linux/tools/perf/util/dso.c
Ian Rogers 37862d6fdc perf dso: Use container_of() to avoid a pointer in 'struct dso_data'
The dso pointer in 'struct dso_data' is necessary for reference count
checking to account for the dso_data forming a global list of open dso's
with references to the dso.

The dso pointer also allows for the indirection that reference count
checking needs. Outside of reference count checking the indirection
isn't needed and container_of() is more efficient and saves space.

The reference count won't be increased by placing items onto the global
list, matching how things were before the reference count checking
change, but we assert the dso is in dsos holding it live (and that the
set of open dsos is a subset of all dsos for the machine).

Update the DSO data tests so that they use a dsos struct to make the
invariant true.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Link: https://lore.kernel.org/r/20240506180104.485674-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2024-05-06 16:08:31 -03:00

1655 lines
39 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <asm/bug.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/zalloc.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#ifdef HAVE_LIBBPF_SUPPORT
#include <bpf/libbpf.h>
#include "bpf-event.h"
#include "bpf-utils.h"
#endif
#include "compress.h"
#include "env.h"
#include "namespaces.h"
#include "path.h"
#include "map.h"
#include "symbol.h"
#include "srcline.h"
#include "dso.h"
#include "dsos.h"
#include "machine.h"
#include "auxtrace.h"
#include "util.h" /* O_CLOEXEC for older systems */
#include "debug.h"
#include "string2.h"
#include "vdso.h"
#include "annotate-data.h"
static const char * const debuglink_paths[] = {
"%.0s%s",
"%s/%s",
"%s/.debug/%s",
"/usr/lib/debug%s/%s"
};
void dso__set_nsinfo(struct dso *dso, struct nsinfo *nsi)
{
nsinfo__put(RC_CHK_ACCESS(dso)->nsinfo);
RC_CHK_ACCESS(dso)->nsinfo = nsi;
}
char dso__symtab_origin(const struct dso *dso)
{
static const char origin[] = {
[DSO_BINARY_TYPE__KALLSYMS] = 'k',
[DSO_BINARY_TYPE__VMLINUX] = 'v',
[DSO_BINARY_TYPE__JAVA_JIT] = 'j',
[DSO_BINARY_TYPE__DEBUGLINK] = 'l',
[DSO_BINARY_TYPE__BUILD_ID_CACHE] = 'B',
[DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO] = 'D',
[DSO_BINARY_TYPE__FEDORA_DEBUGINFO] = 'f',
[DSO_BINARY_TYPE__UBUNTU_DEBUGINFO] = 'u',
[DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO] = 'x',
[DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO] = 'o',
[DSO_BINARY_TYPE__BUILDID_DEBUGINFO] = 'b',
[DSO_BINARY_TYPE__SYSTEM_PATH_DSO] = 'd',
[DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE] = 'K',
[DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP] = 'm',
[DSO_BINARY_TYPE__GUEST_KALLSYMS] = 'g',
[DSO_BINARY_TYPE__GUEST_KMODULE] = 'G',
[DSO_BINARY_TYPE__GUEST_KMODULE_COMP] = 'M',
[DSO_BINARY_TYPE__GUEST_VMLINUX] = 'V',
};
if (dso == NULL || dso__symtab_type(dso) == DSO_BINARY_TYPE__NOT_FOUND)
return '!';
return origin[dso__symtab_type(dso)];
}
bool dso__is_object_file(const struct dso *dso)
{
switch (dso__binary_type(dso)) {
case DSO_BINARY_TYPE__KALLSYMS:
case DSO_BINARY_TYPE__GUEST_KALLSYMS:
case DSO_BINARY_TYPE__JAVA_JIT:
case DSO_BINARY_TYPE__BPF_PROG_INFO:
case DSO_BINARY_TYPE__BPF_IMAGE:
case DSO_BINARY_TYPE__OOL:
return false;
case DSO_BINARY_TYPE__VMLINUX:
case DSO_BINARY_TYPE__GUEST_VMLINUX:
case DSO_BINARY_TYPE__DEBUGLINK:
case DSO_BINARY_TYPE__BUILD_ID_CACHE:
case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
case DSO_BINARY_TYPE__GUEST_KMODULE:
case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
case DSO_BINARY_TYPE__KCORE:
case DSO_BINARY_TYPE__GUEST_KCORE:
case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
case DSO_BINARY_TYPE__NOT_FOUND:
default:
return true;
}
}
int dso__read_binary_type_filename(const struct dso *dso,
enum dso_binary_type type,
char *root_dir, char *filename, size_t size)
{
char build_id_hex[SBUILD_ID_SIZE];
int ret = 0;
size_t len;
switch (type) {
case DSO_BINARY_TYPE__DEBUGLINK:
{
const char *last_slash;
char dso_dir[PATH_MAX];
char symfile[PATH_MAX];
unsigned int i;
len = __symbol__join_symfs(filename, size, dso__long_name(dso));
last_slash = filename + len;
while (last_slash != filename && *last_slash != '/')
last_slash--;
strncpy(dso_dir, filename, last_slash - filename);
dso_dir[last_slash-filename] = '\0';
if (!is_regular_file(filename)) {
ret = -1;
break;
}
ret = filename__read_debuglink(filename, symfile, PATH_MAX);
if (ret)
break;
/* Check predefined locations where debug file might reside */
ret = -1;
for (i = 0; i < ARRAY_SIZE(debuglink_paths); i++) {
snprintf(filename, size,
debuglink_paths[i], dso_dir, symfile);
if (is_regular_file(filename)) {
ret = 0;
break;
}
}
break;
}
case DSO_BINARY_TYPE__BUILD_ID_CACHE:
