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Commit 180b2061 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Arnaldo Carvalho de Melo
Browse files

perf probe: Add supported for type casting by the running kernel 



Add a checking routine what types are supported by the running kernel by
finding the pattern in <debugfs>/tracing/README.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naohiro Aota <naohiro.aota@hgst.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/147151071172.12957.3340095690753291085.stgit@devbox


[ 'enum probe_type' has no negative entries, so ends up as 'unsigned', remove '< 0'
   test to fix the build on at least centos:5, debian:7 & ubuntu:12.04.5 ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 86425625

tools/perf/util/probe-file.c

+57 −0
Original line number Diff line number Diff line
@@ -877,3 +877,60 @@ int probe_cache__show_all_caches(struct strfilter *filter) 


	return 0;

}



static struct {

	const char *pattern;

	bool	avail;

	bool	checked;

} probe_type_table[] = {

#define DEFINE_TYPE(idx, pat, def_avail)	\

	[idx] = {.pattern = pat, .avail = (def_avail)}

	DEFINE_TYPE(PROBE_TYPE_U, "* u8/16/32/64,*", true),

	DEFINE_TYPE(PROBE_TYPE_S, "* s8/16/32/64,*", true),

	DEFINE_TYPE(PROBE_TYPE_X, "* x8/16/32/64,*", false),

	DEFINE_TYPE(PROBE_TYPE_STRING, "* string,*", true),

	DEFINE_TYPE(PROBE_TYPE_BITFIELD,

		    "* b<bit-width>@<bit-offset>/<container-size>", true),

};



bool probe_type_is_available(enum probe_type type)

{

	FILE *fp;

	char *buf = NULL;

	size_t len = 0;

	bool target_line = false;

	bool ret = probe_type_table[type].avail;



	if (type >= PROBE_TYPE_END)

		return false;

	/* We don't have to check the type which supported by default */

	if (ret || probe_type_table[type].checked)

		return ret;



	if (asprintf(&buf, "%s/README", tracing_path) < 0)

		return ret;



	fp = fopen(buf, "r");

	if (!fp)

		goto end;



	zfree(&buf);

	while (getline(&buf, &len, fp) > 0 && !ret) {

		if (!target_line) {

			target_line = !!strstr(buf, " type: ");

			if (!target_line)

				continue;

		} else if (strstr(buf, "\t          ") != buf)

			break;

		ret = strglobmatch(buf, probe_type_table[type].pattern);

	}

	/* Cache the result */

	probe_type_table[type].checked = true;

	probe_type_table[type].avail = ret;



	fclose(fp);

end:

	free(buf);



	return ret;

}

tools/perf/util/probe-file.h

+10 −0
Original line number Diff line number Diff line
@@ -19,6 +19,15 @@ struct probe_cache { 
	struct list_head entries;

};



enum probe_type {

	PROBE_TYPE_U = 0,

	PROBE_TYPE_S,

	PROBE_TYPE_X,

	PROBE_TYPE_STRING,

	PROBE_TYPE_BITFIELD,

	PROBE_TYPE_END,

};



#define PF_FL_UPROBE	1

#define PF_FL_RW	2

#define for_each_probe_cache_entry(entry, pcache) \
@@ -54,6 +63,7 @@ struct probe_cache_entry *probe_cache__find(struct probe_cache *pcache, 
struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache,

					const char *group, const char *event);

int probe_cache__show_all_caches(struct strfilter *filter);

bool probe_type_is_available(enum probe_type type);

#else	/* ! HAVE_LIBELF_SUPPORT */

static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused)

{

tools/perf/util/probe-finder.c

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ 
#include "util.h"

#include "symbol.h"

#include "probe-finder.h"

#include "probe-file.h"



/* Kprobe tracer basic type is up to u64 */

#define MAX_BASIC_TYPE_BITS	64