Merge branch 'sa1100' into devel

1 files changed, 484 insertions, 0 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
new file mode 100644
index 00000000000..cd7fbda5e2a
--- /dev/null
+++ b/tools/perf/util/probe-event.c
@@ -0,0 +1,484 @@
+/*
+ * probe-event.c : perf-probe definition to kprobe_events format converter
+ *
+ * Written by Masami Hiramatsu <mhiramat@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <sys/utsname.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <limits.h>
+
+#undef _GNU_SOURCE
+#include "event.h"
+#include "string.h"
+#include "strlist.h"
+#include "debug.h"
+#include "parse-events.h"  /* For debugfs_path */
+#include "probe-event.h"
+
+#define MAX_CMDLEN 256
+#define MAX_PROBE_ARGS 128
+#define PERFPROBE_GROUP "probe"
+
+#define semantic_error(msg ...) die("Semantic error :" msg)
+
+/* If there is no space to write, returns -E2BIG. */
+static int e_snprintf(char *str, size_t size, const char *format, ...)
+{
+	int ret;
+	va_list ap;
+	va_start(ap, format);
+	ret = vsnprintf(str, size, format, ap);
+	va_end(ap);
+	if (ret >= (int)size)
+		ret = -E2BIG;
+	return ret;
+}
+
+/* Parse probepoint definition. */
+static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
+{
+	char *ptr, *tmp;
+	char c, nc = 0;
+	/*
+	 * <Syntax>
+	 * perf probe SRC:LN
+	 * perf probe FUNC[+OFFS|%return][@SRC]
+	 */
+
+	ptr = strpbrk(arg, ":+@%");
+	if (ptr) {
+		nc = *ptr;
+		*ptr++ = '\0';
+	}
+
+	/* Check arg is function or file and copy it */
+	if (strchr(arg, '.'))	/* File */
+		pp->file = strdup(arg);
+	else			/* Function */
+		pp->function = strdup(arg);
+	DIE_IF(pp->file == NULL && pp->function == NULL);
+
+	/* Parse other options */
+	while (ptr) {
+		arg = ptr;
+		c = nc;
+		ptr = strpbrk(arg, ":+@%");
+		if (ptr) {
+			nc = *ptr;
+			*ptr++ = '\0';
+		}
+		switch (c) {
+		case ':':	/* Line number */
+			pp->line = strtoul(arg, &tmp, 0);
+			if (*tmp != '\0')
+				semantic_error("There is non-digit charactor"
+						" in line number.");
+			break;
+		case '+':	/* Byte offset from a symbol */
+			pp->offset = strtoul(arg, &tmp, 0);
+			if (*tmp != '\0')
+				semantic_error("There is non-digit charactor"
+						" in offset.");
+			break;
+		case '@':	/* File name */
+			if (pp->file)
+				semantic_error("SRC@SRC is not allowed.");
+			pp->file = strdup(arg);
+			DIE_IF(pp->file == NULL);
+			if (ptr)
+				semantic_error("@SRC must be the last "
+					       "option.");
+			break;
+		case '%':	/* Probe places */
+			if (strcmp(arg, "return") == 0) {
+				pp->retprobe = 1;
+			} else	/* Others not supported yet */
+				semantic_error("%%%s is not supported.", arg);
+			break;
+		default:
+			DIE_IF("Program has a bug.");
+			break;
+		}
+	}
+
+	/* Exclusion check */
+	if (pp->line && pp->offset)
+		semantic_error("Offset can't be used with line number.");
+
+	if (!pp->line && pp->file && !pp->function)
+		semantic_error("File always requires line number.");
+
+	if (pp->offset && !pp->function)
+		semantic_error("Offset requires an entry function.");
+
+	if (pp->retprobe && !pp->function)
+		semantic_error("Return probe requires an entry function.");
+
+	if ((pp->offset || pp->line) && pp->retprobe)
+		semantic_error("Offset/Line can't be used with return probe.");
+
+	pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
+		 pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
+}
+
+/* Parse perf-probe event definition */
+int parse_perf_probe_event(const char *str, struct probe_point *pp)
+{
+	char **argv;
+	int argc, i, need_dwarf = 0;
+
+	argv = argv_split(str, &argc);
+	if (!argv)
+		die("argv_split failed.");
+	if (argc > MAX_PROBE_ARGS + 1)
+		semantic_error("Too many arguments");
+
+	/* Parse probe point */
+	parse_perf_probe_probepoint(argv[0], pp);
