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* [PATCH -tip 1/2] perf probe: Cleanup debuginfo related code
@ 2010-03-17 22:11 Masami Hiramatsu
  2010-03-17 22:12 ` [PATCH -tip 2/2] perf probe: Add NO_DWARF make option Masami Hiramatsu
  0 siblings, 1 reply; 2+ messages in thread
From: Masami Hiramatsu @ 2010-03-17 22:11 UTC (permalink / raw)
  To: Ingo Molnar, lkml
  Cc: systemtap, DLE, Masami Hiramatsu, Frederic Weisbecker,
	Arnaldo Carvalho de Melo, Paul Mackerras, Mike Galbraith,
	Peter Zijlstra

Cleanup debuginfo related code to eliminate fragile code which
pointed by Ingo (Thanks!).
1) Invert logic of NO_DWARF_SUPPORT to DWARF_SUPPORT.
2) For removing assymetric/local variable ifdefs, introduce
  more helper functions.
3) Change options order to reduce the number of ifdefs.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Reported-by: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
---

 tools/perf/Makefile            |    3 
 tools/perf/builtin-probe.c     |   28 ++-
 tools/perf/util/probe-event.c  |  343 +++++++++++++++++++++-------------------
 tools/perf/util/probe-finder.h |    4 
 4 files changed, 200 insertions(+), 178 deletions(-)

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 0abd25e..c991818 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -506,9 +506,8 @@ endif
 
 ifneq ($(shell sh -c "(echo '\#include <dwarf.h>'; echo '\#include <libdw.h>'; echo 'int main(void) { Dwarf *dbg; dbg = dwarf_begin(0, DWARF_C_READ); return (long)dbg; }') | $(CC) -x c - $(ALL_CFLAGS) -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/elfutils -ldw -lelf -o $(BITBUCKET) $(ALL_LDFLAGS) $(EXTLIBS) "$(QUIET_STDERR)" && echo y"), y)
 	msg := $(warning No libdw.h found or old libdw.h found, disables dwarf support. Please install elfutils-devel/elfutils-dev);
-	BASIC_CFLAGS += -DNO_DWARF_SUPPORT
 else
-	BASIC_CFLAGS += -I/usr/include/elfutils
+	BASIC_CFLAGS += -I/usr/include/elfutils -DDWARF_SUPPORT
 	EXTLIBS += -lelf -ldw
 	LIB_OBJS += util/probe-finder.o
 endif
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index e0dafd9..cf2ffa5 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -109,7 +109,7 @@ static int opt_del_probe_event(const struct option *opt __used,
 	return 0;
 }
 
