c87a124a5d
Roman Gushchin discovered that udp4_lib_lookup2() was not reloading first item in the rcu protected list, in case the loop was restarted. This produced soft lockups as in https://lkml.org/lkml/2013/4/16/37 rcu_dereference(X)/ACCESS_ONCE(X) seem to not work as intended if X is ptr->field : In some cases, gcc caches the value or ptr->field in a register. Use a barrier() to disallow such caching, as documented in Documentation/atomic_ops.txt line 114 Thanks a lot to Roman for providing analysis and numerous patches. Diagnosed-by: Roman Gushchin <klamm@yandex-team.ru> Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Boris Zhmurov <zhmurov@yandex-team.ru> Signed-off-by: Roman Gushchin <klamm@yandex-team.ru> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| video | ||
| xen | ||
| Kbuild | ||