blob: eb5f18b754028e863e3b72970842cc33d2fb997d [file] [log] [blame]
/*
* probe-event.c : perf-probe definition to probe_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.
*
*/
#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>
#include <elf.h>
#include "util.h"
#include "event.h"
#include "strlist.h"
#include "debug.h"
#include "cache.h"
#include "color.h"
#include "symbol.h"
#include "thread.h"
#include <api/fs/debugfs.h>
#include <api/fs/tracefs.h>
#include "trace-event.h" /* For __maybe_unused */
#include "probe-event.h"
#include "probe-finder.h"
#include "probe-file.h"
#include "session.h"
#define MAX_CMDLEN 256
#define PERFPROBE_GROUP "probe"
bool probe_event_dry_run; /* Dry run flag */
struct probe_conf probe_conf;
#define semantic_error(msg ...) pr_err("Semantic error :" msg)
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 *host_machine;
/* Initialize symbol maps and path of vmlinux/modules */
static int init_symbol_maps(bool user_only)
{
int ret;
symbol_conf.sort_by_name = true;
symbol_conf.allow_aliases = true;
ret = symbol__init(NULL);
if (ret < 0) {
pr_debug("Failed to init symbol map.\n");
goto out;
}
if (host_machine || user_only) /* already initialized */
return 0;
if (symbol_conf.vmlinux_name)
pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);
host_machine = machine__new_host();
if (!host_machine) {
pr_debug("machine__new_host() failed.\n");
symbol__exit();
ret = -1;
}
out:
if (ret < 0)
pr_warning("Failed to init vmlinux path.\n");
return ret;
}
static void exit_symbol_maps(void)
{
if (host_machine) {
machine__delete(host_machine);
host_machine = NULL;
}
symbol__exit();
}
static struct symbol *__find_kernel_function_by_name(const char *name,
struct map **mapp)
{
return machine__find_kernel_function_by_name(host_machine, name, mapp,
NULL);
}
static struct symbol *__find_kernel_function(u64 addr, struct map **mapp)
{
return machine__find_kernel_function(host_machine, addr, mapp, NULL);
}
static struct ref_reloc_sym *kernel_get_ref_reloc_sym(void)
{
/* kmap->ref_reloc_sym should be set if host_machine is initialized */
struct kmap *kmap;
if (map__load(host_machine->vmlinux_maps[MAP__FUNCTION], NULL) < 0)
return NULL;
kmap = map__kmap(host_machine->vmlinux_maps[MAP__FUNCTION]);
if (!kmap)
return NULL;
return kmap->ref_reloc_sym;
}
static u64 kernel_get_symbol_address_by_name(const char *name, bool reloc)
{
struct ref_reloc_sym *reloc_sym;
struct symbol *sym;
struct map *map;
/* ref_reloc_sym is just a label. Need a special fix*/
reloc_sym = kernel_get_ref_reloc_sym();
if (reloc_sym && strcmp(name, reloc_sym->name) == 0)
return (reloc) ? reloc_sym->addr : reloc_sym->unrelocated_addr;
else {
sym = __find_kernel_function_by_name(name, &map);
if (sym)
return map->unmap_ip(map, sym->start) -
((reloc) ? 0 : map->reloc);
}
return 0;
}
static struct map *kernel_get_module_map(const char *module)
{
struct map_groups *grp = &host_machine->kmaps;
struct maps *maps = &grp->maps[MAP__FUNCTION];
struct map *pos;
/* A file path -- this is an offline module */
if (module && strchr(module, '/'))
return machine__findnew_module_map(host_machine, 0, module);
if (!module)
module = "kernel";
for (pos = maps__first(maps); pos; pos = map__next(pos)) {
if (strncmp(pos->dso->short_name + 1, module,
pos->dso->short_name_len - 2) == 0) {
return pos;
}
}
return NULL;
}
static struct map *get_target_map(const char *target, bool user)
{
/* Init maps of given executable or kernel */
if (user)
return dso__new_map(target);
else
return kernel_get_module_map(target);
}
static void put_target_map(struct map *map, bool user)
{
if (map && user) {
/* Only the user map needs to be released */
map__put(map);
}
}
static int convert_exec_to_group(const char *exec, char **result)
{
char *ptr1, *ptr2, *exec_copy;
char buf[64];
int ret;
exec_copy = strdup(exec);
if (!exec_copy)
return -ENOMEM;
ptr1 = basename(exec_copy);
if (!ptr1) {
ret = -EINVAL;
goto out;
}
ptr2 = strpbrk(ptr1, "-._");
if (ptr2)
*ptr2 = '\0';
ret = e_snprintf(buf, 64, "%s_%s", PERFPROBE_GROUP, ptr1);
if (ret < 0)
goto out;
*result = strdup(buf);
ret = *result ? 0 : -ENOMEM;
out:
free(exec_copy);
return ret;
}
static void clear_perf_probe_point(struct perf_probe_point *pp)
{
free(pp->file);
free(pp->function);
free(pp->lazy_line);
}
static void clear_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
{
int i;
for (i = 0; i < ntevs; i++)
clear_probe_trace_event(tevs + i);
}
static bool kprobe_blacklist__listed(unsigned long address);
static bool kprobe_warn_out_range(const char *symbol, unsigned long address)
{
u64 etext_addr;
/* Get the address of _etext for checking non-probable text symbol */
etext_addr = kernel_get_symbol_address_by_name("_etext", false);
if (etext_addr != 0 && etext_addr < address)
pr_warning("%s is out of .text, skip it.\n", symbol);
else if (kprobe_blacklist__listed(address))
pr_warning("%s is blacklisted function, skip it.\n", symbol);
else
return false;
return true;
}
#ifdef HAVE_DWARF_SUPPORT
static int kernel_get_module_dso(const char *module, struct dso **pdso)
{
struct dso *dso;
struct map *map;
const char *vmlinux_name;
int ret = 0;
if (module) {
list_for_each_entry(dso, &host_machine->dsos.head, node) {
if (!dso->kernel)
continue;
if (strncmp(dso->short_name + 1, module,
dso->short_name_len - 2) == 0)
goto found;
}
pr_debug("Failed to find module %s.\n", module);
return -ENOENT;
}
map = host_machine->vmlinux_maps[MAP__FUNCTION];
dso = map->dso;
vmlinux_name = symbol_conf.vmlinux_name;
dso->load_errno = 0;
if (vmlinux_name)
ret = dso__load_vmlinux(dso, map, vmlinux_name, false, NULL);
else
ret = dso__load_vmlinux_path(dso, map, NULL);
found:
*pdso = dso;
return ret;
}
/*
* Some binaries like glibc have special symbols which are on the symbol
* table, but not in the debuginfo. If we can find the address of the
* symbol from map, we can translate the address back to the probe point.
