* [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl()
@ 2020-06-10 17:47 Tom Seewald
2020-06-10 17:50 ` Jason Gunthorpe
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: Tom Seewald @ 2020-06-10 17:47 UTC (permalink / raw)
To: linux-rdma; +Cc: tseewald, Bernard Metzler, Doug Ledford, Jason Gunthorpe
The variable buf_addr is type dma_addr_t, which may not be the same size
as a pointer. To ensure it is the correct size, cast to a uintptr_t.
Signed-off-by: Tom Seewald <tseewald@gmail.com>
---
drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c b/drivers/infiniband/sw/siw/siw_qp_rx.c
index 650520244ed0..7271d705f4b0 100644
--- a/drivers/infiniband/sw/siw/siw_qp_rx.c
+++ b/drivers/infiniband/sw/siw/siw_qp_rx.c
@@ -139,7 +139,8 @@ static int siw_rx_pbl(struct siw_rx_stream *srx, int *pbl_idx,
break;
bytes = min(bytes, len);
- if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) {
+ if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) ==
+ bytes) {
copied += bytes;
offset += bytes;
len -= bytes;
--
2.20.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-10 17:47 [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() Tom Seewald @ 2020-06-10 17:50 ` Jason Gunthorpe 2020-06-10 18:21 ` Tom Seewald 2020-06-11 10:21 ` Bernard Metzler 2020-06-16 14:03 ` Jason Gunthorpe 2 siblings, 1 reply; 11+ messages in thread From: Jason Gunthorpe @ 2020-06-10 17:50 UTC (permalink / raw) To: Tom Seewald; +Cc: linux-rdma, Bernard Metzler, Doug Ledford On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: > The variable buf_addr is type dma_addr_t, which may not be the same size > as a pointer. To ensure it is the correct size, cast to a uintptr_t. > > Signed-off-by: Tom Seewald <tseewald@gmail.com> > drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c b/drivers/infiniband/sw/siw/siw_qp_rx.c > index 650520244ed0..7271d705f4b0 100644 > +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c > @@ -139,7 +139,8 @@ static int siw_rx_pbl(struct siw_rx_stream *srx, int *pbl_idx, > break; > > bytes = min(bytes, len); > - if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) { > + if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) == > + bytes) { How is a dma_addr_t being cast to a void *? That can't be right? Bernard?? Jason ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-10 17:50 ` Jason Gunthorpe @ 2020-06-10 18:21 ` Tom Seewald 0 siblings, 0 replies; 11+ messages in thread From: Tom Seewald @ 2020-06-10 18:21 UTC (permalink / raw) To: Jason Gunthorpe; +Cc: linux-rdma, Bernard Metzler, Doug Ledford On Wed, Jun 10, 2020 at 12:50 PM Jason Gunthorpe <jgg@ziepe.ca> wrote: > How is a dma_addr_t being cast to a void *? That can't be right? > Bernard?? I was also confused about that, as I couldn't tell how/if it is able to guarantee the bus address is the same as the cpu address. I just assumed it was my lack of familiarity with the codebase. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-10 17:47 [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() Tom Seewald 2020-06-10 17:50 ` Jason Gunthorpe @ 2020-06-11 10:21 ` Bernard Metzler 2020-06-11 11:35 ` Jason Gunthorpe 2020-06-11 14:11 ` Bernard Metzler 2020-06-16 14:03 ` Jason Gunthorpe 2 siblings, 2 replies; 11+ messages in thread From: Bernard Metzler @ 2020-06-11 10:21 UTC (permalink / raw) To: Jason Gunthorpe; +Cc: Tom Seewald, linux-rdma, Doug Ledford -----"Jason Gunthorpe" <jgg@ziepe.ca> wrote: ----- >To: "Tom Seewald" <tseewald@gmail.com> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >Date: 06/10/2020 07:50PM >Cc: linux-rdma@vger.kernel.org, "Bernard Metzler" ><bmt@zurich.ibm.com>, "Doug Ledford" <dledford@redhat.com> >Subject: [EXTERNAL] Re: [PATCH next] siw: Fix pointer-to-int-cast >warning in siw_rx_pbl() > >On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: >> The variable buf_addr is type dma_addr_t, which may not be the same >size >> as a pointer. To ensure it is the correct size, cast to a >uintptr_t. >> >> Signed-off-by: Tom Seewald <tseewald@gmail.com> >> drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c >b/drivers/infiniband/sw/siw/siw_qp_rx.c >> index 650520244ed0..7271d705f4b0 100644 >> +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c >> @@ -139,7 +139,8 @@ static int siw_rx_pbl(struct siw_rx_stream >*srx, int *pbl_idx, >> break; >> >> bytes = min(bytes, len); >> - if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) { >> + if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) == >> + bytes) { > >How is a dma_addr_t being cast to a void *? That can't be right? >Bernard?? > >Jason > Hi Tom, Hi Jason, Thanks for looking into that. siw_rx_kva() calls skb_copy_bits() to move data to its kernel clients destination. It expects a void * target address. This is why I chose it for siw_rx_kva() as well. One could say siw_rx_kva() should better get an uintptr_t as target argument, which would probably make it look more clean. And we rename it to siw_rx_kbuf(), and we cast from uintptr_t to (void *) just for skb_copy_bits(skb *, off, (void *)dest, len) This would avoid all those nasty (void *) casting at all (!) the places we are calling siw_rx_kva(). Makes sense? Thanks, Bernard. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-11 10:21 ` Bernard Metzler @ 2020-06-11 11:35 ` Jason Gunthorpe 2020-06-11 14:11 ` Bernard Metzler 1 sibling, 0 replies; 11+ messages in thread From: Jason Gunthorpe @ 2020-06-11 11:35 UTC (permalink / raw) To: Bernard Metzler; +Cc: Tom Seewald, linux-rdma, Doug Ledford On Thu, Jun 11, 2020 at 10:21:49AM +0000, Bernard Metzler wrote: > > >To: "Tom Seewald" <tseewald@gmail.com> > >From: "Jason Gunthorpe" <jgg@ziepe.ca> > >Date: 06/10/2020 07:50PM > >Cc: linux-rdma@vger.kernel.org, "Bernard Metzler" > ><bmt@zurich.ibm.com>, "Doug Ledford" <dledford@redhat.com> > >Subject: [EXTERNAL] Re: [PATCH next] siw: Fix pointer-to-int-cast > >warning in siw_rx_pbl() > > > >On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: > >> The variable buf_addr is type dma_addr_t, which may not be the same > >size > >> as a pointer. To ensure it is the correct size, cast to a > >uintptr_t. > >> > >> Signed-off-by: Tom Seewald <tseewald@gmail.com> > >> drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- > >> 1 file changed, 2 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c > >b/drivers/infiniband/sw/siw/siw_qp_rx.c > >> index 650520244ed0..7271d705f4b0 100644 > >> +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c > >> @@ -139,7 +139,8 @@ static int siw_rx_pbl(struct siw_rx_stream > >*srx, int *pbl_idx, > >> break; > >> > >> bytes = min(bytes, len); > >> - if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) { > >> + if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) == > >> + bytes) { > > > >How is a dma_addr_t being cast to a void *? That can't be right? > >Bernard?? > > > >Jason > > > Hi Tom, Hi Jason, > > Thanks for looking into that. > > siw_rx_kva() calls skb_copy_bits() to move data to its > kernel clients destination. It expects a void * target > address. This is why I chose it for siw_rx_kva() as well. > One could say siw_rx_kva() should better get an uintptr_t > as target argument, which would probably make it look > more clean. And we rename it to siw_rx_kbuf(), and we > cast from uintptr_t to (void *) just for > skb_copy_bits(skb *, off, (void *)dest, len) > > This would avoid all those nasty (void *) casting at all (!) > the places we are calling siw_rx_kva(). But where did the dma_addr_t come from? Jason ^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-11 10:21 ` Bernard Metzler 2020-06-11 11:35 ` Jason Gunthorpe @ 2020-06-11 14:11 ` Bernard Metzler 2020-06-11 14:23 ` Jason Gunthorpe 2020-06-11 15:06 ` Bernard Metzler 1 sibling, 2 replies; 11+ messages in thread From: Bernard Metzler @ 2020-06-11 14:11 UTC (permalink / raw) To: Jason Gunthorpe; +Cc: Tom Seewald, linux-rdma, Doug Ledford -----"Jason Gunthorpe" <jgg@ziepe.ca> wrote: ----- >To: "Bernard Metzler" <BMT@zurich.ibm.com> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >Date: 06/11/2020 01:35PM >Cc: "Tom Seewald" <tseewald@gmail.com>, linux-rdma@vger.kernel.org, >"Doug Ledford" <dledford@redhat.com> >Subject: [EXTERNAL] Re: Re: [PATCH next] siw: Fix pointer-to-int-cast >warning in siw_rx_pbl() > >On Thu, Jun 11, 2020 at 10:21:49AM +0000, Bernard Metzler wrote: >> >> >To: "Tom Seewald" <tseewald@gmail.com> >> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >> >Date: 06/10/2020 07:50PM >> >Cc: linux-rdma@vger.kernel.org, "Bernard Metzler" >> ><bmt@zurich.ibm.com>, "Doug Ledford" <dledford@redhat.com> >> >Subject: [EXTERNAL] Re: [PATCH next] siw: Fix pointer-to-int-cast >> >warning in siw_rx_pbl() >> > >> >On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: >> >> The variable buf_addr is type dma_addr_t, which may not be the >same >> >size >> >> as a pointer. To ensure it is the correct size, cast to a >> >uintptr_t. >> >> >> >> Signed-off-by: Tom Seewald <tseewald@gmail.com> >> >> drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- >> >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> >> >> diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c >> >b/drivers/infiniband/sw/siw/siw_qp_rx.c >> >> index 650520244ed0..7271d705f4b0 100644 >> >> +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c >> >> @@ -139,7 +139,8 @@ static int siw_rx_pbl(struct siw_rx_stream >> >*srx, int *pbl_idx, >> >> break; >> >> >> >> bytes = min(bytes, len); >> >> - if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) { >> >> + if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) == >> >> + bytes) { >> > >> >How is a dma_addr_t being cast to a void *? That can't be right? >> >Bernard?? >> > >> >Jason >> > >> Hi Tom, Hi Jason, >> >> Thanks for looking into that. >> >> siw_rx_kva() calls skb_copy_bits() to move data to its >> kernel clients destination. It expects a void * target >> address. This is why I chose it for siw_rx_kva() as well. >> One could say siw_rx_kva() should better get an uintptr_t >> as target argument, which would probably make it look >> more clean. And we rename it to siw_rx_kbuf(), and we >> cast from uintptr_t to (void *) just for >> skb_copy_bits(skb *, off, (void *)dest, len) >> >> This would avoid all those nasty (void *) casting at all (!) >> the places we are calling siw_rx_kva(). > >But where did the dma_addr_t come from? > It initially comes from the scatterlist provided by the kernel user via drivers .map_mr_sg() method. There we get a dma_addr_t describing the users buffer. Thanks, Bernard. