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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-23 04:34:11 +08:00
linux-next/tools/perf/util/probe-event.c
Masami Hiramatsu 15eca306ec perf probe: Fix to use symtab only if no debuginfo
Fix perf probe to use symtab only if there is no debuginfo, because debuginfo
has more information than symtab.

If we can't find a function in debuginfo, we never find it in symtab.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100421195624.24664.46214.stgit@localhost6.localdomain6>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-04-26 15:32:37 -03:00

1642 lines
36 KiB
C

/*
* 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 "util.h"
#include "event.h"
#include "string.h"
#include "strlist.h"
#include "debug.h"
#include "cache.h"
#include "color.h"
#include "symbol.h"
#include "thread.h"
#include "debugfs.h"
#include "trace-event.h" /* For __unused */
#include "probe-event.h"
#include "probe-finder.h"
#define MAX_CMDLEN 256
#define MAX_PROBE_ARGS 128
#define PERFPROBE_GROUP "probe"
bool probe_event_dry_run; /* Dry run flag */
#define semantic_error(msg ...) pr_err("Semantic error :" msg)
/* If there is no space to write, returns -E2BIG. */
static int e_snprintf(char *str, size_t size, const char *format, ...)
__attribute__((format(printf, 3, 4)));
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;
}
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 and path of vmlinux */
static int init_vmlinux(void)
{
struct dso *kernel;
int ret;
symbol_conf.sort_by_name = true;
if (symbol_conf.vmlinux_name == NULL)
symbol_conf.try_vmlinux_path = true;
else
pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);
ret = symbol__init();
if (ret < 0) {
pr_debug("Failed to init symbol map.\n");
goto out;
}
kernel = dso__new_kernel(symbol_conf.vmlinux_name);
if (kernel == NULL)
die("Failed to create kernel dso.");
map_groups__init(&kmap_groups);
ret = __map_groups__create_kernel_maps(&kmap_groups, kmaps, kernel);
if (ret < 0)
pr_debug("Failed to create kernel maps.\n");
out:
if (ret < 0)
pr_warning("Failed to init vmlinux path.\n");
return ret;
}
#ifdef DWARF_SUPPORT
static int open_vmlinux(void)
{
if (map__load(kmaps[MAP__FUNCTION], NULL) < 0) {
pr_debug("Failed to load kernel map.\n");
return -EINVAL;
}
pr_debug("Try to open %s\n", kmaps[MAP__FUNCTION]->dso->long_name);
return open(kmaps[MAP__FUNCTION]->dso->long_name, O_RDONLY);
}
/* Convert trace point to probe point with debuginfo */
static int convert_to_perf_probe_point(struct kprobe_trace_point *tp,
struct perf_probe_point *pp)
{
struct symbol *sym;
int fd, ret = -ENOENT;
sym = map__find_symbol_by_name(kmaps[MAP__FUNCTION],
tp->symbol, NULL);
if (sym) {
fd = open_vmlinux();
if (fd >= 0) {
ret = find_perf_probe_point(fd,
sym->start + tp->offset, pp);
close(fd);
}
}
if (ret <= 0) {
pr_debug("Failed to find corresponding probes from "
"debuginfo. Use kprobe event information.\n");
pp->function = strdup(tp->symbol);
if (pp->function == NULL)
return -ENOMEM;
pp->offset = tp->offset;
}
pp->retprobe = tp->retprobe;
return 0;
}
/* 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) {
pr_warning("Failed to open debuginfo file.\n");
return fd;
}
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 */
pr_debug("find %d kprobe_trace_events.\n", ntevs);
return ntevs;
}
if (ntevs == 0) { /* No error but failed to find probe point. */
pr_warning("Probe point '%s' not found.\n",
synthesize_perf_probe_point(&pev->point));
return -ENOENT;
}
/* Error path : ntevs < 0 */
pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs);
if (ntevs == -EBADF) {
pr_warning("Warning: No dwarf info found in the vmlinux - "
"please rebuild kernel with CONFIG_DEBUG_INFO=y.\n");
if (!need_dwarf) {
pr_debug("Trying to use symbols.\nn");
return 0;
}
}
return ntevs;
}
#define LINEBUF_SIZE 256
#define NR_ADDITIONAL_LINES 2
static int show_one_line(FILE *fp, 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, "%7d %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 0;
error:
if (feof(fp))
pr_warning("Source file is shorter than expected.\n");
else
pr_warning("File read error: %s\n", strerror(errno));
return -1;
}
/*
* Show line-range always requires debuginfo to find source file and
* line number.