*/
static int find_alternative_probe_point(struct debuginfo *dinfo,
struct perf_probe_point *pp,
struct perf_probe_point *result,
const char *target, bool uprobes)
{
struct map *map = NULL;
struct symbol *sym;
u64 address = 0;
int ret = -ENOENT;
/* This can work only for function-name based one */
if (!pp->function || pp->file)
return -ENOTSUP;
map = get_target_map(target, uprobes);
if (!map)
return -EINVAL;
/* Find the address of given function */
map__for_each_symbol_by_name(map, pp->function, sym) {
if (uprobes)
address = sym->start;
else
address = map->unmap_ip(map, sym->start);
break;
}
if (!address) {
ret = -ENOENT;
goto out;
}
pr_debug("Symbol %s address found : %" PRIx64 "\n",
pp->function, address);
ret = debuginfo__find_probe_point(dinfo, (unsigned long)address,
result);
if (ret <= 0)
ret = (!ret) ? -ENOENT : ret;
else {
result->offset += pp->offset;
result->line += pp->line;
result->retprobe = pp->retprobe;
ret = 0;
}
out:
put_target_map(map, uprobes);
return ret;
}
static int get_alternative_probe_event(struct debuginfo *dinfo,
struct perf_probe_event *pev,
struct perf_probe_point *tmp)
{
int ret;
memcpy(tmp, &pev->point, sizeof(*tmp));
memset(&pev->point, 0, sizeof(pev->point));
ret = find_alternative_probe_point(dinfo, tmp, &pev->point,
pev->target, pev->uprobes);
if (ret < 0)
memcpy(&pev->point, tmp, sizeof(*tmp));
return ret;
}
static int get_alternative_line_range(struct debuginfo *dinfo,
struct line_range *lr,
const char *target, bool user)
{
struct perf_probe_point pp = { .function = lr->function,
.file = lr->file,
.line = lr->start };
struct perf_probe_point result;
int ret, len = 0;
memset(&result, 0, sizeof(result));
if (lr->end != INT_MAX)
len = lr->end - lr->start;
ret = find_alternative_probe_point(dinfo, &pp, &result,
target, user);
if (!ret) {
lr->function = result.function;
lr->file = result.file;
lr->start = result.line;
if (lr->end != INT_MAX)
lr->end = lr->start + len;
clear_perf_probe_point(&pp);
}
return ret;
}
/* Open new debuginfo of given module */
static struct debuginfo *open_debuginfo(const char *module, bool silent)
{
const char *path = module;
char reason[STRERR_BUFSIZE];
struct debuginfo *ret = NULL;
struct dso *dso = NULL;
int err;
if (!module || !strchr(module, '/')) {
err = kernel_get_module_dso(module, &dso);
if (err < 0) {
if (!dso || dso->load_errno == 0) {
if (!strerror_r(-err, reason, STRERR_BUFSIZE))
strcpy(reason, "(unknown)");
} else
dso__strerror_load(dso, reason, STRERR_BUFSIZE);
if (!silent)
pr_err("Failed to find the path for %s: %s\n",
module ?: "kernel", reason);
return NULL;
}
path = dso->long_name;
}
ret = debuginfo__new(path);
if (!ret && !silent) {
pr_warning("The %s file has no debug information.\n", path);
if (!module || !strtailcmp(path, ".ko"))
pr_warning("Rebuild with CONFIG_DEBUG_INFO=y, ");
else
pr_warning("Rebuild with -g, ");
pr_warning("or install an appropriate debuginfo package.\n");
}
return ret;
}
/* For caching the last debuginfo */
static struct debuginfo *debuginfo_cache;
static char *debuginfo_cache_path;
static struct debuginfo *debuginfo_cache__open(const char *module, bool silent)
{
if ((debuginfo_cache_path && !strcmp(debuginfo_cache_path, module)) ||
(!debuginfo_cache_path && !module && debuginfo_cache))
goto out;
/* Copy module path */
free(debuginfo_cache_path);
if (module) {
debuginfo_cache_path = strdup(module);
if (!debuginfo_cache_path) {
debuginfo__delete(debuginfo_cache);
debuginfo_cache = NULL;
goto out;
}
}
debuginfo_cache = open_debuginfo(module, silent);
if (!debuginfo_cache)
zfree(&debuginfo_cache_path);
out:
return debuginfo_cache;
}
static void debuginfo_cache__exit(void)
{
debuginfo__delete(debuginfo_cache);
debuginfo_cache = NULL;
zfree(&debuginfo_cache_path);
}
static int get_text_start_address(const char *exec, unsigned long *address)
{
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
int fd, ret = -ENOENT;
fd = open(exec, O_RDONLY);
if (fd < 0)
return -errno;
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
if (elf == NULL)
return -EINVAL;
if (gelf_getehdr(elf, &ehdr) == NULL)
goto out;
if (!elf_section_by_name(elf, &ehdr, &shdr, ".text", NULL))
goto out;
*address = shdr.sh_addr - shdr.sh_offset;
ret = 0;
out:
elf_end(elf);
return ret;
}
/*
* Convert trace point to probe point with debuginfo
*/
static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp,
struct perf_probe_point *pp,
bool is_kprobe)
{
struct debuginfo *dinfo = NULL;
unsigned long stext = 0;
u64 addr = tp->address;
int ret = -ENOENT;
/* convert the address to dwarf address */
if (!is_kprobe) {
if (!addr) {
ret = -EINVAL;
goto error;
}
ret = get_text_start_address(tp->module, &stext);
if (ret < 0)
goto error;
addr += stext;
} else if (tp->symbol) {
addr = kernel_get_symbol_address_by_name(tp->symbol, false);
if (addr == 0)
goto error;
addr += tp->offset;
}
pr_debug("try to find information at %" PRIx64 " in %s\n", addr,
tp->module ? : "kernel");
dinfo = debuginfo_cache__open(tp->module, verbose == 0);
if (dinfo)
ret = debuginfo__find_probe_point(dinfo,
(unsigned long)addr, pp);
else
ret = -ENOENT;
if (ret > 0) {
pp->retprobe = tp->retprobe;
return 0;
}
error:
pr_debug("Failed to find corresponding probes from debuginfo.\n");
return ret ? : -ENOENT;
}
static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *exec)
{
int i, ret = 0;
unsigned long stext = 0;
if (!exec)
return 0;
ret = get_text_start_address(exec, &stext);
if (ret < 0)
return ret;
for (i = 0; i < ntevs && ret >= 0; i++) {
/* point.address is the addres of point.symbol + point.offset */
tevs[i].point.address -= stext;
tevs[i].point.module = strdup(exec);
if (!tevs[i].point.module) {
ret = -ENOMEM;
break;
}
tevs[i].uprobes = true;
}
return ret;
}
static int add_module_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *module)
{
int i, ret = 0;
char *tmp;
if (!module)
return 0;
tmp = strrchr(module, '/');
if (tmp) {
/* This is a module path -- get the module name */
module = strdup(tmp + 1);
if (!module)
return -ENOMEM;
tmp = strchr(module, '.');
if (tmp)
*tmp = '\0';
tmp = (char *)module; /* For free() */
}
for (i = 0; i < ntevs; i++) {
tevs[i].point.module = strdup(module);
if (!tevs[i].point.module) {
ret = -ENOMEM;
break;
}
}
free(tmp);
return ret;
}
/* Post processing the probe events */
static int post_process_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *module,
bool uprobe)
{
struct ref_reloc_sym *reloc_sym;
char *tmp;
int i, skipped = 0;
if (uprobe)
return add_exec_to_probe_trace_events(tevs, ntevs, module);
