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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-06-19 17:08:37 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-08-31 18:19:39 +0200 |
| commit | a42e3c4de9642d5de524a0a48a7ce96872662dca (patch) | |
| tree | 75303cede44b02307d5d504bf4a0d1ce84dcee24 /kernel/trace/trace_probe.h | |
| parent | tracing/probe: Add immediate parameter support (diff) | |
| download | linux-a42e3c4de9642d5de524a0a48a7ce96872662dca.tar.xz linux-a42e3c4de9642d5de524a0a48a7ce96872662dca.zip | |
tracing/probe: Add immediate string parameter support
Add immediate string parameter (\"string") support to
probe events. This allows you to specify an immediate
(or dummy) parameter instead of fetching a string from
memory.
This feature looks odd, but imagine that you put a probe
on a code to trace some string data. If the code is
compiled into 2 instructions and 1 instruction has a
string on memory but other has no string 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 string
like foo=\"(optimized)":string instead of something
like foo=+0(+0(%bp)):string.
Link: http://lkml.kernel.org/r/156095691687.28024.13372712423865047991.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 | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index cc113b82a4ce..f805cc4cbe7c 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -89,6 +89,7 @@ enum fetch_op { FETCH_OP_COMM, /* Current comm */ FETCH_OP_ARG, /* Function argument : .param */ FETCH_OP_FOFFS, /* File offset: .immediate */ + FETCH_OP_DATA, /* Allocated data: .data */ // Stage 2 (dereference) op FETCH_OP_DEREF, /* Dereference: .offset */ FETCH_OP_UDEREF, /* User-space Dereference: .offset */ @@ -409,6 +410,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(BAD_REG_NAME, "Invalid register name"), \ C(BAD_MEM_ADDR, "Invalid memory address"), \ C(BAD_IMM, "Invalid immediate value"), \ + C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \ 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"), \ |