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-11 14:11 ` Bernard Metzler @ 2020-06-11 14:23 ` Jason Gunthorpe 2020-06-11 15:06 ` Bernard Metzler 1 sibling, 0 replies; 11+ messages in thread From: Jason Gunthorpe @ 2020-06-11 14:23 UTC (permalink / raw) To: Bernard Metzler; +Cc: Tom Seewald, linux-rdma, Doug Ledford On Thu, Jun 11, 2020 at 02:11:51PM +0000, Bernard Metzler wrote: > > >To: "Bernard Metzler" <BMT@zurich.ibm.com> > >From: "Jason Gunthorpe" <jgg@ziepe.ca> > >Date: 06/11/2020 01:35PM > >Cc: "Tom Seewald" <tseewald@gmail.com>, linux-rdma@vger.kernel.org, > >"Doug Ledford" <dledford@redhat.com> > >Subject: [EXTERNAL] Re: Re: [PATCH next] siw: Fix pointer-to-int-cast > >warning in siw_rx_pbl() > > > >On Thu, Jun 11, 2020 at 10:21:49AM +0000, Bernard Metzler wrote: > >> > >> >To: "Tom Seewald" <tseewald@gmail.com> > >> >From: "Jason Gunthorpe" <jgg@ziepe.ca> > >> >Date: 06/10/2020 07:50PM > >> >Cc: linux-rdma@vger.kernel.org, "Bernard Metzler" > >> ><bmt@zurich.ibm.com>, "Doug Ledford" <dledford@redhat.com> > >> >Subject: [EXTERNAL] Re: [PATCH next] siw: Fix pointer-to-int-cast > >> >warning in siw_rx_pbl() > >> > > >> >On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: > >> >> The variable buf_addr is type dma_addr_t, which may not be the > >same > >> >size > >> >> as a pointer. To ensure it is the correct size, cast to a > >> >uintptr_t. > >> >> > >> >> Signed-off-by: Tom Seewald <tseewald@gmail.com> > >> >> drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- > >> >> 1 file changed, 2 insertions(+), 1 deletion(-) > >> >> > >> >> diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c > >> >b/drivers/infiniband/sw/siw/siw_qp_rx.c > >> >> index 650520244ed0..7271d705f4b0 100644 > >> >> +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c > >> >> @@ -139,7 +139,8 @@ static int siw_rx_pbl(struct siw_rx_stream > >> >*srx, int *pbl_idx, > >> >> break; > >> >> > >> >> bytes = min(bytes, len); > >> >> - if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) { > >> >> + if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) == > >> >> + bytes) { > >> > > >> >How is a dma_addr_t being cast to a void *? That can't be right? > >> >Bernard?? > >> > > >> >Jason > >> > > >> Hi Tom, Hi Jason, > >> > >> Thanks for looking into that. > >> > >> siw_rx_kva() calls skb_copy_bits() to move data to its > >> kernel clients destination. It expects a void * target > >> address. This is why I chose it for siw_rx_kva() as well. > >> One could say siw_rx_kva() should better get an uintptr_t > >> as target argument, which would probably make it look > >> more clean. And we rename it to siw_rx_kbuf(), and we > >> cast from uintptr_t to (void *) just for > >> skb_copy_bits(skb *, off, (void *)dest, len) > >> > >> This would avoid all those nasty (void *) casting at all (!) > >> the places we are calling siw_rx_kva(). > > > >But where did the dma_addr_t come from? > > > It initially comes from the scatterlist provided by the > kernel user via drivers .map_mr_sg() method. There we get a > dma_addr_t describing the users buffer. For the SW dma maps you have to convert the dma_addr_t to a kva using kmap, it cannot just be casted. Jason ^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-11 14:11 ` Bernard Metzler 2020-06-11 14:23 ` Jason Gunthorpe @ 2020-06-11 15:06 ` Bernard Metzler 2020-06-11 17:05 ` Jason Gunthorpe 2020-06-12 15:56 ` Bernard Metzler 1 sibling, 2 replies; 11+ messages in thread From: Bernard Metzler @ 2020-06-11 15:06 UTC (permalink / raw) To: Jason Gunthorpe; +Cc: Tom Seewald, linux-rdma, Doug Ledford -----"Jason Gunthorpe" <jgg@ziepe.ca> wrote: ----- >To: "Bernard Metzler" <BMT@zurich.ibm.com> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >Date: 06/11/2020 04:24PM >Cc: "Tom Seewald" <tseewald@gmail.com>, linux-rdma@vger.kernel.org, >"Doug Ledford" <dledford@redhat.com> >Subject: [EXTERNAL] Re: Re: [PATCH next] siw: Fix pointer-to-int-cast >warning in siw_rx_pbl() > >On Thu, Jun 11, 2020 at 02:11:51PM +0000, Bernard Metzler wrote: >> >> >To: "Bernard Metzler" <BMT@zurich.ibm.com> >> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >> >Date: 