/* Note that currently ref_reloc_sym based probe is not for drivers */
if (module)
return add_module_to_probe_trace_events(tevs, ntevs, module);
reloc_sym = kernel_get_ref_reloc_sym();
if (!reloc_sym) {
pr_warning("Relocated base symbol is not found!\n");
return -EINVAL;
}
for (i = 0; i < ntevs; i++) {
if (!tevs[i].point.address || tevs[i].point.retprobe)
continue;
/* If we found a wrong one, mark it by NULL symbol */
if (kprobe_warn_out_range(tevs[i].point.symbol,
tevs[i].point.address)) {
tmp = NULL;
skipped++;
} else {
tmp = strdup(reloc_sym->name);
if (!tmp)
return -ENOMEM;
}
/* If we have no realname, use symbol for it */
if (!tevs[i].point.realname)
tevs[i].point.realname = tevs[i].point.symbol;
else
free(tevs[i].point.symbol);
tevs[i].point.symbol = tmp;
tevs[i].point.offset = tevs[i].point.address -
reloc_sym->unrelocated_addr;
}
return skipped;
}
/* Try to find perf_probe_event with debuginfo */
static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs)
{
bool need_dwarf = perf_probe_event_need_dwarf(pev);
struct perf_probe_point tmp;
struct debuginfo *dinfo;
int ntevs, ret = 0;
dinfo = open_debuginfo(pev->target, !need_dwarf);
if (!dinfo) {
if (need_dwarf)
return -ENOENT;
pr_debug("Could not open debuginfo. Try to use symbols.\n");
return 0;
}
pr_debug("Try to find probe point from debuginfo.\n");
/* Searching trace events corresponding to a probe event */
ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);
if (ntevs == 0) { /* Not found, retry with an alternative */
ret = get_alternative_probe_event(dinfo, pev, &tmp);
if (!ret) {
ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);
/*
* Write back to the original probe_event for
* setting appropriate (user given) event name
*/
clear_perf_probe_point(&pev->point);
memcpy(&pev->point, &tmp, sizeof(tmp));
}
}
debuginfo__delete(dinfo);
if (ntevs > 0) { /* Succeeded to find trace events */
pr_debug("Found %d probe_trace_events.\n", ntevs);
ret = post_process_probe_trace_events(*tevs, ntevs,
pev->target, pev->uprobes);
if (ret < 0 || ret == ntevs) {
clear_probe_trace_events(*tevs, ntevs);
zfree(tevs);
}
if (ret != ntevs)
return ret < 0 ? ret : ntevs;
ntevs = 0;
/* Fall through */
}
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 < 0) {
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.\n");
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], sbuf[STRERR_BUFSIZE];
const char *color = show_num ? "" : PERF_COLOR_BLUE;
const char *prefix = NULL;
do {
if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
goto error;
if (skip)
continue;
if (!prefix) {
prefix = show_num ? "%7d " : " ";
color_fprintf(stdout, color, prefix, l);
}
color_fprintf(stdout, color, "%s", buf);
} while (strchr(buf, '\n') == NULL);
return 1;
error:
if (ferror(fp)) {
pr_warning("File read error: %s\n",
strerror_r(errno, sbuf, sizeof(sbuf)));
return -1;
}
return 0;
}
static int _show_one_line(FILE *fp, int l, bool skip, bool show_num)
{
int rv = __show_one_line(fp, l, skip, show_num);
if (rv == 0) {
pr_warning("Source file is shorter than expected.\n");
rv = -1;
}
return rv;
}
#define show_one_line_with_num(f,l) _show_one_line(f,l,false,true)
#define show_one_line(f,l) _show_one_line(f,l,false,false)
#define skip_one_line(f,l) _show_one_line(f,l,true,false)
#define show_one_line_or_eof(f,l) __show_one_line(f,l,false,false)
/*
* Show line-range always requires debuginfo to find source file and
* line number.
*/
static int __show_line_range(struct line_range *lr, const char *module,
bool user)
{
int l = 1;
struct int_node *ln;
struct debuginfo *dinfo;
FILE *fp;
int ret;
char *tmp;
char sbuf[STRERR_BUFSIZE];
/* Search a line range */
dinfo = open_debuginfo(module, false);
if (!dinfo)
return -ENOENT;
ret = debuginfo__find_line_range(dinfo, lr);
if (!ret) { /* Not found, retry with an alternative */
ret = get_alternative_line_range(dinfo, lr, module, user);
if (!ret)
ret = debuginfo__find_line_range(dinfo, lr);
}
debuginfo__delete(dinfo);
if (ret == 0 || ret == -ENOENT) {
pr_warning("Specified source line is not found.\n");
return -ENOENT;
} else if (ret < 0) {
pr_warning("Debuginfo analysis failed.\n");
return ret;
}
/* Convert source file path */
tmp = lr->path;
ret = get_real_path(tmp, lr->comp_dir, &lr->path);
/* Free old path when new path is assigned */
if (tmp != lr->path)
free(tmp);
if (ret < 0) {
pr_warning("Failed to find source file path.\n");
return ret;
}
setup_pager();
if (lr->function)
fprintf(stdout, "<%s@%s:%d>\n", lr->function, lr->path,
lr->start - lr->offset);
else
fprintf(stdout, "<%s:%d>\n", lr->path, lr->start);
fp = fopen(lr->path, "r");
if (fp == NULL) {
pr_warning("Failed to open %s: %s\n", lr->path,
strerror_r(errno, sbuf, sizeof(sbuf)));
return -errno;
}
/* Skip to starting line number */
while (l < lr->start) {
ret = skip_one_line(fp, l++);
if (ret < 0)
goto end;
}
intlist__for_each(ln, lr->line_list) {
for (; ln->i > l; l++) {
ret = show_one_line(fp, l - lr->offset);
if (ret < 0)
goto end;
}
ret = show_one_line_with_num(fp, l++ - lr->offset);
if (ret < 0)
goto end;
}
if (lr->end == INT_MAX)
lr->end = l + NR_ADDITIONAL_LINES;
while (l <= lr->end) {
ret = show_one_line_or_eof(fp, l++ - lr->offset);
if (ret <= 0)
break;
}
end:
fclose(fp);
return ret;
}
int show_line_range(struct line_range *lr, const char *module, bool user)
{
int ret;
ret = init_symbol_maps(user);
if (ret < 0)
return ret;
ret = __show_line_range(lr, module, user);
exit_symbol_maps();
return ret;
}
static int show_available_vars_at(struct debuginfo *dinfo,
struct perf_probe_event *pev,
struct strfilter *_filter)
{
char *buf;
int ret, i, nvars;
struct str_node *node;
struct variable_list *vls = NULL, *vl;
struct perf_probe_point tmp;
const char *var;
buf = synthesize_perf_probe_point(&pev->point);
if (!buf)
return -EINVAL;
pr_debug("Searching variables at %s\n", buf);
ret = debuginfo__find_available_vars_at(dinfo, pev, &vls);
if (!ret) { /* Not found, retry with an alternative */
ret = get_alternative_probe_event(dinfo, pev, &tmp);
if (!ret) {
ret = debuginfo__find_available_vars_at(dinfo, pev,
&vls);
/* Release the old probe_point */
clear_perf_probe_point(&tmp);
}
}
if (ret <= 0) {
if (ret == 0 || ret == -ENOENT) {
pr_err("Failed to find the address of %s\n", buf);
ret = -ENOENT;
} else
pr_warning("Debuginfo analysis failed.\n");
goto end;
}
/* Some variables are found */
fprintf(stdout, "Available variables at %s\n", buf);
for (i = 0; i < ret; i++) {
vl = &vls[i];
/*
* A probe point might be converted to
* several trace points.