*/
int show_line_range(struct line_range *lr)
{
int l = 1;
struct line_node *ln;
FILE *fp;
int fd, ret;
/* Search a line range */
ret = init_vmlinux();
if (ret < 0)
return ret;
fd = open_vmlinux();
if (fd < 0) {
pr_warning("Failed to open debuginfo file.\n");
return fd;
}
ret = find_line_range(fd, lr);
close(fd);
if (ret == 0) {
pr_warning("Specified source line is not found.\n");
return -ENOENT;
} else if (ret < 0) {
pr_warning("Debuginfo analysis failed. (%d)\n", ret);
return ret;
}
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) {
pr_warning("Failed to open %s: %s\n", lr->path,
strerror(errno));
return -errno;
}
/* Skip to starting line number */
while (l < lr->start && ret >= 0)
ret = show_one_line(fp, l++, true, false);
if (ret < 0)
goto end;
list_for_each_entry(ln, &lr->line_list, list) {
while (ln->line > l && ret >= 0)
ret = show_one_line(fp, (l++) - lr->offset,
false, false);
if (ret >= 0)
ret = show_one_line(fp, (l++) - lr->offset,
false, true);
if (ret < 0)
goto end;
}
if (lr->end == INT_MAX)
lr->end = l + NR_ADDITIONAL_LINES;
while (l <= lr->end && !feof(fp) && ret >= 0)
ret = show_one_line(fp, (l++) - lr->offset, false, false);
end:
fclose(fp);
return ret;
}
#else /* !DWARF_SUPPORT */
static int convert_to_perf_probe_point(struct kprobe_trace_point *tp,
struct perf_probe_point *pp)
{
pp->function = strdup(tp->symbol);
if (pp->function == NULL)
return -ENOMEM;
pp->offset = tp->offset;
pp->retprobe = tp->retprobe;
return 0;
}
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)) {
pr_warning("Debuginfo-analysis is not supported.\n");
return -ENOSYS;
}
return 0;
}
int show_line_range(struct line_range *lr __unused)
{
pr_warning("Debuginfo-analysis is not supported.\n");
return -ENOSYS;
}
#endif
int parse_line_range_desc(const char *arg, struct line_range *lr)
{
const char *ptr;
char *tmp;
/*
* <Syntax>
* SRC:SLN[+NUM|-ELN]
* FUNC[:SLN[+NUM|-ELN]]
*/
ptr = strchr(arg, ':');
if (ptr) {
lr->start = (int)strtoul(ptr + 1, &tmp, 0);
if (*tmp == '+') {
lr->end = lr->start + (int)strtoul(tmp + 1, &tmp, 0);
lr->end--; /*
* Adjust the number of lines here.
* If the number of lines == 1, the
* the end of line should be equal to
* the start of line.
*/
} else if (*tmp == '-')
lr->end = (int)strtoul(tmp + 1, &tmp, 0);
else
lr->end = INT_MAX;
pr_debug("Line range is %d to %d\n", lr->start, lr->end);
if (lr->start > lr->end) {
semantic_error("Start line must be smaller"
" than end line.\n");
return -EINVAL;
}
if (*tmp != '\0') {
semantic_error("Tailing with invalid character '%d'.\n",
*tmp);
return -EINVAL;
}
tmp = strndup(arg, (ptr - arg));
} else {
tmp = strdup(arg);
lr->end = INT_MAX;
}
if (tmp == NULL)
return -ENOMEM;
if (strchr(tmp, '.'))
lr->file = tmp;
else
lr->function = tmp;
return 0;
}
/* Check the name is good for event/group */
static bool check_event_name(const char *name)
{
if (!isalpha(*name) && *name != '_')
return false;
while (*++name != '\0') {
if (!isalpha(*name) && !isdigit(*name) && *name != '_')
return false;
}
return true;
}
/* Parse probepoint definition. */
static int parse_perf_probe_point(char *arg, struct perf_probe_event *pev)
{
struct perf_probe_point *pp = &pev->point;
char *ptr, *tmp;
char c, nc = 0;
/*
* <Syntax>
* perf probe [EVENT=]SRC[:LN|;PTN]
* perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
*
* TODO:Group name support
*/
ptr = strpbrk(arg, ";=@+%");
if (ptr && *ptr == '=') { /* Event name */
*ptr = '\0';
tmp = ptr + 1;
if (strchr(arg, ':')) {
semantic_error("Group name is not supported yet.\n");
return -ENOTSUP;
}
if (!check_event_name(arg)) {
semantic_error("%s is bad for event name -it must "
"follow C symbol-naming rule.\n", arg);
return -EINVAL;
}
pev->event = strdup(arg);
if (pev->event == NULL)
return -ENOMEM;
pev->group = NULL;
arg = tmp;
}
ptr = strpbrk(arg, ";:+@%");
if (ptr) {
nc = *ptr;
*ptr++ = '\0';
}
tmp = strdup(arg);
if (tmp == NULL)
return -ENOMEM;
/* Check arg is function or file and copy it */
if (strchr(tmp, '.')) /* File */
pp->file = tmp;
else /* Function */
pp->function = tmp;
/* Parse other options */
while (ptr) {
arg = ptr;
c = nc;
if (c == ';') { /* Lazy pattern must be the last part */
pp->lazy_line = strdup(arg);
if (pp->lazy_line == NULL)
return -ENOMEM;
break;
}
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 char"
" in line number.\n");
return -EINVAL;
}
break;
case '+': /* Byte offset from a symbol */
pp->offset = strtoul(arg, &tmp, 0);
if (*tmp != '\0') {
semantic_error("There is non-digit character"
" in offset.\n");
return -EINVAL;
}
break;
case '@': /* File name */
if (pp->file) {
semantic_error("SRC@SRC is not allowed.\n");
return -EINVAL;
}
pp->file = strdup(arg);
if (pp->file == NULL)
return -ENOMEM;
break;
case '%': /* Probe places */
if (strcmp(arg, "return") == 0) {
pp->retprobe = 1;
} else { /* Others not supported yet */
semantic_error("%%%s is not supported.\n", arg);
return -ENOTSUP;
}
break;
default: /* Buggy case */
pr_err("This program has a bug at %s:%d.\n",
__FILE__, __LINE__);
return -ENOTSUP;
break;
}
}
/* Exclusion check */
if (pp->lazy_line && pp->line) {
semantic_error("Lazy pattern can't be used with line number.");
return -EINVAL;
}
if (pp->lazy_line && pp->offset) {
semantic_error("Lazy pattern can't be used with offset.");
return -EINVAL;
}
if (pp->line && pp->offset) {
semantic_error("Offset can't be used with line number.");
return -EINVAL;
}
if (!pp->line && !pp->lazy_line && pp->file && !pp->function) {
semantic_error("File always requires line number or "
"lazy pattern.");
return -EINVAL;
}
if (pp->offset && !pp->function) {
semantic_error("Offset requires an entry function.");
return -EINVAL;
}
if (pp->retprobe && !pp->function) {
semantic_error("Return probe requires an entry function.");
return -EINVAL;
}
if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe) {
semantic_error("Offset/Line/Lazy pattern can't be used with "
"return probe.");
return -EINVAL;
}
pr_debug("symbol:%s file:%s line:%d offset:%lu return:%d lazy:%s\n",
pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
pp->lazy_line);
return 0;
}
/* Parse perf-probe event argument */
static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg)
{
char *tmp;
struct perf_probe_arg_field **fieldp;
pr_debug("parsing arg: %s into ", str);
tmp = strchr(str, '=');
if (tmp) {
arg->name = strndup(str, tmp - str);
if (arg->name == NULL)
return -ENOMEM;
pr_debug("name:%s ", arg->name);
str = tmp + 1;
}
tmp = strchr(str, ':');
if (tmp) { /* Type setting */
*tmp = '\0';
arg->type = strdup(tmp + 1);
if (arg->type == NULL)
return -ENOMEM;
pr_debug("type:%s ", arg->type);
}
tmp = strpbrk(str, "-.");
if (!is_c_varname(str) || !tmp) {
/* A variable, register, symbol or special value */
arg->var = strdup(str);
if (arg->var == NULL)
return -ENOMEM;
pr_debug("%s\n", arg->var);
return 0;
}
/* Structure fields */
arg->var = strndup(str, tmp - str);
if (arg->var == NULL)
return -ENOMEM;
pr_debug("%s, ", arg->var);
fieldp = &arg->field;
do {
*fieldp = zalloc(sizeof(struct perf_probe_arg_field));
if (*fieldp == NULL)
return -ENOMEM;
if (*tmp == '.') {
str = tmp + 1;
(*fieldp)->ref = false;
} else if (tmp[1] == '>') {
str = tmp + 2;
(*fieldp)->ref = true;
} else {
semantic_error("Argument parse error: %s\n", str);
return -EINVAL;
}
tmp = strpbrk(str, "-.");
if (tmp) {
(*fieldp)->name = strndup(str, tmp - str);
if ((*fieldp)->name == NULL)
return -ENOMEM;
pr_debug("%s(%d), ", (*fieldp)->name, (*fieldp)->ref);
fieldp = &(*fieldp)->next;
}
} while (tmp);
(*fieldp)->name = strdup(str);
if ((*fieldp)->name == NULL)
return -ENOMEM;
pr_debug("%s(%d)\n", (*fieldp)->name, (*fieldp)->ref);
/* If no name is specified, set the last field name */
if (!arg->name) {
arg->name = strdup((*fieldp)->name);
if (arg->name == NULL)
return -ENOMEM;
}
return 0;
}
/* Parse perf-probe event command */
int parse_perf_probe_command(const char *cmd, struct perf_probe_event *pev)
{
char **argv;
int argc, i, ret = 0;
argv = argv_split(cmd, &argc);
if (!argv) {
pr_debug("Failed to split arguments.\n");
return -ENOMEM;
}
if (argc - 1 > MAX_PROBE_ARGS) {
semantic_error("Too many probe arguments (%d).\n", argc - 1);
ret = -ERANGE;
goto out;
}
/* Parse probe point */
ret = parse_perf_probe_point(argv[0], pev);
if (ret < 0)
goto out;
/* Copy arguments and ensure return probe has no C argument */
pev->nargs = argc - 1;
pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs);
if (pev->args == NULL) {
ret = -ENOMEM;
goto out;
}
for (i = 0; i < pev->nargs && ret >= 0; i++) {
ret = parse_perf_probe_arg(argv[i + 1], &pev->args[i]);
if (ret >= 0 &&
is_c_varname(pev->args[i].var) && pev->point.retprobe) {
semantic_error("You can't specify local variable for"
" kretprobe.\n");
ret = -EINVAL;
}
}
out:
argv_free(argv);
return ret;
}
/* Return true if this perf_probe_event requires debuginfo */
bool perf_probe_event_need_dwarf(struct perf_probe_event *pev)
{
int i;
if (pev->point.file || pev->point.line || pev->point.lazy_line)
return true;
for (i = 0; i < pev->nargs; i++)
if (is_c_varname(pev->args[i].var))
return true;
return false;
}
/* Parse kprobe_events event into struct probe_point */
int parse_kprobe_trace_command(const char *cmd, struct kprobe_trace_event *tev)
{
struct kprobe_trace_point *tp = &tev->point;
char pr;
char *p;
int ret, i, argc;
char **argv;
pr_debug("Parsing kprobe_events: %s\n", cmd);
argv = argv_split(cmd, &argc);
if (!argv) {
pr_debug("Failed to split arguments.\n");
return -ENOMEM;
}
if (argc < 2) {
semantic_error("Too few probe arguments.\n");
ret = -ERANGE;
goto out;
}
/* Scan event and group name. */
ret = sscanf(argv[0], "%c:%a[^/ \t]/%a[^ \t]",
&pr, (float *)(void *)&tev->group,
(float *)(void *)&tev->event);
if (ret != 3) {
semantic_error("Failed to parse event name: %s\n", argv[0]);
ret = -EINVAL;
goto out;
}
pr_debug("Group:%s Event:%s probe:%c\n", tev->group, tev->event, pr);
tp->retprobe = (pr == 'r');
/* Scan function name and offset */
ret = sscanf(argv[1], "%a[^+]+%lu", (float *)(void *)&tp->symbol,
&tp->offset);
if (ret == 1)
tp->offset = 0;
tev->nargs = argc - 2;
tev->args = zalloc(sizeof(struct kprobe_trace_arg) * tev->nargs);
if (tev->args == NULL) {
ret = -ENOMEM;
goto out;
}
for (i = 0; i < tev->nargs; i++) {
p = strchr(argv[i + 2], '=');
if (p) /* We don't need which register is assigned. */
*p++ = '\0';
else
p = argv[i + 2];
tev->args[i].name = strdup(argv[i + 2]);
/* TODO: parse regs and offset */
tev->args[i].value = strdup(p);
if (tev->args[i].name == NULL || tev->args[i].value == NULL) {
ret = -ENOMEM;
goto out;
}
}
ret = 0;
out:
argv_free(argv);
return ret;
}
/* Compose only probe arg */
int synthesize_perf_probe_arg(struct perf_probe_arg *pa, char *buf, size_t len)
{
struct perf_probe_arg_field *field = pa->field;
int ret;
char *tmp = buf;
if (pa->name && pa->var)
ret = e_snprintf(tmp, len, "%s=%s", pa->name, pa->var);
else
ret = e_snprintf(tmp, len, "%s", pa->name ? pa->name : pa->var);
if (ret <= 0)
goto error;
tmp += ret;
len -= ret;
while (field) {
ret = e_snprintf(tmp, len, "%s%s", field->ref ? "->" : ".",
field->name);
if (ret <= 0)
goto error;
tmp += ret;
len -= ret;
field = field->next;
}
if (pa->type) {
ret = e_snprintf(tmp, len, ":%s", pa->type);
if (ret <= 0)
goto error;
tmp += ret;
len -= ret;
}
return tmp - buf;
error:
pr_debug("Failed to synthesize perf probe argument: %s",
strerror(-ret));
return ret;
}
