linuxdebug/tools/perf/util/util.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
#include "util.h"
#include "debug.h"
#include "event.h"
#include <api/fs/fs.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <dirent.h>
#include <fcntl.h>
#include <inttypes.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/time64.h>
#include <linux/overflow.h>
#include <unistd.h>
#include "cap.h"
#include "strlist.h"
#include "string2.h"
/*
* XXX We need to find a better place for these things...
*/
bool perf_singlethreaded = true;
void perf_set_singlethreaded(void)
{
perf_singlethreaded = true;
}
void perf_set_multithreaded(void)
{
perf_singlethreaded = false;
}
int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;
int sysctl__max_stack(void)
{
int value;
if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
sysctl_perf_event_max_stack = value;
if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
sysctl_perf_event_max_contexts_per_stack = value;
return sysctl_perf_event_max_stack;
}
bool sysctl__nmi_watchdog_enabled(void)
{
static bool cached;
static bool nmi_watchdog;
int value;
if (cached)
return nmi_watchdog;
if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
return false;
nmi_watchdog = (value > 0) ? true : false;
cached = true;
return nmi_watchdog;
}
bool test_attr__enabled;
bool perf_host = true;
bool perf_guest = false;
void event_attr_init(struct perf_event_attr *attr)
{
if (!perf_host)
attr->exclude_host = 1;
if (!perf_guest)
attr->exclude_guest = 1;
/* to capture ABI version */
attr->size = sizeof(*attr);
}
int mkdir_p(char *path, mode_t mode)
{
struct stat st;
int err;
char *d = path;
if (*d != '/')
return -1;
if (stat(path, &st) == 0)
return 0;
while (*++d == '/');
while ((d = strchr(d, '/'))) {
*d = '\0';
err = stat(path, &st) && mkdir(path, mode);
*d++ = '/';
if (err)
return -1;
while (*d == '/')
++d;
}
return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
}
static bool match_pat(char *file, const char **pat)
{
int i = 0;
if (!pat)
return true;
while (pat[i]) {
if (strglobmatch(file, pat[i]))
return true;
i++;
}
return false;
}
/*
* The depth specify how deep the removal will go.
* 0 - will remove only files under the 'path' directory
* 1 .. x - will dive in x-level deep under the 'path' directory
*
* If specified the pat is array of string patterns ended with NULL,
* which are checked upon every file/directory found. Only matching
* ones are removed.
*
* The function returns:
* 0 on success
* -1 on removal failure with errno set
* -2 on pattern failure
*/
static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
{
DIR *dir;
int ret;
struct dirent *d;
char namebuf[PATH_MAX];
struct stat statbuf;
/* Do not fail if there's no file. */
ret = lstat(path, &statbuf);
if (ret)
return 0;
/* Try to remove any file we get. */
if (!(statbuf.st_mode & S_IFDIR))
return unlink(path);
/* We have directory in path. */
dir = opendir(path);
if (dir == NULL)
return -1;
while ((d = readdir(dir)) != NULL && !ret) {
if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
continue;
if (!match_pat(d->d_name, pat)) {
ret = -2;
break;
}
scnprintf(namebuf, sizeof(namebuf), "%s/%s",
path, d->d_name);
/* We have to check symbolic link itself */
ret = lstat(namebuf, &statbuf);
if (ret < 0) {
pr_debug("stat failed: %s\n", namebuf);
break;
}
if (S_ISDIR(statbuf.st_mode))
ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
else
ret = unlink(namebuf);
}
closedir(dir);
if (ret < 0)
return ret;
return rmdir(path);
}
static int rm_rf_a_kcore_dir(const char *path, const char *name)
{
char kcore_dir_path[PATH_MAX];
const char *pat[] = {
"kcore",
"kallsyms",
"modules",
NULL,
};
snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/%s", path, name);
return rm_rf_depth_pat(kcore_dir_path, 0, pat);
}
static bool kcore_dir_filter(const char *name __maybe_unused, struct dirent *d)
{
const char *pat[] = {
"kcore_dir",
"kcore_dir__[1-9]*",
NULL,
};
return match_pat(d->d_name, pat);
}
static int rm_rf_kcore_dir(const char *path)
{
struct strlist *kcore_dirs;
struct str_node *nd;
int ret;
kcore_dirs = lsdir(path, kcore_dir_filter);
if (!kcore_dirs)
return 0;
strlist__for_each_entry(nd, kcore_dirs) {
ret = rm_rf_a_kcore_dir(path, nd->s);
if (ret)
return ret;
}
strlist__delete(kcore_dirs);
return 0;
}
int rm_rf_perf_data(const char *path)
{
const char *pat[] = {
"data",
"data.*",
NULL,
};
rm_rf_kcore_dir(path);
return rm_rf_depth_pat(path, 0, pat);
}
int rm_rf(const char *path)
{
return rm_rf_depth_pat(path, INT_MAX, NULL);
}
/* A filter which removes dot files */
bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
{
return d->d_name[0] != '.';
}
/* lsdir reads a directory and store it in strlist */
struct strlist *lsdir(const char *name,
bool (*filter)(const char *, struct dirent *))
{
struct strlist *list = NULL;
DIR *dir;
struct dirent *d;
dir = opendir(name);
if (!dir)
return NULL;
list = strlist__new(NULL, NULL);
if (!list) {
errno = ENOMEM;
goto out;
}
while ((d = readdir(dir)) != NULL) {
if (!filter || filter(name, d))
strlist__add(list, d->d_name);
}
out:
closedir(dir);
return list;
}
size_t hex_width(u64 v)
{
size_t n = 1;
while ((v >>= 4))
++n;
return n;
}
int perf_event_paranoid(void)
{
int value;
if (sysctl__read_int("kernel/perf_event_paranoid", &value))
return INT_MAX;
return value;
}
bool perf_event_paranoid_check(int max_level)
{
return perf_cap__capable(CAP_SYS_ADMIN) ||
perf_cap__capable(CAP_PERFMON) ||
perf_event_paranoid() <= max_level;
}
static int
fetch_ubuntu_kernel_version(unsigned int *puint)
{
ssize_t len;
size_t line_len = 0;
char *ptr, *line = NULL;
int version, patchlevel, sublevel, err;
FILE *vsig;
if (!puint)
return 0;
vsig = fopen("/proc/version_signature", "r");
if (!vsig) {
pr_debug("Open /proc/version_signature failed: %s\n",
strerror(errno));
return -1;
}
len = getline(&line, &line_len, vsig);
fclose(vsig);
err = -1;
if (len <= 0) {
pr_debug("Reading from /proc/version_signature failed: %s\n",
strerror(errno));
goto errout;
}
ptr = strrchr(line, ' ');
if (!ptr) {
pr_debug("Parsing /proc/version_signature failed: %s\n", line);
goto errout;
}
err = sscanf(ptr + 1, "%d.%d.%d",
&version, &patchlevel, &sublevel);
if (err != 3) {
pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
line);
goto errout;
}
*puint = (version << 16) + (patchlevel << 8) + sublevel;
err = 0;
errout:
free(line);
return err;
}
int
fetch_kernel_version(unsigned int *puint, char *str,
size_t str_size)
{
struct utsname utsname;
int version, patchlevel, sublevel, err;
bool int_ver_ready = false;
if (access("/proc/version_signature", R_OK) == 0)
if (!fetch_ubuntu_kernel_version(puint))
int_ver_ready = true;
if (uname(&utsname))
return -1;
if (str && str_size) {
strncpy(str, utsname.release, str_size);
str[str_size - 1] = '\0';
}
if (!puint || int_ver_ready)
return 0;
err = sscanf(utsname.release, "%d.%d.%d",
&version, &patchlevel, &sublevel);
if (err != 3) {
pr_debug("Unable to get kernel version from uname '%s'\n",
utsname.release);
return -1;
}
*puint = (version << 16) + (patchlevel << 8) + sublevel;
return 0;
}
int perf_tip(char **strp, const char *dirpath)
{
struct strlist *tips;
struct str_node *node;
struct strlist_config conf = {
.dirname = dirpath,
.file_only = true,
};
int ret = 0;
*strp = NULL;
tips = strlist__new("tips.txt", &conf);
if (tips == NULL)
return -errno;
if (strlist__nr_entries(tips) == 0)
goto out;
node = strlist__entry(tips, random() % strlist__nr_entries(tips));
if (asprintf(strp, "Tip: %s", node->s) < 0)
ret = -ENOMEM;
out:
strlist__delete(tips);
return ret;
}
char *perf_exe(char *buf, int len)
{
int n = readlink("/proc/self/exe", buf, len);
if (n > 0) {
buf[n] = 0;
return buf;
}
return strcpy(buf, "perf");
}
void perf_debuginfod_setup(struct perf_debuginfod *di)
{
/*
* By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
* processing is not triggered, otherwise we set it to 'di->urls'
* value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
*/
if (!di->set)
setenv("DEBUGINFOD_URLS", "", 1);
else if (di->urls && strcmp(di->urls, "system"))
setenv("DEBUGINFOD_URLS", di->urls, 1);
pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));
#ifndef HAVE_DEBUGINFOD_SUPPORT
if (di->set)
pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");
#endif
}
/*
* Return a new filename prepended with task's root directory if it's in
* a chroot. Callers should free the returned string.
*/
char *filename_with_chroot(int pid, const char *filename)
{
char buf[PATH_MAX];
char proc_root[32];
char *new_name = NULL;
int ret;
scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);
ret = readlink(proc_root, buf, sizeof(buf) - 1);
if (ret <= 0)
return NULL;
/* readlink(2) does not append a null byte to buf */
buf[ret] = '\0';
if (!strcmp(buf, "/"))
return NULL;
if (strstr(buf, "(deleted)"))
return NULL;
if (asprintf(&new_name, "%s/%s", buf, filename) < 0)
return NULL;
return new_name;
}
/*
* Reallocate an array *arr of size *arr_sz so that it is big enough to contain
* x elements of size msz, initializing new entries to *init_val or zero if
* init_val is NULL
*/
int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)
{
size_t new_sz = *arr_sz;
void *new_arr;
size_t i;
if (!new_sz)
new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */
while (x >= new_sz) {
if (check_mul_overflow(new_sz, (size_t)2, &new_sz))
return -ENOMEM;
}
if (new_sz == *arr_sz)
return 0;
new_arr = calloc(new_sz, msz);
if (!new_arr)
return -ENOMEM;
memcpy(new_arr, *arr, *arr_sz * msz);
if (init_val) {
for (i = *arr_sz; i < new_sz; i++)
memcpy(new_arr + (i * msz), init_val, msz);
}
*arr = new_arr;
*arr_sz = new_sz;
return 0;
}