*/
fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
vl->point.offset);
zfree(&vl->point.symbol);
nvars = 0;
if (vl->vars) {
strlist__for_each(node, vl->vars) {
var = strchr(node->s, '\t') + 1;
if (strfilter__compare(_filter, var)) {
fprintf(stdout, "\t\t%s\n", node->s);
nvars++;
}
}
strlist__delete(vl->vars);
}
if (nvars == 0)
fprintf(stdout, "\t\t(No matched variables)\n");
}
free(vls);
end:
free(buf);
return ret;
}
/* Show available variables on given probe point */
int show_available_vars(struct perf_probe_event *pevs, int npevs,
struct strfilter *_filter)
{
int i, ret = 0;
struct debuginfo *dinfo;
ret = init_symbol_maps(pevs->uprobes);
if (ret < 0)
return ret;
dinfo = open_debuginfo(pevs->target, false);
if (!dinfo) {
ret = -ENOENT;
goto out;
}
setup_pager();
for (i = 0; i < npevs && ret >= 0; i++)
ret = show_available_vars_at(dinfo, &pevs[i], _filter);
debuginfo__delete(dinfo);
out:
exit_symbol_maps();
return ret;
}
#else /* !HAVE_DWARF_SUPPORT */
static void debuginfo_cache__exit(void)
{
}
static int
find_perf_probe_point_from_dwarf(struct probe_trace_point *tp __maybe_unused,
struct perf_probe_point *pp __maybe_unused,
bool is_kprobe __maybe_unused)
{
return -ENOSYS;
}
static int try_to_find_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event **tevs __maybe_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 __maybe_unused,
const char *module __maybe_unused,
bool user __maybe_unused)
{
pr_warning("Debuginfo-analysis is not supported.\n");
return -ENOSYS;
}
int show_available_vars(struct perf_probe_event *pevs __maybe_unused,
int npevs __maybe_unused,
struct strfilter *filter __maybe_unused)
{
pr_warning("Debuginfo-analysis is not supported.\n");
return -ENOSYS;
}
#endif
void line_range__clear(struct line_range *lr)
{
free(lr->function);
free(lr->file);
free(lr->path);
free(lr->comp_dir);
intlist__delete(lr->line_list);
memset(lr, 0, sizeof(*lr));
}
int line_range__init(struct line_range *lr)
{
memset(lr, 0, sizeof(*lr));
lr->line_list = intlist__new(NULL);
if (!lr->line_list)
return -ENOMEM;
else
return 0;
}
static int parse_line_num(char **ptr, int *val, const char *what)
{
const char *start = *ptr;
errno = 0;
*val = strtol(*ptr, ptr, 0);
if (errno || *ptr == start) {
semantic_error("'%s' is not a valid number.\n", what);
return -EINVAL;
}
return 0;
}
/* Check the name is good for event, group or function */
static bool is_c_func_name(const char *name)
{
if (!isalpha(*name) && *name != '_')
return false;
while (*++name != '\0') {
if (!isalpha(*name) && !isdigit(*name) && *name != '_')
return false;
}
return true;
}
/*
* Stuff 'lr' according to the line range described by 'arg'.
* The line range syntax is described by:
*
* SRC[:SLN[+NUM|-ELN]]
* FNC[@SRC][:SLN[+NUM|-ELN]]
*/
int parse_line_range_desc(const char *arg, struct line_range *lr)
{
char *range, *file, *name = strdup(arg);
int err;
if (!name)
return -ENOMEM;
lr->start = 0;
lr->end = INT_MAX;
range = strchr(name, ':');
if (range) {
*range++ = '\0';
err = parse_line_num(&range, &lr->start, "start line");
if (err)
goto err;
if (*range == '+' || *range == '-') {
const char c = *range++;
err = parse_line_num(&range, &lr->end, "end line");
if (err)
goto err;
if (c == '+') {
lr->end += lr->start;
/*
* 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.
*/
lr->end--;
}
}
pr_debug("Line range is %d to %d\n", lr->start, lr->end);
err = -EINVAL;
if (lr->start > lr->end) {
semantic_error("Start line must be smaller"
" than end line.\n");
goto err;
}
if (*range != '\0') {
semantic_error("Tailing with invalid str '%s'.\n", range);
goto err;
}
}
file = strchr(name, '@');
if (file) {
*file = '\0';
lr->file = strdup(++file);
if (lr->file == NULL) {
err = -ENOMEM;
goto err;
}
lr->function = name;
} else if (strchr(name, '/') || strchr(name, '.'))
lr->file = name;
else if (is_c_func_name(name))/* We reuse it for checking funcname */
lr->function = name;
else { /* Invalid name */
semantic_error("'%s' is not a valid function name.\n", name);
err = -EINVAL;
goto err;
}
return 0;
err:
free(name);
return err;
}
/* 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;
bool file_spec = false;
/*
* <Syntax>
* perf probe [EVENT=]SRC[:LN|;PTN]
* perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
*
* TODO:Group name support
*/
if (!arg)
return -EINVAL;
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 (!is_c_func_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;
}
/*
* Check arg is function or file name and copy it.