+	if (pp->file || pp->line)
+		need_dwarf = 1;
+
+	/* Copy arguments and ensure return probe has no C argument */
+	pp->nr_args = argc - 1;
+	pp->args = zalloc(sizeof(char *) * pp->nr_args);
+	for (i = 0; i < pp->nr_args; i++) {
+		pp->args[i] = strdup(argv[i + 1]);
+		if (!pp->args[i])
+			die("Failed to copy argument.");
+		if (is_c_varname(pp->args[i])) {
+			if (pp->retprobe)
+				semantic_error("You can't specify local"
+						" variable for kretprobe");
+			need_dwarf = 1;
+		}
+	}
+
+	argv_free(argv);
+	return need_dwarf;
+}
+
+/* Parse kprobe_events event into struct probe_point */
+void parse_trace_kprobe_event(const char *str, char **group, char **event,
+			      struct probe_point *pp)
+{
+	char pr;
+	char *p;
+	int ret, i, argc;
+	char **argv;
+
+	pr_debug("Parsing kprobe_events: %s\n", str);
+	argv = argv_split(str, &argc);
+	if (!argv)
+		die("argv_split failed.");
+	if (argc < 2)
+		semantic_error("Too less arguments.");
+
+	/* Scan event and group name. */
+	ret = sscanf(argv[0], "%c:%a[^/ \t]/%a[^ \t]",
+		     &pr, (float *)(void *)group, (float *)(void *)event);
+	if (ret != 3)
+		semantic_error("Failed to parse event name: %s", argv[0]);
+	pr_debug("Group:%s Event:%s probe:%c\n", *group, *event, pr);
+
+	if (!pp)
+		goto end;
+
+	pp->retprobe = (pr == 'r');
+
+	/* Scan function name and offset */
+	ret = sscanf(argv[1], "%a[^+]+%d", (float *)(void *)&pp->function, &pp->offset);
+	if (ret == 1)
+		pp->offset = 0;
+
+	/* kprobe_events doesn't have this information */
+	pp->line = 0;
+	pp->file = NULL;
+
+	pp->nr_args = argc - 2;
+	pp->args = zalloc(sizeof(char *) * pp->nr_args);
+	for (i = 0; i < pp->nr_args; i++) {
+		p = strchr(argv[i + 2], '=');
+		if (p)	/* We don't need which register is assigned. */
+			*p = '\0';
+		pp->args[i] = strdup(argv[i + 2]);
+		if (!pp->args[i])
+			die("Failed to copy argument.");
+	}
+
+end:
+	argv_free(argv);
+}
+
+int synthesize_perf_probe_event(struct probe_point *pp)
+{
+	char *buf;
+	char offs[64] = "", line[64] = "";
+	int i, len, ret;
+
+	pp->probes[0] = buf = zalloc(MAX_CMDLEN);
+	if (!buf)
+		die("Failed to allocate memory by zalloc.");
+	if (pp->offset) {
+		ret = e_snprintf(offs, 64, "+%d", pp->offset);
+		if (ret <= 0)
+			goto error;
+	}
+	if (pp->line) {
+		ret = e_snprintf(line, 64, ":%d", pp->line);
+		if (ret <= 0)
+			goto error;
+	}
+
+	if (pp->function)
+		ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->function,
+				 offs, pp->retprobe ? "%return" : "", line);
+	else
+		ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->file, line);
+	if (ret <= 0)
+		goto error;
+	len = ret;
+
+	for (i = 0; i < pp->nr_args; i++) {
+		ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+				 pp->args[i]);
+		if (ret <= 0)
+			goto error;
+		len += ret;
+	}
+	pp->found = 1;
+
+	return pp->found;
+error:
+	free(pp->probes[0]);
+
+	return ret;
+}
+
+int synthesize_trace_kprobe_event(struct probe_point *pp)
+{
+	char *buf;
+	int i, len, ret;
+
+	pp->probes[0] = buf = zalloc(MAX_CMDLEN);
+	if (!buf)
+		die("Failed to allocate memory by zalloc.");
+	ret = e_snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);
+	if (ret <= 0)
+		goto error;
+	len = ret;
+
+	for (i = 0; i < pp->nr_args; i++) {
+		ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+				 pp->args[i]);
+		if (ret <= 0)
+			goto error;
+		len += ret;
+	}
+	pp->found = 1;
+
+	return pp->found;
+error:
+	free(pp->probes[0]);
+
+	return ret;
+}
+
+static int open_kprobe_events(int flags, int mode)
+{
+	char buf[PATH_MAX];
+	int ret;
+
+	ret = e_snprintf(buf, PATH_MAX, "%s/../kprobe_events", debugfs_path);
+	if (ret < 0)
+		die("Failed to make kprobe_events path.");
+
+	ret = open(buf, flags, mode);
+	if (ret < 0) {
+		if (errno == ENOENT)
