| Message ID | 1472186949-9025-1-git-send-email-christophe.jaillet@wanadoo.fr (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On 8/26/2016 12:49 AM, Christophe JAILLET wrote: > The 2nd parameter of 'find_first_bit' is the number of bits to search. > In this case, we are passing 'sizeof(unsigned long)' which is likely to > be 4 or 8. If the size can be 4 or 8, then using 64 universally is not correct. Why not use sizeof() * 8 (or << 3)? > It is likely that the number of bits of 'port_mask' was expected here. This > variable is a 'u64', so use 64 instead. > > It has been spotted by the following coccinelle script: > @@ > expression ret, x; > > @@ > * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); > > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> > --- > Not sure that using 64 directly is the best option. > Maybe '8 * sizeof(port_mask)' as used in the same file for > 'for_each_set_bit' would be better > --- > drivers/infiniband/hw/hfi1/mad.c | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) > > diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c > index 1263abe01999..2c6c138c41b2 100644 > --- a/drivers/infiniband/hw/hfi1/mad.c > +++ b/drivers/infiniband/hw/hfi1/mad.c > @@ -2632,8 +2632,7 @@ static int pma_get_opa_datacounters(struct opa_pma_mad *pmp, > * port the request came in on. > */ > port_mask = be64_to_cpu(req->port_select_mask[3]); > - port_num = find_first_bit((unsigned long *)&port_mask, > - sizeof(port_mask)); > + port_num = find_first_bit((unsigned long *)&port_mask, 64); > > if ((u8)port_num != port) { > pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; > @@ -2836,8 +2835,7 @@ static int pma_get_opa_porterrors(struct opa_pma_mad *pmp, > * port the request came in on. > */ > port_mask = be64_to_cpu(req->port_select_mask[3]); > - port_num = find_first_bit((unsigned long *)&port_mask, > - sizeof(port_mask)); > + port_num = find_first_bit((unsigned long *)&port_mask, 64); > > if (port_num != port) { > pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; > @@ -3009,8 +3007,7 @@ static int pma_get_opa_errorinfo(struct opa_pma_mad *pmp, > * the request came in on. > */ > port_mask = be64_to_cpu(req->port_select_mask[3]); > - port_num = find_first_bit((unsigned long *)&port_mask, > - sizeof(port_mask)); > + port_num = find_first_bit((unsigned long *)&port_mask, 64); > > if (port_num != port) { > pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; > @@ -3246,8 +3243,7 @@ static int pma_set_opa_errorinfo(struct opa_pma_mad *pmp, > * the request came in on. > */ > port_mask = be64_to_cpu(req->port_select_mask[3]); > - port_num = find_first_bit((unsigned long *)&port_mask, > - sizeof(port_mask)); > + port_num = find_first_bit((unsigned long *)&port_mask, 64); > > if (port_num != port) { > pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; >
Le 26/08/2016 à 15:35, Doug Ledford a écrit : > On 8/26/2016 12:49 AM, Christophe JAILLET wrote: >> The 2nd parameter of 'find_first_bit' is the number of bits to search. >> In this case, we are passing 'sizeof(unsigned long)' which is likely to >> be 4 or 8. > If the size can be 4 or 8, then using 64 universally is not correct. > Why not use sizeof() * 8 (or << 3)? I agree with you... BTW, the log message is wrong. 'port_mask' is a u64. (not an unsigned long). So the sizeof should always be 8. (cut and paste error from another patch, sorry) > >> It is likely that the number of bits of 'port_mask' was expected >> here. This >> variable is a 'u64', so use 64 instead. >> >> It has been spotted by the following coccinelle script: >> @@ >> expression ret, x; >> >> @@ >> * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); >> >> Signed-off-by: Christophe JAILLET >> <christophe.jaillet-39ZsbGIQGT5GWvitb5QawA@public.gmane.org> >> --- >> Not sure that using 64 directly is the best option. >> Maybe '8 * sizeof(port_mask)' as used in the same file for >> 'for_each_set_bit' would be better >> --- ... as noted here Would you like a v2 patch or, will you update it by yourself? Best regards, CJ --- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 8/27/2016 1:25 AM, Christophe JAILLET wrote: > Le 26/08/2016 à 15:35, Doug Ledford a écrit : >> On 8/26/2016 12:49 AM, Christophe JAILLET wrote: >>> The 2nd parameter of 'find_first_bit' is the number of bits to search. >>> In this case, we are passing 'sizeof(unsigned long)' which is likely to >>> be 4 or 8. >> If the size can be 4 or 8, then using 64 universally is not correct. >> Why not use sizeof() * 8 (or << 3)? > I agree with you... > > BTW, the log message is wrong. 