Module Name: src
Committed By: msaitoh
Date: Thu Aug 2 04:28:56 UTC 2018
Modified Files:
src/sys/kern: uipc_mbuf2.c
Log Message:
Adjust alignment in m_pulldown().
IP6_EXTHDR_GET() and M_REGION_GET() do m_pulldown(). When m_pulldown() copies
data into M_TRAILINGSPACE, the alignment might be changed. There are a lot of
IP6_EXTHDR_GET() calls, so I think it's not good to check the alignment after
every IP6_EXTHDR_GET() call. This change fixes this problem in m_pulldown().
In this commit, the next mbuf are 4 byte aligned. For networking, I've never
heard that 64bit alignment is required, so I think it would be OK.
I don't know this is the best solution, but it's better than nothing.
OK'd by maxv@.
After committing this change, the workaround code for PR#50776 can be removed.
To generate a diff of this commit:
cvs rdiff -u -r1.32 -r1.33 src/sys/kern/uipc_mbuf2.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/uipc_mbuf2.c
diff -u src/sys/kern/uipc_mbuf2.c:1.32 src/sys/kern/uipc_mbuf2.c:1.33
--- src/sys/kern/uipc_mbuf2.c:1.32 Sun Apr 29 07:13:10 2018
+++ src/sys/kern/uipc_mbuf2.c Thu Aug 2 04:28:56 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: uipc_mbuf2.c,v 1.32 2018/04/29 07:13:10 maxv Exp $ */
+/* $NetBSD: uipc_mbuf2.c,v 1.33 2018/08/02 04:28:56 msaitoh Exp $ */
/* $KAME: uipc_mbuf2.c,v 1.29 2001/02/14 13:42:10 itojun Exp $ */
/*
@@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf2.c,v 1.32 2018/04/29 07:13:10 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf2.c,v 1.33 2018/08/02 04:28:56 msaitoh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -118,7 +118,12 @@ m_pulldown(struct mbuf *m, int off, int
* The target data is on <n, off>. If we got enough data on the mbuf
* "n", we're done.
*/
+#ifdef __NO_STRICT_ALIGNMENT
if ((off == 0 || offp) && len <= n->m_len - off && !sharedcluster)
+#else
+ if ((off == 0 || offp) && len <= n->m_len - off && !sharedcluster &&
+ ALIGNED_POINTER((mtod(n, char *) + off), uint32_t))
+#endif
goto ok;
/*
@@ -180,6 +185,9 @@ m_pulldown(struct mbuf *m, int off, int
goto ok;
}
if ((off == 0 || offp) && M_LEADINGSPACE(n->m_next) >= hlen &&
+#ifndef __NO_STRICT_ALIGNMENT
+ ALIGNED_POINTER((n->m_next->m_data - hlen), uint32_t) &&
+#endif
!sharedcluster && n->m_next->m_len >= tlen) {
n->m_next->m_data -= hlen;
n->m_next->m_len += hlen;
