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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-06-20 00:08:27 +0900 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-08-31 12:19:39 -0400 |
| commit | 6218bf9f4d2942e88d97b60abc8c2ca0532e41a8 (patch) | |
| tree | cb0b878e89295891667eefc528e75e69650fc52c /kernel/trace/trace_probe.h | |
| parent | ab10d69eb714961d1eca4129e4f8cda5e0618f66 (diff) | |
| download | linux-6218bf9f4d2942e88d97b60abc8c2ca0532e41a8.tar.gz | |
tracing/probe: Add immediate parameter support
Add immediate value parameter (\1234) support to probe events. This allows you to specify an immediate (or dummy) parameter instead of fetching from memory or register. This feature looks odd, but imagine when you put a probe on a code to trace some data. If the code is compiled into 2 instructions and 1 instruction has a value but other has nothing since it is optimized out. In that case, you can not fold those into one event, even if ftrace supported multiple probes on one event. With this feature, you can set a dummy value like foo=\deadbeef instead of something like foo=%di. Link: http://lkml.kernel.org/r/156095690733.28024.13258186548822649469.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_probe.h')
| -rw-r--r-- | kernel/trace/trace_probe.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 2dcc4e317787..cc113b82a4ce 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -408,6 +408,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(BAD_VAR, "Invalid $-valiable specified"), \ C(BAD_REG_NAME, "Invalid register name"), \ C(BAD_MEM_ADDR, "Invalid memory address"), \ + C(BAD_IMM, "Invalid immediate value"), \ C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \ C(BAD_FILE_OFFS, "Invalid file offset value"), \ C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \ |