pahole: Search and use running kernel vmlinux when no file is passed
Seems like a nice shortcut for kernel hackers, and one that makes sure the right vmlinux file is used, as it reads the running kernel build id from /sys/kernel/notes and then searches the well known path for vmlinux files: vmlinux /boot/vmlinux /boot/vmlinux-4.14.0+ /usr/lib/debug/boot/vmlinux-`uname -r` /lib/modules/`uname -r`/build/vmlinux /usr/lib/debug/lib/modules/`uname -r`/vmlinux /usr/lib/debug/boot/vmlinux-`uname -r`.debug To find one with a matching build id (.notes ELF section, then nhdr->n_type == NT_GNU_BUILD_ID), just like the Linux kernel 'perf tools', where this code comes from, with some minor modifications to cope with not having symbol_conf, symfs, etc. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo
parent
5f057919a0
commit
02a456f5f5
354
dwarves.c
354
dwarves.c
|
|
@ -18,10 +18,12 @@
|
|||
#include <libelf.h>
|
||||
#include <search.h>
|
||||
#include <stdio.h>
|
||||
#include <stdarg.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <unistd.h>
|
||||
#include <sys/stat.h>
|
||||
#include <sys/utsname.h>
|
||||
|
||||
#include "config.h"
|
||||
#include "list.h"
|
||||
|
|
@ -1487,6 +1489,356 @@ int cus__load_file(struct cus *cus, struct conf_load *conf,
|
|||
return -EINVAL;
|
||||
}
|
||||
|
||||
#define BUILD_ID_SIZE 20
|
||||
#define SBUILD_ID_SIZE (BUILD_ID_SIZE * 2 + 1)
|
||||
|
||||
#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
|
||||
|
||||
#define NT_GNU_BUILD_ID 3
|
||||
|
||||
#ifndef min
|
||||
#define min(x, y) ({ \
|
||||
typeof(x) _min1 = (x); \
|
||||
typeof(y) _min2 = (y); \
|
||||
(void) (&_min1 == &_min2); \
|
||||
_min1 < _min2 ? _min1 : _min2; })
|
||||
#endif
|
||||
|
||||
/* Force a compilation error if condition is true, but also produce a
|
||||
result (of value 0 and type size_t), so the expression can be used
|
||||
e.g. in a structure initializer (or where-ever else comma expressions
|
||||
aren't permitted). */
|
||||
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
|
||||
|
||||
/* Are two types/vars the same type (ignoring qualifiers)? */
|
||||
#ifndef __same_type
|
||||
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
|
||||
#endif
|
||||
|
||||
/* &a[0] degrades to a pointer: a different type from an array */
|
||||
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
|
||||
|
||||
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
|
||||
|
||||
static int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
|
||||
{
|
||||
int fd, err = -1;
|
||||
|
||||
if (size < BUILD_ID_SIZE)
|
||||
goto out;
|
||||
|
||||
fd = open(filename, O_RDONLY);
|
||||
if (fd < 0)
|
||||
goto out;
|
||||
|
||||
while (1) {
|
||||
char bf[BUFSIZ];
|
||||
GElf_Nhdr nhdr;
|
||||
size_t namesz, descsz;
|
||||
|
||||
if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
|
||||
break;
|
||||
|
||||
namesz = NOTE_ALIGN(nhdr.n_namesz);
|
||||
descsz = NOTE_ALIGN(nhdr.n_descsz);
|
||||
if (nhdr.n_type == NT_GNU_BUILD_ID &&
|
||||
nhdr.n_namesz == sizeof("GNU")) {
|
||||
if (read(fd, bf, namesz) != (ssize_t)namesz)
|
||||
break;
|
||||
if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
|
||||
size_t sz = min(descsz, size);
|
||||
if (read(fd, build_id, sz) == (ssize_t)sz) {
|
||||
memset(build_id + sz, 0, size - sz);
|
||||
err = 0;
|
||||
break;
|
||||
}
|
||||
} else if (read(fd, bf, descsz) != (ssize_t)descsz)
|
||||
break;
|
||||
} else {
|
||||
int n = namesz + descsz;
|
||||
|
||||
if (n > (int)sizeof(bf)) {
|
||||
n = sizeof(bf);
|
||||
fprintf(stderr, "%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
|
||||
__func__, filename, nhdr.n_namesz, nhdr.n_descsz);
|
||||
}
|
||||
if (read(fd, bf, n) != n)
|
||||
break;
|
||||
}
|
||||
}
|
||||
close(fd);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int elf_read_build_id(Elf *elf, void *bf, size_t size)
