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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/tools/perf/util/probe-event.c

1647 строки
36 KiB
C
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/*
* 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 machine machine;
/* 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;
}
ret = machine__init(&machine, "/", 0);
if (ret < 0)
goto out;
kernel = dso__new_kernel(symbol_conf.vmlinux_name);
if (kernel == NULL)
die("Failed to create kernel dso.");
ret = __machine__create_kernel_maps(&machine, 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(machine.vmlinux_maps[MAP__FUNCTION], NULL) < 0) {
pr_debug("Failed to load kernel map.\n");
return -EINVAL;
}
pr_debug("Try to open %s\n", machine.vmlinux_maps[MAP__FUNCTION]->dso->long_name);
return open(machine.vmlinux_maps[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(machine.vmlinux_maps[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,
int max_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, max_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,
int max_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,
int max_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, max_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(machine.vmlinux_maps[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 max_tevs)
{
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, max_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;
}
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