if (dso__build_id_filename(dso, filename, size, false) == NULL)
ret = -1;
break;
case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
if (dso__build_id_filename(dso, filename, size, true) == NULL)
ret = -1;
break;
case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
snprintf(filename + len, size - len, "%s.debug", dso__long_name(dso));
break;
case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
snprintf(filename + len, size - len, "%s", dso__long_name(dso));
break;
case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
/*
* Ubuntu can mixup /usr/lib with /lib, putting debuginfo in
* /usr/lib/debug/lib when it is expected to be in
* /usr/lib/debug/usr/lib
*/
if (strlen(dso__long_name(dso)) < 9 ||
strncmp(dso__long_name(dso), "/usr/lib/", 9)) {
ret = -1;
break;
}
len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
snprintf(filename + len, size - len, "%s", dso__long_name(dso) + 4);
break;
case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
{
const char *last_slash;
size_t dir_size;
last_slash = dso__long_name(dso) + dso__long_name_len(dso);
while (last_slash != dso__long_name(dso) && *last_slash != '/')
last_slash--;
len = __symbol__join_symfs(filename, size, "");
dir_size = last_slash - dso__long_name(dso) + 2;
if (dir_size > (size - len)) {
ret = -1;
break;
}
len += scnprintf(filename + len, dir_size, "%s", dso__long_name(dso));
len += scnprintf(filename + len , size - len, ".debug%s",
last_slash);
break;
}
case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
if (!dso__has_build_id(dso)) {
ret = -1;
break;
}
build_id__sprintf(dso__bid_const(dso), build_id_hex);
len = __symbol__join_symfs(filename, size, "/usr/lib/debug/.build-id/");
snprintf(filename + len, size - len, "%.2s/%s.debug",
build_id_hex, build_id_hex + 2);
break;
case DSO_BINARY_TYPE__VMLINUX:
case DSO_BINARY_TYPE__GUEST_VMLINUX:
case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
__symbol__join_symfs(filename, size, dso__long_name(dso));
break;
case DSO_BINARY_TYPE__GUEST_KMODULE:
case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
path__join3(filename, size, symbol_conf.symfs,
root_dir, dso__long_name(dso));
break;
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
__symbol__join_symfs(filename, size, dso__long_name(dso));
break;
case DSO_BINARY_TYPE__KCORE:
case DSO_BINARY_TYPE__GUEST_KCORE:
snprintf(filename, size, "%s", dso__long_name(dso));
break;
default:
case DSO_BINARY_TYPE__KALLSYMS:
case DSO_BINARY_TYPE__GUEST_KALLSYMS:
case DSO_BINARY_TYPE__JAVA_JIT:
case DSO_BINARY_TYPE__BPF_PROG_INFO:
case DSO_BINARY_TYPE__BPF_IMAGE:
case DSO_BINARY_TYPE__OOL:
case DSO_BINARY_TYPE__NOT_FOUND:
ret = -1;
break;
}
return ret;
}
enum {
COMP_ID__NONE = 0,
};
static const struct {
const char *fmt;
int (*decompress)(const char *input, int output);
bool (*is_compressed)(const char *input);
} compressions[] = {
[COMP_ID__NONE] = { .fmt = NULL, },
#ifdef HAVE_ZLIB_SUPPORT
{ "gz", gzip_decompress_to_file, gzip_is_compressed },
#endif
#ifdef HAVE_LZMA_SUPPORT
{ "xz", lzma_decompress_to_file, lzma_is_compressed },
#endif
{ NULL, NULL, NULL },
};
static int is_supported_compression(const char *ext)
{
unsigned i;
for (i = 1; compressions[i].fmt; i++) {
if (!strcmp(ext, compressions[i].fmt))
return i;
}
return COMP_ID__NONE;
}
bool is_kernel_module(const char *pathname, int cpumode)
{
struct kmod_path m;
int mode = cpumode & PERF_RECORD_MISC_CPUMODE_MASK;
WARN_ONCE(mode != cpumode,
"Internal error: passing unmasked cpumode (%x) to is_kernel_module",
cpumode);
switch (mode) {
case PERF_RECORD_MISC_USER:
case PERF_RECORD_MISC_HYPERVISOR:
case PERF_RECORD_MISC_GUEST_USER:
return false;
/* Treat PERF_RECORD_MISC_CPUMODE_UNKNOWN as kernel */
default:
if (kmod_path__parse(&m, pathname)) {
pr_err("Failed to check whether %s is a kernel module or not. Assume it is.",
pathname);
return true;
}
}
return m.kmod;
}
bool dso__needs_decompress(struct dso *dso)
{
return dso__symtab_type(dso) == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
dso__symtab_type(dso) == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
}
int filename__decompress(const char *name, char *pathname,
size_t len, int comp, int *err)
{
char tmpbuf[] = KMOD_DECOMP_NAME;
int fd = -1;
/*
* We have proper compression id for DSO and yet the file
* behind the 'name' can still be plain uncompressed object.
*
* The reason is behind the logic we open the DSO object files,
* when we try all possible 'debug' objects until we find the
* data. So even if the DSO is represented by 'krava.xz' module,
* we can end up here opening ~/.debug/....23432432/debug' file
* which is not compressed.
*
* To keep this transparent, we detect this and return the file
* descriptor to the uncompressed file.
