* Re: BUG warnings in 4.14.9 [not found] <CAK2bqV+NqMz0e-uVGREMvmmi_NgKRYyqZ8kd+yEfxT0pcCWE+g@mail.gmail.com> @ 2017-12-26 18:59 ` Willy Tarreau 2017-12-26 20:54 ` Ido Schimmel 2017-12-26 23:08 ` alexander.levin 0 siblings, 2 replies; 5+ messages in thread From: Willy Tarreau @ 2017-12-26 18:59 UTC (permalink / raw) To: Wei Wang Cc: Martin KaFai Lau, Eric Dumazet, David S. Miller, Sasha Levin, Greg Kroah-Hartman, Chris Rankin, linux-kernel, stable, netdev Guys, Chris reported the bug below and confirmed that reverting commit 9704f81 (ipv6: grab rt->rt6i_ref before allocating pcpu rt) seems to have fixed the issue for him. This patch is a94b9367 in mainline. I personally have no opinion on the patch, just found it because it was the only one touching this area between 4.14.8 and 4.14.9 :-) Should this be reverted or maybe fixed differently ? thanks, Willy On Tue, Dec 26, 2017 at 01:49:59AM +0000, Chris Rankin wrote: > Hi, > > I've just raised https://bugzilla.kernel.org/show_bug.cgi?id=198271 > because the new 4.14.9 kernel is generating lots of BUG warnings, e.g. > > [ 35.069924] BUG: using smp_processor_id() in preemptible [00000000] > code: avahi-daemon/761 > [ 35.078187] caller is ip6_pol_route+0x46b/0x509 [ipv6] > [ 35.083340] CPU: 5 PID: 761 Comm: avahi-daemon Tainted: G > I 4.14.9 #1 > [ 35.091176] Hardware name: Gigabyte Technology Co., Ltd. > EX58-UD3R/EX58-UD3R, BIOS FB 05/04/2009 > [ 35.100181] Call Trace: > [ 35.102709] dump_stack+0x46/0x59 > [ 35.106095] check_preemption_disabled+0xca/0xda > [ 35.110786] ip6_pol_route+0x46b/0x509 [ipv6] > [ 35.115224] fib6_rule_lookup+0x15/0x4b [ipv6] > [ 35.119745] ip6_dst_lookup_tail+0x11d/0x18f [ipv6] > [ 35.124702] ip6_dst_lookup_flow+0x30/0x6f [ipv6] > [ 35.129481] udpv6_sendmsg+0x5c5/0xa10 [ipv6] > [ 35.133914] ? ip_reply_glue_bits+0x48/0x48 > [ 35.138187] ? rw_copy_check_uvector+0x6d/0xf9 > [ 35.142701] ? sock_sendmsg+0x28/0x34 > [ 35.146393] sock_sendmsg+0x28/0x34 > [ 35.149912] ___sys_sendmsg+0x1b4/0x246 > [ 35.153821] ? poll_select_copy_remaining+0x104/0x104 > [ 35.158995] ? current_time+0x11/0x52 > [ 35.162738] ? pipe_write+0x353/0x365 > [ 35.166483] ? __sys_sendmsg+0x3c/0x5d > [ 35.170304] __sys_sendmsg+0x3c/0x5d > [ 35.173909] do_syscall_64+0x4a/0xe1 > [ 35.177482] entry_SYSCALL64_slow_path+0x25/0x25 > [ 35.177484] RIP: 0033:0x7f963d7097b7 > [ 35.177485] RSP: 002b:00007ffff7ffbd18 EFLAGS: 00000246 ORIG_RAX: > 000000000000002e > [ 35.177486] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f963d7097b7 > [ 35.177487] RDX: 0000000000000000 RSI: 00007ffff7ffbde0 RDI: 000000000000000d > [ 35.177487] RBP: 0000000000000000 R08: 0000000000000001 R09: 00007ffff7ffbd42 > [ 35.177488] R10: 0000000000000002 R11: 0000000000000246 R12: 00007ffff7ffbde0 > [ 35.177489] R13: 000055e4e1af29cc R14: 000000000000000d R15: 0000000000000002 > [ 35.177565] IN=eth0 OUT= MAC= > SRC=fe80:0000:0000:0000:0224:1dff:fecd:0f3a > DST=ff02:0000:0000:0000:0000:0000:0000:00fb LEN=245 TC=0 HOPLIMIT=255 > FLOWLBL=147873 PROTO=UDP SPT=5353 DPT=5353 LEN=205 > > Cheers, > Chris ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: BUG warnings in 4.14.9 2017-12-26 18:59 ` BUG warnings in 4.14.9 Willy Tarreau @ 2017-12-26 20:54 ` Ido Schimmel 2017-12-27 4:25 ` alexander.levin 2017-12-26 23:08 ` alexander.levin 1 sibling, 1 reply; 5+ messages in thread From: Ido Schimmel @ 2017-12-26 20:54 UTC (permalink / raw) To: Willy Tarreau Cc: Wei Wang, Martin KaFai Lau, Eric Dumazet, David S. Miller, Sasha Levin, Greg Kroah-Hartman, Chris Rankin, linux-kernel, stable, netdev On Tue, Dec 26, 2017 at 07:59:55PM +0100, Willy Tarreau wrote: > Guys, > > Chris reported the bug below and confirmed that reverting commit > 9704f81 (ipv6: grab rt->rt6i_ref before allocating pcpu rt) seems to > have fixed the issue for him. This patch is a94b9367 in mainline. > > I personally have no opinion on the patch, just found it because it > was the only one touching this area between 4.14.8 and 4.14.9 :-) > > Should this be reverted or maybe fixed differently ? Maybe I'm missing something, but how come this patch even made its way into 4.14.y? It's part of a series to RCU-ify IPv6 FIB lookup that went into 4.15. Anyway, the mentioned bug was already fixed by commit 951f788a80ff ("ipv6: fix a BUG in rt6_get_pcpu_route()") when the code was still in net-next. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: BUG warnings in 4.14.9 2017-12-26 20:54 ` Ido Schimmel @ 2017-12-27 4:25 ` alexander.levin 2017-12-27 12:57 ` Greg Kroah-Hartman 0 siblings, 1 reply; 5+ messages in thread From: alexander.levin @ 2017-12-27 4:25 UTC (permalink / raw) To: Ido Schimmel Cc: Willy Tarreau, Wei Wang, Martin KaFai Lau, Eric Dumazet, David S. Miller, Greg Kroah-Hartman, Chris Rankin, linux-kernel@vger.kernel.org, stable@vger.kernel.org, netdev@vger.kernel.org On Tue, Dec 26, 2017 at 10:54:37PM +0200, Ido Schimmel wrote: >On Tue, Dec 26, 2017 at 07:59:55PM +0100, Willy Tarreau wrote: >> Guys, >> >> Chris reported the bug below and confirmed that reverting commit >> 9704f81 (ipv6: grab rt->rt6i_ref before allocating pcpu rt) seems to >> have fixed the issue for him. This patch is a94b9367 in mainline. >> >> I personally have no opinion on the patch, just found it because it >> was the only one touching this area between 4.14.8 and 4.14.9 :-) >> >> Should this be reverted or maybe fixed differently ? > >Maybe I'm missing something, but how come this patch even made its way >into 4.14.y? It's part of a series to RCU-ify IPv6 FIB lookup that went >into 4.15. > >Anyway, the mentioned bug was already fixed by commit 951f788a80ff >("ipv6: fix a BUG in rt6_get_pcpu_route()") when the code was still in >net-next. Uh, you're right. Greg, please just revert 9704f81. Thanks! -- Thanks, Sasha ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: BUG warnings in 4.14.9 2017-12-27 4:25 ` alexander.levin @ 2017-12-27 12:57 ` Greg Kroah-Hartman 0 siblings, 0 replies; 5+ messages in thread From: Greg Kroah-Hartman @ 2017-12-27 12:57 UTC (permalink / raw) To: alexander.levin Cc: Ido Schimmel, Willy Tarreau, Wei Wang, Martin KaFai Lau, Eric Dumazet, David S. Miller, Chris Rankin, linux-kernel@vger.kernel.org, stable@vger.kernel.org, netdev@vger.kernel.org On Wed, Dec 27, 2017 at 04:25:00AM +0000, alexander.levin@verizon.com wrote: > On Tue, Dec 26, 2017 at 10:54:37PM +0200, Ido Schimmel wrote: > >On Tue, Dec 26, 2017 at 07:59:55PM +0100, Willy Tarreau wrote: > >> Guys, > >> > >> Chris reported the bug below and confirmed that reverting commit > >> 9704f81 (ipv6: grab rt->rt6i_ref before allocating pcpu rt) seems to > >> have fixed the issue for him. This patch is a94b9367 in mainline. > >> > >> I personally have no opinion on the patch, just found it because it > >> was the only one touching this area between 4.14.8 and 4.14.9 :-) > >> > >> Should