2015-03-30 21:13:48

by Fabian Frédérick

Subject: [PATCH 7/9 net-next] sunrpc: replace if/BUG by BUG_ON

Signed-off-by: Fabian Frederick <[email protected]>
---
net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------
net/sunrpc/svc_xprt.c | 3 +--
2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 1095be9..09f8a1c6 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -840,11 +840,9 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct g
return stat;
if (integ_len > buf->len)
return stat;
- if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
- BUG();
+ BUG_ON(xdr_buf_subsegment(buf, &integ_buf, 0, integ_len));
/* copy out mic... */
- if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
- BUG();
+ BUG_ON(read_u32_from_xdr_buf(buf, integ_len, &mic.len));
if (mic.len > RPC_MAX_AUTH_SIZE)
return stat;
mic.data = kmalloc(mic.len, GFP_KERNEL);
@@ -1595,8 +1593,7 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
BUG_ON(integ_len % 4);
*p++ = htonl(integ_len);
*p++ = htonl(gc->gc_seq);
- if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
- BUG();
+ BUG_ON(xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len));
if (resbuf->tail[0].iov_base == NULL) {
if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
goto out_err;
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 163ac45..2f82e8b 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -960,8 +960,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
struct svc_deferred_req *dr;

/* Only do this once */
- if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
- BUG();
+ BUG_ON(test_and_set_bit(XPT_DEAD, &xprt->xpt_flags));

dprintk("svc: svc_delete_xprt(%p)\n", xprt);
xprt->xpt_ops->xpo_detach(xprt);
--
1.9.1

2015-03-30 21:25:20

by J. Bruce Fields

Subject: Re: [PATCH 7/9 net-next] sunrpc: replace if/BUG by BUG_ON

Huh, I thought this wasn't recommended:

http://lkml.kernel.org/r/[email protected]

"I'd prefer that we not move code which has side-effects into
BUG_ONs"

--b.

On Mon, Mar 30, 2015 at 11:13:15PM +0200, Fabian Frederick wrote:
> Signed-off-by: Fabian Frederick <[email protected]>
> ---
> net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------
> net/sunrpc/svc_xprt.c | 3 +--
> 2 files changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
> index 1095be9..09f8a1c6 100644
> --- a/net/sunrpc/auth_gss/svcauth_gss.c
> +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> @@ -840,11 +840,9 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct g
> return stat;
> if (integ_len > buf->len)
> return stat;
> - if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
> - BUG();
> + BUG_ON(xdr_buf_subsegment(buf, &integ_buf, 0, integ_len));
> /* copy out mic... */
> - if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
> - BUG();
> + BUG_ON(read_u32_from_xdr_buf(buf, integ_len, &mic.len));
> if (mic.len > RPC_MAX_AUTH_SIZE)
> return stat;
> mic.data = kmalloc(mic.len, GFP_KERNEL);
> @@ -1595,8 +1593,7 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
> BUG_ON(integ_len % 4);
> *p++ = htonl(integ_len);
> *p++ = htonl(gc->gc_seq);
> - if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
> - BUG();
> + BUG_ON(xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len));
> if (resbuf->tail[0].iov_base == NULL) {
> if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
> goto out_err;
> diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> index 163ac45..2f82e8b 100644
> --- a/net/sunrpc/svc_xprt.c
> +++ b/net/sunrpc/svc_xprt.c
> @@ -960,8 +960,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
> struct svc_deferred_req *dr;
>
> /* Only do this once */
> - if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
> - BUG();
> + BUG_ON(test_and_set_bit(XPT_DEAD, &xprt->xpt_flags));
>
> dprintk("svc: svc_delete_xprt(%p)\n", xprt);
> xprt->xpt_ops->xpo_detach(xprt);
> --
> 1.9.1

2015-03-31 19:00:42

by Fabian Frédérick

Subject: Re: [PATCH 7/9 net-next] sunrpc: replace if/BUG by BUG_ON

> On 30 March 2015 at 23:25 "J. Bruce Fields" <[email protected]> wrote:
>
>
> Huh, I thought this wasn't recommended:
>
>       http://lkml.kernel.org/r/[email protected]
>
>       "I'd prefer that we not move code which has side-effects into
>       BUG_ONs"

Thanks for the link, I wasn't aware of that problem. Maybe we should add some
documentation and fix coccinelle detection then ?