*/
if (!compressions[comp].is_compressed(name))
return open(name, O_RDONLY);
fd = mkstemp(tmpbuf);
if (fd < 0) {
*err = errno;
return -1;
}
if (compressions[comp].decompress(name, fd)) {
*err = DSO_LOAD_ERRNO__DECOMPRESSION_FAILURE;
close(fd);
fd = -1;
}
if (!pathname || (fd < 0))
unlink(tmpbuf);
if (pathname && (fd >= 0))
strlcpy(pathname, tmpbuf, len);
return fd;
}
static int decompress_kmodule(struct dso *dso, const char *name,
char *pathname, size_t len)
{
if (!dso__needs_decompress(dso))
return -1;
if (dso__comp(dso) == COMP_ID__NONE)
return -1;
return filename__decompress(name, pathname, len, dso__comp(dso), dso__load_errno(dso));
}
int dso__decompress_kmodule_fd(struct dso *dso, const char *name)
{
return decompress_kmodule(dso, name, NULL, 0);
}
int dso__decompress_kmodule_path(struct dso *dso, const char *name,
char *pathname, size_t len)
{
int fd = decompress_kmodule(dso, name, pathname, len);
close(fd);
return fd >= 0 ? 0 : -1;
}
/*
* Parses kernel module specified in @path and updates
* @m argument like:
*
* @comp - true if @path contains supported compression suffix,
* false otherwise
* @kmod - true if @path contains '.ko' suffix in right position,
* false otherwise
* @name - if (@alloc_name && @kmod) is true, it contains strdup-ed base name
* of the kernel module without suffixes, otherwise strudup-ed
* base name of @path
* @ext - if (@alloc_ext && @comp) is true, it contains strdup-ed string
* the compression suffix
*
* Returns 0 if there's no strdup error, -ENOMEM otherwise.
*/
int __kmod_path__parse(struct kmod_path *m, const char *path,
bool alloc_name)
{
const char *name = strrchr(path, '/');
const char *ext = strrchr(path, '.');
bool is_simple_name = false;
memset(m, 0x0, sizeof(*m));
name = name ? name + 1 : path;
/*
* '.' is also a valid character for module name. For example:
* [aaa.bbb] is a valid module name. '[' should have higher
* priority than '.ko' suffix.
*
* The kernel names are from machine__mmap_name. Such
* name should belong to kernel itself, not kernel module.
*/
if (name[0] == '[') {
is_simple_name = true;
if ((strncmp(name, "[kernel.kallsyms]", 17) == 0) ||
(strncmp(name, "[guest.kernel.kallsyms", 22) == 0) ||
(strncmp(name, "[vdso]", 6) == 0) ||
(strncmp(name, "[vdso32]", 8) == 0) ||
(strncmp(name, "[vdsox32]", 9) == 0) ||
(strncmp(name, "[vsyscall]", 10) == 0)) {
m->kmod = false;
} else
m->kmod = true;
}
/* No extension, just return name. */
if ((ext == NULL) || is_simple_name) {
if (alloc_name) {
m->name = strdup(name);
return m->name ? 0 : -ENOMEM;
}
return 0;
}
m->comp = is_supported_compression(ext + 1);
if (m->comp > COMP_ID__NONE)
ext -= 3;
/* Check .ko extension only if there's enough name left. */
if (ext > name)
m->kmod = !strncmp(ext, ".ko", 3);
if (alloc_name) {
if (m->kmod) {
if (asprintf(&m->name, "[%.*s]", (int) (ext - name), name) == -1)
return -ENOMEM;
} else {
if (asprintf(&m->name, "%s", name) == -1)
return -ENOMEM;
}
strreplace(m->name, '-', '_');
}
return 0;
}
void dso__set_module_info(struct dso *dso, struct kmod_path *m,
struct machine *machine)
{
if (machine__is_host(machine))
dso__set_symtab_type(dso, DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE);
else
dso__set_symtab_type(dso, DSO_BINARY_TYPE__GUEST_KMODULE);
/* _KMODULE_COMP should be next to _KMODULE */
if (m->kmod && m->comp) {
dso__set_symtab_type(dso, dso__symtab_type(dso) + 1);
dso__set_comp(dso, m->comp);
}
dso__set_is_kmod(dso);
dso__set_short_name(dso, strdup(m->name), true);
}
/*
* Global list of open DSOs and the counter.
*/
static LIST_HEAD(dso__data_open);
static long dso__data_open_cnt;
static pthread_mutex_t dso__data_open_lock = PTHREAD_MUTEX_INITIALIZER;
static void dso__list_add(struct dso *dso)
{
list_add_tail(&dso__data(dso)->open_entry, &dso__data_open);
#ifdef REFCNT_CHECKING
dso__data(dso)->dso = dso__get(dso);
#endif
/* Assume the dso is part of dsos, hence the optional reference count above. */
assert(dso__dsos(dso));
dso__data_open_cnt++;
}
static void dso__list_del(struct dso *dso)
{
list_del_init(&dso__data(dso)->open_entry);
#ifdef REFCNT_CHECKING
dso__put(dso__data(dso)->dso);
#endif
WARN_ONCE(dso__data_open_cnt <= 0,
"DSO data fd counter out of bounds.");
dso__data_open_cnt--;
}
static void close_first_dso(void);
static int do_open(char *name)
{
int fd;
char sbuf[STRERR_BUFSIZE];
do {
fd = open(name, O_RDONLY|O_CLOEXEC);
if (fd >= 0)
return fd;
pr_debug("dso open failed: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
if (!dso__data_open_cnt || errno != EMFILE)
break;
close_first_dso();
} while (1);
return -1;
}
char *dso__filename_with_chroot(const struct dso *dso, const char *filename)
{
return filename_with_chroot(nsinfo__pid(dso__nsinfo_const(dso)), filename);
}
static int __open_dso(struct dso *dso, struct machine *machine)
{
int fd = -EINVAL;
char *root_dir = (char *)"";
char *name = malloc(PATH_MAX);
bool decomp = false;
if (!name)
return -ENOMEM;
mutex_lock(dso__lock(dso));
if (machine)
root_dir = machine->root_dir;
if (dso__read_binary_type_filename(dso, dso__binary_type(dso),
root_dir, name, PATH_MAX))
goto out;
if (!is_regular_file(name)) {
char *new_name;
if (errno != ENOENT || dso__nsinfo(dso) == NULL)
goto out;
new_name = dso__filename_with_chroot(dso, name);
if (!new_name)
goto out;
free(name);
name = new_name;
}
if (dso__needs_decompress(dso)) {
char newpath[KMOD_DECOMP_LEN];
size_t len = sizeof(newpath);
if (dso__decompress_kmodule_path(dso, name, newpath, len) < 0) {
fd = -(*dso__load_errno(dso));
goto out;
}
decomp = true;
strcpy(name, newpath);
}
fd = do_open(name);
if (decomp)
unlink(name);
out:
mutex_unlock(dso__lock(dso));
free(name);
return fd;
}
static void check_data_close(void);
/**
* dso_close - Open DSO data file
* @dso: dso object
*
* Open @dso's data file descriptor and updates
* list/count of open DSO objects.