-#ifndef NO_DWARF_SUPPORT
+#ifdef DWARF_SUPPORT
 static int opt_show_lines(const struct option *opt __used,
 			  const char *str, int unset __used)
 {
@@ -126,7 +126,7 @@ static const char * const probe_usage[] = {
 	"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
 	"perf probe [<options>] --del '[GROUP:]EVENT' ...",
 	"perf probe --list",
-#ifndef NO_DWARF_SUPPORT
+#ifdef DWARF_SUPPORT
 	"perf probe --line 'LINEDESC'",
 #endif
 	NULL
@@ -135,20 +135,16 @@ static const char * const probe_usage[] = {
 static const struct option options[] = {
 	OPT_BOOLEAN('v', "verbose", &verbose,
 		    "be more verbose (show parsed arguments, etc)"),
-#ifndef NO_DWARF_SUPPORT
-	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
-		   "file", "vmlinux pathname"),
-#endif
 	OPT_BOOLEAN('l', "list", &params.list_events,
 		    "list up current probe events"),
 	OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
 		opt_del_probe_event),
 	OPT_CALLBACK('a', "add", NULL,
-#ifdef NO_DWARF_SUPPORT
-		"[EVENT=]FUNC[+OFF|%return] [ARG ...]",
-#else
+#ifdef DWARF_SUPPORT
 		"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
 		" [ARG ...]",
+#else
+		"[EVENT=]FUNC[+OFF|%return] [ARG ...]",
 #endif
 		"probe point definition, where\n"
 		"\t\tGROUP:\tGroup name (optional)\n"
@@ -156,23 +152,25 @@ static const struct option options[] = {
 		"\t\tFUNC:\tFunction name\n"
 		"\t\tOFF:\tOffset from function entry (in byte)\n"
 		"\t\t%return:\tPut the probe at function return\n"
-#ifdef NO_DWARF_SUPPORT
-		"\t\tARG:\tProbe argument (only \n"
-#else
+#ifdef DWARF_SUPPORT
 		"\t\tSRC:\tSource code path\n"
 		"\t\tRL:\tRelative line number from function entry.\n"
 		"\t\tAL:\tAbsolute line number in file.\n"
 		"\t\tPT:\tLazy expression of line code.\n"
 		"\t\tARG:\tProbe argument (local variable name or\n"
-#endif
 		"\t\t\tkprobe-tracer argument format.)\n",
+#else
+		"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
+#endif
 		opt_add_probe_event),
 	OPT_BOOLEAN('f', "force", &params.force_add, "forcibly add events"
 		    " with existing name"),
-#ifndef NO_DWARF_SUPPORT
+#ifdef DWARF_SUPPORT
 	OPT_CALLBACK('L', "line", NULL,
 		     "FUNC[:RLN[+NUM|:RLN2]]|SRC:ALN[+NUM|:ALN2]",
 		     "Show source code lines.", opt_show_lines),
+	OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
+		   "file", "vmlinux pathname"),
 #endif
 	OPT__DRY_RUN(&probe_event_dry_run),
 	OPT_END()
@@ -211,7 +209,7 @@ int cmd_probe(int argc, const char **argv, const char *prefix __used)
 		return 0;
 	}
 
-#ifndef NO_DWARF_SUPPORT
+#ifdef DWARF_SUPPORT
 	if (params.show_lines) {
 		if (params.nevents != 0 || params.dellist) {
 			pr_warning("  Error: Don't use --line with"
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f333269..284294d 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -42,7 +42,8 @@
 #include "color.h"
 #include "symbol.h"
 #include "thread.h"
-#include "parse-events.h"  /* For debugfs_path */
+#include "trace-event.h"	/* For __unused */
+#include "parse-events.h"	/* For debugfs_path */
 #include "probe-event.h"
 #include "probe-finder.h"
 
@@ -70,10 +71,11 @@ static int e_snprintf(char *str, size_t size, const char *format, ...)
 	return ret;
 }
 
+static char *synthesize_perf_probe_point(struct perf_probe_point *pp);
 static struct map_groups kmap_groups;
 static struct map *kmaps[MAP__NR_TYPES];
 
-/* Initialize symbol maps for vmlinux */
+/* Initialize symbol maps and path of vmlinux */
 static void init_vmlinux(void)
 {
 	symbol_conf.sort_by_name = true;
@@ -89,7 +91,7 @@ static void init_vmlinux(void)
 		die("Failed to create kernel maps.");
 }
 