'port_mask' is a u64. (not an unsigned > long). So the sizeof should always be 8. > (cut and paste error from another patch, sorry) Log message modified, then patch modified to use sizeof() * 8, result applied. Thanks. >> >>> It is likely that the number of bits of 'port_mask' was expected >>> here. This >>> variable is a 'u64', so use 64 instead. >>> >>> It has been spotted by the following coccinelle script: >>> @@ >>> expression ret, x; >>> >>> @@ >>> * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); >>> >>> Signed-off-by: Christophe JAILLET >>> <christophe.jaillet-39ZsbGIQGT5GWvitb5QawA@public.gmane.org> >>> --- >>> Not sure that using 64 directly is the best option. >>> Maybe '8 * sizeof(port_mask)' as used in the same file for >>> 'for_each_set_bit' would be better >>> --- > ... as noted here > > Would you like a v2 patch or, will you update it by yourself? > > Best regards, > CJ > > --- > L'absence de virus dans ce courrier électronique a été vérifiée par le > logiciel antivirus Avast. > https://www.avast.com/antivirus >
diff --git a/drivers/infiniband/hw/hfi1/mad.c b/drivers/infiniband/hw/hfi1/mad.c index 1263abe01999..2c6c138c41b2 100644 --- a/drivers/infiniband/hw/hfi1/mad.c +++ b/drivers/infiniband/hw/hfi1/mad.c @@ -2632,8 +2632,7 @@ static int pma_get_opa_datacounters(struct opa_pma_mad *pmp, * port the request came in on. */ port_mask = be64_to_cpu(req->port_select_mask[3]); - port_num = find_first_bit((unsigned long *)&port_mask, - sizeof(port_mask)); + port_num = find_first_bit((unsigned long *)&port_mask, 64); if ((u8)port_num != port) { pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; @@ -2836,8 +2835,7 @@ static int pma_get_opa_porterrors(struct opa_pma_mad *pmp, * port the request came in on. */ port_mask = be64_to_cpu(req->port_select_mask[3]); - port_num = find_first_bit((unsigned long *)&port_mask, - sizeof(port_mask)); + port_num = find_first_bit((unsigned long *)&port_mask, 64); if (port_num != port) { pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; @@ -3009,8 +3007,7 @@ static int pma_get_opa_errorinfo(struct opa_pma_mad *pmp, * the request came in on. */ port_mask = be64_to_cpu(req->port_select_mask[3]); - port_num = find_first_bit((unsigned long *)&port_mask, - sizeof(port_mask)); + port_num = find_first_bit((unsigned long *)&port_mask, 64); if (port_num != port) { pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD; @@ -3246,8 +3243,7 @@ static int pma_set_opa_errorinfo(struct opa_pma_mad *pmp, * the request came in on. */ port_mask = be64_to_cpu(req->port_select_mask[3]); - port_num = find_first_bit((unsigned long *)&port_mask, - sizeof(port_mask)); + port_num = find_first_bit((unsigned long *)&port_mask, 64); if (port_num != port) { pmp->mad_hdr.status |= IB_SMP_INVALID_FIELD;
The 2nd parameter of 'find_first_bit' is the number of bits to search. In this case, we are passing 'sizeof(unsigned long)' which is likely to be 4 or 8. It is likely that the number of bits of 'port_mask' was expected here. This variable is a 'u64', so use 64 instead. It has been spotted by the following coccinelle script: @@ expression ret, x; @@ * ret = \(find_first_bit \| find_first_zero_bit\) (x, sizeof(...)); Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- Not sure that using 64 directly is the best option. Maybe '8 * sizeof(port_mask)' as used in the same file for 'for_each_set_bit' would be better --- drivers/infiniband/hw/hfi1/mad.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)