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linux-next/tools/perf/util/dso.c
Matija Glavinic Pecotic 9343e45bf6 perf unwind: Fix looking up dwarf unwind stack info
Using perf with call graph method dwarf fails to provide backtrace
support for stripped binary even though .gnu_debuglink points to *.dbg
flavor with properly populated debug symbols.

Problem is reproduced on ARM (v7, v8), kernels 3.14.y, 4.4.y and
4.10.rc3.  Perf is configured with libunwind, and unwind dwarf support
[1]. Test code (stress_bt.c) can be found on [2].

Running (explicitly disable other unwinding methods):

  $ gcc -g -o stress_bt -fomit-frame-pointer -fno-unwind-tables \
	-fno-asynchronous-unwind-tables stress_bt.c
  $ perf record -N --call-graph dwarf ./stress_bt
  $ perf report

results in properly generated call graph. Stripping the binary and running
it results with missing call graph. Expected result is to have call graph:

  $ gcc -g -o stress_bt -fomit-frame-pointer -fno-unwind-tables \
	  -fno-asynchronous-unwind-tables stress_bt.c
  $ objcopy --only-keep-debug stress_bt stress_bt.dbg
  $ objcopy --strip-debug stress_bt
  $ objcopy --add-gnu-debuglink=stress_bt.dbg stress_bt
  $ perf record -N --call-graph dwarf ./stress_bt
  $ perf report

Problem is that perf doesn't try to read symbols pointed by gnu
debuglink.  Patch adds checking, and reading of the symbols from
debuglink and symsrc.  Order of the check is to first check within dso,
then check whether symsrc is defined and try to read from it. Finally,
debuglink is checked. Default locations of debug files are discussed in
[3] and [4]. Comments on RFC are on [5].

[1] https://wiki.linaro.org/LEG/Engineering/TOOLS/perf-callstack-unwinding
[2] [1]#Backtrace_stress_application
[3] https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html
[4] https://sourceware.org/binutils/docs/binutils/objcopy.html
[5] https://lkml.org/lkml/2016/8/22/473

Signed-off-by: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/d309d40a-463f-482b-68e1-1465326efdc1@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-01-18 12:29:52 -03:00