Regards,
Fabian

>
> --b.
>
> On Mon, Mar 30, 2015 at 11:13:15PM +0200, Fabian Frederick wrote:
> > Signed-off-by: Fabian Frederick <[email protected]>
> > ---
> >  net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------
> >  net/sunrpc/svc_xprt.c             | 3 +--
> >  2 files changed, 4 insertions(+), 8 deletions(-)
> >
> > diff --git a/net/sunrpc/auth_gss/svcauth_gss.c
> > b/net/sunrpc/auth_gss/svcauth_gss.c
> > index 1095be9..09f8a1c6 100644
> > --- a/net/sunrpc/auth_gss/svcauth_gss.c
> > +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> > @@ -840,11 +840,9 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct
> > xdr_buf *buf, u32 seq, struct g
> >             return stat;
> >     if (integ_len > buf->len)
> >             return stat;
> > -   if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
> > -           BUG();
> > +   BUG_ON(xdr_buf_subsegment(buf, &integ_buf, 0, integ_len));
> >     /* copy out mic... */
> > -   if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
> > -           BUG();
> > +   BUG_ON(read_u32_from_xdr_buf(buf, integ_len, &mic.len));
> >     if (mic.len > RPC_MAX_AUTH_SIZE)
> >             return stat;
> >     mic.data = kmalloc(mic.len, GFP_KERNEL);
> > @@ -1595,8 +1593,7 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
> >     BUG_ON(integ_len % 4);
> >     *p++ = htonl(integ_len);
> >     *p++ = htonl(gc->gc_seq);
> > -   if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
> > -           BUG();
> > +   BUG_ON(xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len));
> >     if (resbuf->tail[0].iov_base == NULL) {
> >             if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
> >                     goto out_err;
> > diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> > index 163ac45..2f82e8b 100644
> > --- a/net/sunrpc/svc_xprt.c
> > +++ b/net/sunrpc/svc_xprt.c
> > @@ -960,8 +960,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
> >     struct svc_deferred_req *dr;
> > 
> >     /* Only do this once */
> > -   if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
> > -           BUG();
> > +   BUG_ON(test_and_set_bit(XPT_DEAD, &xprt->xpt_flags));
> > 
> >     dprintk("svc: svc_delete_xprt(%p)\n", xprt);
> >     xprt->xpt_ops->xpo_detach(xprt);
> > --
> > 1.9.1

2015-03-31 19:11:34

by Julia Lawall

Subject: Re: [PATCH 7/9 net-next] sunrpc: replace if/BUG by BUG_ON

On Tue, 31 Mar 2015, Fabian Frederick wrote:

>
>
> > On 30 March 2015 at 23:25 "J. Bruce Fields" <[email protected]> wrote:
> >
> >
> > Huh, I thought this wasn't recommended:
> >
> >       http://lkml.kernel.org/r/[email protected]
> >
> >       "I'd prefer that we not move code which has side-effects into
> >       BUG_ONs"
>
> Thanks for the link, I wasn't aware of that problem. Maybe we should add some
> documentation and fix coccinelle detection then ?

Maybe the comment in the Coccinelle rule could just be made more clear?
The only practical choices are to ignore all function calls and to allow
all fuction calls, since Coccinelle doesn't know which ones have side
effects.

julia

> Regards,
> Fabian
>
> >
> > --b.
> >
> > On Mon, Mar 30, 2015 at 11:13:15PM +0200, Fabian Frederick wrote:
> > > Signed-off-by: Fabian Frederick <[email protected]>
> > > ---
> > >  net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------
> > >  net/sunrpc/svc_xprt.c             | 3 +--
> > >  2 files changed, 4 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/net/sunrpc/auth_gss/svcauth_gss.c
> > > b/net/sunrpc/auth_gss/svcauth_gss.c
> > > index 1095be9..09f8a1c6 100644
> > > --- a/net/sunrpc/auth_gss/svcauth_gss.c
> > > +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> > > @@ -840,11 +840,9 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct
> > > xdr_buf *buf, u32 seq, struct g
> > >             return stat;
> > >     if (integ_len > buf->len)
> > >             return stat;
> > > -   if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
> > > -           BUG();
> > > +   BUG_ON(xdr_buf_subsegment(buf, &integ_buf, 0, integ_len));
> > >     /* copy out mic... */
> > > -   if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
> > > -           BUG();
> > > +   BUG_ON(read_u32_from_xdr_buf(buf, integ_len, &mic.len));
> > >     if (mic.len > RPC_MAX_AUTH_SIZE)
> > >             return stat;
> > >     mic.data = kmalloc(mic.len, GFP_KERNEL);
> > > @@ -1595,8 +1593,7 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst *rqstp)
> > >     BUG_ON(integ_len % 4);
> > >     *p++ = htonl(integ_len);
> > >     *p++ = htonl(gc->gc_seq);
> > > -   if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
> > > -           BUG();
> > > +   BUG_ON(xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len));
> > >     if (resbuf->tail[0].iov_base == NULL) {
> > >             if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
> > >                     goto out_err;
> > > diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> > > index 163ac45..2f82e8b 100644
> > > --- a/net/sunrpc/svc_xprt.c
> > > +++ b/net/sunrpc/svc_xprt.c
> > > @@ -960,8 +960,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
> > >     struct svc_deferred_req *dr;
> > > 
> > >     /* Only do this once */
> > > -   if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
> > > -           BUG();
> > > +   BUG_ON(test_and_set_bit(XPT_DEAD, &xprt->xpt_flags));
> > > 
> > >     dprintk("svc: svc_delete_xprt(%p)\n", xprt);
> > >     xprt->xpt_ops->xpo_detach(xprt);
> > > --
> > > 1.9.1
>