this be reverted or maybe fixed differently ? > > > >Maybe I'm missing something, but how come this patch even made its way > >into 4.14.y? It's part of a series to RCU-ify IPv6 FIB lookup that went > >into 4.15. > > > >Anyway, the mentioned bug was already fixed by commit 951f788a80ff > >("ipv6: fix a BUG in rt6_get_pcpu_route()") when the code was still in > >net-next. > > Uh, you're right. Greg, please just revert 9704f81. Thanks! Now reverted, sorry about this. greg k-h ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: BUG warnings in 4.14.9 2017-12-26 18:59 ` BUG warnings in 4.14.9 Willy Tarreau 2017-12-26 20:54 ` Ido Schimmel @ 2017-12-26 23:08 ` alexander.levin 1 sibling, 0 replies; 5+ messages in thread From: alexander.levin @ 2017-12-26 23:08 UTC (permalink / raw) To: Willy Tarreau Cc: Wei Wang, Martin KaFai Lau, Eric Dumazet, David S. Miller, Greg Kroah-Hartman, Chris Rankin, linux-kernel@vger.kernel.org, stable@vger.kernel.org, netdev@vger.kernel.org On Tue, Dec 26, 2017 at 07:59:55PM +0100, Willy Tarreau wrote: >Guys, > >Chris reported the bug below and confirmed that reverting commit >9704f81 (ipv6: grab rt->rt6i_ref before allocating pcpu rt) seems to >have fixed the issue for him. This patch is a94b9367 in mainline. > >I personally have no opinion on the patch, just found it because it >was the only one touching this area between 4.14.8 and 4.14.9 :-) > >Should this be reverted or maybe fixed differently ? Hi Willy, This seems to be fixed upstream: commit 951f788a80ff8b6339c5c1ab888b0d4b4352efd8 Author: Eric Dumazet <edumazet@google.com> Date: Sun Oct 8 21:07:18 2017 -0700 ipv6: fix a BUG in rt6_get_pcpu_route() Ido reported following splat and provided a patch. [ 122.221814] BUG: using smp_processor_id() in preemptible [00000000] code: sshd/2672 [ 122.221845] caller is debug_smp_processor_id+0x17/0x20 [ 122.221866] CPU: 0 PID: 2672 Comm: sshd Not tainted 4.14.0-rc3-idosch-next-custom #639 [ 122.221880] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016 [ 122.221893] Call Trace: [ 122.221919] dump_stack+0xb1/0x10c [ 122.221946] ? _atomic_dec_and_lock+0x124/0x124 [ 122.221974] ? ___ratelimit+0xfe/0x240 [ 122.222020] check_preemption_disabled+0x173/0x1b0 [ 122.222060] debug_smp_processor_id+0x17/0x20 [ 122.222083] ip6_pol_route+0x1482/0x24a0 ... I believe we can simplify this code path a bit, since we no longer hold a read_lock and need to release it to avoid a dead lock. By disabling BH, we make sure we'll prevent code re-entry and rt6_get_pcpu_route()/rt6_make_pcpu_route() run on the same cpu. Fixes: 66f5d6ce53e6 ("ipv6: replace rwlock with rcu and spinlock in fib6_table") Reported-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Which itself would depend on: commit d3843fe5fd45be0e04a251a2cc68893c859a31bd Author: Wei Wang <weiwan@google.com> Date: Fri Oct 6 12:06:06 2017 -0700 ipv6: replace dst_hold() with dst_hold_safe() in routing code Which applies with a small conflict. -- Thanks, Sasha ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-12-27 12:57 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <CAK2bqV+NqMz0e-uVGREMvmmi_NgKRYyqZ8kd+yEfxT0pcCWE+g@mail.gmail.com>
2017-12-26 18:59 ` BUG warnings in 4.14.9 Willy Tarreau
2017-12-26 20:54 ` Ido Schimmel
2017-12-27 4:25 ` alexander.levin
2017-12-27 12:57 ` Greg Kroah-Hartman
2017-12-26 23:08 ` alexander.levin
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).