06/11/2020 01:35PM >> >Cc: "Tom Seewald" <tseewald@gmail.com>, >linux-rdma@vger.kernel.org, >> >"Doug Ledford" <dledford@redhat.com> >> >Subject: [EXTERNAL] Re: Re: [PATCH next] siw: Fix >pointer-to-int-cast >> >warning in siw_rx_pbl() >> > >> >On Thu, Jun 11, 2020 at 10:21:49AM +0000, Bernard Metzler wrote: >> >> >> >> >To: "Tom Seewald" <tseewald@gmail.com> >> >> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >> >> >Date: 06/10/2020 07:50PM >> >> >Cc: linux-rdma@vger.kernel.org, "Bernard Metzler" >> >> ><bmt@zurich.ibm.com>, "Doug Ledford" <dledford@redhat.com> >> >> >Subject: [EXTERNAL] Re: [PATCH next] siw: Fix >pointer-to-int-cast >> >> >warning in siw_rx_pbl() >> >> > >> >> >On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: >> >> >> The variable buf_addr is type dma_addr_t, which may not be >the >> >same >> >> >size >> >> >> as a pointer. To ensure it is the correct size, cast to a >> >> >uintptr_t. >> >> >> >> >> >> Signed-off-by: Tom Seewald <tseewald@gmail.com> >> >> >> drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- >> >> >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> >> >> >> >> diff --git a/drivers/infiniband/sw/siw/siw_qp_rx.c >> >> >b/drivers/infiniband/sw/siw/siw_qp_rx.c >> >> >> index 650520244ed0..7271d705f4b0 100644 >> >> >> +++ b/drivers/infiniband/sw/siw/siw_qp_rx.c >> >> >> @@ -139,7 +139,8 @@ static int siw_rx_pbl(struct >siw_rx_stream >> >> >*srx, int *pbl_idx, >> >> >> break; >> >> >> >> >> >> bytes = min(bytes, len); >> >> >> - if (siw_rx_kva(srx, (void *)buf_addr, bytes) == bytes) { >> >> >> + if (siw_rx_kva(srx, (void *)(uintptr_t)buf_addr, bytes) == >> >> >> + bytes) { >> >> > >> >> >How is a dma_addr_t being cast to a void *? That can't be >right? >> >> >Bernard?? >> >> > >> >> >Jason >> >> > >> >> Hi Tom, Hi Jason, >> >> >> >> Thanks for looking into that. >> >> >> >> siw_rx_kva() calls skb_copy_bits() to move data to its >> >> kernel clients destination. It expects a void * target >> >> address. This is why I chose it for siw_rx_kva() as well. >> >> One could say siw_rx_kva() should better get an uintptr_t >> >> as target argument, which would probably make it look >> >> more clean. And we rename it to siw_rx_kbuf(), and we >> >> cast from uintptr_t to (void *) just for >> >> skb_copy_bits(skb *, off, (void *)dest, len) >> >> >> >> This would avoid all those nasty (void *) casting at all (!) >> >> the places we are calling siw_rx_kva(). >> > >> >But where did the dma_addr_t come from? >> > >> It initially comes from the scatterlist provided by the >> kernel user via drivers .map_mr_sg() method. There we get a >> dma_addr_t describing the users buffer. > >For the SW dma maps you have to convert the dma_addr_t to a kva using >kmap, it cannot just be casted. > True for a real dma addr. But here the user initially came with an address it got from dma_virt_ops.dma_virt_map_page(), which provides the virtual address of the page referenced, casted to dma_addr_t. So we mimic some great dma_addr_t stuff we do not need for a SW driver and in the end we even have to call heavy kmap_atomic() to just get the very same addr again. This I don't want. It's why I just casted it back to void *. hmmm. Thanks, Bernard. ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-11 15:06 ` Bernard Metzler @ 2020-06-11 17:05 ` Jason Gunthorpe 2020-06-12 15:56 ` Bernard Metzler 1 sibling, 0 replies; 11+ messages in thread From: Jason Gunthorpe @ 2020-06-11 17:05 UTC (permalink / raw) To: Bernard Metzler; +Cc: Tom Seewald, linux-rdma, Doug Ledford On Thu, Jun 11, 2020 at 03:06:12PM +0000, Bernard Metzler wrote: > >> It initially comes from the scatterlist provided by the > >> kernel user via drivers .map_mr_sg() method. There we get a > >> dma_addr_t describing the users buffer. > > > >For the SW dma maps you have to convert the dma_addr_t to a kva using > >kmap, it cannot just be casted. > > > True for a real dma addr. But here the user initially came > with an address it got from dma_virt_ops.dma_virt_map_page(), > which provides the virtual address of the page referenced, > casted to dma_addr_t. Oh, that's curiously broken on highmem systems, but OK siw is fine with it like that, though I think it would have been better to have some helper function connected to dma_virt do this cast. Jason ^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-11 15:06 ` Bernard Metzler 2020-06-11 17:05 ` Jason Gunthorpe @ 2020-06-12 15:56 ` Bernard Metzler 1 sibling, 0 replies; 11+ messages in thread From: Bernard Metzler @ 2020-06-12 15:56 UTC (permalink / raw) To: Jason Gunthorpe; +Cc: Tom Seewald, linux-rdma, Doug Ledford -----"Jason Gunthorpe" <jgg@ziepe.ca> wrote: ----- >To: "Bernard Metzler" <BMT@zurich.ibm.com> >From: "Jason Gunthorpe" <jgg@ziepe.ca> >Date: 06/11/2020 07:05PM >Cc: "Tom Seewald" <tseewald@gmail.com>, linux-rdma@vger.kernel.org, >"Doug Ledford" <dledford@redhat.com> >Subject: [EXTERNAL] Re: Re: [PATCH next] siw: Fix pointer-to-int-cast >warning in siw_rx_pbl() > >On Thu, Jun 11, 2020 at 03:06:12PM +0000, Bernard Metzler wrote: >> >> It initially comes from the scatterlist provided by the >> >> kernel user via drivers .map_mr_sg() method. There we get a >> >> dma_addr_t describing the users buffer. >> > >> >For the SW dma maps you have to convert the dma_addr_t to a kva >using >> >kmap, it cannot just be casted. >> > >> True for a real dma addr. But here the user initially came >> with an address it got from dma_virt_ops.dma_virt_map_page(), >> which provides the virtual address of the page referenced, >> casted to dma_addr_t. > >Oh, that's curiously broken on highmem systems, but OK siw is fine >with it like that, though I think it would have been better to have >some helper function connected to dma_virt do this cast. > >Jason > With that, lets take Tom's simple patch for now. Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() 2020-06-10 17:47 [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() Tom Seewald 2020-06-10 17:50 ` Jason Gunthorpe 2020-06-11 10:21 ` Bernard Metzler @ 2020-06-16 14:03 ` Jason Gunthorpe 2 siblings, 0 replies; 11+ messages in thread From: Jason Gunthorpe @ 2020-06-16 14:03 UTC (permalink / raw) To: Tom Seewald; +Cc: linux-rdma, Bernard Metzler, Doug Ledford On Wed, Jun 10, 2020 at 12:47:17PM -0500, Tom Seewald wrote: > The variable buf_addr is type dma_addr_t, which may not be the same size > as a pointer. To ensure it is the correct size, cast to a uintptr_t. > > Signed-off-by: Tom Seewald <tseewald@gmail.com> > Reviewed-by: Bernard Metzler <bmt@zurich.ibm.com> > drivers/infiniband/sw/siw/siw_qp_rx.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Applied to for-rc, thanks Jason ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2020-06-16 14:03 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-06-10 17:47 [PATCH next] siw: Fix pointer-to-int-cast warning in siw_rx_pbl() Tom Seewald 2020-06-10 17:50 ` Jason Gunthorpe 2020-06-10 18:21 ` Tom Seewald 2020-06-11 10:21 ` Bernard Metzler 2020-06-11 11:35 ` Jason Gunthorpe 2020-06-11 14:11 ` Bernard Metzler 2020-06-11 14:23 ` Jason Gunthorpe 2020-06-11 15:06 ` Bernard Metzler 2020-06-11 17:05 ` Jason Gunthorpe 2020-06-12 15:56 ` Bernard Metzler 2020-06-16 14:03 ` Jason Gunthorpe
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).