/* Compose only probe point (not argument) */
static char *synthesize_perf_probe_point(struct perf_probe_point *pp)
{
char *buf, *tmp;
char offs[32] = "", line[32] = "", file[32] = "";
int ret, len;
buf = zalloc(MAX_CMDLEN);
if (buf == NULL) {
ret = -ENOMEM;
goto error;
}
if (pp->offset) {
ret = e_snprintf(offs, 32, "+%lu", pp->offset);
if (ret <= 0)
goto error;
}
if (pp->line) {
ret = e_snprintf(line, 32, ":%d", pp->line);
if (ret <= 0)
goto error;
}
if (pp->file) {
len = strlen(pp->file) - 31;
if (len < 0)
len = 0;
tmp = strchr(pp->file + len, '/');
if (!tmp)
tmp = pp->file + len;
ret = e_snprintf(file, 32, "@%s", tmp + 1);
if (ret <= 0)
goto error;
}
if (pp->function)
ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s%s", pp->function,
offs, pp->retprobe ? "%return" : "", line,
file);
else
ret = e_snprintf(buf, MAX_CMDLEN, "%s%s", file, line);
if (ret <= 0)
goto error;
return buf;
error:
pr_debug("Failed to synthesize perf probe point: %s",
strerror(-ret));
if (buf)
free(buf);
return NULL;
}
#if 0
char *synthesize_perf_probe_command(struct perf_probe_event *pev)
{
char *buf;
int i, len, ret;
buf = synthesize_perf_probe_point(&pev->point);
if (!buf)
return NULL;
len = strlen(buf);
for (i = 0; i < pev->nargs; i++) {
ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
pev->args[i].name);
if (ret <= 0) {
free(buf);
return NULL;
}
len += ret;
}
return buf;
}
#endif
static int __synthesize_kprobe_trace_arg_ref(struct kprobe_trace_arg_ref *ref,
char **buf, size_t *buflen,
int depth)
{
int ret;
if (ref->next) {
depth = __synthesize_kprobe_trace_arg_ref(ref->next, buf,
buflen, depth + 1);
if (depth < 0)
goto out;
}
ret = e_snprintf(*buf, *buflen, "%+ld(", ref->offset);
if (ret < 0)
depth = ret;
else {
*buf += ret;
*buflen -= ret;
}
out:
return depth;
}
static int synthesize_kprobe_trace_arg(struct kprobe_trace_arg *arg,
char *buf, size_t buflen)
{
int ret, depth = 0;
char *tmp = buf;
/* Argument name or separator */
if (arg->name)
ret = e_snprintf(buf, buflen, " %s=", arg->name);
else
ret = e_snprintf(buf, buflen, " ");
if (ret < 0)
return ret;
buf += ret;
buflen -= ret;
/* Dereferencing arguments */
if (arg->ref) {
depth = __synthesize_kprobe_trace_arg_ref(arg->ref, &buf,
&buflen, 1);
if (depth < 0)
return depth;
}
/* Print argument value */
ret = e_snprintf(buf, buflen, "%s", arg->value);
if (ret < 0)
return ret;
buf += ret;
buflen -= ret;
/* Closing */
while (depth--) {
ret = e_snprintf(buf, buflen, ")");
if (ret < 0)
return ret;
buf += ret;
buflen -= ret;
}
/* Print argument type */
if (arg->type) {
ret = e_snprintf(buf, buflen, ":%s", arg->type);
if (ret <= 0)
return ret;
buf += ret;
}
return buf - tmp;
}
char *synthesize_kprobe_trace_command(struct kprobe_trace_event *tev)
{
struct kprobe_trace_point *tp = &tev->point;
char *buf;
int i, len, ret;
buf = zalloc(MAX_CMDLEN);
if (buf == NULL)
return NULL;
len = e_snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s+%lu",
tp->retprobe ? 'r' : 'p',
tev->group, tev->event,
tp->symbol, tp->offset);
if (len <= 0)
goto error;
for (i = 0; i < tev->nargs; i++) {
ret = synthesize_kprobe_trace_arg(&tev->args[i], buf + len,
MAX_CMDLEN - len);
if (ret <= 0)
goto error;
len += ret;
}
return buf;
error:
free(buf);
return NULL;
}
int convert_to_perf_probe_event(struct kprobe_trace_event *tev,
struct perf_probe_event *pev)
{
char buf[64] = "";
int i, ret;
/* Convert event/group name */
pev->event = strdup(tev->event);
pev->group = strdup(tev->group);
if (pev->event == NULL || pev->group == NULL)
return -ENOMEM;
/* Convert trace_point to probe_point */
ret = convert_to_perf_probe_point(&tev->point, &pev->point);
if (ret < 0)
return ret;
/* Convert trace_arg to probe_arg */
pev->nargs = tev->nargs;
pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs);
if (pev->args == NULL)
return -ENOMEM;
