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authorDavid Lebrun <david.lebrun@uclouvain.be>2017-01-12 21:30:01 +0100
committerDavid S. Miller <davem@davemloft.net>2017-01-13 18:29:55 +0100
commitfa79581ea66ca43d56ef065346ac5be767fcb418 (patch)
treed683a22fc392c9eca7ff842e00c8c36df94b8005
parentnet: systemport: Decouple flow control from __bcm_sysport_tx_reclaim (diff)
downloadlinux-fa79581ea66ca43d56ef065346ac5be767fcb418.tar.xz
linux-fa79581ea66ca43d56ef065346ac5be767fcb418.zip
ipv6: sr: fix several BUGs when preemption is enabled
When CONFIG_PREEMPT=y, CONFIG_IPV6=m and CONFIG_SEG6_HMAC=y, seg6_hmac_init() is called during the initialization of the ipv6 module. This causes a subsequent call to smp_processor_id() with preemption enabled, resulting in the following trace. [ 20.451460] BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1 [ 20.452556] caller is debug_smp_processor_id+0x17/0x19 [ 20.453304] CPU: 0 PID: 1 Comm: systemd Not tainted 4.9.0-rc5-00973-g46738b1 #1 [ 20.454406] ffffc9000062fc18 ffffffff813607b2 0000000000000000 ffffffff81a7f782 [ 20.455528] ffffc9000062fc48 ffffffff813778dc 0000000000000000 00000000001dcf98 [ 20.456539] ffffffffa003bd08 ffffffff81af93e0 ffffc9000062fc58 ffffffff81377905 [ 20.456539] Call Trace: [ 20.456539] [<ffffffff813607b2>] dump_stack+0x63/0x7f [ 20.456539] [<ffffffff813778dc>] check_preemption_disabled+0xd1/0xe3 [ 20.456539] [<ffffffff81377905>] debug_smp_processor_id+0x17/0x19 [ 20.460260] [<ffffffffa0061f3b>] seg6_hmac_init+0xfa/0x192 [ipv6] [ 20.460260] [<ffffffffa0061ccc>] seg6_init+0x39/0x6f [ipv6] [ 20.460260] [<ffffffffa006121a>] inet6_init+0x21a/0x321 [ipv6] [ 20.460260] [<ffffffffa0061000>] ? 0xffffffffa0061000 [ 20.460260] [<ffffffff81000457>] do_one_initcall+0x8b/0x115 [ 20.460260] [<ffffffff811328a3>] do_init_module+0x53/0x1c4 [ 20.460260] [<ffffffff8110650a>] load_module+0x1153/0x14ec [ 20.460260] [<ffffffff81106a7b>] SYSC_finit_module+0x8c/0xb9 [ 20.460260] [<ffffffff81106a7b>] ? SYSC_finit_module+0x8c/0xb9 [ 20.460260] [<ffffffff81106abc>] SyS_finit_module+0x9/0xb [ 20.460260] [<ffffffff810014d1>] do_syscall_64+0x62/0x75 [ 20.460260] [<ffffffff816834f0>] entry_SYSCALL64_slow_path+0x25/0x25 Moreover, dst_cache_* functions also call smp_processor_id(), generating a similar trace. This patch uses raw_cpu_ptr() in seg6_hmac_init() rather than this_cpu_ptr() and disable preemption when using dst_cache_* functions. Signed-off-by: David Lebrun <david.lebrun@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv6/seg6_hmac.c2
-rw-r--r--net/ipv6/seg6_iptunnel.c4
2 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c
index ef1c8a46e7ac..03a064803626 100644
--- a/net/ipv6/seg6_hmac.c
+++ b/net/ipv6/seg6_hmac.c
@@ -400,7 +400,7 @@ static int seg6_hmac_init_algo(void)
*p_tfm = tfm;
}
- p_tfm = this_cpu_ptr(algo->tfms);
+ p_tfm = raw_cpu_ptr(algo->tfms);
tfm = *p_tfm;
shsize = sizeof(*shash) + crypto_shash_descsize(tfm);
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index bbfca22c34ae..1d60cb132835 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -265,7 +265,9 @@ int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
#ifdef CONFIG_DST_CACHE
+ preempt_disable();
dst = dst_cache_get(&slwt->cache);
+ preempt_enable();
#endif
if (unlikely(!dst)) {
@@ -286,7 +288,9 @@ int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
}
#ifdef CONFIG_DST_CACHE
+ preempt_disable();
dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr);
+ preempt_enable();
#endif
}