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| author |  Masami Hiramatsu (Google) <mhiramat@kernel.org>
| 2023-06-06 21:39:56 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org>
| 2023-06-06 21:39:56 +0900 |
| commit | b576e09701c7d045bbe5cd85d53e2f34426aa214 (patch) | |
| tree | 20d10ab0213b47f5640051cf45a6510c8f1d625a /kernel/trace/trace.c | |
| parent | tracing/probes: Move event parameter fetching code to common parser (diff) | |
| download | linux-b576e09701c7d045bbe5cd85d53e2f34426aa214.tar.gz linux-b576e09701c7d045bbe5cd85d53e2f34426aa214.tar.bz2 linux-b576e09701c7d045bbe5cd85d53e2f34426aa214.zip | |
tracing/probes: Support function parameters if BTF is available
Support function or tracepoint parameters by name if BTF support is enabled
and the event is for function entry (this feature can be used with kprobe-
events, fprobe-events and tracepoint probe events.)
Note that the BTF variable syntax does not require a prefix. If it starts
with an alphabetic character or an underscore ('_') without a prefix like
'$' and '%', it is considered as a BTF variable.
If you specify only the BTF variable name, the argument name will also
be the same name instead of 'arg*'.
# echo 'p vfs_read count pos' >> dynamic_events
# echo 'f vfs_write count pos' >> dynamic_events
# echo 't sched_overutilized_tp rd overutilized' >> dynamic_events
# cat dynamic_events
p:kprobes/p_vfs_read_0 vfs_read count=count pos=pos
f:fprobes/vfs_write__entry vfs_write count=count pos=pos
t:tracepoints/sched_overutilized_tp sched_overutilized_tp rd=rd overutilized=overutilized
Link: https://lore.kernel.org/all/168507474014.913472.16963996883278039183.stgit@mhiramat.roam.corp.google.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index fa4e1a18da70..a70b22235eaf 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5698,7 +5698,11 @@ static const char readme_msg[] = "\t args: <name>=fetcharg[:type]\n" "\t fetcharg: (%<register>|$<efield>), @<address>, @<symbol>[+|-<offset>],\n" #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API +#ifdef CONFIG_PROBE_EVENTS_BTF_ARGS + "\t $stack<index>, $stack, $retval, $comm, $arg<N>, <argname>\n" +#else "\t $stack<index>, $stack, $retval, $comm, $arg<N>,\n" +#endif #else "\t $stack<index>, $stack, $retval, $comm,\n" #endif |