Messages in this thread Patch in this message | | | Date | Wed, 2 Dec 2009 14:19:16 -0500 | From | Neil Horman <> | Subject | [PATCH] Fix tracing infrastructure to support multiple includes when defining CREATE_TRACE_POINTS |
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Fix tracing infrastructure to allow multiple header files with TRACE_EVENTS to be included with CREATE_TRACE_EVENTS defined
I've been workingon adding a few tracepoints to the network stack, and in so doing it was convienient for me to add a second include file to net/core/net-traces.c with TRACE_EVENTS defined in them. net-traces.c defines CREATE_TRACE_EVENTS, and during the build it was failing, complaining about duplicate definitions of __tpstrtab_<name>. I tracked down the bug to find that define_trace.h redefined DECLARE_TRACE to be DEFINE_TRACE, so after the first run through define_trace.h (which is included from skb.h, included in net-trace.c first), the DECLARE_TRACE macro was left with an improper definition to start a new cycle with the next header.
The fix I came up with was to make sure that DECLARE_TRACE was undefined at the end of define_trace.h, and to add a conditional re-definition in tracepoint.h. This places us back in the proper state to define a new set of tracepoints in a subsequent header file. Not sure if theres a better way to handle this, but this worked well for me, allowing me to include multiple headers with TRACE_EVENT macros in a c file with CREATE_TRACE_POINTS defined.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
linux/tracepoint.h | 18 ++++++++++++++++++ trace/define_trace.h | 1 + 2 files changed, 19 insertions(+)
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 2aac8a8..562d8ba 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -173,6 +173,24 @@ static inline void tracepoint_synchronize_unregister(void) * trace event headers under one "CREATE_TRACE_POINTS" the first include * will override the TRACE_EVENT and break the second include. */ +#ifndef DECLARE_TRACE +#define DECLARE_TRACE(name, proto, args) \ + extern struct tracepoint __tracepoint_##name; \ + static inline void trace_##name(proto) \ + { \ + if (unlikely(__tracepoint_##name.state)) \ + __DO_TRACE(&__tracepoint_##name, \ + TP_PROTO(proto), TP_ARGS(args)); \ + } \ + static inline int register_trace_##name(void (*probe)(proto)) \ + { \ + return tracepoint_probe_register(#name, (void *)probe); \ + } \ + static inline int unregister_trace_##name(void (*probe)(proto)) \ + { \ + return tracepoint_probe_unregister(#name, (void *)probe);\ + } +#endif #ifndef TRACE_EVENT /* diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h index 2a4b3bf..a3e0095 100644 --- a/include/trace/define_trace.h +++ b/include/trace/define_trace.h @@ -64,6 +64,7 @@ #undef TRACE_EVENT #undef TRACE_EVENT_FN #undef TRACE_HEADER_MULTI_READ +#undef DECLARE_TRACE /* Only undef what we defined in this file */ #ifdef UNDEF_TRACE_INCLUDE_FILE
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