linux/tools/perf/util/data.c
Adrian Hunter eeb399b531 perf record: Put a copy of kcore into the perf.data directory
Add a new 'perf record' option '--kcore' which will put a copy of
/proc/kcore, kallsyms and modules into a perf.data directory. Note, that
without the --kcore option, output goes to a file as previously.  The
tools' -o and -i options work with either a file name or directory name.

Example:

  $ sudo perf record --kcore uname

  $ sudo tree perf.data
  perf.data
  ├── kcore_dir
  │   ├── kallsyms
  │   ├── kcore
  │   └── modules
  └── data

  $ sudo perf script -v
  build id event received for vmlinux: 1eaa285996affce2d74d8e66dcea09a80c9941de
  build id event received for [vdso]: 8bbaf5dc62a9b644b4d4e4539737e104e4a84541
  Samples for 'cycles' event do not have CPU attribute set. Skipping 'cpu' field.
  Using CPUID GenuineIntel-6-8E-A
  Using perf.data/kcore_dir/kcore for kernel data
  Using perf.data/kcore_dir/kallsyms for symbols
             perf 19058 506778.423729:          1 cycles:  ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
             perf 19058 506778.423733:          1 cycles:  ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
             perf 19058 506778.423734:          7 cycles:  ffffffffa2caa548 native_write_msr+0x8 (vmlinux)
             perf 19058 506778.423736:        117 cycles:  ffffffffa2caa54a native_write_msr+0xa (vmlinux)
             perf 19058 506778.423738:       2092 cycles:  ffffffffa2c9b7b0 native_apic_msr_write+0x0 (vmlinux)
             perf 19058 506778.423740:      37380 cycles:  ffffffffa2f121d0 perf_event_addr_filters_exec+0x0 (vmlinux)
            uname 19058 506778.423751:     582673 cycles:  ffffffffa303a407 propagate_protected_usage+0x147 (vmlinux)
            uname 19058 506778.423892:    2241841 cycles:  ffffffffa2cae0c9 unwind_next_frame.part.5+0x79 (vmlinux)
            uname 19058 506778.424430:    2457397 cycles:  ffffffffa3019232 check_memory_region+0x52 (vmlinux)

Committer testing:

  # rm -rf perf.data*
  # perf record sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.024 MB perf.data (7 samples) ]
  # ls -l perf.data
  -rw-------. 1 root root 34772 Oct 21 11:08 perf.data
  # perf record --kcore uname
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.024 MB perf.data (7 samples) ]
  ls[root@quaco ~]# ls -lad perf.data*
  drwx------. 3 root root  4096 Oct 21 11:08 perf.data
  -rw-------. 1 root root 34772 Oct 21 11:08 perf.data.old
  # perf evlist -v
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  # perf evlist -v -i perf.data/data
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  #

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lore.kernel.org/lkml/20191004083121.12182-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06 15:43:05 -03:00

