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authorYashpal Dutta <yashpal.dutta@freescale.com>2013-09-11 19:24:06 +0000
committerHerbert Xu <herbert@gondor.apana.org.au>2013-09-24 06:02:20 +1000
commit82ad6bcadeb87c2a289e714a680eadba294294df (patch)
treed63f1702bdda17af9487f4621b15fb4b0ea9fa6b /drivers/crypto
parent1005bccd7a4a6345d995449b77cb1ba748ff9a28 (diff)
downloadlinux-linaro-stable-82ad6bcadeb87c2a289e714a680eadba294294df.tar.gz
crypto: caam - map src buffer before access
KMap the buffers before copying trailing bytes during hmac into a session temporary buffer. This is required if pinned buffer from user-space is send during hmac and is safe even if hmac request is generated from within kernel. Signed-off-by: Yashpal Dutta <yashpal.dutta@freescale.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/caam/sg_sw_sec4.h34
1 files changed, 25 insertions, 9 deletions
diff --git a/drivers/crypto/caam/sg_sw_sec4.h b/drivers/crypto/caam/sg_sw_sec4.h
index e0037c8ee243..b12ff85f4241 100644
--- a/drivers/crypto/caam/sg_sw_sec4.h
+++ b/drivers/crypto/caam/sg_sw_sec4.h
@@ -117,6 +117,21 @@ static int dma_unmap_sg_chained(struct device *dev, struct scatterlist *sg,
return nents;
}
+/* Map SG page in kernel virtual address space and copy */
+static inline void sg_map_copy(u8 *dest, struct scatterlist *sg,
+ int len, int offset)
+{
+ u8 *mapped_addr;
+
+ /*
+ * Page here can be user-space pinned using get_user_pages
+ * Same must be kmapped before use and kunmapped subsequently
+ */
+ mapped_addr = kmap_atomic(sg_page(sg));
+ memcpy(dest, mapped_addr + offset, len);
+ kunmap_atomic(mapped_addr);
+}
+
/* Copy from len bytes of sg to dest, starting from beginning */
static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len)
{
@@ -124,15 +139,15 @@ static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len)
int cpy_index = 0, next_cpy_index = current_sg->length;
while (next_cpy_index < len) {
- memcpy(dest + cpy_index, (u8 *) sg_virt(current_sg),
- current_sg->length);
+ sg_map_copy(dest + cpy_index, current_sg, current_sg->length,
+ current_sg->offset);
current_sg = scatterwalk_sg_next(current_sg);
cpy_index = next_cpy_index;
next_cpy_index += current_sg->length;
}
if (cpy_index < len)
- memcpy(dest + cpy_index, (u8 *) sg_virt(current_sg),
- len - cpy_index);
+ sg_map_copy(dest + cpy_index, current_sg, len-cpy_index,
+ current_sg->offset);
}
/* Copy sg data, from to_skip to end, to dest */
@@ -140,7 +155,7 @@ static inline void sg_copy_part(u8 *dest, struct scatterlist *sg,
int to_skip, unsigned int end)
{
struct scatterlist *current_sg = sg;
- int sg_index, cpy_index;
+ int sg_index, cpy_index, offset;
sg_index = current_sg->length;
while (sg_index <= to_skip) {
@@ -148,9 +163,10 @@ static inline void sg_copy_part(u8 *dest, struct scatterlist *sg,
sg_index += current_sg->length;
}
cpy_index = sg_index - to_skip;
- memcpy(dest, (u8 *) sg_virt(current_sg) +
- current_sg->length - cpy_index, cpy_index);
- current_sg = scatterwalk_sg_next(current_sg);
- if (end - sg_index)
+ offset = current_sg->offset + current_sg->length - cpy_index;
+ sg_map_copy(dest, current_sg, cpy_index, offset);
+ if (end - sg_index) {
+ current_sg = scatterwalk_sg_next(current_sg);
sg_copy(dest + cpy_index, current_sg, end - sg_index);
+ }
}