*
* We consider arg to be a file spec if and only if it satisfies
* all of the below criteria::
* - it does not include any of "+@%",
* - it includes one of ":;", and
* - it has a period '.' in the name.
*
* Otherwise, we consider arg to be a function specification.
*/
if (!strpbrk(arg, "+@%") && (ptr = strpbrk(arg, ";:")) != NULL) {
/* This is a file spec if it includes a '.' before ; or : */
if (memchr(arg, '.', ptr - arg))
file_spec = true;
}
ptr = strpbrk(arg, ";:+@%");
if (ptr) {
nc = *ptr;
*ptr++ = '\0';
}
if (arg[0] == '\0')
tmp = NULL;
else {
tmp = strdup(arg);
if (tmp == NULL)
return -ENOMEM;
}
if (file_spec)
pp->file = tmp;
else {
pp->function = tmp;
/*
* Keep pp->function even if this is absolute address,
* so it can mark whether abs_address is valid.
* Which make 'perf probe lib.bin 0x0' possible.
*
* Note that checking length of tmp is not needed
* because when we access tmp[1] we know tmp[0] is '0',
* so tmp[1] should always valid (but could be '\0').
*/
if (tmp && !strncmp(tmp, "0x", 2)) {
pp->abs_address = strtoul(pp->function, &tmp, 0);
if (*tmp != '\0') {
semantic_error("Invalid absolute address.\n");
return -EINVAL;
}
}
}
/* 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.\n");
return -EINVAL;
}
if (pp->lazy_line && pp->offset) {
semantic_error("Lazy pattern can't be used with offset.\n");
return -EINVAL;
}
if (pp->line && pp->offset) {
semantic_error("Offset can't be used with line number.\n");
return -EINVAL;
}
if (!pp->line && !pp->lazy_line && pp->file && !pp->function) {
semantic_error("File always requires line number or "
"lazy pattern.\n");
return -EINVAL;
}
if (pp->offset && !pp->function) {
semantic_error("Offset requires an entry function.\n");
return -EINVAL;
}
if (pp->retprobe && !pp->function) {
semantic_error("Return probe requires an entry function.\n");
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.\n");
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, *goodname;
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 or array element */
arg->var = strndup(str, tmp - str);
if (arg->var == NULL)
return -ENOMEM;
goodname = arg->var;
pr_debug("%s, ", arg->var);
fieldp = &arg->field;
do {
*fieldp = zalloc(sizeof(struct perf_probe_arg_field));
if (*fieldp == NULL)
return -ENOMEM;
if (*tmp == '[') { /* Array */
str = tmp;
(*fieldp)->index = strtol(str + 1, &tmp, 0);
(*fieldp)->ref = true;
if (*tmp != ']' || tmp == str + 1) {
semantic_error("Array index must be a"
" number.\n");
return -EINVAL;
}
tmp++;
if (*tmp == '\0')
tmp = NULL;
} else { /* Structure */
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;
if (*str != '[')
goodname = (*fieldp)->name;
pr_debug("%s(%d), ", (*fieldp)->name, (*fieldp)->ref);
fieldp = &(*fieldp)->next;
}
} while (tmp);
(*fieldp)->name = strdup(str);
if ((*fieldp)->name == NULL)
return -ENOMEM;
if (*str != '[')
goodname = (*fieldp)->name;
pr_debug("%s(%d)\n", (*fieldp)->name, (*fieldp)->ref);
/* If no name is specified, set the last field name (not array index)*/
if (!arg->name) {
arg->name = strdup(goodname);
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 probe_events event into struct probe_point */
int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev)
{
struct probe_trace_point *tp = &tev->point;
char pr;
char *p;
char *argv0_str = NULL, *fmt, *fmt1_str, *fmt2_str, *fmt3_str;
int ret, i, argc;
char **argv;
pr_debug("Parsing probe_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. */
argv0_str = strdup(argv[0]);
if (argv0_str == NULL) {
ret = -ENOMEM;
goto out;
}
fmt1_str = strtok_r(argv0_str, ":", &fmt);
fmt2_str = strtok_r(NULL, "/", &fmt);
fmt3_str = strtok_r(NULL, " \t", &fmt);
if (fmt1_str == NULL || strlen(fmt1_str) != 1 || fmt2_str == NULL
|| fmt3_str == NULL) {
semantic_error("Failed to parse event name: %s\n", argv[0]);
ret = -EINVAL;
goto out;
}
pr = fmt1_str[0];
tev->group = strdup(fmt2_str);
tev->event = strdup(fmt3_str);
if (tev->group == NULL || tev->event == NULL) {
ret = -ENOMEM;
goto out;
}
pr_debug("Group:%s Event:%s probe:%c\n", tev->group, tev->event, pr);
tp->retprobe = (pr == 'r');
/* Scan module name(if there), function name and offset */
p = strchr(argv[1], ':');
if (p) {
tp->module = strndup(argv[1], p - argv[1]);
p++;
} else
p = argv[1];
fmt1_str = strtok_r(p, "+", &fmt);
/* only the address started with 0x */
if (fmt1_str[0] == '0') {
/*
* Fix a special case:
* if address == 0, kernel reports something like:
* p:probe_libc/abs_0 /lib/libc-2.18.so:0x (null) arg1=%ax
* Newer kernel may fix that, but we want to
* support old kernel also.