*/
static int open_dso(struct dso *dso, struct machine *machine)
{
int fd;
struct nscookie nsc;
if (dso__binary_type(dso) != DSO_BINARY_TYPE__BUILD_ID_CACHE) {
mutex_lock(dso__lock(dso));
nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
mutex_unlock(dso__lock(dso));
}
fd = __open_dso(dso, machine);
if (dso__binary_type(dso) != DSO_BINARY_TYPE__BUILD_ID_CACHE)
nsinfo__mountns_exit(&nsc);
if (fd >= 0) {
dso__list_add(dso);
/*
* Check if we crossed the allowed number
* of opened DSOs and close one if needed.
*/
check_data_close();
}
return fd;
}
static void close_data_fd(struct dso *dso)
{
if (dso__data(dso)->fd >= 0) {
close(dso__data(dso)->fd);
dso__data(dso)->fd = -1;
dso__data(dso)->file_size = 0;
dso__list_del(dso);
}
}
/**
* dso_close - Close DSO data file
* @dso: dso object
*
* Close @dso's data file descriptor and updates
* list/count of open DSO objects.
*/
static void close_dso(struct dso *dso)
{
close_data_fd(dso);
}
static void close_first_dso(void)
{
struct dso_data *dso_data;
struct dso *dso;
dso_data = list_first_entry(&dso__data_open, struct dso_data, open_entry);
#ifdef REFCNT_CHECKING
dso = dso_data->dso;
#else
dso = container_of(dso_data, struct dso, data);
#endif
close_dso(dso);
}
static rlim_t get_fd_limit(void)
{
struct rlimit l;
rlim_t limit = 0;
/* Allow half of the current open fd limit. */
if (getrlimit(RLIMIT_NOFILE, &l) == 0) {
if (l.rlim_cur == RLIM_INFINITY)
limit = l.rlim_cur;
else
limit = l.rlim_cur / 2;
} else {
pr_err("failed to get fd limit\n");
limit = 1;
}
return limit;
}
static rlim_t fd_limit;
/*
* Used only by tests/dso-data.c to reset the environment
* for tests. I dont expect we should change this during
* standard runtime.
*/
void reset_fd_limit(void)
{
fd_limit = 0;
}
static bool may_cache_fd(void)
{
if (!fd_limit)
fd_limit = get_fd_limit();
if (fd_limit == RLIM_INFINITY)
return true;
return fd_limit > (rlim_t) dso__data_open_cnt;
}
/*
* Check and close LRU dso if we crossed allowed limit
* for opened dso file descriptors. The limit is half
* of the RLIMIT_NOFILE files opened.
*/
static void check_data_close(void)
{
bool cache_fd = may_cache_fd();
if (!cache_fd)
close_first_dso();
}
/**
* dso__data_close - Close DSO data file
* @dso: dso object
*
* External interface to close @dso's data file descriptor.
*/
void dso__data_close(struct dso *dso)
{
pthread_mutex_lock(&dso__data_open_lock);
close_dso(dso);
pthread_mutex_unlock(&dso__data_open_lock);
}
static void try_to_open_dso(struct dso *dso, struct machine *machine)
{
enum dso_binary_type binary_type_data[] = {
DSO_BINARY_TYPE__BUILD_ID_CACHE,
DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
DSO_BINARY_TYPE__NOT_FOUND,
};
int i = 0;
struct dso_data *dso_data = dso__data(dso);
if (dso_data->fd >= 0)
return;
if (dso__binary_type(dso) != DSO_BINARY_TYPE__NOT_FOUND) {
dso_data->fd = open_dso(dso, machine);
goto out;
}
do {
dso__set_binary_type(dso, binary_type_data[i++]);
dso_data->fd = open_dso(dso, machine);
if (dso_data->fd >= 0)
goto out;
} while (dso__binary_type(dso) != DSO_BINARY_TYPE__NOT_FOUND);
out:
if (dso_data->fd >= 0)
dso_data->status = DSO_DATA_STATUS_OK;
else
dso_data->status = DSO_DATA_STATUS_ERROR;
}
/**
* dso__data_get_fd - Get dso's data file descriptor
* @dso: dso object
* @machine: machine object
*
* External interface to find dso's file, open it and
* returns file descriptor. It should be paired with
* dso__data_put_fd() if it returns non-negative value.