for (i = 0; i < tev->nargs && ret >= 0; i++) {
if (tev->args[i].name)
pev->args[i].name = strdup(tev->args[i].name);
else {
ret = synthesize_kprobe_trace_arg(&tev->args[i],
buf, 64);
pev->args[i].name = strdup(buf);
}
if (pev->args[i].name == NULL && ret >= 0)
ret = -ENOMEM;
}
if (ret < 0)
clear_perf_probe_event(pev);
return ret;
}
void clear_perf_probe_event(struct perf_probe_event *pev)
{
struct perf_probe_point *pp = &pev->point;
struct perf_probe_arg_field *field, *next;
int i;
if (pev->event)
free(pev->event);
if (pev->group)
free(pev->group);
if (pp->file)
free(pp->file);
if (pp->function)
free(pp->function);
if (pp->lazy_line)
free(pp->lazy_line);
for (i = 0; i < pev->nargs; i++) {
if (pev->args[i].name)
free(pev->args[i].name);
if (pev->args[i].var)
free(pev->args[i].var);
if (pev->args[i].type)
free(pev->args[i].type);
field = pev->args[i].field;
while (field) {
next = field->next;
if (field->name)
free(field->name);
free(field);
field = next;
}
}
if (pev->args)
free(pev->args);
memset(pev, 0, sizeof(*pev));
}
void clear_kprobe_trace_event(struct kprobe_trace_event *tev)
{
struct kprobe_trace_arg_ref *ref, *next;
int i;
if (tev->event)
free(tev->event);
if (tev->group)
free(tev->group);
if (tev->point.symbol)
free(tev->point.symbol);
for (i = 0; i < tev->nargs; i++) {
if (tev->args[i].name)
free(tev->args[i].name);
if (tev->args[i].value)
free(tev->args[i].value);
if (tev->args[i].type)
free(tev->args[i].type);
ref = tev->args[i].ref;
while (ref) {
next = ref->next;
free(ref);
ref = next;
}
}
if (tev->args)
free(tev->args);
memset(tev, 0, sizeof(*tev));
}
static int open_kprobe_events(bool readwrite)
{
char buf[PATH_MAX];
const char *__debugfs;
int ret;
__debugfs = debugfs_find_mountpoint();
if (__debugfs == NULL) {
pr_warning("Debugfs is not mounted.\n");
return -ENOENT;
}
ret = e_snprintf(buf, PATH_MAX, "%stracing/kprobe_events", __debugfs);
if (ret >= 0) {
pr_debug("Opening %s write=%d\n", buf, readwrite);
if (readwrite && !probe_event_dry_run)
ret = open(buf, O_RDWR, O_APPEND);
else
ret = open(buf, O_RDONLY, 0);
}
if (ret < 0) {
if (errno == ENOENT)
pr_warning("kprobe_events file does not exist - please"
" rebuild kernel with CONFIG_KPROBE_EVENT.\n");
else
pr_warning("Failed to open kprobe_events file: %s\n",
strerror(errno));
}
return ret;
}
/* Get raw string list of current kprobe_events */
static struct strlist *get_kprobe_trace_command_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) {
pr_debug("strlist__add failed: %s\n", strerror(-ret));
strlist__delete(sl);
return NULL;
}
}
fclose(fp);
return sl;
}
/* Show an event */
static int show_perf_probe_event(struct perf_probe_event *pev)
{
int i, ret;
char buf[128];
char *place;
/* Synthesize only event probe point */
place = synthesize_perf_probe_point(&pev->point);
if (!place)
return -EINVAL;
ret = e_snprintf(buf, 128, "%s:%s", pev->group, pev->event);
if (ret < 0)
return ret;
printf(" %-20s (on %s", buf, place);
if (pev->nargs > 0) {
printf(" with");
for (i = 0; i < pev->nargs; i++) {
ret = synthesize_perf_probe_arg(&pev->args[i],
buf, 128);
if (ret < 0)
break;
printf(" %s", buf);
}
}
printf(")\n");
free(place);
return ret;
}
/* List up current perf-probe events */
int show_perf_probe_events(void)
{
int fd, ret;
struct kprobe_trace_event tev;
struct perf_probe_event pev;
struct strlist *rawlist;
struct str_node *ent;
setup_pager();
ret = init_vmlinux();
if (ret < 0)
return ret;
memset(&tev, 0, sizeof(tev));
memset(&pev, 0, sizeof(pev));
fd = open_kprobe_events(false);
if (fd < 0)
return fd;
rawlist = get_kprobe_trace_command_rawlist(fd);
close(fd);
if (!rawlist)
return -ENOENT;
strlist__for_each(ent, rawlist) {
ret = parse_kprobe_trace_command(ent->s, &tev);
if (ret >= 0) {
ret = convert_to_perf_probe_event(&tev, &pev);
if (ret >= 0)