+			die("kprobe_events file does not exist -"
+			    " please rebuild with CONFIG_KPROBE_TRACER.");
+		else
+			die("Could not open kprobe_events file: %s",
+			    strerror(errno));
+	}
+	return ret;
+}
+
+/* Get raw string list of current kprobe_events */
+static struct strlist *get_trace_kprobe_event_rawlist(int fd)
+{
+	int ret, idx;
+	FILE *fp;
+	char buf[MAX_CMDLEN];
+	char *p;
+	struct strlist *sl;
+
+	sl = strlist__new(true, NULL);
+
+	fp = fdopen(dup(fd), "r");
+	while (!feof(fp)) {
+		p = fgets(buf, MAX_CMDLEN, fp);
+		if (!p)
+			break;
+
+		idx = strlen(p) - 1;
+		if (p[idx] == '\n')
+			p[idx] = '\0';
+		ret = strlist__add(sl, buf);
+		if (ret < 0)
+			die("strlist__add failed: %s", strerror(-ret));
+	}
+	fclose(fp);
+
+	return sl;
+}
+
+/* Free and zero clear probe_point */
+static void clear_probe_point(struct probe_point *pp)
+{
+	int i;
+
+	if (pp->function)
+		free(pp->function);
+	if (pp->file)
+		free(pp->file);
+	for (i = 0; i < pp->nr_args; i++)
+		free(pp->args[i]);
+	if (pp->args)
+		free(pp->args);
+	for (i = 0; i < pp->found; i++)
+		free(pp->probes[i]);
+	memset(pp, 0, sizeof(pp));
+}
+
+/* List up current perf-probe events */
+void show_perf_probe_events(void)
+{
+	unsigned int i;
+	int fd;
+	char *group, *event;
+	struct probe_point pp;
+	struct strlist *rawlist;
+	struct str_node *ent;
+
+	fd = open_kprobe_events(O_RDONLY, 0);
+	rawlist = get_trace_kprobe_event_rawlist(fd);
+	close(fd);
+
+	for (i = 0; i < strlist__nr_entries(rawlist); i++) {
+		ent = strlist__entry(rawlist, i);
+		parse_trace_kprobe_event(ent->s, &group, &event, &pp);
+		synthesize_perf_probe_event(&pp);
+		printf("[%s:%s]\t%s\n", group, event, pp.probes[0]);
+		free(group);
+		free(event);
+		clear_probe_point(&pp);
+	}
+
+	strlist__delete(rawlist);
+}
+
+/* Get current perf-probe event names */
+static struct strlist *get_perf_event_names(int fd)
+{
+	unsigned int i;
+	char *group, *event;
+	struct strlist *sl, *rawlist;
+	struct str_node *ent;
+
+	rawlist = get_trace_kprobe_event_rawlist(fd);
+
+	sl = strlist__new(false, NULL);
+	for (i = 0; i < strlist__nr_entries(rawlist); i++) {
+		ent = strlist__entry(rawlist, i);
+		parse_trace_kprobe_event(ent->s, &group, &event, NULL);
+		strlist__add(sl, event);
+		free(group);
+	}
+
+	strlist__delete(rawlist);
+
+	return sl;
+}
+
+static int write_trace_kprobe_event(int fd, const char *buf)
+{
+	int ret;
+
+	ret = write(fd, buf, strlen(buf));
+	if (ret <= 0)
+		die("Failed to create event.");
+	else
+		printf("Added new event: %s\n", buf);
+
+	return ret;
+}
+
+static void get_new_event_name(char *buf, size_t len, const char *base,
+			       struct strlist *namelist)
+{
+	int i, ret;
+	for (i = 0; i < MAX_EVENT_INDEX; i++) {
+		ret = e_snprintf(buf, len, "%s_%d", base, i);
+		if (ret < 0)
+			die("snprintf() failed: %s", strerror(-ret));
+		if (!strlist__has_entry(namelist, buf))
+			break;
+	}
+	if (i == MAX_EVENT_INDEX)
+		die("Too many events are on the same function.");
+}
+
+void add_trace_kprobe_events(struct probe_point *probes, int nr_probes)
+{
+	int i, j, fd;
+	struct probe_point *pp;
+	char buf[MAX_CMDLEN];
+	char event[64];
+	struct strlist *namelist;
+
+	fd = open_kprobe_events(O_RDWR, O_APPEND);
+	/* Get current event names */
+	namelist = get_perf_event_names(fd);
+
+	for (j = 0; j < nr_probes; j++) {
+		pp = probes + j;
+		for (i = 0; i < pp->found; i++) {
+			/* Get an unused new event name */
+			get_new_event_name(event, 64, pp->function, namelist);
+			snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s\n",
+				 pp->retprobe ? 'r' : 'p',
+				 PERFPROBE_GROUP, event,
+				 pp->probes[i]);
+			write_trace_kprobe_event(fd, buf);
+			/* Add added event name to namelist */
+			strlist__add(namelist, event);
+		}
+	}
+	close(fd);
+}