > #21/ 7 sockhash::txmsg test skb:FAIL
> > > > #36/ 7 sockhash:ktls:txmsg test skb:FAIL
> > > > Pass: 42 Fail: 3
> > 
> > Sorry, I didn't notice these fails in my testing before, they do
> > exist.
> > I'll try to fix them and sent a v2 soon.
> 
> Not 100% sure but a hint. I would look into where the stream parser
> is waking up the sock here. I'm not sure there is an easy fix tbh.
> I can help look at this soon as well if you don't beat me to a fix.
> 
> Thanks for looking into it.

I just sent a v2, please review it for me.

Thanks,
-Geliang

> 
> > 
> > Thanks,
> > -Geliang