perf: Add perf probe subcommand, a kprobe-event setup helper
Add perf probe subcommand that implements a kprobe-event setup helper
to the perf command.
This allows user to define kprobe events using C expressions (C line
numbers, C function names, and C local variables).
Usage
-----
perf probe [<options>] -P 'PROBEDEF' [-P 'PROBEDEF' ...]
-k, --vmlinux <file> vmlinux/module pathname
-P, --probe <p|r:[GRP/]NAME FUNC[+OFFS][@SRC]|@SRC:LINE [ARG ...]>
probe point definition, where
p: kprobe probe
r: kretprobe probe
GRP: Group name (optional)
NAME: Event name
FUNC: Function name
OFFS: Offset from function entry (in byte)
SRC: Source code path
LINE: Line number
ARG: Probe argument (local variable name or
kprobe-tracer argument format is supported.)
Changes in v4:
- Add _GNU_SOURCE macro for strndup().
Changes in v3:
- Remove -r option because perf always be used for online kernel.
- Check malloc/calloc results.
Changes in v2:
- Check synthesized string length.
- Rename perf kprobe to perf probe.
- Use spaces for separator and update usage comment.
- Check error paths in parse_probepoint().
- Check optimized-out variables.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
LKML-Reference: <20091008211737.29299.14784.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
new file mode 100644
index 0000000..af920de
--- /dev/null
+++ b/tools/perf/util/probe-finder.h
@@ -0,0 +1,68 @@
+#ifndef _PROBE_FINDER_H
+#define _PROBE_FINDER_H
+
+#define _stringify(n) #n
+#define stringify(n) _stringify(n)
+
+#ifdef DEBUG
+#define debug(fmt ...) \
+ fprintf(stderr, "DBG(" __FILE__ ":" stringify(__LINE__) "): " fmt)
+#else
+#define debug(fmt ...) do {} while (0)
+#endif
+
+#define ERR_IF(cnd) \
+ do { if (cnd) { \
+ fprintf(stderr, "Error (" __FILE__ ":" stringify(__LINE__) \
+ "): " stringify(cnd) "\n"); \
+ exit(1); \
+ } } while (0)
+
+#define MAX_PATH_LEN 256
+#define MAX_PROBE_BUFFER 1024
+#define MAX_PROBES 128
+
+static inline int is_c_varname(const char *name)
+{
+ /* TODO */
+ return isalpha(name[0]) || name[0] == '_';
+}
+
+struct probe_point {
+ /* Inputs */
+ char *file; /* File name */
+ int line; /* Line number */
+
+ char *function; /* Function name */
+ int offset; /* Offset bytes */
+
+ int nr_args; /* Number of arguments */
+ char **args; /* Arguments */
+
+ /* Output */
+ int found; /* Number of found probe points */
+ char *probes[MAX_PROBES]; /* Output buffers (will be allocated)*/
+};
+
+extern int find_probepoint(int fd, struct probe_point *pp);
+
+#include <libdwarf/dwarf.h>
+#include <libdwarf/libdwarf.h>
+
+struct probe_finder {
+ struct probe_point *pp; /* Target probe point */
+
+ /* For function searching */
+ Dwarf_Addr addr; /* Address */
+ Dwarf_Unsigned fno; /* File number */
+ Dwarf_Off inl_offs; /* Inline offset */
+
+ /* For variable searching */
+ Dwarf_Addr cu_base; /* Current CU base address */
+ Dwarf_Locdesc fbloc; /* Location of Current Frame Base */
+ const char *var; /* Current variable name */
+ char *buf; /* Current output buffer */
+ int len; /* Length of output buffer */
+};
+
+#endif /*_PROBE_FINDER_H */