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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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f5f99309fa
Do not set sk_err when dequeuing errors from the error queue. Doing so results in: a) Bugs: By overwriting existing sk_err values, it possibly hides legitimate errors. It is also incorrect when local errors are queued with ip_local_error. That happens in the context of a system call, which already returns the error code. b) Inconsistent behavior: When there are pending errors on the error queue, sk_err is sometimes 0 (e.g., for the first timestamp on the error queue) and sometimes set to an error code (after dequeuing the first timestamp). c) Suboptimality: Setting sk_err to ENOMSG on simple TX timestamps can abort parallel reads and writes. Removing this line doesn't break userspace. This is because userspace code cannot rely on sk_err for detecting whether there is something on the error queue. Except for ICMP messages received for UDP and RAW, sk_err is not set at enqueue time, and as a result sk_err can be 0 while there are plenty of errors on the error queue. For ICMP packets in UDP and RAW, sk_err is set when they are enqueued on the error queue, but that does not result in aborting reads and writes. For such cases, sk_err is only readable via getsockopt(SO_ERROR) which will reset the value of sk_err on its own. More importantly, prior to this patch, recvmsg(MSG_ERRQUEUE) has a race on setting sk_err (i.e., sk_err is set by sock_dequeue_err_skb without atomic ops or locks) which can store 0 in sk_err even when we have ICMP messages pending. Removing this line from sock_dequeue_err_skb eliminates that race. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| datagram.c | ||
| dev_addr_lists.c | ||
| dev_ioctl.c | ||
| dev.c | ||
| devlink.c | ||
| drop_monitor.c | ||
| dst_cache.c | ||
| dst.c | ||
| ethtool.c | ||
| fib_rules.c | ||
| filter.c | ||
| flow_dissector.c | ||
| flow.c | ||
| gen_estimator.c | ||
| gen_stats.c | ||
| hwbm.c | ||
| link_watch.c | ||
| lwtunnel.c | ||
| Makefile | ||
| neighbour.c | ||
| net_namespace.c | ||
| net-procfs.c | ||
| net-sysfs.c | ||
| net-sysfs.h | ||
| net-traces.c | ||
| netclassid_cgroup.c | ||
| netevent.c | ||
| netpoll.c | ||
| netprio_cgroup.c | ||
| pktgen.c | ||
| ptp_classifier.c | ||
| request_sock.c | ||
| rtnetlink.c | ||
| scm.c | ||
| secure_seq.c | ||
| skbuff.c | ||
| sock_diag.c | ||
| sock_reuseport.c | ||
| sock.c | ||
| stream.c | ||
| sysctl_net_core.c | ||
| timestamping.c | ||
| tso.c | ||
| utils.c | ||