Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 82ad6bca authored by Yashpal Dutta's avatar Yashpal Dutta Committed by Herbert Xu
Browse files

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: default avatarYashpal Dutta <yashpal.dutta@freescale.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 1005bccd

drivers/crypto/caam/sg_sw_sec4.h

+25 −9
Original line number Diff line number Diff line
@@ -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);

	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);

	if (end - sg_index)

		sg_copy(dest + cpy_index, current_sg, end - sg_index);

	}

}