*/
int dso__data_get_fd(struct dso *dso, struct machine *machine)
{
if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
return -1;
if (pthread_mutex_lock(&dso__data_open_lock) < 0)
return -1;
try_to_open_dso(dso, machine);
if (dso__data(dso)->fd < 0)
pthread_mutex_unlock(&dso__data_open_lock);
return dso__data(dso)->fd;
}
void dso__data_put_fd(struct dso *dso __maybe_unused)
{
pthread_mutex_unlock(&dso__data_open_lock);
}
bool dso__data_status_seen(struct dso *dso, enum dso_data_status_seen by)
{
u32 flag = 1 << by;
if (dso__data(dso)->status_seen & flag)
return true;
dso__data(dso)->status_seen |= flag;
return false;
}
#ifdef HAVE_LIBBPF_SUPPORT
static ssize_t bpf_read(struct dso *dso, u64 offset, char *data)
{
struct bpf_prog_info_node *node;
ssize_t size = DSO__DATA_CACHE_SIZE;
struct dso_bpf_prog *dso_bpf_prog = dso__bpf_prog(dso);
u64 len;
u8 *buf;
node = perf_env__find_bpf_prog_info(dso_bpf_prog->env, dso_bpf_prog->id);
if (!node || !node->info_linear) {
dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
return -1;
}
len = node->info_linear->info.jited_prog_len;
buf = (u8 *)(uintptr_t)node->info_linear->info.jited_prog_insns;
if (offset >= len)
return -1;
size = (ssize_t)min(len - offset, (u64)size);
memcpy(data, buf + offset, size);
return size;
}
static int bpf_size(struct dso *dso)
{
struct bpf_prog_info_node *node;
struct dso_bpf_prog *dso_bpf_prog = dso__bpf_prog(dso);
node = perf_env__find_bpf_prog_info(dso_bpf_prog->env, dso_bpf_prog->id);
if (!node || !node->info_linear) {
dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
return -1;
}
dso__data(dso)->file_size = node->info_linear->info.jited_prog_len;
return 0;
}
#endif // HAVE_LIBBPF_SUPPORT
static void
dso_cache__free(struct dso *dso)
{
struct rb_root *root = &dso__data(dso)->cache;
struct rb_node *next = rb_first(root);
mutex_lock(dso__lock(dso));
while (next) {
struct dso_cache *cache;
cache = rb_entry(next, struct dso_cache, rb_node);
next = rb_next(&cache->rb_node);
rb_erase(&cache->rb_node, root);
free(cache);
}
mutex_unlock(dso__lock(dso));
}
static struct dso_cache *__dso_cache__find(struct dso *dso, u64 offset)
{
const struct rb_root *root = &dso__data(dso)->cache;
struct rb_node * const *p = &root->rb_node;
const struct rb_node *parent = NULL;
struct dso_cache *cache;
while (*p != NULL) {
u64 end;
parent = *p;
cache = rb_entry(parent, struct dso_cache, rb_node);
end = cache->offset + DSO__DATA_CACHE_SIZE;
if (offset < cache->offset)
p = &(*p)->rb_left;
else if (offset >= end)
p = &(*p)->rb_right;
else
return cache;
}
return NULL;
}
static struct dso_cache *
dso_cache__insert(struct dso *dso, struct dso_cache *new)
{
struct rb_root *root = &dso__data(dso)->cache;
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct dso_cache *cache;
u64 offset = new->offset;
mutex_lock(dso__lock(dso));
while (*p != NULL) {
u64 end;
parent = *p;
cache = rb_entry(parent, struct dso_cache, rb_node);
end = cache->offset + DSO__DATA_CACHE_SIZE;
if (offset < cache->offset)
p = &(*p)->rb_left;
else if (offset >= end)
p = &(*p)->rb_right;
else
goto out;
}
rb_link_node(&new->rb_node, parent, p);
rb_insert_color(&new->rb_node, root);
cache = NULL;
out:
mutex_unlock(dso__lock(dso));
return cache;
}
static ssize_t dso_cache__memcpy(struct dso_cache *cache, u64 offset, u8 *data,
u64 size, bool out)
{
u64 cache_offset = offset - cache->offset;
u64 cache_size = min(cache->size - cache_offset, size);
if (out)
memcpy(data, cache->data + cache_offset, cache_size);
else
memcpy(cache->data + cache_offset, data, cache_size);
return cache_size;
}
static ssize_t file_read(struct dso *dso, struct machine *machine,
u64 offset, char *data)
{
ssize_t ret;
pthread_mutex_lock(&dso__data_open_lock);
/*
* dso__data(dso)->fd might be closed if other thread opened another
* file (dso) due to open file limit (RLIMIT_NOFILE).
*/
try_to_open_dso(dso, machine);
if (dso__data(dso)->fd < 0) {
dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
ret = -errno;
goto out;
}
ret = pread(dso__data(dso)->fd, data, DSO__DATA_CACHE_SIZE, offset);
out:
pthread_mutex_unlock(&dso__data_open_lock);
return ret;
}
static struct dso_cache *dso_cache__populate(struct dso *dso,
struct machine *machine,
u64 offset, ssize_t *ret)
{
u64 cache_offset = offset & DSO__DATA_CACHE_MASK;
struct dso_cache *cache;
struct dso_cache *old;
cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
if (!cache) {
*ret = -ENOMEM;
return NULL;
}
#ifdef HAVE_LIBBPF_SUPPORT
if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
*ret = bpf_read(dso, cache_offset, cache->data);
else
#endif
if (dso__binary_type(dso) == DSO_BINARY_TYPE__OOL)
*ret = DSO__DATA_CACHE_SIZE;
else
*ret = file_read(dso, machine, cache_offset, cache->data);
if (*ret <= 0) {
free(cache);
return NULL;
}
cache->offset = cache_offset;
cache->size = *ret;
old = dso_cache__insert(dso, cache);
if (old) {
/* we lose the race */
free(cache);
cache = old;
}
return cache;
}
static struct dso_cache *dso_cache__find(struct dso *dso,
struct machine *machine,
u64 offset,
ssize_t *ret)
{
struct dso_cache *cache = __dso_cache__find(dso, offset);
return cache ? cache : dso_cache__populate(dso, machine, offset, ret);
}
static ssize_t dso_cache_io(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size, bool out)
{
struct dso_cache *cache;
ssize_t ret = 0;
cache = dso_cache__find(dso, machine, offset, &ret);
if (!cache)
return ret;
return dso_cache__memcpy(cache, offset, data, size, out);
}
/*
* Reads and caches dso data DSO__DATA_CACHE_SIZE size chunks
* in the rb_tree. Any read to already cached data is served
* by cached data. Writes update the cache only, not the backing file.
