| Message ID | 20171023181635.GA25334@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
In the past we've avoided BUG_ON(X) where X might have side effects, on the theory that it should actually be OK just to compile out BUG_ON()s. Has that changed? In any case, I don't find that this improves readability; dropping. --b. On Mon, Oct 23, 2017 at 01:16:35PM -0500, Gustavo A. R. Silva wrote: > Use BUG_ON instead of if condition followed by BUG. > > This issue was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> > --- > net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c > index 7b1ee5a..a10ce43 100644 > --- a/net/sunrpc/auth_gss/svcauth_gss.c > +++ b/net/sunrpc/auth_gss/svcauth_gss.c > @@ -855,11 +855,9 @@ 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); > @@ -1611,8 +1609,7 @@ 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; > -- > 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Is there a reason to BUG() in these places? Couldn't we WARN_ON_ONCE and return an error? -dros > On Oct 23, 2017, at 4:31 PM, J. Bruce Fields <bfields@fieldses.org> wrote: > > In the past we've avoided BUG_ON(X) where X might have side effects, on > the theory that it should actually be OK just to compile out BUG_ON()s. > Has that changed? > > In any case, I don't find that this improves readability; dropping. > > --b. > > On Mon, Oct 23, 2017 at 01:16:35PM -0500, Gustavo A. R. Silva wrote: >> Use BUG_ON instead of if condition followed by BUG. >> >> This issue was detected with the help of Coccinelle. >> >> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> >> --- >> net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c >> index 7b1ee5a..a10ce43 100644 >> --- a/net/sunrpc/auth_gss/svcauth_gss.c >> +++ b/net/sunrpc/auth_gss/svcauth_gss.c >> @@ -855,11 +855,9 @@ 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); >> @@ -1611,8 +1609,7 @@ 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; >> -- >> 2.7.4 > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Oct 24, 2017 at 01:26:49PM -0400, Weston Andros Adamson wrote: > Is there a reason to BUG() in these places? Couldn't we WARN_ON_ONCE and return an error? I think the BUG() will just kill an nfsd thread that isn't holding any interesting locks. The failures look unlikely. (Except for that read_u32... return, I wonder if we're missing a check there.) --b. > > -dros > > > On Oct 23, 2017, at 4:31 PM, J. Bruce Fields <bfields@fieldses.org> wrote: > > > > In the past we've avoided BUG_ON(X) where X might have side effects, on > > the theory that it should actually be OK just to compile out BUG_ON()s. > > Has that changed? > > > > In any case, I don't find that this improves readability; dropping. > > > > --b. > > > > On Mon, Oct 23, 2017 at 01:16:35PM -0500, Gustavo A. R. Silva wrote: > >> Use BUG_ON instead of if condition followed by BUG. > >> > >> This issue was detected with the help of Coccinelle. > >> > >> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> > >> --- > >> net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------ > >> 1 file changed, 3 insertions(+), 6 deletions(-) > >> > >> diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c > >> index 7b1ee5a..a10ce43 100644 > >> --- a/net/sunrpc/auth_gss/svcauth_gss.c > >> +++ b/net/sunrpc/auth_gss/svcauth_gss.c > >> @@ -855,11 +855,9 @@ 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); > >> @@ -1611,8 +1609,7 @@ 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; > >> -- > >> 2.7.4 > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 2017-10-24 at 13:53 -0400, J. Bruce Fields wrote: > On Tue, Oct 24, 2017 at 01:26:49PM -0400, Weston Andros Adamson wrote: > > Is there a reason to BUG() in these places? Couldn't we WARN_ON_ONCE and return an error? > > I think the BUG() will just kill an nfsd thread that isn't holding any > interesting locks. > Not necessarily. If panic_on_oops is set (and it usually is in "production" setups), it'll crash the box there. > The failures look unlikely. (Except for that read_u32... return, I > wonder if we're missing a check there.) > Agreed, looks like you only hit an error if the read attempts to go out of bounds. In principle that shouldn't ever happen (and I haven't seen any reports of it). Still...I agree with Dros that it's better to handle this without oopsing if we can. We can return an error from either of those functions. A sane error and a WARN_ONCE would be better here. > --b. > > > > > -dros > > > > > On Oct 23, 2017, at 4:31 PM, J. Bruce Fields <bfields@fieldses.org> wrote: > > > > > > In the past we've avoided BUG_ON(X) where X might have side effects, on > > > the theory that it should actually be OK just to compile out BUG_ON()s. > > > Has that changed? > > > > > > In any case, I don't find that this improves readability; dropping. > > > > > > --b. > > > > > > On Mon, Oct 23, 2017 at 01:16:35PM -0500, Gustavo A. R. Silva wrote: > > > > Use BUG_ON instead of if condition followed by BUG. > > > > > > > > This issue was detected with the help of Coccinelle. > > > > > > > > Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> > > > > --- > > > > net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------ > > > > 1 file changed, 3 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c > > > > index 7b1ee5a..a10ce43 100644 > > > > --- a/net/sunrpc/auth_gss/svcauth_gss.c > > > > +++ b/net/sunrpc/auth_gss/svcauth_gss.c > > > > @@ -855,11 +855,9 @@ 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); > > > > @@ -1611,8 +1609,7 @@ 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; > > > > -- > > > > 2.7.4 > > > > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > > > the body of a message to majordomo@vger.kernel.org > > > More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index 7b1ee5a..a10ce43 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -855,11 +855,9 @@ 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); @@ -1611,8 +1609,7 @@ 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;
Use BUG_ON instead of if condition followed by BUG. This issue was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> --- net/sunrpc/auth_gss/svcauth_gss.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)