kernel.git/net/sctp/outqueue.c, branch linux-4.19.y

sctp: move trace_sctp_probe_path into sctp_outq_sack

2020-10-01T11:14:30Z

[ Upstream commit f643ee295c1c63bc117fb052d4da681354d6f732 ] The original patch bringed in the "SCTP ACK tracking trace event" feature was committed at Dec.20, 2017, it replaced jprobe usage with trace events, and bringed in two trace events, one is TRACE_EVENT(sctp_probe), another one is TRACE_EVENT(sctp_probe_path). The original patch intended to trigger the trace_sctp_probe_path in TRACE_EVENT(sctp_probe) as below code, +TRACE_EVENT(sctp_probe, + + TP_PROTO(const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + struct sctp_chunk *chunk), + + TP_ARGS(ep, asoc, chunk), + + TP_STRUCT__entry( + __field(__u64, asoc) + __field(__u32, mark) + __field(__u16, bind_port) + __field(__u16, peer_port) + __field(__u32, pathmtu) + __field(__u32, rwnd) + __field(__u16, unack_data) + ), + + TP_fast_assign( + struct sk_buff *skb = chunk->skb; + + __entry->asoc = (unsigned long)asoc; + __entry->mark = skb->mark; + __entry->bind_port = ep->base.bind_addr.port; + __entry->peer_port = asoc->peer.port; + __entry->pathmtu = asoc->pathmtu; + __entry->rwnd = asoc->peer.rwnd; + __entry->unack_data = asoc->unack_data; + + if (trace_sctp_probe_path_enabled()) { + struct sctp_transport *sp; + + list_for_each_entry(sp, &asoc->peer.transport_addr_list, + transports) { + trace_sctp_probe_path(sp, asoc); + } + } + ), But I found it did not work when I did testing, and trace_sctp_probe_path had no output, I finally found that there is trace buffer lock operation(trace_event_buffer_reserve) in include/trace/trace_events.h: static notrace void \ trace_event_raw_event_##call(void *__data, proto) \ { \ struct trace_event_file *trace_file = __data; \ struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\ struct trace_event_buffer fbuffer; \ struct trace_event_raw_##call *entry; \ int __data_size; \ \ if (trace_trigger_soft_disabled(trace_file)) \ return; \ \ __data_size = trace_event_get_offsets_##call(&__data_offsets, args); \ \ entry = trace_event_buffer_reserve(&fbuffer, trace_file, \ sizeof(*entry) + __data_size); \ \ if (!entry) \ return; \ \ tstruct \ \ { assign; } \ \ trace_event_buffer_commit(&fbuffer); \ } The reason caused no output of trace_sctp_probe_path is that trace_sctp_probe_path written in TP_fast_assign part of TRACE_EVENT(sctp_probe), and it will be placed( { assign; } ) after the trace_event_buffer_reserve() when compiler expands Macro, entry = trace_event_buffer_reserve(&fbuffer, trace_file, \ sizeof(*entry) + __data_size); \ \ if (!entry) \ return; \ \ tstruct \ \ { assign; } \ so trace_sctp_probe_path finally can not acquire trace_event_buffer and return no output, that is to say the nest of tracepoint entry function is not allowed. The function call flow is: trace_sctp_probe() -> trace_event_raw_event_sctp_probe() -> lock buffer -> trace_sctp_probe_path() -> trace_event_raw_event_sctp_probe_path() --nested -> buffer has been locked and return no output. This patch is to remove trace_sctp_probe_path from the TP_fast_assign part of TRACE_EVENT(sctp_probe) to avoid the nest of entry function, and trigger sctp_probe_path_trace in sctp_outq_sack. After this patch, you can enable both events individually, # cd /sys/kernel/debug/tracing # echo 1 > events/sctp/sctp_probe/enable # echo 1 > events/sctp/sctp_probe_path/enable Or, you can enable all the events under sctp. # echo 1 > events/sctp/enable Signed-off-by: Kevin Kou Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

sctp: define SCTP_SS_DEFAULT for Stream schedulers

2018-11-23T07:17:06Z

[ Upstream commit 12480e3b16982c4026de10dd8155823219cd6391 ] According to rfc8260#section-4.3.2, SCTP_SS_DEFAULT is required to defined as SCTP_SS_FCFS or SCTP_SS_RR. SCTP_SS_FCFS is used for SCTP_SS_DEFAULT's value in this patch. Fixes: 5bbbbe32a431 ("sctp: introduce stream scheduler foundations") Reported-by: Jianwen Ji Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix fall-through annotation

2018-10-03T16:33:13Z

Replace "fallthru" with a proper "fall through" annotation. This fix is part of the ongoing efforts to enabling -Wimplicit-fallthrough Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller

net/sctp: Make wrappers for accessing in/out streams

2018-08-11T19:25:15Z

This patch introduces wrappers for accessing in/out streams indirectly. This will enable to replace physically contiguous memory arrays of streams with flexible arrays (or maybe any other appropriate mechanism) which do memory allocation on a per-page basis. Signed-off-by: Oleg Babin Signed-off-by: Konstantin Khorenko Signed-off-by: David S. Miller

sctp: checkpatch fixups

2018-05-15T03:15:27Z

A collection of fixups from previous patches, left for later to not introduce unnecessary changes while moving code around. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: add asoc and packet to sctp_flush_ctx

2018-05-15T03:15:27Z

Pre-compute these so the compiler won't reload them (due to no-strict-aliasing). Changes since v2: - Do not replace a return with a break in sctp_outq_flush_data Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: add sctp_flush_ctx, a context struct on outq_flush routines

2018-05-15T03:15:27Z

With this struct we avoid passing lots of variables around and taking care of updating the current transport/packet. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: rework switch cases in sctp_outq_flush_data

2018-05-15T02:57:15Z

Remove an inner one, which tended to be error prone due to the cascading and it can be replaced by a simple if (). Rework the outer one so that the actual flush code is not inside it. Now we first validate if we can or cannot send data, return if not, and then the flush code. Suggested-by: Xin Long Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: make use of gfp on retransmissions

2018-05-15T02:57:15Z

Retransmissions may be triggered when in user context, so lets make use of gfp. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: move transport flush code out of sctp_outq_flush

2018-05-15T02:57:15Z

To the new sctp_outq_flush_transports. Comment on Nagle is outdated and removed. Nagle is performed earlier, while checking if the chunk fits the packet: if the outq length is not enough to fill the packet, it returns SCTP_XMIT_DELAY. So by when it gets to sctp_outq_flush_transports, it has to go through all enlisted transports. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller