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Groups > linux.kernel > #1559773 > unrolled thread
| Started by | Tvrtko Ursulin <tursulin@ursulin.net> |
|---|---|
| First post | 2017-01-16 15:20 +0100 |
| Last post | 2017-01-30 10:50 +0100 |
| Articles | 4 — 2 participants |
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[PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Tvrtko Ursulin <tursulin@ursulin.net> - 2017-01-16 15:20 +0100
[PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow Tvrtko Ursulin <tursulin@ursulin.net> - 2017-01-16 15:20 +0100
[PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin <tursulin@ursulin.net> - 2017-01-16 15:20 +0100
Re: [Intel-gfx] [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Daniel Vetter <daniel@ffwll.ch> - 2017-01-30 10:50 +0100
| From | Tvrtko Ursulin <tursulin@ursulin.net> |
|---|---|
| Date | 2017-01-16 15:20 +0100 |
| Subject | [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages |
| Message-ID | <t0giB-1uH-3@gated-at.bofh.it> |
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 fb6a177be461..51e8765bc3c6 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -478,7 +478,7 @@ 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;
@@ -506,7 +506,7 @@ 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 9013a585507e..0fae29ff47ba 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 cb3c8fe6acd7..c981bee1a3ae 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 004fc70fc56a..e05e7fc98892 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;
--
2.7.4
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| From | Tvrtko Ursulin <tursulin@ursulin.net> |
|---|---|
| Date | 2017-01-16 15:20 +0100 |
| Subject | [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow |
| Message-ID | <t0giB-1uH-17@gated-at.bofh.it> |
| In reply to | #1559773 |
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Since the scatterlist length field is an unsigned int, make
sure that sg_alloc_table_from_pages does not overflow it while
coallescing pages to a single entry.
v2: Drop reference to future use. Use UINT_MAX.
v3: max_segment must be page aligned.
v4: Do not rely on compiler to optimise out the rounddown.
(Joonas Lahtinen)
v5: Simplified loops and use post-increments rather than
pre-increments. Use PAGE_MASK and fix comment typo.
(Andy Shevchenko)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
---
include/linux/scatterlist.h | 6 ++++++
lib/scatterlist.c | 31 ++++++++++++++++++++-----------
2 files changed, 26 insertions(+), 11 deletions(-)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index c981bee1a3ae..4768eeeb7054 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -21,6 +21,12 @@ struct scatterlist {
};
/*
+ * Since the above length field is an unsigned int, below we define the maximum
+ * length in bytes that can be stored in one scatterlist entry.
+ */
+#define SCATTERLIST_MAX_SEGMENT (UINT_MAX & PAGE_MASK)
+
+/*
* These macros should be used after a dma_map_sg call has been done
* to get bus addresses of each of the SG entries and their lengths.
* You should only work with the number of sg entries dma_map_sg
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index e05e7fc98892..65f375645df5 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -394,17 +394,22 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
unsigned int offset, unsigned long size,
gfp_t gfp_mask)
{
- unsigned int chunks;
- unsigned int i;
- unsigned int cur_page;
+ const unsigned int max_segment = SCATTERLIST_MAX_SEGMENT;
+ unsigned int chunks, cur_page, seg_len, i;
int ret;
struct scatterlist *s;
/* compute number of contiguous chunks */
chunks = 1;
- for (i = 1; i < n_pages; ++i)
- if (page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1)
- ++chunks;
+ seg_len = 0;
+ for (i = 1; i < n_pages; i++) {
+ seg_len += PAGE_SIZE;
+ if (seg_len >= max_segment ||
+ page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) {
+ chunks++;
+ seg_len = 0;
+ }
+ }
ret = sg_alloc_table(sgt, chunks, gfp_mask);
if (unlikely(ret))
@@ -413,17 +418,21 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
/* merging chunks and putting them into the scatterlist */
cur_page = 0;
for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
- unsigned long chunk_size;
- unsigned int j;
+ unsigned int j, chunk_size;
/* look for the end of the current chunk */
- for (j = cur_page + 1; j < n_pages; ++j)
- if (page_to_pfn(pages[j]) !=
+ seg_len = 0;
+ for (j = cur_page + 1; j < n_pages; j++) {
+ seg_len += PAGE_SIZE;
+ if (seg_len >= max_segment ||
+ page_to_pfn(pages[j]) !=
page_to_pfn(pages[j - 1]) + 1)
break;
+ }
chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset;
- sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
+ sg_set_page(s, pages[cur_page],
+ min_t(unsigned long, size, chunk_size), offset);
size -= chunk_size;
offset = 0;
cur_page = j;
--
2.7.4
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| From | Tvrtko Ursulin <tursulin@ursulin.net> |
|---|---|
| Date | 2017-01-16 15:20 +0100 |
| Subject | [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages |
| Message-ID | <t0giC-1uH-31@gated-at.bofh.it> |
| In reply to | #1559773 |
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Drivers like i915 benefit from being able to control the maxium
size of the sg coallesced segment while building the scatter-
gather list.