*/
if (strcmp(fmt1_str, "0x") == 0) {
if (!argv[2] || strcmp(argv[2], "(null)")) {
ret = -EINVAL;
goto out;
}
tp->address = 0;
free(argv[2]);
for (i = 2; argv[i + 1] != NULL; i++)
argv[i] = argv[i + 1];
argv[i] = NULL;
argc -= 1;
} else
tp->address = strtoul(fmt1_str, NULL, 0);
} else {
/* Only the symbol-based probe has offset */
tp->symbol = strdup(fmt1_str);
if (tp->symbol == NULL) {
ret = -ENOMEM;
goto out;
}
fmt2_str = strtok_r(NULL, "", &fmt);
if (fmt2_str == NULL)
tp->offset = 0;
else
tp->offset = strtoul(fmt2_str, NULL, 10);
}
tev->nargs = argc - 2;
tev->args = zalloc(sizeof(struct probe_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:
free(argv0_str);
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) {
if (field->name[0] == '[')
ret = e_snprintf(tmp, len, "%s", field->name);
else
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: %d\n", 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) {
tmp = pp->file;
len = strlen(tmp);
if (len > 30) {
tmp = strchr(pp->file + len - 30, '/');
tmp = tmp ? tmp + 1 : pp->file + len - 30;
}
ret = e_snprintf(file, 32, "@%s", tmp);
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: %d\n", ret);
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_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
char **buf, size_t *buflen,
int depth)
{
int ret;
if (ref->next) {
depth = __synthesize_probe_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_probe_trace_arg(struct probe_trace_arg *arg,
char *buf, size_t buflen)
{
struct probe_trace_arg_ref *ref = arg->ref;
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;
/* Special case: @XXX */
if (arg->value[0] == '@' && arg->ref)
ref = ref->next;
/* Dereferencing arguments */
if (ref) {
depth = __synthesize_probe_trace_arg_ref(ref, &buf,
&buflen, 1);
if (depth < 0)
return depth;
}
/* Print argument value */
if (arg->value[0] == '@' && arg->ref)
ret = e_snprintf(buf, buflen, "%s%+ld", arg->value,
arg->ref->offset);
else
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_probe_trace_command(struct probe_trace_event *tev)
{
struct probe_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 ", tp->retprobe ? 'r' : 'p',
tev->group, tev->event);
if (len <= 0)
goto error;
/* Uprobes must have tp->module */
if (tev->uprobes && !tp->module)
goto error;
/*
* If tp->address == 0, then this point must be a
* absolute address uprobe.
* try_to_find_absolute_address() should have made
* tp->symbol to "0x0".
*/
if (tev->uprobes && !tp->address) {
if (!tp->symbol || strcmp(tp->symbol, "0x0"))
goto error;
}
/* Use the tp->address for uprobes */
if (tev->uprobes)
ret = e_snprintf(buf + len, MAX_CMDLEN - len, "%s:0x%lx",
tp->module, tp->address);
else if (!strncmp(tp->symbol, "0x", 2))
/* Absolute address. See try_to_find_absolute_address() */
ret = e_snprintf(buf + len, MAX_CMDLEN - len, "%s%s0x%lx",
tp->module ?: "", tp->module ? ":" : "",
tp->address);
else
ret = e_snprintf(buf + len, MAX_CMDLEN - len, "%s%s%s+%lu",
tp->module ?: "", tp->module ? ":" : "",
tp->symbol, tp->offset);
if (ret <= 0)
goto error;
len += ret;
for (i = 0; i < tev->nargs; i++) {
ret = synthesize_probe_trace_arg(&tev->args[i], buf + len,
MAX_CMDLEN - len);
if (ret <= 0)
goto error;
len += ret;
}
return buf;
error:
free(buf);
return NULL;
}
static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
struct perf_probe_point *pp,
bool is_kprobe)
{
struct symbol *sym = NULL;
struct map *map;
u64 addr = tp->address;
int ret = -ENOENT;
if (!is_kprobe) {
map = dso__new_map(tp->module);
if (!map)
goto out;
sym = map__find_symbol(map, addr, NULL);
} else {
if (tp->symbol)
addr = kernel_get_symbol_address_by_name(tp->symbol, true);
if (addr) {
addr += tp->offset;
sym = __find_kernel_function(addr, &map);
}
}
if (!sym)
goto out;
pp->retprobe = tp->retprobe;
pp->offset = addr - map->unmap_ip(map, sym->start);
pp->function = strdup(sym->name);
ret = pp->function ? 0 : -ENOMEM;
out:
if (map && !is_kprobe) {
map__put(map);
}
return ret;
}
static int convert_to_perf_probe_point(struct probe_trace_point *tp,
struct perf_probe_point *pp,
bool is_kprobe)
{
char buf[128];
int ret;
ret = find_perf_probe_point_from_dwarf(tp, pp, is_kprobe);
if (!ret)
return 0;
ret = find_perf_probe_point_from_map(tp, pp, is_kprobe);
if (!ret)
return 0;
pr_debug("Failed to find probe point from both of dwarf and map.\n");
if (tp->symbol) {
pp->function = strdup(tp->symbol);
pp->offset = tp->offset;
} else {
ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address);
if (ret < 0)
return ret;
pp->function = strdup(buf);
pp->offset = 0;
}
if (pp->function == NULL)
return -ENOMEM;
pp->retprobe = tp->retprobe;
return 0;
}
static int convert_to_perf_probe_event(struct probe_trace_event *tev,
struct perf_probe_event *pev, bool is_kprobe)
{
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, is_kprobe);
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_probe_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_arg_field *field, *next;
int i;
free(pev->event);
free(pev->group);
free(pev->target);
clear_perf_probe_point(&pev->point);
for (i = 0; i < pev->nargs; i++) {
free(pev->args[i].name);
free(pev->args[i].var);
free(pev->args[i].type);
field = pev->args[i].field;
while (field) {
next = field->next;
zfree(&field->name);
free(field);
field = next;
}
}
free(pev->args);
memset(pev, 0, sizeof(*pev));
}
void clear_probe_trace_event(struct probe_trace_event *tev)