2015-03-31 20:13:52

by Fabian Frédérick

Subject: Re: [PATCH 7/9 net-next] sunrpc: replace if/BUG by BUG_ON

> On 31 March 2015 at 21:11 Julia Lawall <[email protected]> wrote:
>
>
>
>
> On Tue, 31 Mar 2015, Fabian Frederick wrote:
>
> >
> >
> > > On 30 March 2015 at 23:25 "J. Bruce Fields" <[email protected]> wrote:
> > >
> > >
> > > Huh, I thought this wasn't recommended:
> > >
> > >       http://lkml.kernel.org/r/[email protected]
> > >
> > >       "I'd prefer that we not move code which has side-effects into
> > >       BUG_ONs"
> >
> > Thanks for the link, I wasn't aware of that problem. Maybe we should add
> > some
> > documentation and fix coccinelle detection then ?
>
> Maybe the comment in the Coccinelle rule could just be made more clear? 

Fair enough. Current "WARNING: Use BUG_ON" looks misleading.
Maybe some BUG_ON(function()) detection script would be interesting as well ?
There are nearly 5000 BUG_ON() in drivers branch only ... 

Regards,
Fabian
> The only practical choices are to ignore all function calls and to allow
> all fuction calls, since Coccinelle doesn't know which ones have side
> effects.
>
> julia
>
> > Regards,
> > Fabian
> >
> > >
> > > --b.
> > >
> > > On Mon, Mar 30, 2015 at 11:13:15PM +0200, Fabian Frederick wrote:
> > > > Signed-off-by: Fabian Frederick <[email protected]>
> > > > ---
> > > >  net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------
> > > >  net/sunrpc/svc_xprt.c             | 3 +--
> > > >  2 files changed, 4 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/net/sunrpc/auth_gss/svcauth_gss.c
> > > > b/net/sunrpc/auth_gss/svcauth_gss.c
> > > > index 1095be9..09f8a1c6 100644
> > > > --- a/net/sunrpc/auth_gss/svcauth_gss.c
> > > > +++ b/net/sunrpc/auth_gss/svcauth_gss.c
> > > > @@ -840,11 +840,9 @@ unwrap_integ_data(struct svc_rqst *rqstp, struct
> > > > xdr_buf *buf, u32 seq, struct g
> > > >             return stat;
> > > >     if (integ_len > buf->len)
> > > >             return stat;
> > > > -   if (xdr_buf_subsegment(buf, &integ_buf, 0, integ_len))
> > > > -           BUG();
> > > > +   BUG_ON(xdr_buf_subsegment(buf, &integ_buf, 0, integ_len));
> > > >     /* copy out mic... */
> > > > -   if (read_u32_from_xdr_buf(buf, integ_len, &mic.len))
> > > > -           BUG();
> > > > +   BUG_ON(read_u32_from_xdr_buf(buf, integ_len, &mic.len));
> > > >     if (mic.len > RPC_MAX_AUTH_SIZE)
> > > >             return stat;
> > > >     mic.data = kmalloc(mic.len, GFP_KERNEL);
> > > > @@ -1595,8 +1593,7 @@ svcauth_gss_wrap_resp_integ(struct svc_rqst
> > > > *rqstp)
> > > >     BUG_ON(integ_len % 4);
> > > >     *p++ = htonl(integ_len);
> > > >     *p++ = htonl(gc->gc_seq);
> > > > -   if (xdr_buf_subsegment(resbuf, &integ_buf, integ_offset, integ_len))
> > > > -           BUG();
> > > > +   BUG_ON(xdr_buf_subsegment(resbuf, &integ_buf, integ_offset,
> > > > integ_len));
> > > >     if (resbuf->tail[0].iov_base == NULL) {
> > > >             if (resbuf->head[0].iov_len + RPC_MAX_AUTH_SIZE > PAGE_SIZE)
> > > >                     goto out_err;
> > > > diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> > > > index 163ac45..2f82e8b 100644
> > > > --- a/net/sunrpc/svc_xprt.c
> > > > +++ b/net/sunrpc/svc_xprt.c
> > > > @@ -960,8 +960,7 @@ static void svc_delete_xprt(struct svc_xprt *xprt)
> > > >     struct svc_deferred_req *dr;
> > > > 
> > > >     /* Only do this once */
> > > > -   if (test_and_set_bit(XPT_DEAD, &xprt->xpt_flags))
> > > > -           BUG();
> > > > +   BUG_ON(test_and_set_bit(XPT_DEAD, &xprt->xpt_flags));
> > > > 
> > > >     dprintk("svc: svc_delete_xprt(%p)\n", xprt);
> > > >     xprt->xpt_ops->xpo_detach(xprt);
> > > > --
> > > > 1.9.1
> >