*/
static ssize_t cached_io(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size, bool out)
{
ssize_t r = 0;
u8 *p = data;
do {
ssize_t ret;
ret = dso_cache_io(dso, machine, offset, p, size, out);
if (ret < 0)
return ret;
/* Reached EOF, return what we have. */
if (!ret)
break;
BUG_ON(ret > size);
r += ret;
p += ret;
offset += ret;
size -= ret;
} while (size);
return r;
}
static int file_size(struct dso *dso, struct machine *machine)
{
int ret = 0;
struct stat st;
char sbuf[STRERR_BUFSIZE];
pthread_mutex_lock(&dso__data_open_lock);
/*
* dso__data(dso)->fd might be closed if other thread opened another
* file (dso) due to open file limit (RLIMIT_NOFILE).
*/
try_to_open_dso(dso, machine);
if (dso__data(dso)->fd < 0) {
ret = -errno;
dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
goto out;
}
if (fstat(dso__data(dso)->fd, &st) < 0) {
ret = -errno;
pr_err("dso cache fstat failed: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
dso__data(dso)->status = DSO_DATA_STATUS_ERROR;
goto out;
}
dso__data(dso)->file_size = st.st_size;
out:
pthread_mutex_unlock(&dso__data_open_lock);
return ret;
}
int dso__data_file_size(struct dso *dso, struct machine *machine)
{
if (dso__data(dso)->file_size)
return 0;
if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
return -1;
#ifdef HAVE_LIBBPF_SUPPORT
if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
return bpf_size(dso);
#endif
return file_size(dso, machine);
}
/**
* dso__data_size - Return dso data size
* @dso: dso object
* @machine: machine object
*
* Return: dso data size
*/
off_t dso__data_size(struct dso *dso, struct machine *machine)
{
if (dso__data_file_size(dso, machine))
return -1;
/* For now just estimate dso data size is close to file size */
return dso__data(dso)->file_size;
}
static ssize_t data_read_write_offset(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size,
bool out)
{
if (dso__data_file_size(dso, machine))
return -1;
/* Check the offset sanity. */
if (offset > dso__data(dso)->file_size)
return -1;
if (offset + size < offset)
return -1;
return cached_io(dso, machine, offset, data, size, out);
}
/**
* dso__data_read_offset - Read data from dso file offset
* @dso: dso object
* @machine: machine object
* @offset: file offset
* @data: buffer to store data
* @size: size of the @data buffer
*
* External interface to read data from dso file offset. Open
* dso data file and use cached_read to get the data.
*/
ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
return -1;
return data_read_write_offset(dso, machine, offset, data, size, true);
}
/**
* dso__data_read_addr - Read data from dso address
* @dso: dso object
* @machine: machine object
* @add: virtual memory address
* @data: buffer to store data
* @size: size of the @data buffer
*
* External interface to read data from dso address.
*/
ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr,
u8 *data, ssize_t size)
{
u64 offset = map__map_ip(map, addr);
return dso__data_read_offset(dso, machine, offset, data, size);
}
/**
* dso__data_write_cache_offs - Write data to dso data cache at file offset
* @dso: dso object
* @machine: machine object
* @offset: file offset
* @data: buffer to write
* @size: size of the @data buffer
*
* Write into the dso file data cache, but do not change the file itself.
*/
ssize_t dso__data_write_cache_offs(struct dso *dso, struct machine *machine,
u64 offset, const u8 *data_in, ssize_t size)
{
u8 *data = (u8 *)data_in; /* cast away const to use same fns for r/w */
if (dso__data(dso)->status == DSO_DATA_STATUS_ERROR)
return -1;
return data_read_write_offset(dso, machine, offset, data, size, false);
}
/**
* dso__data_write_cache_addr - Write data to dso data cache at dso address
* @dso: dso object
* @machine: machine object
* @add: virtual memory address
* @data: buffer to write
* @size: size of the @data buffer
*
* External interface to write into the dso file data cache, but do not change
* the file itself.
*/
ssize_t dso__data_write_cache_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr,
const u8 *data, ssize_t size)
{
u64 offset = map__map_ip(map, addr);
return dso__data_write_cache_offs(dso, machine, offset, data, size);
}
struct map *dso__new_map(const char *name)
{
struct map *map = NULL;
struct dso *dso = dso__new(name);
if (dso) {
map = map__new2(0, dso);
dso__put(dso);
}
return map;
}
struct dso *machine__findnew_kernel(struct machine *machine, const char *name,
const char *short_name, int dso_type)
{
/*
* The kernel dso could be created by build_id processing.
*/
struct dso *dso = machine__findnew_dso(machine, name);
/*
* We need to run this in all cases, since during the build_id
* processing we had no idea this was the kernel dso.
*/
if (dso != NULL) {
dso__set_short_name(dso, short_name, false);
dso__set_kernel(dso, dso_type);
}
return dso;
}
static void dso__set_long_name_id(struct dso *dso, const char *name, bool name_allocated)
{
struct dsos *dsos = dso__dsos(dso);
if (name == NULL)
return;
if (dsos) {
/*
* Need to avoid re-sorting the dsos breaking by non-atomically
* renaming the dso.