|
||||
{
|
||||
int err = -1;
|
||||
GElf_Ehdr ehdr;
|
||||
GElf_Shdr shdr;
|
||||
Elf_Data *data;
|
||||
Elf_Scn *sec;
|
||||
Elf_Kind ek;
|
||||
void *ptr;
|
||||
|
||||
if (size < BUILD_ID_SIZE)
|
||||
goto out;
|
||||
|
||||
ek = elf_kind(elf);
|
||||
if (ek != ELF_K_ELF)
|
||||
goto out;
|
||||
|
||||
if (gelf_getehdr(elf, &ehdr) == NULL) {
|
||||
fprintf(stderr, "%s: cannot get elf header.\n", __func__);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* Check following sections for notes:
|
||||
* '.note.gnu.build-id'
|
||||
* '.notes'
|
||||
* '.note' (VDSO specific)
|
||||
*/
|
||||
do {
|
||||
sec = elf_section_by_name(elf, &ehdr, &shdr,
|
||||
".note.gnu.build-id", NULL);
|
||||
if (sec)
|
||||
break;
|
||||
|
||||
sec = elf_section_by_name(elf, &ehdr, &shdr,
|
||||
".notes", NULL);
|
||||
if (sec)
|
||||
break;
|
||||
|
||||
sec = elf_section_by_name(elf, &ehdr, &shdr,
|
||||
".note", NULL);
|
||||
if (sec)
|
||||
break;
|
||||
|
||||
return err;
|
||||
|
||||
} while (0);
|
||||
|
||||
data = elf_getdata(sec, NULL);
|
||||
if (data == NULL)
|
||||
goto out;
|
||||
|
||||
ptr = data->d_buf;
|
||||
while (ptr < (data->d_buf + data->d_size)) {
|
||||
GElf_Nhdr *nhdr = ptr;
|
||||
size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
|
||||
descsz = NOTE_ALIGN(nhdr->n_descsz);
|
||||
const char *name;
|
||||
|
||||
ptr += sizeof(*nhdr);
|
||||
name = ptr;
|
||||
ptr += namesz;
|
||||
if (nhdr->n_type == NT_GNU_BUILD_ID &&
|
||||
nhdr->n_namesz == sizeof("GNU")) {
|
||||
if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
|
||||
size_t sz = min(size, descsz);
|
||||
memcpy(bf, ptr, sz);
|
||||
memset(bf + sz, 0, size - sz);
|
||||
err = descsz;
|
||||
break;
|
||||
}
|
||||
}
|
||||
ptr += descsz;
|
||||
}
|
||||
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int filename__read_build_id(const char *filename, void *bf, size_t size)
|
||||
{
|
||||
int fd, err = -1;
|
||||
Elf *elf;
|
||||
|
||||
if (size < BUILD_ID_SIZE)
|
||||
goto out;
|
||||
|
||||
fd = open(filename, O_RDONLY);
|
||||
if (fd < 0)
|
||||
goto out;
|
||||
|
||||
elf = elf_begin(fd, ELF_C_READ, NULL);
|
||||
if (elf == NULL) {
|
||||
fprintf(stderr, "%s: cannot read %s ELF file.\n", __func__, filename);
|
||||
goto out_close;
|
||||
}
|
||||
|
||||
err = elf_read_build_id(elf, bf, size);
|
||||
|
||||
elf_end(elf);
|
||||
out_close:
|
||||
close(fd);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int build_id__sprintf(const unsigned char *build_id, int len, char *bf)
|
||||
{
|
||||
char *bid = bf;
|
||||
const unsigned char *raw = build_id;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < len; ++i) {
|
||||
sprintf(bid, "%02x", *raw);
|
||||
++raw;
|
||||
bid += 2;
|
||||
}
|
||||
|
||||
return (bid - bf) + 1;
|
||||
}
|
||||
|
||||
static int sysfs__sprintf_build_id(const char *root_dir, char *sbuild_id)
|
||||
{
|
||||
char notes[PATH_MAX];
|
||||
unsigned char build_id[BUILD_ID_SIZE];
|
||||
int ret;
|
||||
|
||||
if (!root_dir)
|
||||
root_dir = "";
|
||||
|
||||
snprintf(notes, sizeof(notes), "%s/sys/kernel/notes", root_dir);
|
||||
|
||||
ret = sysfs__read_build_id(notes, build_id, sizeof(build_id));
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
|
||||
}
|
||||
|
||||
static int filename__sprintf_build_id(const char *pathname, char *sbuild_id)
|
||||
{
|
||||
unsigned char build_id[BUILD_ID_SIZE];
|
||||
int ret;
|
||||
|
||||
ret = filename__read_build_id(pathname, build_id, sizeof(build_id));
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
else if (ret != sizeof(build_id))
|
||||
return -EINVAL;
|
||||
|
||||
return build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
|
||||
}
|
||||
|
||||
/* asnprintf consolidates asprintf and snprintf */
|
||||
static int asnprintf(char **strp, size_t size, const char *fmt, ...)
