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perf probe: Cleanup debuginfo related code

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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.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1269274229-20442-2-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
tirimbino
Masami Hiramatsu 15 years ago committed by Ingo Molnar
parent f3a1f0ea94
commit 4b4da7f766
4 changed files with 200 additions and 178 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 3
      tools/perf/Makefile
  2. 28
      tools/perf/builtin-probe.c
  3. 343
      tools/perf/util/probe-event.c
  4. 4
      tools/perf/util/probe-finder.h

3
tools/perf/Makefile
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@ -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

28
tools/perf/builtin-probe.c
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@ -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"

343
tools/perf/util/probe-event.c
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@ -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);
}

4
tools/perf/util/probe-finder.h
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@ -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 */

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