1413 lines
32 KiB
C

#include <asm/bug.h>
#include <sys/time.h>
#include <sys/resource.h>
#include "symbol.h"
#include "dso.h"
#include "machine.h"
#include "auxtrace.h"
#include "util.h"
#include "debug.h"
#include "vdso.h"
static const char * const debuglink_paths[] = {
"%.0s%s",
"%s/%s",
"%s/.debug/%s",
"/usr/lib/debug%s/%s"
};
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__FEDORA_DEBUGINFO] = 'f',
[DSO_BINARY_TYPE__UBUNTU_DEBUGINFO] = 'u',
[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_BINARY_TYPE__NOT_FOUND)
return '!';
return origin[dso->symtab_type];
}
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);
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) == 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);
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);
break;
case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
{
const char *last_slash;
size_t dir_size;
last_slash = dso->long_name + dso->long_name_len;
while (last_slash != dso->long_name && *last_slash != '/')
last_slash--;
len = __symbol__join_symfs(filename, size, "");
dir_size = last_slash - dso->long_name + 2;
if (dir_size > (size - len)) {
ret = -1;
break;
}
len += scnprintf(filename + len, dir_size, "%s", dso->long_name);
len += scnprintf(filename + len , size - len, ".debug%s",
last_slash);
break;
}
case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
if (!dso->has_build_id) {
ret = -1;
break;
}
build_id__sprintf(dso->build_id,
sizeof(dso->build_id),
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);
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);
break;
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
__symbol__join_symfs(filename, size, dso->long_name);
break;
case DSO_BINARY_TYPE__KCORE:
case DSO_BINARY_TYPE__GUEST_KCORE:
snprintf(filename, size, "%s", dso->long_name);
break;
default:
case DSO_BINARY_TYPE__KALLSYMS:
case DSO_BINARY_TYPE__GUEST_KALLSYMS:
case DSO_BINARY_TYPE__JAVA_JIT:
case DSO_BINARY_TYPE__NOT_FOUND:
ret = -1;
break;
}
return ret;
}
static const struct {
const char *fmt;
int (*decompress)(const char *input, int output);
} compressions[] = {
#ifdef HAVE_ZLIB_SUPPORT
{ "gz", gzip_decompress_to_file },
#endif
#ifdef HAVE_LZMA_SUPPORT
{ "xz", lzma_decompress_to_file },
#endif
{ NULL, NULL },
};
bool is_supported_compression(const char *ext)
{
unsigned i;
for (i = 0; compressions[i].fmt; i++) {
if (!strcmp(ext, compressions[i].fmt))
return true;
}
return false;
}
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 decompress_to_file(const char *ext, const char *filename, int output_fd)
{
unsigned i;
for (i = 0; compressions[i].fmt; i++) {
if (!strcmp(ext, compressions[i].fmt))
return !compressions[i].decompress(filename,
output_fd);
}
return false;
}
bool dso__needs_decompress(struct dso *dso)
{
return dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
}
/*
* 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, bool alloc_ext)
{
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, "[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;
}
if (is_supported_compression(ext + 1)) {
m->comp = true;
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;
}
strxfrchar(m->name, '-', '_');
}
if (alloc_ext && m->comp) {
m->ext = strdup(ext + 4);
if (!m->ext) {
free((void *) m->name);
return -ENOMEM;
}
}
return 0;
}
/*
* 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.open_entry, &dso__data_open);
dso__data_open_cnt++;
}
static void dso__list_del(struct dso *dso)
{
list_del(&dso->data.open_entry);
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);
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;
}
static int __open_dso(struct dso *dso, struct machine *machine)
{
int fd;
char *root_dir = (char *)"";
char *name = malloc(PATH_MAX);
if (!name)
return -ENOMEM;
if (machine)
root_dir = machine->root_dir;
if (dso__read_binary_type_filename(dso, dso->binary_type,
root_dir, name, PATH_MAX)) {
free(name);
return -EINVAL;
}
if (!is_regular_file(name))
return -EINVAL;
fd = do_open(name);
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 = __open_dso(dso, machine);
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.fd >= 0) {
close(dso->data.fd);
dso->data.fd = -1;
dso->data.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 *dso;
dso = list_first_entry(&dso__data_open, struct dso, data.open_entry);
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;
if (dso->data.fd >= 0)
return;
if (dso->binary_type != DSO_BINARY_TYPE__NOT_FOUND) {
dso->data.fd = open_dso(dso, machine);
goto out;
}
do {
dso->binary_type = binary_type_data[i++];
dso->data.fd = open_dso(dso, machine);
if (dso->data.fd >= 0)
goto out;
} while (dso->binary_type != 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.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.fd < 0)
pthread_mutex_unlock(&dso__data_open_lock);
return dso->data.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.status_seen & flag)
return true;
dso->data.status_seen |= flag;
return false;
}
static void
dso_cache__free(struct dso *dso)
{
struct rb_root *root = &dso->data.cache;
struct rb_node *next = rb_first(root);
pthread_mutex_lock(&dso->lock);
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);
}
pthread_mutex_unlock(&dso->lock);
}
static struct dso_cache *dso_cache__find(struct dso *dso, u64 offset)
