From: "Philippe De Muyter" <phdm@macqel.be>
Avoid ppp-generated kernel crashes on machines where unaligned accesses are
forbidden (ie: 68000-based CPUs)
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
drivers/net/ppp_async.c | 17 ++++++++++++++++-
1 files changed, 16 insertions(+), 1 deletion(-)
diff -puN drivers/net/ppp_async.c~ppp-handle-misaligned-accesses drivers/net/ppp_async.c
--- 25/drivers/net/ppp_async.c~ppp-handle-misaligned-accesses Mon Jun 20 15:30:35 2005
+++ 25-akpm/drivers/net/ppp_async.c Mon Jun 20 15:30:35 2005
@@ -31,6 +31,7 @@
#include <linux/spinlock.h>
#include <linux/init.h>
#include <asm/uaccess.h>
+#include <asm/string.h>
#define PPP_VERSION "2.4.2"
@@ -816,7 +817,15 @@ process_input_packet(struct asyncppp *ap
proto = p[0];
if (proto & 1) {
/* protocol is compressed */
- skb_push(skb, 1)[0] = 0;
+ if ((unsigned long)skb->data & 1)
+ skb_push(skb, 1)[0] = 0;
+ else { /* Ditto, but realign the payload to 4-byte boundary */
+ short len = skb->len;
+
+ skb_put(skb, 3);
+ memmove(skb->data + 3, skb->data, len);
+ skb_pull(skb, 2)[0] = 0;
+ }
} else {
if (skb->len < 2)
goto err;
@@ -890,6 +899,12 @@ ppp_async_input(struct asyncppp *ap, con
if (skb == 0)
goto nomem;
/* Try to get the payload 4-byte aligned */
+ /* This should match the
+ ** PPP_ALLSTATIONS/PPP_UI/compressed tests
+ ** in process_input_packet,
+ ** but we do not have enough chars here and
+ ** now to test buf[1] and buf[2].
+ */
if (buf[0] != PPP_ALLSTATIONS)
skb_reserve(skb, 2 + (buf[0] & 1));
ap->rpkt = skb;
_