Tony Lindgren bc417e30f8 net: Add back alignment for size for __alloc_skb ... Commit 87fb4b7b53 (net: more accurate skb truesize) changed the alignment of size. This can cause problems at least on some machines with NFS root: Unhandled fault: alignment exception (0x801) at 0xc183a43a Internal error: : 801 [#1] PREEMPT Modules linked in: CPU: 0 Not tainted (3.1.0-08784-g5eeee4a #733) pc : [<c02fbba0>] lr : [<c02fbb9c>] psr: 60000013 sp : c180fef8 ip : 00000000 fp : c181f580 r10: 00000000 r9 : c044b28c r8 : 00000001 r7 : c183a3a0 r6 : c1835be0 r5 : c183a412 r4 : 000001f2 r3 : 00000000 r2 : 00000000 r1 : ffffffe6 r0 : c183a43a Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 0005317f Table: 10004000 DAC: 00000017 Process swapper (pid: 1, stack limit = 0xc180e270) Stack: (0xc180fef8 to 0xc1810000) fee0: 00000024 00000000 ff00: 00000000 c183b9c0 c183b8e0 c044b28c c0507ccc c019dfc4 c180ff2c c0503cf8 ff20: c180ff4c c180ff4c 00000000 c1835420 c182c740 c18349c0 c05233c0 00000000 ff40: 00000000 c00e6bb8 c180e000 00000000 c04dd82c c0507e7c c050cc18 c183b9c0 ff60: c05233c0 00000000 00000000 c01f34f4 c0430d70 c019d364 c04dd898 c04dd898 ff80: c04dd82c c0507e7c c180e000 00000000 c04c584c c01f4918 c04dd898 c04dd82c ffa0: c04ddd28 c180e000 00000000 c0008758 c181fa60 3231d82c 00000037 00000000 ffc0: 00000000 c04dd898 c04dd82c c04ddd28 00000013 00000000 00000000 00000000 ffe0: 00000000 c04b2224 00000000 c04b21a0 c001056c c001056c 00000000 00000000 Function entered at [<c02fbba0>] from [<c019dfc4>] Function entered at [<c019dfc4>] from [<c01f34f4>] Function entered at [<c01f34f4>] from [<c01f4918>] Function entered at [<c01f4918>] from [<c0008758>] Function entered at [<c0008758>] from [<c04b2224>] Function entered at [<c04b2224>] from [<c001056c>] Code: e1a00005 e3a01028 ebfa7cb0 e35a0000 (e5858028) Here PC is at __alloc_skb and &shinfo->dataref is unaligned because skb->end can be unaligned without this patch. As explained by Eric Dumazet <eric.dumazet@gmail.com>, this happens only with SLOB, and not with SLAB or SLUB: * Eric Dumazet <eric.dumazet@gmail.com> [111102 15:56]: > > Your patch is absolutely needed, I completely forgot about SLOB :( > > since, kmalloc(386) on SLOB gives exactly ksize=386 bytes, not nearest > power of two. > > [ 60.305763] malloc(size=385)->ffff880112c11e38 ksize=386 -> nsize=2 > [ 60.305921] malloc(size=385)->ffff88007c92ce28 ksize=386 -> nsize=2 > [ 60.306898] malloc(size=656)->ffff88007c44ad28 ksize=656 -> nsize=272 > [ 60.325385] malloc(size=656)->ffff88007c575868 ksize=656 -> nsize=272 > [ 60.325531] malloc(size=656)->ffff88011c777230 ksize=656 -> nsize=272 > [ 60.325701] malloc(size=656)->ffff880114011008 ksize=656 -> nsize=272 > [ 60.346716] malloc(size=385)->ffff880114142008 ksize=386 -> nsize=2 > [ 60.346900] malloc(size=385)->ffff88011c777690 ksize=386 -> nsize=2 Signed-off-by: Tony Lindgren <tony@atomide.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2011-11-03 18:09:16 -04:00
..
9p	net/9p: Convert net/9p protocol dumps to tracepoints	2011-10-24 11:13:12 -05:00
802
8021q	vlan: Don't propagate flag changes on down interfaces.	2011-11-01 17:51:03 -04:00
appletalk	net: add skb frag size accessors	2011-10-19 03:10:46 -04:00
atm	Merge branch 'master' of github.com:davem330/net	2011-09-22 03:23:13 -04:00
ax25
batman-adv	Merge branch 'batman-adv/maint' of git://git.open-mesh.org/linux-merge	2011-10-30 03:05:07 -04:00
bluetooth	Merge branch 'master' of ra.kernel.org:/pub/scm/linux/kernel/git/davem/net	2011-10-24 18:18:09 -04:00
bridge	netfilter: Remove unnecessary OOM logging messages	2011-11-01 09:19:49 +01:00
caif	caif: Fix BUG() with network namespaces	2011-10-25 19:22:23 -04:00
can	can: remove references to berlios mailinglist	2011-10-17 19:22:46 -04:00
ceph	libceph: force resend of osd requests if we skip an osdmap	2011-10-25 16:10:17 -07:00
core	net: Add back alignment for size for __alloc_skb	2011-11-03 18:09:16 -04:00
dcb	dcb: add DCBX mode to event notifier attributes	2011-10-06 15:49:51 -04:00
dccp	net: add missing bh_unlock_sock() calls	2011-11-03 18:06:18 -04:00
decnet
dns_resolver
dsa
econet
ethernet
ieee802154
ipv4	net: add missing bh_unlock_sock() calls	2011-11-03 18:06:18 -04:00
ipv6	net: make the tcp and udp file_operations for the /proc stuff const	2011-11-01 17:56:14 -04:00
ipx
irda	Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty	2011-10-26 15:11:09 +02:00
iucv	net: more accurate skb truesize	2011-10-13 16:05:07 -04:00
key
l2tp	l2tp: fix race in l2tp_recv_dequeue()	2011-11-03 18:02:13 -04:00
lapb
llc
mac80211	Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm	2011-10-25 15:18:39 +02:00
netfilter	netfilter: do not propagate nf_queue errors in nf_hook_slow	2011-11-01 09:57:21 +01:00
netlabel
netlink	af_unix: dont send SCM_CREDENTIALS by default	2011-09-28 13:29:50 -04:00
netrom
nfc	treewide: use __printf not __attribute__((format(printf,...)))	2011-10-31 17:30:54 -07:00
packet	macvlan: handle fragmented multicast frames	2011-10-18 23:22:07 -04:00
phonet
rds	treewide: use __printf not __attribute__((format(printf,...)))	2011-10-31 17:30:54 -07:00
rfkill	net:rfkill: add a gpio setup function into GPIO rfkill	2011-10-03 15:19:19 -04:00
rose
rxrpc
sched	net_sched: cls_flow: use skb_header_pointer()	2011-10-24 18:40:14 -04:00
sctp	ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAIT	2011-10-27 00:44:35 -04:00
sunrpc	treewide: use __printf not __attribute__((format(printf,...)))	2011-10-31 17:30:54 -07:00
tipc
unix	af_unix: dont send SCM_CREDENTIALS by default	2011-09-28 13:29:50 -04:00
wanrouter
wimax
wireless	nl80211: Add sta_flags to the station info	2011-10-14 14:48:23 -04:00
x25	x25: Fix NULL dereference in x25_recvmsg	2011-11-02 00:49:49 -04:00
xfrm	net: add skb frag size accessors	2011-10-19 03:10:46 -04:00
compat.c
Kconfig
Makefile
nonet.c
socket.c	Merge branch 'master' of github.com:davem330/net	2011-09-22 03:23:13 -04:00
sysctl_net.c