460 lines
8.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/zalloc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <asm/bug.h>
#include <dirent.h>
#include "data.h"
#include "util.h" // rm_rf_perf_data()
#include "debug.h"
#include "header.h"
#include <internal/lib.h>
static void close_dir(struct perf_data_file *files, int nr)
{
while (--nr >= 1) {
close(files[nr].fd);
zfree(&files[nr].path);
}
free(files);
}
void perf_data__close_dir(struct perf_data *data)
{
close_dir(data->dir.files, data->dir.nr);
}
int perf_data__create_dir(struct perf_data *data, int nr)
{
struct perf_data_file *files = NULL;
int i, ret = -1;
if (WARN_ON(!data->is_dir))
return -EINVAL;
files = zalloc(nr * sizeof(*files));
if (!files)
return -ENOMEM;
data->dir.version = PERF_DIR_VERSION;
data->dir.files = files;
data->dir.nr = nr;
for (i = 0; i < nr; i++) {
struct perf_data_file *file = &files[i];
if (asprintf(&file->path, "%s/data.%d", data->path, i) < 0)
goto out_err;
ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
if (ret < 0)
goto out_err;
file->fd = ret;
}
return 0;
out_err:
close_dir(files, i);
return ret;
}
int perf_data__open_dir(struct perf_data *data)
{
struct perf_data_file *files = NULL;
struct dirent *dent;
int ret = -1;
DIR *dir;
int nr = 0;
/*
* Directory containing a single regular perf data file which is already
* open, means there is nothing more to do here.
*/
if (perf_data__is_single_file(data))
return 0;
if (WARN_ON(!data->is_dir))
return -EINVAL;
/* The version is provided by DIR_FORMAT feature. */
if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
return -1;
dir = opendir(data->path);
if (!dir)
return -EINVAL;
while ((dent = readdir(dir)) != NULL) {
struct perf_data_file *file;
char path[PATH_MAX];
struct stat st;
snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
if (stat(path, &st))
continue;
if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5))
continue;
ret = -ENOMEM;
file = realloc(files, (nr + 1) * sizeof(*files));
if (!file)
goto out_err;
files = file;
file = &files[nr++];
file->path = strdup(path);
if (!file->path)
goto out_err;
ret = open(file->path, O_RDONLY);
if (ret < 0)
goto out_err;
file->fd = ret;
file->size = st.st_size;
}
if (!files)
return -EINVAL;
data->dir.files = files;
data->dir.nr = nr;
return 0;
out_err:
close_dir(files, nr);
return ret;
}
int perf_data__update_dir(struct perf_data *data)
{
int i;
if (WARN_ON(!data->is_dir))
return -EINVAL;
for (i = 0; i < data->dir.nr; i++) {
struct perf_data_file *file = &data->dir.files[i];
struct stat st;
if (fstat(file->fd, &st))
return -1;
file->size = st.st_size;
}
return 0;
}
static bool check_pipe(struct perf_data *data)
{
struct stat st;
bool is_pipe = false;
int fd = perf_data__is_read(data) ?
STDIN_FILENO : STDOUT_FILENO;
if (!data->path) {
if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
is_pipe = true;
} else {
if (!strcmp(data->path, "-"))
is_pipe = true;
}
if (is_pipe)
data->file.fd = fd;
return data->is_pipe = is_pipe;
}
static int check_backup(struct perf_data *data)
{
struct stat st;
if (perf_data__is_read(data))
return 0;
if (!stat(data->path, &st) && st.st_size) {
char oldname[PATH_MAX];
int ret;
snprintf(oldname, sizeof(oldname), "%s.old",
data->path);
ret = rm_rf_perf_data(oldname);
if (ret) {
pr_err("Can't remove old data: %s (%s)\n",
ret == -2 ?
"Unknown file found" : strerror(errno),
oldname);
return -1;
}
if (rename(data->path, oldname)) {
pr_err("Can't move data: %s (%s to %s)\n",
strerror(errno),
data->path, oldname);
return -1;
}
}
return 0;
}
static bool is_dir(struct perf_data *data)
{
struct stat st;
if (stat(data->path, &st))
return false;
return (st.st_mode & S_IFMT) == S_IFDIR;
}
static int open_file_read(struct perf_data *data)
{
struct stat st;
int fd;
char sbuf[STRERR_BUFSIZE];
fd = open(data->file.path, O_RDONLY);
if (fd < 0) {
int err = errno;
pr_err("failed to open %s: %s", data->file.path,
str_error_r(err, sbuf, sizeof(sbuf)));
if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
pr_err(" (try 'perf record' first)");
pr_err("\n");
return -err;
}
if (fstat(fd, &st) < 0)
goto out_close;
if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
pr_err("File %s not owned by current user or root (use -f to override)\n",
data->file.path);
goto out_close;
}
if (!st.st_size) {
pr_info("zero-sized data (%s), nothing to do!\n",
data->file.path);
goto out_close;
}
data->file.size = st.st_size;
return fd;
out_close:
close(fd);
return -1;
}
static int open_file_write(struct perf_data *data)
{
int fd;
char sbuf[STRERR_BUFSIZE];
fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
S_IRUSR|S_IWUSR);
if (fd < 0)
pr_err("failed to open %s : %s\n", data->file.path,
str_error_r(errno, sbuf, sizeof(sbuf)));
return fd;
}
static int open_file(struct perf_data *data)
{
int fd;
fd = perf_data__is_read(data) ?
open_file_read(data) : open_file_write(data);
if (fd < 0) {
zfree(&data->file.path);
return -1;
}
data->file.fd = fd;
return 0;
}
static int open_file_dup(struct perf_data *data)
{
data->file.path = strdup(data->path);
if (!data->file.path)
return -ENOMEM;
return open_file(data);
}
static int open_dir(struct perf_data *data)
{
int ret;
/*
* So far we open only the header, so we can read the data version and
* layout.
*/
if (asprintf(&data->file.path, "%s/data", data->path) < 0)
return -1;
if (perf_data__is_write(data) &&
mkdir(data->path, S_IRWXU) < 0)
return -1;
ret = open_file(data);
/* Cleanup whatever we managed to create so far. */
if (ret && perf_data__is_write(data))
rm_rf_perf_data(data->path);
return ret;
}
int perf_data__open(struct perf_data *data)
{
if (check_pipe(data))
return 0;
if (!data->path)
data->path = "perf.data";
if (check_backup(data))
return -1;
if (perf_data__is_read(data))
data->is_dir = is_dir(data);
return perf_data__is_dir(data) ?
open_dir(data) : open_file_dup(data);
}
void perf_data__close(struct perf_data *data)
{
if (perf_data__is_dir(data))
perf_data__close_dir(data);
zfree(&data->file.path);
close(data->file.fd);
}
ssize_t perf_data_file__write(struct perf_data_file *file,
void *buf, size_t size)
{
return writen(file->fd, buf, size);
}
ssize_t perf_data__write(struct perf_data *data,
void *buf, size_t size)
{
return perf_data_file__write(&data->file, buf, size);
}
int perf_data__switch(struct perf_data *data,
const char *postfix,
size_t pos, bool at_exit,
char **new_filepath)
{
int ret;
if (check_pipe(data))
return -EINVAL;
if (perf_data__is_read(data))
return -EINVAL;
if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
return -ENOMEM;
/*
* Only fire a warning, don't return error, continue fill
* original file.
*/
if (rename(data->path, *new_filepath))
pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
if (!at_exit) {
close(data->file.fd);
ret = perf_data__open(data);
if (ret < 0)
goto out;
if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
ret = -errno;
pr_debug("Failed to lseek to %zu: %s",
pos, strerror(errno));
goto out;
}
}
ret = data->file.fd;
out:
return ret;
}
unsigned long perf_data__size(struct perf_data *data)
{
u64 size = data->file.size;
int i;
if (perf_data__is_single_file(data))
return size;
for (i = 0; i < data->dir.nr; i++) {
struct perf_data_file *file = &data->dir.files[i];
size += file->size;
}
return size;
}
int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
{
int ret;
if (!data->is_dir)
return -1;
ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
if (ret < 0 || (size_t)ret >= buf_sz)
return -1;
return mkdir(buf, S_IRWXU);
}
char *perf_data__kallsyms_name(struct perf_data *data)
{
char *kallsyms_name;
struct stat st;
if (!data->is_dir)
return NULL;
if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
return NULL;
if (stat(kallsyms_name, &st)) {
free(kallsyms_name);
return NULL;
}
return kallsyms_name;
}