ret = show_perf_probe_event(&pev);
}
clear_perf_probe_event(&pev);
clear_kprobe_trace_event(&tev);
if (ret < 0)
break;
}
strlist__delete(rawlist);
return ret;
}
/* Get current perf-probe event names */
static struct strlist *get_kprobe_trace_event_names(int fd, bool include_group)
{
char buf[128];
struct strlist *sl, *rawlist;
struct str_node *ent;
struct kprobe_trace_event tev;
int ret = 0;
memset(&tev, 0, sizeof(tev));
rawlist = get_kprobe_trace_command_rawlist(fd);
sl = strlist__new(true, NULL);
strlist__for_each(ent, rawlist) {
ret = parse_kprobe_trace_command(ent->s, &tev);
if (ret < 0)
break;
if (include_group) {
ret = e_snprintf(buf, 128, "%s:%s", tev.group,
tev.event);
if (ret >= 0)
ret = strlist__add(sl, buf);
} else
ret = strlist__add(sl, tev.event);
clear_kprobe_trace_event(&tev);
if (ret < 0)
break;
}
strlist__delete(rawlist);
if (ret < 0) {
strlist__delete(sl);
return NULL;
}
return sl;
}
static int write_kprobe_trace_event(int fd, struct kprobe_trace_event *tev)
{
int ret = 0;
char *buf = synthesize_kprobe_trace_command(tev);
if (!buf) {
pr_debug("Failed to synthesize kprobe trace event.\n");
return -EINVAL;
}
pr_debug("Writing event: %s\n", buf);
if (!probe_event_dry_run) {
ret = write(fd, buf, strlen(buf));
if (ret <= 0)
pr_warning("Failed to write event: %s\n",
strerror(errno));
}
free(buf);
return ret;
}
static int get_new_event_name(char *buf, size_t len, const char *base,
struct strlist *namelist, bool allow_suffix)
{
int i, ret;
/* Try no suffix */
ret = e_snprintf(buf, len, "%s", base);
if (ret < 0) {
pr_debug("snprintf() failed: %s\n", strerror(-ret));
return ret;
}
if (!strlist__has_entry(namelist, buf))
return 0;
if (!allow_suffix) {
pr_warning("Error: event \"%s\" already exists. "
"(Use -f to force duplicates.)\n", base);
return -EEXIST;
}
/* Try to add suffix */
for (i = 1; i < MAX_EVENT_INDEX; i++) {
ret = e_snprintf(buf, len, "%s_%d", base, i);
if (ret < 0) {
pr_debug("snprintf() failed: %s\n", strerror(-ret));
return ret;
}
if (!strlist__has_entry(namelist, buf))
break;
}
if (i == MAX_EVENT_INDEX) {
pr_warning("Too many events are on the same function.\n");
ret = -ERANGE;
}
return ret;
}
static int __add_kprobe_trace_events(struct perf_probe_event *pev,
struct kprobe_trace_event *tevs,
int ntevs, bool allow_suffix)
{
int i, fd, ret;
struct kprobe_trace_event *tev = NULL;
char buf[64];
const char *event, *group;
struct strlist *namelist;
fd = open_kprobe_events(true);
if (fd < 0)
return fd;
/* Get current event names */
namelist = get_kprobe_trace_event_names(fd, false);
if (!namelist) {
pr_debug("Failed to get current event list.\n");
return -EIO;
}
ret = 0;
printf("Add new event%s\n", (ntevs > 1) ? "s:" : ":");
for (i = 0; i < ntevs; i++) {
tev = &tevs[i];
if (pev->event)
event = pev->event;
else
if (pev->point.function)
event = pev->point.function;
else
event = tev->point.symbol;
if (pev->group)
group = pev->group;
else
group = PERFPROBE_GROUP;
/* Get an unused new event name */
ret = get_new_event_name(buf, 64, event,
namelist, allow_suffix);
if (ret < 0)
break;
event = buf;
tev->event = strdup(event);
tev->group = strdup(group);
if (tev->event == NULL || tev->group == NULL) {
ret = -ENOMEM;
break;
}
ret = write_kprobe_trace_event(fd, tev);
if (ret < 0)
break;
/* Add added event name to namelist */
strlist__add(namelist, event);
/* Trick here - save current event/group */
event = pev->event;
group = pev->group;
pev->event = tev->event;
pev->group = tev->group;
show_perf_probe_event(pev);
/* Trick here - restore current event/group */
pev->event = (char *)event;
pev->group = (char *)group;
/*
* Probes after the first probe which comes from same
* user input are always allowed to add suffix, because
* there might be several addresses corresponding to
* one code line.