*/
down_write(&dsos->lock);
}
if (dso__long_name_allocated(dso))
free((char *)dso__long_name(dso));
RC_CHK_ACCESS(dso)->long_name = name;
RC_CHK_ACCESS(dso)->long_name_len = strlen(name);
dso__set_long_name_allocated(dso, name_allocated);
if (dsos) {
dsos->sorted = false;
up_write(&dsos->lock);
}
}
static int __dso_id__cmp(const struct dso_id *a, const struct dso_id *b)
{
if (a->maj > b->maj) return -1;
if (a->maj < b->maj) return 1;
if (a->min > b->min) return -1;
if (a->min < b->min) return 1;
if (a->ino > b->ino) return -1;
if (a->ino < b->ino) return 1;
/*
* Synthesized MMAP events have zero ino_generation, avoid comparing
* them with MMAP events with actual ino_generation.
*
* I found it harmful because the mismatch resulted in a new
* dso that did not have a build ID whereas the original dso did have a
* build ID. The build ID was essential because the object was not found
* otherwise. - Adrian
*/
if (a->ino_generation && b->ino_generation) {
if (a->ino_generation > b->ino_generation) return -1;
if (a->ino_generation < b->ino_generation) return 1;
}
return 0;
}
bool dso_id__empty(const struct dso_id *id)
{
if (!id)
return true;
return !id->maj && !id->min && !id->ino && !id->ino_generation;
}
void __dso__inject_id(struct dso *dso, struct dso_id *id)
{
struct dsos *dsos = dso__dsos(dso);
struct dso_id *dso_id = dso__id(dso);
/* dsos write lock held by caller. */
dso_id->maj = id->maj;
dso_id->min = id->min;
dso_id->ino = id->ino;
dso_id->ino_generation = id->ino_generation;
if (dsos)
dsos->sorted = false;
}
int dso_id__cmp(const struct dso_id *a, const struct dso_id *b)
{
/*
* The second is always dso->id, so zeroes if not set, assume passing
* NULL for a means a zeroed id
*/
if (dso_id__empty(a) || dso_id__empty(b))
return 0;
return __dso_id__cmp(a, b);
}
int dso__cmp_id(struct dso *a, struct dso *b)
{
return __dso_id__cmp(dso__id(a), dso__id(b));
}
void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
{
dso__set_long_name_id(dso, name, name_allocated);
}
void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
{
struct dsos *dsos = dso__dsos(dso);
if (name == NULL)
return;
if (dsos) {
/*
* Need to avoid re-sorting the dsos breaking by non-atomically
* renaming the dso.
*/
down_write(&dsos->lock);
}
if (dso__short_name_allocated(dso))
free((char *)dso__short_name(dso));
RC_CHK_ACCESS(dso)->short_name = name;
RC_CHK_ACCESS(dso)->short_name_len = strlen(name);
dso__set_short_name_allocated(dso, name_allocated);
if (dsos) {
dsos->sorted = false;
up_write(&dsos->lock);
}
}
int dso__name_len(const struct dso *dso)
{
if (!dso)
return strlen("[unknown]");
if (verbose > 0)
return dso__long_name_len(dso);
return dso__short_name_len(dso);
}
bool dso__loaded(const struct dso *dso)
{
return RC_CHK_ACCESS(dso)->loaded;
}
bool dso__sorted_by_name(const struct dso *dso)
{
return RC_CHK_ACCESS(dso)->sorted_by_name;
}
void dso__set_sorted_by_name(struct dso *dso)
{
RC_CHK_ACCESS(dso)->sorted_by_name = true;
}
struct dso *dso__new_id(const char *name, struct dso_id *id)
{
RC_STRUCT(dso) *dso = zalloc(sizeof(*dso) + strlen(name) + 1);
struct dso *res;
struct dso_data *data;
if (!dso)
return NULL;
if (ADD_RC_CHK(res, dso)) {
strcpy(dso->name, name);
if (id)
dso->id = *id;
dso__set_long_name_id(res, dso->name, false);
dso__set_short_name(res, dso->name, false);
dso->symbols = RB_ROOT_CACHED;
dso->symbol_names = NULL;
dso->symbol_names_len = 0;
dso->inlined_nodes = RB_ROOT_CACHED;
dso->srclines = RB_ROOT_CACHED;
dso->data_types = RB_ROOT;
dso->global_vars = RB_ROOT;
dso->data.fd = -1;
dso->data.status = DSO_DATA_STATUS_UNKNOWN;
dso->symtab_type = DSO_BINARY_TYPE__NOT_FOUND;
dso->binary_type = DSO_BINARY_TYPE__NOT_FOUND;
dso->is_64_bit = (sizeof(void *) == 8);
dso->loaded = 0;
dso->rel = 0;
dso->sorted_by_name = 0;
dso->has_build_id = 0;
dso->has_srcline = 1;
dso->a2l_fails = 1;
dso->kernel = DSO_SPACE__USER;
dso->is_kmod = 0;
dso->needs_swap = DSO_SWAP__UNSET;
dso->comp = COMP_ID__NONE;
mutex_init(&dso->lock);
refcount_set(&dso->refcnt, 1);
data = &dso->data;
data->cache = RB_ROOT;
data->fd = -1;
data->status = DSO_DATA_STATUS_UNKNOWN;
INIT_LIST_HEAD(&data->open_entry);
#ifdef REFCNT_CHECKING
data->dso = NULL; /* Set when on the open_entry list. */
#endif
}
return res;
}
struct dso *dso__new(const char *name)
{
return dso__new_id(name, NULL);
}
void dso__delete(struct dso *dso)
{
if (dso__dsos(dso))