{
struct probe_trace_arg_ref *ref, *next;
int i;
free(tev->event);
free(tev->group);
free(tev->point.symbol);
free(tev->point.realname);
free(tev->point.module);
for (i = 0; i < tev->nargs; i++) {
free(tev->args[i].name);
free(tev->args[i].value);
free(tev->args[i].type);
ref = tev->args[i].ref;
while (ref) {
next = ref->next;
free(ref);
ref = next;
}
}
free(tev->args);
memset(tev, 0, sizeof(*tev));
}
struct kprobe_blacklist_node {
struct list_head list;
unsigned long start;
unsigned long end;
char *symbol;
};
static void kprobe_blacklist__delete(struct list_head *blacklist)
{
struct kprobe_blacklist_node *node;
while (!list_empty(blacklist)) {
node = list_first_entry(blacklist,
struct kprobe_blacklist_node, list);
list_del(&node->list);
free(node->symbol);
free(node);
}
}
static int kprobe_blacklist__load(struct list_head *blacklist)
{
struct kprobe_blacklist_node *node;
const char *__debugfs = debugfs_find_mountpoint();
char buf[PATH_MAX], *p;
FILE *fp;
int ret;
if (__debugfs == NULL)
return -ENOTSUP;
ret = e_snprintf(buf, PATH_MAX, "%s/kprobes/blacklist", __debugfs);
if (ret < 0)
return ret;
fp = fopen(buf, "r");
if (!fp)
return -errno;
ret = 0;
while (fgets(buf, PATH_MAX, fp)) {
node = zalloc(sizeof(*node));
if (!node) {
ret = -ENOMEM;
break;
}
INIT_LIST_HEAD(&node->list);
list_add_tail(&node->list, blacklist);
if (sscanf(buf, "0x%lx-0x%lx", &node->start, &node->end) != 2) {
ret = -EINVAL;
break;
}
p = strchr(buf, '\t');
if (p) {
p++;
if (p[strlen(p) - 1] == '\n')
p[strlen(p) - 1] = '\0';
} else
p = (char *)"unknown";
node->symbol = strdup(p);
if (!node->symbol) {
ret = -ENOMEM;
break;
}
pr_debug2("Blacklist: 0x%lx-0x%lx, %s\n",
node->start, node->end, node->symbol);
ret++;
}
if (ret < 0)
kprobe_blacklist__delete(blacklist);
fclose(fp);
return ret;
}
static struct kprobe_blacklist_node *
kprobe_blacklist__find_by_address(struct list_head *blacklist,
unsigned long address)
{
struct kprobe_blacklist_node *node;
list_for_each_entry(node, blacklist, list) {
if (node->start <= address && address <= node->end)
return node;
}
return NULL;
}
static LIST_HEAD(kprobe_blacklist);
static void kprobe_blacklist__init(void)
{
if (!list_empty(&kprobe_blacklist))
return;
if (kprobe_blacklist__load(&kprobe_blacklist) < 0)
pr_debug("No kprobe blacklist support, ignored\n");
}
static void kprobe_blacklist__release(void)
{
kprobe_blacklist__delete(&kprobe_blacklist);
}
static bool kprobe_blacklist__listed(unsigned long address)
{
return !!kprobe_blacklist__find_by_address(&kprobe_blacklist, address);
}
static int perf_probe_event__sprintf(const char *group, const char *event,
struct perf_probe_event *pev,
const char *module,
struct strbuf *result)
{
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", group, event);
if (ret < 0)
goto out;
strbuf_addf(result, " %-20s (on %s", buf, place);
if (module)
strbuf_addf(result, " in %s", module);
if (pev->nargs > 0) {
strbuf_addstr(result, " with");
for (i = 0; i < pev->nargs; i++) {
ret = synthesize_perf_probe_arg(&pev->args[i],
buf, 128);
if (ret < 0)
goto out;
strbuf_addf(result, " %s", buf);
}
}
strbuf_addch(result, ')');
out:
free(place);
return ret;
}
/* Show an event */
static int show_perf_probe_event(const char *group, const char *event,
struct perf_probe_event *pev,
const char *module, bool use_stdout)
{
struct strbuf buf = STRBUF_INIT;
int ret;
ret = perf_probe_event__sprintf(group, event, pev, module, &buf);
if (ret >= 0) {
if (use_stdout)
printf("%s\n", buf.buf);
else
pr_info("%s\n", buf.buf);
}
strbuf_release(&buf);
return ret;
}
static bool filter_probe_trace_event(struct probe_trace_event *tev,
struct strfilter *filter)
{
char tmp[128];
/* At first, check the event name itself */
if (strfilter__compare(filter, tev->event))
return true;
/* Next, check the combination of name and group */
if (e_snprintf(tmp, 128, "%s:%s", tev->group, tev->event) < 0)
return false;
return strfilter__compare(filter, tmp);
}
static int __show_perf_probe_events(int fd, bool is_kprobe,
struct strfilter *filter)
{
int ret = 0;
struct probe_trace_event tev;
struct perf_probe_event pev;
struct strlist *rawlist;
struct str_node *ent;
memset(&tev, 0, sizeof(tev));
memset(&pev, 0, sizeof(pev));
rawlist = probe_file__get_rawlist(fd);
if (!rawlist)
return -ENOMEM;
strlist__for_each(ent, rawlist) {
ret = parse_probe_trace_command(ent->s, &tev);
if (ret >= 0) {
if (!filter_probe_trace_event(&tev, filter))
goto next;
ret = convert_to_perf_probe_event(&tev, &pev,
is_kprobe);
if (ret < 0)
goto next;
ret = show_perf_probe_event(pev.group, pev.event,
&pev, tev.point.module,
true);
}
next:
clear_perf_probe_event(&pev);
clear_probe_trace_event(&tev);
if (ret < 0)
break;
}
strlist__delete(rawlist);
/* Cleanup cached debuginfo if needed */
debuginfo_cache__exit();
return ret;
}
/* List up current perf-probe events */
int show_perf_probe_events(struct strfilter *filter)
{
int kp_fd, up_fd, ret;
setup_pager();
ret = init_symbol_maps(false);
if (ret < 0)
return ret;
ret = probe_file__open_both(&kp_fd, &up_fd, 0);
if (ret < 0)
return ret;
if (kp_fd >= 0)
ret = __show_perf_probe_events(kp_fd, true, filter);
if (up_fd >= 0 && ret >= 0)
ret = __show_perf_probe_events(up_fd, false, filter);
if (kp_fd > 0)
close(kp_fd);
if (up_fd > 0)
close(up_fd);
exit_symbol_maps();
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;
char *p;
if (*base == '.')