-#ifndef NO_DWARF_SUPPORT
+#ifdef DWARF_SUPPORT
 static int open_vmlinux(void)
 {
 	if (map__load(kmaps[MAP__FUNCTION], NULL) < 0) {
@@ -99,6 +101,176 @@ static int open_vmlinux(void)
 	pr_debug("Try to open %s\n", kmaps[MAP__FUNCTION]->dso->long_name);
 	return open(kmaps[MAP__FUNCTION]->dso->long_name, O_RDONLY);
 }
+
+static void convert_to_perf_probe_point(struct kprobe_trace_point *tp,
+					struct perf_probe_point *pp)
+{
+	struct symbol *sym;
+	int fd, ret = 0;
+
+	sym = map__find_symbol_by_name(kmaps[MAP__FUNCTION],
+				       tp->symbol, NULL);
+	if (sym) {
+		fd = open_vmlinux();
+		ret = find_perf_probe_point(fd, sym->start + tp->offset, pp);
+		close(fd);
+	}
+	if (ret <= 0) {
+		pp->function = xstrdup(tp->symbol);
+		pp->offset = tp->offset;
+	}
+	pp->retprobe = tp->retprobe;
+}
+
+/* Try to find perf_probe_event with debuginfo */
+static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,
+					   struct kprobe_trace_event **tevs)
+{
+	bool need_dwarf = perf_probe_event_need_dwarf(pev);
+	int fd, ntevs;
+
+	fd = open_vmlinux();
+	if (fd < 0) {
+		if (need_dwarf)
+			die("Could not open debuginfo file.");
+
+		pr_debug("Could not open vmlinux. Try to use symbols.\n");
+		return 0;
+	}
+
+	/* Searching trace events corresponding to probe event */
+	ntevs = find_kprobe_trace_events(fd, pev, tevs);
+	close(fd);
+
+	if (ntevs > 0)	/* Succeeded to find trace events */
+		return ntevs;
+
+	if (ntevs == 0)	/* No error but failed to find probe point. */
+		die("Probe point '%s' not found. - probe not added.",
+		    synthesize_perf_probe_point(&pev->point));
+
+	/* Error path */
+	if (need_dwarf) {
+		if (ntevs == -ENOENT)
+			pr_warning("No dwarf info found in the vmlinux - "
+				"please rebuild with CONFIG_DEBUG_INFO=y.\n");
+		die("Could not analyze debuginfo.");
+	}
+	pr_debug("An error occurred in debuginfo analysis."
+		 " Try to use symbols.\n");
+	return 0;
+
+}
+
+#define LINEBUF_SIZE 256
+#define NR_ADDITIONAL_LINES 2
+
+static void show_one_line(FILE *fp, unsigned int l, bool skip, bool show_num)
+{
+	char buf[LINEBUF_SIZE];
+	const char *color = PERF_COLOR_BLUE;
+
+	if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
+		goto error;
+	if (!skip) {
+		if (show_num)
+			fprintf(stdout, "%7u  %s", l, buf);
+		else
+			color_fprintf(stdout, color, "         %s", buf);
+	}
+
+	while (strlen(buf) == LINEBUF_SIZE - 1 &&
+	       buf[LINEBUF_SIZE - 2] != '\n') {
+		if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
+			goto error;
+		if (!skip) {
+			if (show_num)
+				fprintf(stdout, "%s", buf);
+			else
+				color_fprintf(stdout, color, "%s", buf);
+		}
+	}
+	return;
+error:
+	if (feof(fp))
+		die("Source file is shorter than expected.");
+	else
+		die("File read error: %s", strerror(errno));
+}
+
+/*
+ * Show line-range always requires debuginfo to find source file and
+ * line number.
+ */
+void show_line_range(struct line_range *lr)
+{
+	unsigned int l = 1;
+	struct line_node *ln;
+	FILE *fp;
+	int fd, ret;
+
+	/* Search a line range */
+	init_vmlinux();
+	fd = open_vmlinux();
+	if (fd < 0)
+		die("Could not open debuginfo file.");
+	ret = find_line_range(fd, lr);
+	if (ret <= 0)
+		die("Source line is not found.\n");
+	close(fd);
+
+	setup_pager();
+
+	if (lr->function)
+		fprintf(stdout, "<%s:%d>\n", lr->function,
+			lr->start - lr->offset);
+	else
+		fprintf(stdout, "<%s:%d>\n", lr->file, lr->start);
+
+	fp = fopen(lr->path, "r");
+	if (fp == NULL)
+		die("Failed to open %s: %s", lr->path, strerror(errno));
+	/* Skip to starting line number */
+	while (l < lr->start)
+		show_one_line(fp, l++, true, false);
+
+	list_for_each_entry(ln, &lr->line_list, list) {
+		while (ln->line > l)
+			show_one_line(fp, (l++) - lr->offset, false, false);
+		show_one_line(fp, (l++) - lr->offset, false, true);
+	}
+
+	if (lr->end == INT_MAX)
+		lr->end = l + NR_ADDITIONAL_LINES;
+	while (l < lr->end && !feof(fp))
+		show_one_line(fp, (l++) - lr->offset, false, false);
+
+	fclose(fp);
+}
+
+#else	/* !DWARF_SUPPORT */
+
+static void convert_to_perf_probe_point(struct kprobe_trace_point *tp,
+					struct perf_probe_point *pp)
+{
+	pp->function = xstrdup(tp->symbol);
+	pp->offset = tp->offset;
+	pp->retprobe = tp->retprobe;
+}
+
+static int try_to_find_kprobe_trace_events(struct perf_probe_event *pev,
+				struct kprobe_trace_event **tevs __unused)
+{
+	if (perf_probe_event_need_dwarf(pev))
+		die("Debuginfo-analysis is not supported");
+	return 0;
+}
+
+void show_line_range(struct line_range *lr __unused)
+{
+	die("Debuginfo-analysis is not supported");
+}
+
 #endif
 
 void parse_line_range_desc(const char *arg, struct line_range *lr)
@@ -592,32 +764,14 @@ void convert_to_perf_probe_event(struct kprobe_trace_event *tev,
 {
 	char buf[64];
 	int i;
-#ifndef NO_DWARF_SUPPORT
-	struct symbol *sym;
-	int fd, ret = 0;
-
-	sym = map__find_symbol_by_name(kmaps[MAP__FUNCTION],
-				       tev->point.symbol, NULL);
-	if (sym) {
-		fd = open_vmlinux();
-		ret = find_perf_probe_point(fd, sym->start + tev->point.offset,
-					    &pev->point);
-		close(fd);
-	}
-	if (ret <= 0) {
-		pev->point.function = xstrdup(tev->point.symbol);
-		pev->point.offset = tev->point.offset;
-	}
-#else
-	/* Convert trace_point to probe_point */
-	pev->point.function = xstrdup(tev->point.symbol);
-	pev->point.offset = tev->point.offset;
-#endif
-	pev->point.retprobe = tev->point.retprobe;
 
+	/* Convert event/group name */
 	pev->event = xstrdup(tev->event);
 	pev->group = xstrdup(tev->group);
 
+	/* Convert trace_point to probe_point */
+	convert_to_perf_probe_point(&tev->point, &pev->point);
+
 	/* Convert trace_arg to probe_arg */
 	pev->nargs = tev->nargs;
 	pev->args = xzalloc(sizeof(struct perf_probe_arg) * pev->nargs);
@@ -944,52 +1098,13 @@ static int convert_to_kprobe_trace_events(struct perf_probe_event *pev,
 					  struct kprobe_trace_event **tevs)
 {
 	struct symbol *sym;
-	bool need_dwarf;
-#ifndef NO_DWARF_SUPPORT
-	int fd;
-#endif
 	int ntevs = 0, i;
 	struct kprobe_trace_event *tev;
 
-	need_dwarf = perf_probe_event_need_dwarf(pev);
-
-	if (need_dwarf)
-#ifdef NO_DWARF_SUPPORT
-		die("Debuginfo-analysis is not supported");
-#else	/* !NO_DWARF_SUPPORT */
-		pr_debug("Some probes require debuginfo.\n");
-
-	fd = open_vmlinux();
-	if (fd < 0) {
-		if (need_dwarf)
-			die("Could not open debuginfo file.");
-
-		pr_debug("Could not open vmlinux/module file."
-			 " Try to use symbols.\n");
-		goto end_dwarf;
-	}
-
-	/* Searching probe points */
-	ntevs = find_kprobe_trace_events(fd, pev, tevs);
-
-	if (ntevs > 0)	/* Found */
-		goto found;
-
-	if (ntevs == 0)	/* No error but failed to find probe point. */
-		die("Probe point '%s' not found. - probe not added.",
-		    synthesize_perf_probe_point(&pev->point));
-
-	/* Error path */
-	if (need_dwarf) {
-		if (ntevs == -ENOENT)
-			pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
-		die("Could not analyze debuginfo.");
-	}
-	pr_debug("An error occurred in debuginfo analysis."
-		 " Try to use symbols.\n");
-
-end_dwarf:
-#endif /* !NO_DWARF_SUPPORT */
+	/* Convert perf_probe_event with debuginfo */
+	ntevs = try_to_find_kprobe_trace_events(pev, tevs);
+	if (ntevs > 0)
+		return ntevs;
 