pr_err("DSO %s is still in rbtree when being deleted!\n", dso__long_name(dso));
/* free inlines first, as they reference symbols */
inlines__tree_delete(&RC_CHK_ACCESS(dso)->inlined_nodes);
srcline__tree_delete(&RC_CHK_ACCESS(dso)->srclines);
symbols__delete(&RC_CHK_ACCESS(dso)->symbols);
RC_CHK_ACCESS(dso)->symbol_names_len = 0;
zfree(&RC_CHK_ACCESS(dso)->symbol_names);
annotated_data_type__tree_delete(dso__data_types(dso));
global_var_type__tree_delete(dso__global_vars(dso));
if (RC_CHK_ACCESS(dso)->short_name_allocated) {
zfree((char **)&RC_CHK_ACCESS(dso)->short_name);
RC_CHK_ACCESS(dso)->short_name_allocated = false;
}
if (RC_CHK_ACCESS(dso)->long_name_allocated) {
zfree((char **)&RC_CHK_ACCESS(dso)->long_name);
RC_CHK_ACCESS(dso)->long_name_allocated = false;
}
dso__data_close(dso);
auxtrace_cache__free(RC_CHK_ACCESS(dso)->auxtrace_cache);
dso_cache__free(dso);
dso__free_a2l(dso);
zfree(&RC_CHK_ACCESS(dso)->symsrc_filename);
nsinfo__zput(RC_CHK_ACCESS(dso)->nsinfo);
mutex_destroy(dso__lock(dso));
RC_CHK_FREE(dso);
}
struct dso *dso__get(struct dso *dso)
{
struct dso *result;
if (RC_CHK_GET(result, dso))
refcount_inc(&RC_CHK_ACCESS(dso)->refcnt);
return result;
}
void dso__put(struct dso *dso)
{
if (dso && refcount_dec_and_test(&RC_CHK_ACCESS(dso)->refcnt))
dso__delete(dso);
else
RC_CHK_PUT(dso);
}
void dso__set_build_id(struct dso *dso, struct build_id *bid)
{
RC_CHK_ACCESS(dso)->bid = *bid;
RC_CHK_ACCESS(dso)->has_build_id = 1;
}
bool dso__build_id_equal(const struct dso *dso, struct build_id *bid)
{
const struct build_id *dso_bid = dso__bid_const(dso);
if (dso_bid->size > bid->size && dso_bid->size == BUILD_ID_SIZE) {
/*
* For the backward compatibility, it allows a build-id has
* trailing zeros.
*/
return !memcmp(dso_bid->data, bid->data, bid->size) &&
!memchr_inv(&dso_bid->data[bid->size], 0,
dso_bid->size - bid->size);
}
return dso_bid->size == bid->size &&
memcmp(dso_bid->data, bid->data, dso_bid->size) == 0;
}
void dso__read_running_kernel_build_id(struct dso *dso, struct machine *machine)
{
char path[PATH_MAX];
if (machine__is_default_guest(machine))
return;
sprintf(path, "%s/sys/kernel/notes", machine->root_dir);
if (sysfs__read_build_id(path, dso__bid(dso)) == 0)
dso__set_has_build_id(dso);
}
int dso__kernel_module_get_build_id(struct dso *dso,
const char *root_dir)
{
char filename[PATH_MAX];
/*
* kernel module short names are of the form "[module]" and
* we need just "module" here.
*/
const char *name = dso__short_name(dso) + 1;
snprintf(filename, sizeof(filename),
"%s/sys/module/%.*s/notes/.note.gnu.build-id",
root_dir, (int)strlen(name) - 1, name);
if (sysfs__read_build_id(filename, dso__bid(dso)) == 0)
dso__set_has_build_id(dso);
return 0;
}
static size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
{
char sbuild_id[SBUILD_ID_SIZE];
build_id__sprintf(dso__bid(dso), sbuild_id);
return fprintf(fp, "%s", sbuild_id);
}
size_t dso__fprintf(struct dso *dso, FILE *fp)
{
struct rb_node *nd;
size_t ret = fprintf(fp, "dso: %s (", dso__short_name(dso));
if (dso__short_name(dso) != dso__long_name(dso))
ret += fprintf(fp, "%s, ", dso__long_name(dso));
ret += fprintf(fp, "%sloaded, ", dso__loaded(dso) ? "" : "NOT ");
ret += dso__fprintf_buildid(dso, fp);
ret += fprintf(fp, ")\n");
for (nd = rb_first_cached(dso__symbols(dso)); nd; nd = rb_next(nd)) {
struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
ret += symbol__fprintf(pos, fp);
}
return ret;
}
enum dso_type dso__type(struct dso *dso, struct machine *machine)
{
int fd;
enum dso_type type = DSO__TYPE_UNKNOWN;
fd = dso__data_get_fd(dso, machine);
if (fd >= 0) {
type = dso__type_fd(fd);
dso__data_put_fd(dso);
}
return type;
}
int dso__strerror_load(struct dso *dso, char *buf, size_t buflen)
{
int idx, errnum = *dso__load_errno(dso);
/*
* This must have a same ordering as the enum dso_load_errno.
*/
static const char *dso_load__error_str[] = {
"Internal tools/perf/ library error",
"Invalid ELF file",
"Can not read build id",
"Mismatching build id",
"Decompression failure",
};
BUG_ON(buflen == 0);
if (errnum >= 0) {
const char *err = str_error_r(errnum, buf, buflen);
if (err != buf)
scnprintf(buf, buflen, "%s", err);
return 0;
}
if (errnum < __DSO_LOAD_ERRNO__START || errnum >= __DSO_LOAD_ERRNO__END)
return -1;
idx = errnum - __DSO_LOAD_ERRNO__START;
scnprintf(buf, buflen, "%s", dso_load__error_str[idx]);
return 0;
}