base++;
/* Try no suffix */
ret = e_snprintf(buf, len, "%s", base);
if (ret < 0) {
pr_debug("snprintf() failed: %d\n", ret);
return ret;
}
/* Cut off the postfixes (e.g. .const, .isra)*/
p = strchr(buf, '.');
if (p && p != buf)
*p = '\0';
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: %d\n", 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;
}
/* Warn if the current kernel's uprobe implementation is old */
static void warn_uprobe_event_compat(struct probe_trace_event *tev)
{
int i;
char *buf = synthesize_probe_trace_command(tev);
/* Old uprobe event doesn't support memory dereference */
if (!tev->uprobes || tev->nargs == 0 || !buf)
goto out;
for (i = 0; i < tev->nargs; i++)
if (strglobmatch(tev->args[i].value, "[$@+-]*")) {
pr_warning("Please upgrade your kernel to at least "
"3.14 to have access to feature %s\n",
tev->args[i].value);
break;
}
out:
free(buf);
}
/* Set new name from original perf_probe_event and namelist */
static int probe_trace_event__set_name(struct probe_trace_event *tev,
struct perf_probe_event *pev,
struct strlist *namelist,
bool allow_suffix)
{
const char *event, *group;
char buf[64];
int ret;
if (pev->event)
event = pev->event;
else
if (pev->point.function &&
(strncmp(pev->point.function, "0x", 2) != 0) &&
!strisglob(pev->point.function))
event = pev->point.function;
else
event = tev->point.realname;
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)
return ret;
event = buf;
tev->event = strdup(event);
tev->group = strdup(group);
if (tev->event == NULL || tev->group == NULL)
return -ENOMEM;
/* Add added event name to namelist */
strlist__add(namelist, event);
return 0;
}
static int __add_probe_trace_events(struct perf_probe_event *pev,
struct probe_trace_event *tevs,
int ntevs, bool allow_suffix)
{
int i, fd, ret;
struct probe_trace_event *tev = NULL;
const char *event = NULL, *group = NULL;
struct strlist *namelist;
fd = probe_file__open(PF_FL_RW | (pev->uprobes ? PF_FL_UPROBE : 0));
if (fd < 0)
return fd;
/* Get current event names */
namelist = probe_file__get_namelist(fd);
if (!namelist) {
pr_debug("Failed to get current event list.\n");
ret = -ENOMEM;
goto close_out;
}
ret = 0;
pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":");
for (i = 0; i < ntevs; i++) {
tev = &tevs[i];
/* Skip if the symbol is out of .text or blacklisted */
if (!tev->point.symbol)
continue;
/* Set new name for tev (and update namelist) */
ret = probe_trace_event__set_name(tev, pev, namelist,
allow_suffix);
if (ret < 0)
break;
ret = probe_file__add_event(fd, tev);
if (ret < 0)
break;
/* We use tev's name for showing new events */
show_perf_probe_event(tev->group, tev->event, pev,
tev->point.module, false);
/* Save the last valid name */
event = tev->event;
group = tev->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 == -EINVAL && pev->uprobes)
warn_uprobe_event_compat(tev);
/* Note that it is possible to skip all events because of blacklist */
if (ret >= 0 && event) {
/* Show how to use the event. */
pr_info("\nYou can now use it in all perf tools, such as:\n\n");
pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
}
strlist__delete(namelist);
close_out:
close(fd);
return ret;
}
static int find_probe_functions(struct map *map, char *name,
struct symbol **syms)
{
int found = 0;
struct symbol *sym;
struct rb_node *tmp;
if (map__load(map, NULL) < 0)
return 0;
map__for_each_symbol(map, sym, tmp) {
if (strglobmatch(sym->name, name)) {
found++;
if (syms && found < probe_conf.max_probes)
syms[found - 1] = sym;
}
}
return found;
}
#define strdup_or_goto(str, label) \
({ char *__p = strdup(str); if (!__p) goto label; __p; })
void __weak arch__fix_tev_from_maps(struct perf_probe_event *pev __maybe_unused,
struct probe_trace_event *tev __maybe_unused,
struct map *map __maybe_unused) { }
/*
* Find probe function addresses from map.
* Return an error or the number of found probe_trace_event
*/
static int find_probe_trace_events_from_map(struct perf_probe_event *pev,
struct probe_trace_event **tevs)
{
struct map *map = NULL;
struct ref_reloc_sym *reloc_sym = NULL;
struct symbol *sym;
struct symbol **syms = NULL;
struct probe_trace_event *tev;
struct perf_probe_point *pp = &pev->point;
struct probe_trace_point *tp;
int num_matched_functions;
int ret, i, j, skipped = 0;
map = get_target_map(pev->target, pev->uprobes);
if (!map) {
ret = -EINVAL;
goto out;
}
syms = malloc(sizeof(struct symbol *) * probe_conf.max_probes);
if (!syms) {
ret = -ENOMEM;
goto out;
}
/*
* Load matched symbols: Since the different local symbols may have
* same name but different addresses, this lists all the symbols.
*/
num_matched_functions = find_probe_functions(map, pp->function, syms);
if (num_matched_functions == 0) {
pr_err("Failed to find symbol %s in %s\n", pp->function,
pev->target ? : "kernel");
ret = -ENOENT;
goto out;
} else if (num_matched_functions > probe_conf.max_probes) {
pr_err("Too many functions matched in %s\n",
pev->target ? : "kernel");
ret = -E2BIG;
goto out;
}
if (!pev->uprobes && !pp->retprobe) {
reloc_sym = kernel_get_ref_reloc_sym();
if (!reloc_sym) {
pr_warning("Relocated base symbol is not found!\n");
ret = -EINVAL;
goto out;
}
}
/* Setup result trace-probe-events */
*tevs = zalloc(sizeof(*tev) * num_matched_functions);
if (!*tevs) {
ret = -ENOMEM;
goto out;
}
ret = 0;
for (j = 0; j < num_matched_functions; j++) {
sym = syms[j];
tev = (*tevs) + ret;
tp = &tev->point;
if (ret == num_matched_functions) {
pr_warning("Too many symbols are listed. Skip it.\n");
break;
}
ret++;
if (pp->offset > sym->end - sym->start) {
pr_warning("Offset %ld is bigger than the size of %s\n",
pp->offset, sym->name);
ret = -ENOENT;
goto err_out;
}
/* Add one probe point */
tp->address = map->unmap_ip(map, sym->start) + pp->offset;
/* If we found a wrong one, mark it by NULL symbol */
if (!pev->uprobes &&
kprobe_warn_out_range(sym->name, tp->address)) {
tp->symbol = NULL; /* Skip it */
skipped++;
} else if (reloc_sym) {
tp->symbol = strdup_or_goto(reloc_sym->name, nomem_out);
tp->offset = tp->address - reloc_sym->addr;
} else {
tp->symbol = strdup_or_goto(sym->name, nomem_out);
tp->offset = pp->offset;
}
tp->realname = strdup_or_goto(sym->name, nomem_out);
tp->retprobe = pp->retprobe;
if (pev->target)
tev->point.module = strdup_or_goto(pev->target,
nomem_out);
tev->uprobes = pev->uprobes;
tev->nargs = pev->nargs;
if (tev->nargs) {
tev->args = zalloc(sizeof(struct probe_trace_arg) *
tev->nargs);
if (tev->args == NULL)
goto nomem_out;
}
for (i = 0; i < tev->nargs; i++) {
if (pev->args[i].name)
tev->args[i].name =
strdup_or_goto(pev->args[i].name,
nomem_out);
tev->args[i].value = strdup_or_goto(pev->args[i].var,
nomem_out);
if (pev->args[i].type)
tev->args[i].type =
strdup_or_goto(pev->args[i].type,
nomem_out);
}
arch__fix_tev_from_maps(pev, tev, map);
}
if (ret == skipped) {
ret = -ENOENT;
goto err_out;
}
out:
put_target_map(map, pev->uprobes);
free(syms);
return ret;
nomem_out:
ret = -ENOMEM;
err_out:
clear_probe_trace_events(*tevs, num_matched_functions);
zfree(tevs);
goto out;
}
static int try_to_find_absolute_address(struct perf_probe_event *pev,
struct probe_trace_event **tevs)
{
struct perf_probe_point *pp = &pev->point;
struct probe_trace_event *tev;
struct probe_trace_point *tp;
int i, err;
if (!(pev->point.function && !strncmp(pev->point.function, "0x", 2)))
return -EINVAL;
if (perf_probe_event_need_dwarf(pev))
return -EINVAL;
/*
* This is 'perf probe /lib/libc.so 0xabcd'. Try to probe at
* absolute address.
*
* Only one tev can be generated by this.