2015-01-27 09:54:44

by Cristian Stoica

[permalink] [raw]
Subject: [PATCH] crypto: tcrypt: fix buflen reminder calculation

- This fixes the intent of the code to limit the last scatterlist to
either a full PAGE or a fraction of it, depending on the number of
pages needed by buflen and the available space advertised by XBUFLEN.

The original code always sets the last scatterlist to a fraction of a
PAGE because the first 'if' is never executed.

- Rearrange the second part of the code to remove the conditional from
the loop

Signed-off-by: Cristian Stoica <[email protected]>
---
crypto/tcrypt.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/crypto/tcrypt.c b/crypto/tcrypt.c
index 0043495..2b2486a 100644
--- a/crypto/tcrypt.c
+++ b/crypto/tcrypt.c
@@ -250,19 +250,19 @@ static void sg_init_aead(struct scatterlist *sg, char *xbuf[XBUFSIZE],
int np = (buflen + PAGE_SIZE - 1)/PAGE_SIZE;
int k, rem;

- np = (np > XBUFSIZE) ? XBUFSIZE : np;
- rem = buflen % PAGE_SIZE;
if (np > XBUFSIZE) {
rem = PAGE_SIZE;
np = XBUFSIZE;
+ } else {
+ rem = buflen % PAGE_SIZE;
}
+
sg_init_table(sg, np);
- for (k = 0; k < np; ++k) {
- if (k == (np-1))
- sg_set_buf(&sg[k], xbuf[k], rem);
- else
- sg_set_buf(&sg[k], xbuf[k], PAGE_SIZE);
- }
+ np--;
+ for (k = 0; k < np; k++)
+ sg_set_buf(&sg[k], xbuf[k], PAGE_SIZE);
+
+ sg_set_buf(&sg[k], xbuf[k], rem);
}

static void test_aead_speed(const char *algo, int enc, unsigned int secs,
--
2.2.0