From: Christophe Saout <christophe@saout.de>
- After calling scatterwalk_copychunks walk_in might point to the next
page which will break scatterwalk_samebuf (in this case src_p should
point to tmp_src anyway and scatterwalk_samembuf returns 0).
- scatterwalk_samebuf should also check for equal offsets inside the page
(just bad for performance in some cases).
---
25-akpm/crypto/cipher.c | 7 ++++---
25-akpm/crypto/scatterwalk.h | 1 +
2 files changed, 5 insertions(+), 3 deletions(-)
diff -puN crypto/cipher.c~crypto-scatterwalk-fixes crypto/cipher.c
--- 25/crypto/cipher.c~crypto-scatterwalk-fixes 2004-05-24 01:20:33.432054608 -0700
+++ 25-akpm/crypto/cipher.c 2004-05-24 01:20:33.437053848 -0700
@@ -68,19 +68,20 @@ static int crypt(struct crypto_tfm *tfm,
for(;;) {
u8 *src_p, *dst_p;
+ int in_place;
scatterwalk_map(&walk_in, 0);
scatterwalk_map(&walk_out, 1);
src_p = scatterwalk_whichbuf(&walk_in, bsize, tmp_src);
dst_p = scatterwalk_whichbuf(&walk_out, bsize, tmp_dst);
+ in_place = scatterwalk_samebuf(&walk_in, &walk_out,
+ src_p, dst_p);
nbytes -= bsize;
scatterwalk_copychunks(src_p, &walk_in, bsize, 0);
- prfn(tfm, dst_p, src_p, crfn, enc, info,
- scatterwalk_samebuf(&walk_in, &walk_out,
- src_p, dst_p));
+ prfn(tfm, dst_p, src_p, crfn, enc, info, in_place);
scatterwalk_done(&walk_in, 0, nbytes);
diff -puN crypto/scatterwalk.h~crypto-scatterwalk-fixes crypto/scatterwalk.h
--- 25/crypto/scatterwalk.h~crypto-scatterwalk-fixes 2004-05-24 01:20:33.434054304 -0700
+++ 25-akpm/crypto/scatterwalk.h 2004-05-24 01:20:33.438053696 -0700
@@ -38,6 +38,7 @@ static inline int scatterwalk_samebuf(st
void *src_p, void *dst_p)
{
return walk_in->page == walk_out->page &&
+ walk_in->offset == walk_out->offset &&
walk_in->data == src_p && walk_out->data == dst_p;
}
_