[PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages

Tvrtko Ursulin
2017-07-27T09:05:16Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Scatterlist entries have an unsigned int for the offset so
correct the sg_alloc_table_from_pages function accordingly.

Since these are offsets withing a page, unsigned int is
wide enough.

Also converts callers which were using unsigned long locally
with the lower_32_bits annotation to make it explicitly
clear what is happening.

v2: Use offset_in_page. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: linux-media@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> (v1)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---
drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 ++--
drivers/rapidio/devices/rio_mport_cdev.c | 4 ++--
include/linux/scatterlist.h | 2 +-
lib/scatterlist.c | 2 +-
4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 4f246d166111..2405077fdc71 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -479,7 +479,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
{
struct vb2_dc_buf *buf;
struct frame_vector *vec;
- unsigned long offset;
+ unsigned int offset;
int n_pages, i;
int ret = 0;
struct sg_table *sgt;
@@ -507,7 +507,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
buf->dev = dev;
buf->dma_dir = dma_dir;

- offset = vaddr & ~PAGE_MASK;
+ offset = lower_32_bits(offset_in_page(vaddr));
vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
if (IS_ERR(vec)) {
ret = PTR_ERR(vec);
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 5beb0c361076..5c1b6388122a 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -876,10 +876,10 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
* offset within the internal buffer specified by handle parameter.
*/
if (xfer->loc_addr) {
- unsigned long offset;
+ unsigned int offset;
long pinned;

- offset = (unsigned long)(uintptr_t)xfer->loc_addr & ~PAGE_MASK;
+ offset = lower_32_bits(offset_in_page(xfer->loc_addr));
nr_pages = PAGE_ALIGN(xfer->length + offset) >> PAGE_SHIFT;

page_list = kmalloc_array(nr_pages,
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 4b3286ac60c8..205aefb4ed93 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -263,7 +263,7 @@ int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
int sg_alloc_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages,
- unsigned long offset, unsigned long size,
+ unsigned int offset, unsigned long size,
gfp_t gfp_mask);

size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index be7b4dd6b68d..dee0c5004e2f 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -391,7 +391,7 @@ EXPORT_SYMBOL(sg_alloc_table);
*/
int sg_alloc_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages,
- unsigned long offset, unsigned long size,
+ unsigned int offset, unsigned long size,
gfp_t gfp_mask)
{
unsigned int chunks;
--
2.9.4