|
||||
{
|
||||
va_list ap;
|
||||
int ret;
|
||||
|
||||
if (!strp)
|
||||
return -EINVAL;
|
||||
|
||||
va_start(ap, fmt);
|
||||
if (*strp)
|
||||
ret = vsnprintf(*strp, size, fmt, ap);
|
||||
else
|
||||
ret = vasprintf(strp, fmt, ap);
|
||||
va_end(ap);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
#define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
|
||||
|
||||
static int vmlinux_path__nr_entries;
|
||||
static char **vmlinux_path;
|
||||
|
||||
static void vmlinux_path__exit(void)
|
||||
{
|
||||
while (--vmlinux_path__nr_entries >= 0)
|
||||
zfree(&vmlinux_path[vmlinux_path__nr_entries]);
|
||||
vmlinux_path__nr_entries = 0;
|
||||
|
||||
zfree(&vmlinux_path);
|
||||
}
|
||||
|
||||
static const char * const vmlinux_paths[] = {
|
||||
"vmlinux",
|
||||
"/boot/vmlinux"
|
||||
};
|
||||
|
||||
static const char * const vmlinux_paths_upd[] = {
|
||||
"/boot/vmlinux-%s",
|
||||
"/usr/lib/debug/boot/vmlinux-%s",
|
||||
"/lib/modules/%s/build/vmlinux",
|
||||
"/usr/lib/debug/lib/modules/%s/vmlinux",
|
||||
"/usr/lib/debug/boot/vmlinux-%s.debug"
|
||||
};
|
||||
|
||||
static int vmlinux_path__add(const char *new_entry)
|
||||
{
|
||||
vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
|
||||
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
|
||||
return -1;
|
||||
++vmlinux_path__nr_entries;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int vmlinux_path__init(void)
|
||||
{
|
||||
struct utsname uts;
|
||||
char bf[PATH_MAX];
|
||||
char *kernel_version;
|
||||
unsigned int i;
|
||||
|
||||
vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
|
||||
ARRAY_SIZE(vmlinux_paths_upd)));
|
||||
if (vmlinux_path == NULL)
|
||||
return -1;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
|
||||
if (vmlinux_path__add(vmlinux_paths[i]) < 0)
|
||||
goto out_fail;
|
||||
|
||||
if (uname(&uts) < 0)
|
||||
goto out_fail;
|
||||
|
||||
kernel_version = uts.release;
|
||||
|
||||
for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
|
||||
snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
|
||||
if (vmlinux_path__add(bf) < 0)
|
||||
goto out_fail;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
out_fail:
|
||||
vmlinux_path__exit();
|
||||
return -1;
|
||||
}
|
||||
|
||||
static int cus__load_running_kernel(struct cus *cus, struct conf_load *conf)
|
||||
{
|
||||
int i, err = 0;
|
||||
char running_sbuild_id[SBUILD_ID_SIZE];
|
||||
|
||||
elf_version(EV_CURRENT);
|
||||
vmlinux_path__init();
|
||||
|
||||
sysfs__sprintf_build_id(NULL, running_sbuild_id);
|
||||
|
||||
for (i = 0; i < vmlinux_path__nr_entries; ++i) {
|
||||
char sbuild_id[SBUILD_ID_SIZE];
|
||||
|
||||
if (filename__sprintf_build_id(vmlinux_path[i], sbuild_id) > 0 &&
|
||||
strcmp(sbuild_id, running_sbuild_id) == 0) {
|
||||
err = cus__load_file(cus, conf, vmlinux_path[i]);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
vmlinux_path__exit();
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
int cus__load_files(struct cus *cus, struct conf_load *conf,
|
||||
char *filenames[])
|
||||
{
|
||||
|
|
@ -1498,7 +1850,7 @@ int cus__load_files(struct cus *cus, struct conf_load *conf,
|
|||
++i;
|
||||
}
|
||||
|
||||
return 0;
|
||||
return i ?: cus__load_running_kernel(cus, conf);
|
||||
}
|
||||
|
||||
int cus__fprintf_load_files_err(struct cus *cus, const char *tool, char *argv[], int err, FILE *output)
|
||||
|
|
|
|||
2
pahole.c
2
pahole.c
|
|
@ -1224,7 +1224,7 @@ int main(int argc, char *argv[])
|
|||
int err, remaining, rc = EXIT_FAILURE;
|
||||
|
||||
if (argp_parse(&pahole__argp, argc, argv, 0, &remaining, NULL) ||
|
||||
remaining == argc) {
|
||||
(remaining == argc && class_name == NULL)) {
|
||||
argp_help(&pahole__argp, stderr, ARGP_HELP_SEE, argv[0]);
|
||||
goto out;
|
||||
}
|
||||
|
|
|
|||
2
pfunct.c
2
pfunct.c
|
|
@ -643,7 +643,7 @@ int main(int argc, char *argv[])
|
|||
int err, remaining, rc = EXIT_FAILURE;
|
||||
|
||||
if (argp_parse(&pfunct__argp, argc, argv, 0, &remaining, NULL) ||
|
||||
remaining == argc) {
|
||||
(remaining == argc && class_name == NULL && function_name == NULL)) {
|
||||
argp_help(&pfunct__argp, stderr, ARGP_HELP_SEE, argv[0]);
|
||||
goto out;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue