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authorYanmin Zhang <yanmin_zhang@linux.intel.com>2012-05-23 15:39:45 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-10 00:33:02 +0900
commit49d7872377ba34fc2b2e1e460073a387e7adcfae (patch)
tree8b78d3cff9d7a4d3b0ba87293936474bf1505860 /net
parentf77baf324713ef5d6ae9ae63a77aed2bfbe4333d (diff)
ipv4: fix the rcu race between free_fib_info and ip_route_output_slow
[ Upstream commit e49cc0da7283088c5e03d475ffe2fdcb24a6d5b1 ] We hit a kernel OOPS. <3>[23898.789643] BUG: sleeping function called from invalid context at /data/buildbot/workdir/ics/hardware/intel/linux-2.6/arch/x86/mm/fault.c:1103 <3>[23898.862215] in_atomic(): 0, irqs_disabled(): 0, pid: 10526, name: Thread-6683 <4>[23898.967805] HSU serial 0000:00:05.1: 0000:00:05.2:HSU serial prevented me to suspend... <4>[23899.258526] Pid: 10526, comm: Thread-6683 Tainted: G W 3.0.8-137685-ge7742f9 #1 <4>[23899.357404] HSU serial 0000:00:05.1: 0000:00:05.2:HSU serial prevented me to suspend... <4>[23899.904225] Call Trace: <4>[23899.989209] [<c1227f50>] ? pgtable_bad+0x130/0x130 <4>[23900.000416] [<c1238c2a>] __might_sleep+0x10a/0x110 <4>[23900.007357] [<c1228021>] do_page_fault+0xd1/0x3c0 <4>[23900.013764] [<c18e9ba9>] ? restore_all+0xf/0xf <4>[23900.024024] [<c17c007b>] ? napi_complete+0x8b/0x690 <4>[23900.029297] [<c1227f50>] ? pgtable_bad+0x130/0x130 <4>[23900.123739] [<c1227f50>] ? pgtable_bad+0x130/0x130 <4>[23900.128955] [<c18ea0c3>] error_code+0x5f/0x64 <4>[23900.133466] [<c1227f50>] ? pgtable_bad+0x130/0x130 <4>[23900.138450] [<c17f6298>] ? __ip_route_output_key+0x698/0x7c0 <4>[23900.144312] [<c17f5f8d>] ? __ip_route_output_key+0x38d/0x7c0 <4>[23900.150730] [<c17f63df>] ip_route_output_flow+0x1f/0x60 <4>[23900.156261] [<c181de58>] ip4_datagram_connect+0x188/0x2b0 <4>[23900.161960] [<c18e981f>] ? _raw_spin_unlock_bh+0x1f/0x30 <4>[23900.167834] [<c18298d6>] inet_dgram_connect+0x36/0x80 <4>[23900.173224] [<c14f9e88>] ? _copy_from_user+0x48/0x140 <4>[23900.178817] [<c17ab9da>] sys_connect+0x9a/0xd0 <4>[23900.183538] [<c132e93c>] ? alloc_file+0xdc/0x240 <4>[23900.189111] [<c123925d>] ? sub_preempt_count+0x3d/0x50 Function free_fib_info resets nexthop_nh->nh_dev to NULL before releasing fi. Other cpu might be accessing fi. Fixing it by delaying the releasing. With the patch, we ran MTBF testing on Android mobile for 12 hours and didn't trigger the issue. Thank Eric for very detailed review/checking the issue. Signed-off-by: Yanmin Zhang <yanmin_zhang@linux.intel.com> Signed-off-by: Kun Jiang <kunx.jiang@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/fib_semantics.c20
1 files changed, 13 insertions, 7 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 33e2c35b74b7..7e454ba8e850 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -142,6 +142,18 @@ const struct fib_prop fib_props[RTN_MAX + 1] = {
};
/* Release a nexthop info record */
+static void free_fib_info_rcu(struct rcu_head *head)
+{
+ struct fib_info *fi = container_of(head, struct fib_info, rcu);
+
+ change_nexthops(fi) {
+ if (nexthop_nh->nh_dev)
+ dev_put(nexthop_nh->nh_dev);
+ } endfor_nexthops(fi);
+
+ release_net(fi->fib_net);
+ kfree(fi);
+}
void free_fib_info(struct fib_info *fi)
{
@@ -149,14 +161,8 @@ void free_fib_info(struct fib_info *fi)
pr_warning("Freeing alive fib_info %p\n", fi);
return;
}
- change_nexthops(fi) {
- if (nexthop_nh->nh_dev)
- dev_put(nexthop_nh->nh_dev);
- nexthop_nh->nh_dev = NULL;
- } endfor_nexthops(fi);
fib_info_cnt--;
- release_net(fi->fib_net);
- kfree_rcu(fi, rcu);
+ call_rcu(&fi->rcu, free_fib_info_rcu);
}
void fib_release_info(struct fib_info *fi)