Introduce and export the __sg_alloc_table_from_pages function
which will allow it that control.
v2: Reorder parameters. (Chris Wilson)
v3: Fix incomplete reordering in v2.
v4: max_segment needs to be page aligned.
v5: Rebase.
v6: Rebase.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-kernel@vger.kernel.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
include/linux/scatterlist.h | 11 +++++----
lib/scatterlist.c | 58 +++++++++++++++++++++++++++++++++++----------
2 files changed, 52 insertions(+), 17 deletions(-)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 4768eeeb7054..4d67a9652c7d 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -267,10 +267,13 @@ void sg_free_table(struct sg_table *);
int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
struct scatterlist *, gfp_t, sg_alloc_fn *);
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 int offset, unsigned long size,
- gfp_t gfp_mask);
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask);
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
size_t buflen, off_t skip, bool to_buffer);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 65f375645df5..326119281167 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
EXPORT_SYMBOL(sg_alloc_table);
/**
- * sg_alloc_table_from_pages - Allocate and initialize an sg table from
- * an array of pages
- * @sgt: The sg table header to use
- * @pages: Pointer to an array of page pointers
- * @n_pages: Number of pages in the pages array
- * @offset: Offset from start of the first page to the start of a buffer
- * @size: Number of valid bytes in the buffer (after offset)
- * @gfp_mask: GFP allocation mask
+ * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @max_segment: Maximum size of a scatterlist node in bytes (page aligned)
+ * @gfp_mask: GFP allocation mask
*
* Description:
* Allocate and initialize an sg table from a list of pages. Contiguous
@@ -389,16 +390,18 @@ EXPORT_SYMBOL(sg_alloc_table);
* Returns:
* 0 on success, negative error on failure
*/
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask)
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask)
{
- const unsigned int max_segment = SCATTERLIST_MAX_SEGMENT;
unsigned int chunks, cur_page, seg_len, i;
int ret;
struct scatterlist *s;
+ if (WARN_ON(!max_segment || offset_in_page(max_segment)))
+ return -EINVAL;
+
/* compute number of contiguous chunks */
chunks = 1;
seg_len = 0;
@@ -440,6 +443,35 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
return 0;
}
+EXPORT_SYMBOL(__sg_alloc_table_from_pages);
+
+/**
+ * sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @gfp_mask: GFP allocation mask
+ *
+ * Description:
+ * Allocate and initialize an sg table from a list of pages. Contiguous
+ * ranges of the pages are squashed into a single scatterlist node. A user
+ * may provide an offset at a start and a size of valid data in a buffer
+ * specified by the page array. The returned sg table is released by
+ * sg_free_table.
+ *
+ * Returns:
+ * 0 on success, negative error on failure
+ */
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask)
+{
+ return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset, size,
+ SCATTERLIST_MAX_SEGMENT, gfp_mask);
+}
EXPORT_SYMBOL(sg_alloc_table_from_pages);
void __sg_page_iter_start(struct sg_page_iter *piter,
--
2.7.4
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| From | Daniel Vetter <daniel@ffwll.ch> |
|---|---|
| Date | 2017-01-30 10:50 +0100 |
| Subject | Re: [Intel-gfx] [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages |
| Message-ID | <t5gL0-2ll-35@gated-at.bofh.it> |
| In reply to | #1559773 |
Hi all,
Ok if we merge the entire series through drm-intel (likely for 4.12, 4.11
is getting a bit late)? We'd like to use this there, and Mauro already
reviewed the v4l side ...
Thanks, Daniel
On Mon, Jan 16, 2017 at 02:12:07PM +0000, Tvrtko Ursulin wrote:
> 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 fb6a177be461..51e8765bc3c6 100644
> --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
> +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
> @@ -478,7 +478,7 @@ 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;
> @@ -506,7 +506,7 @@ 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 9013a585507e..0fae29ff47ba 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 cb3c8fe6acd7..c981bee1a3ae 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 004fc70fc56a..e05e7fc98892 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;
> --
> 2.7.4
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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