diff options
| author | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2017-08-03 10:13:12 +0100 |
|---|---|---|
| committer | Tvrtko Ursulin <tvrtko.ursulin@intel.com> | 2017-09-07 10:48:28 +0100 |
| commit | c125906b839b794c580a5de911de65bd2c63aaee (patch) | |
| tree | d0a71a8b3ceb1d76b0b06387436bb7fab2801ef2 /include/linux/scatterlist.h | |
| parent | c4860ad60564838994b74e7ee7dd12ceeda0f520 (diff) | |
lib/scatterlist: Avoid potential scatterlist entry overflow
Since the scatterlist length field is an unsigned int, make
sure that sg_alloc_table_from_pages does not overflow it while
coalescing 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)
v6: Commit spelling fix.
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>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170803091312.22875-1-tvrtko.ursulin@linux.intel.com
Diffstat (limited to 'include/linux/scatterlist.h')
| -rw-r--r-- | include/linux/scatterlist.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 205aefb4ed93..6dd2ddbc6230 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 |