This patch adds a check for in scatterwalk_map_and_copy to avoid copying from the same address to the same address. This is going to be used for IV copying in AEAD IV generators. There is no provision for partial overlaps. This patch also uses the new scatterwalk_ffwd instead of doing it by hand in scatterwalk_map_and_copy. Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> --- crypto/scatterwalk.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c index db920b5..8690324 100644 --- a/crypto/scatterwalk.c +++ b/crypto/scatterwalk.c @@ -104,22 +104,18 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg, unsigned int start, unsigned int nbytes, int out) { struct scatter_walk walk; - unsigned int offset = 0; + struct scatterlist tmp[2]; if (!nbytes) return; - for (;;) { - scatterwalk_start(&walk, sg); - - if (start < offset + sg->length) - break; + sg = scatterwalk_ffwd(tmp, sg, start); - offset += sg->length; - sg = sg_next(sg); - } + if (sg_page(sg) == virt_to_page(buf) && + sg->offset == offset_in_page(buf)) + return; - scatterwalk_advance(&walk, start - offset); + scatterwalk_start(&walk, sg); scatterwalk_copychunks(buf, &walk, nbytes, out); scatterwalk_done(&walk, out, 0); } -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html