*/
allow_suffix = true;
}
if (ret >= 0) {
/* Show how to use the event. */
printf("\nYou can now use it on all perf tools, such as:\n\n");
printf("\tperf record -e %s:%s -aR sleep 1\n\n", tev->group,
tev->event);
}
strlist__delete(namelist);
close(fd);
return ret;
}
static int convert_to_kprobe_trace_events(struct perf_probe_event *pev,
struct kprobe_trace_event **tevs)
{
struct symbol *sym;
int ret = 0, i;
struct kprobe_trace_event *tev;
/* Convert perf_probe_event with debuginfo */
ret = try_to_find_kprobe_trace_events(pev, tevs);
if (ret != 0)
return ret;
/* Allocate trace event buffer */
tev = *tevs = zalloc(sizeof(struct kprobe_trace_event));
if (tev == NULL)
return -ENOMEM;
/* Copy parameters */
tev->point.symbol = strdup(pev->point.function);
if (tev->point.symbol == NULL) {
ret = -ENOMEM;
goto error;
}
tev->point.offset = pev->point.offset;
tev->nargs = pev->nargs;
if (tev->nargs) {
tev->args = zalloc(sizeof(struct kprobe_trace_arg)
* tev->nargs);
if (tev->args == NULL) {
ret = -ENOMEM;
goto error;
}
for (i = 0; i < tev->nargs; i++) {
if (pev->args[i].name) {
tev->args[i].name = strdup(pev->args[i].name);
if (tev->args[i].name == NULL) {
ret = -ENOMEM;
goto error;
}
}
tev->args[i].value = strdup(pev->args[i].var);
if (tev->args[i].value == NULL) {
ret = -ENOMEM;
goto error;
}
if (pev->args[i].type) {
tev->args[i].type = strdup(pev->args[i].type);
if (tev->args[i].type == NULL) {
ret = -ENOMEM;
goto error;
}
}
}
}
/* Currently just checking function name from symbol map */
sym = map__find_symbol_by_name(kmaps[MAP__FUNCTION],
tev->point.symbol, NULL);
if (!sym) {
pr_warning("Kernel symbol \'%s\' not found.\n",
tev->point.symbol);
ret = -ENOENT;
goto error;
}
return 1;
error:
clear_kprobe_trace_event(tev);
free(tev);
*tevs = NULL;
return ret;
}
struct __event_package {
struct perf_probe_event *pev;
struct kprobe_trace_event *tevs;
int ntevs;
};
int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
bool force_add)
{
int i, j, ret;
struct __event_package *pkgs;
pkgs = zalloc(sizeof(struct __event_package) * npevs);
if (pkgs == NULL)
return -ENOMEM;
/* Init vmlinux path */
ret = init_vmlinux();
if (ret < 0)
return ret;
/* Loop 1: convert all events */
for (i = 0; i < npevs; i++) {
pkgs[i].pev = &pevs[i];
/* Convert with or without debuginfo */
ret = convert_to_kprobe_trace_events(pkgs[i].pev,
&pkgs[i].tevs);
if (ret < 0)
goto end;
pkgs[i].ntevs = ret;
}
/* Loop 2: add all events */
for (i = 0; i < npevs && ret >= 0; i++)
ret = __add_kprobe_trace_events(pkgs[i].pev, pkgs[i].tevs,
pkgs[i].ntevs, force_add);
end:
/* Loop 3: cleanup trace events */
for (i = 0; i < npevs; i++)
for (j = 0; j < pkgs[i].ntevs; j++)
clear_kprobe_trace_event(&pkgs[i].tevs[j]);
return ret;
}
static int __del_trace_kprobe_event(int fd, struct str_node *ent)
{
char *p;
char buf[128];
int ret;
/* Convert from perf-probe event to trace-kprobe event */
ret = e_snprintf(buf, 128, "-:%s", ent->s);
if (ret < 0)
goto error;
p = strchr(buf + 2, ':');
if (!p) {
pr_debug("Internal error: %s should have ':' but not.\n",
ent->s);
ret = -ENOTSUP;
goto error;
}
*p = '/';
pr_debug("Writing event: %s\n", buf);
ret = write(fd, buf, strlen(buf));
if (ret < 0)
goto error;
printf("Remove event: %s\n", ent->s);
return 0;
error:
pr_warning("Failed to delete event: %s\n", strerror(-ret));
return ret;
}
static int del_trace_kprobe_event(int fd, const char *group,
const char *event, struct strlist *namelist)
{
char buf[128];
struct str_node *ent, *n;
int found = 0, ret = 0;
ret = e_snprintf(buf, 128, "%s:%s", group, event);
if (ret < 0) {
pr_err("Failed to copy event.");
return ret;
}
if (strpbrk(buf, "*?")) { /* Glob-exp */
strlist__for_each_safe(ent, n, namelist)
if (strglobmatch(ent->s, buf)) {
found++;
ret = __del_trace_kprobe_event(fd, ent);
if (ret < 0)
break;
strlist__remove(namelist, ent);
}
} else {
ent = strlist__find(namelist, buf);
if (ent) {
found++;
ret = __del_trace_kprobe_event(fd, ent);
if (ret >= 0)
strlist__remove(namelist, ent);
}
}
if (found == 0 && ret >= 0)
pr_info("Info: Event \"%s\" does not exist.\n", buf);
return ret;
}
int del_perf_probe_events(struct strlist *dellist)
{
int fd, ret = 0;
const char *group, *event;
char *p, *str;
struct str_node *ent;
struct strlist *namelist;
fd = open_kprobe_events(true);
if (fd < 0)
return fd;
/* Get current event names */
namelist = get_kprobe_trace_event_names(fd, true);
if (namelist == NULL)
return -EINVAL;
strlist__for_each(ent, dellist) {
str = strdup(ent->s);
if (str == NULL) {
ret = -ENOMEM;
break;
}
pr_debug("Parsing: %s\n", str);
p = strchr(str, ':');
if (p) {
group = str;
*p = '\0';
event = p + 1;
} else {
group = "*";
event = str;
}
pr_debug("Group: %s, Event: %s\n", group, event);
ret = del_trace_kprobe_event(fd, group, event, namelist);
free(str);
if (ret < 0)
break;
}
strlist__delete(namelist);
close(fd);
return ret;
}