 	/* Allocate trace event buffer */
 	ntevs = 1;
@@ -1012,10 +1127,7 @@ end_dwarf:
 	if (!sym)
 		die("Kernel symbol \'%s\' not found - probe not added.",
 		    tev->point.symbol);
-#ifndef NO_DWARF_SUPPORT
-found:
-	close(fd);
-#endif
+
 	return ntevs;
 }
 
@@ -1133,90 +1245,3 @@ void del_perf_probe_events(struct strlist *dellist)
 	close(fd);
 }
 
-#define LINEBUF_SIZE 256
-#define NR_ADDITIONAL_LINES 2
-
-static void show_one_line(FILE *fp, unsigned int l, bool skip, bool show_num)
-{
-	char buf[LINEBUF_SIZE];
-	const char *color = PERF_COLOR_BLUE;
-
-	if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
-		goto error;
-	if (!skip) {
-		if (show_num)
-			fprintf(stdout, "%7u  %s", l, buf);
-		else
-			color_fprintf(stdout, color, "         %s", buf);
-	}
-
-	while (strlen(buf) == LINEBUF_SIZE - 1 &&
-	       buf[LINEBUF_SIZE - 2] != '\n') {
-		if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
-			goto error;
-		if (!skip) {
-			if (show_num)
-				fprintf(stdout, "%s", buf);
-			else
-				color_fprintf(stdout, color, "%s", buf);
-		}
-	}
-	return;
-error:
-	if (feof(fp))
-		die("Source file is shorter than expected.");
-	else
-		die("File read error: %s", strerror(errno));
-}
-
-void show_line_range(struct line_range *lr)
-{
-	unsigned int l = 1;
-	struct line_node *ln;
-	FILE *fp;
-#ifndef NO_DWARF_SUPPORT
-	int fd, ret;
-#endif
-
-	/* Search a line range */
-	init_vmlinux();
-#ifndef NO_DWARF_SUPPORT
-	fd = open_vmlinux();
-	if (fd < 0)
-		die("Could not open debuginfo file.");
-	ret = find_line_range(fd, lr);
-	if (ret <= 0)
-		die("Source line is not found.\n");
-	close(fd);
-#endif
-
-	setup_pager();
-
-	if (lr->function)
-		fprintf(stdout, "<%s:%d>\n", lr->function,
-			lr->start - lr->offset);
-	else
-		fprintf(stdout, "<%s:%d>\n", lr->file, lr->start);
-
-	fp = fopen(lr->path, "r");
-	if (fp == NULL)
-		die("Failed to open %s: %s", lr->path, strerror(errno));
-	/* Skip to starting line number */
-	while (l < lr->start)
-		show_one_line(fp, l++, true, false);
-
-	list_for_each_entry(ln, &lr->line_list, list) {
-		while (ln->line > l)
-			show_one_line(fp, (l++) - lr->offset, false, false);
-		show_one_line(fp, (l++) - lr->offset, false, true);
-	}
-
-	if (lr->end == INT_MAX)
-		lr->end = l + NR_ADDITIONAL_LINES;
-	while (l < lr->end && !feof(fp))
-		show_one_line(fp, (l++) - lr->offset, false, false);
-
-	fclose(fp);
-}
-
-
diff --git a/tools/perf/util/probe-finder.h b/tools/perf/util/probe-finder.h
index 2f2307d..3564f22 100644
--- a/tools/perf/util/probe-finder.h
+++ b/tools/perf/util/probe-finder.h
@@ -15,7 +15,7 @@ static inline int is_c_varname(const char *name)
 	return isalpha(name[0]) || name[0] == '_';
 }
 
-#ifndef NO_DWARF_SUPPORT
+#ifdef DWARF_SUPPORT
 /* Find kprobe_trace_events specified by perf_probe_event from debuginfo */
 extern int find_kprobe_trace_events(int fd, struct perf_probe_event *pev,
 				    struct kprobe_trace_event **tevs);
@@ -57,6 +57,6 @@ struct line_finder {
 	int			found;
 };
 
-#endif /* NO_DWARF_SUPPORT */
+#endif /* DWARF_SUPPORT */
 
 #endif /*_PROBE_FINDER_H */


-- 
Masami Hiramatsu
e-mail: mhiramat@redhat.com

^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2010-03-17 22:04 UTC | newest]

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