{
const struct rb_root *root = &dso->data.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.cache;
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct dso_cache *cache;
u64 offset = new->offset;
pthread_mutex_lock(&dso->lock);
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:
pthread_mutex_unlock(&dso->lock);
return cache;
}
static ssize_t
dso_cache__memcpy(struct dso_cache *cache, u64 offset,
u8 *data, u64 size)
{
u64 cache_offset = offset - cache->offset;
u64 cache_size = min(cache->size - cache_offset, size);
memcpy(data, cache->data + cache_offset, cache_size);
return cache_size;
}
static ssize_t
dso_cache__read(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
struct dso_cache *cache;
struct dso_cache *old;
ssize_t ret;
do {
u64 cache_offset;
cache = zalloc(sizeof(*cache) + DSO__DATA_CACHE_SIZE);
if (!cache)
return -ENOMEM;
pthread_mutex_lock(&dso__data_open_lock);
/*
* dso->data.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.fd < 0) {
ret = -errno;
dso->data.status = DSO_DATA_STATUS_ERROR;
break;
}
cache_offset = offset & DSO__DATA_CACHE_MASK;
ret = pread(dso->data.fd, cache->data, DSO__DATA_CACHE_SIZE, cache_offset);
if (ret <= 0)
break;
cache->offset = cache_offset;
cache->size = ret;
} while (0);
pthread_mutex_unlock(&dso__data_open_lock);
if (ret > 0) {
old = dso_cache__insert(dso, cache);
if (old) {
/* we lose the race */
free(cache);
cache = old;
}
ret = dso_cache__memcpy(cache, offset, data, size);
}
if (ret <= 0)
free(cache);
return ret;
}
static ssize_t dso_cache_read(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
struct dso_cache *cache;
cache = dso_cache__find(dso, offset);
if (cache)
return dso_cache__memcpy(cache, offset, data, size);
else
return dso_cache__read(dso, machine, offset, data, size);
}
/*
* 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.
*/
static ssize_t cached_read(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
ssize_t r = 0;
u8 *p = data;
do {
ssize_t ret;
ret = dso_cache_read(dso, machine, offset, p, size);
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 data_file_size(struct dso *dso, struct machine *machine)
{
int ret = 0;
struct stat st;
char sbuf[STRERR_BUFSIZE];
if (dso->data.file_size)
return 0;
if (dso->data.status == DSO_DATA_STATUS_ERROR)
return -1;
pthread_mutex_lock(&dso__data_open_lock);
/*
* dso->data.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.fd < 0) {
ret = -errno;
dso->data.status = DSO_DATA_STATUS_ERROR;
goto out;
}
if (fstat(dso->data.fd, &st) < 0) {
ret = -errno;
pr_err("dso cache fstat failed: %s\n",
str_error_r(errno, sbuf, sizeof(sbuf)));
dso->data.status = DSO_DATA_STATUS_ERROR;
goto out;
}
dso->data.file_size = st.st_size;
out:
pthread_mutex_unlock(&dso__data_open_lock);
return ret;
}
/**
* 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 (data_file_size(dso, machine))
return -1;
/* For now just estimate dso data size is close to file size */
return dso->data.file_size;
}
static ssize_t data_read_offset(struct dso *dso, struct machine *machine,
u64 offset, u8 *data, ssize_t size)
{
if (data_file_size(dso, machine))
return -1;
/* Check the offset sanity. */
if (offset > dso->data.file_size)
return -1;
if (offset + size < offset)
return -1;
return cached_read(dso, machine, offset, data, size);
}
/**
* 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.status == DSO_DATA_STATUS_ERROR)
return -1;
return data_read_offset(dso, machine, offset, data, size);
}
/**
* 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);
}
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, MAP__FUNCTION);
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->kernel = dso_type;
}
return dso;
}
/*
* Find a matching entry and/or link current entry to RB tree.
* Either one of the dso or name parameter must be non-NULL or the
* function will not work.
*/
static struct dso *__dso__findlink_by_longname(struct rb_root *root,
struct dso *dso, const char *name)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
if (!name)
name = dso->long_name;
/*
* Find node with the matching name
*/
while (*p) {
struct dso *this = rb_entry(*p, struct dso, rb_node);
int rc = strcmp(name, this->long_name);
parent = *p;
if (rc == 0) {
/*
* In case the new DSO is a duplicate of an existing
* one, print an one-time warning & put the new entry
* at the end of the list of duplicates.
*/
if (!dso || (dso == this))
return this; /* Find matching dso */
/*
* The core kernel DSOs may have duplicated long name.
* In this case, the short name should be different.
* Comparing the short names to differentiate the DSOs.
*/
rc = strcmp(dso->short_name, this->short_name);
if (rc == 0) {
pr_err("Duplicated dso name: %s\n", name);
return NULL;
}
}
if (rc < 0)
p = &parent->rb_left;
else
p = &parent->rb_right;
}
if (dso) {
/* Add new node and rebalance tree */
rb_link_node(&dso->rb_node, parent, p);
rb_insert_color(&dso->rb_node, root);
dso->root = root;
}
return NULL;
}
static inline struct dso *__dso__find_by_longname(struct rb_root *root,
const char *name)
{
return __dso__findlink_by_longname(root, NULL, name);
}
void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
{
struct rb_root *root = dso->root;
if (name == NULL)
return;
if (dso->long_name_allocated)
free((char *)dso->long_name);
if (root) {
rb_erase(&dso->rb_node, root);
/*
* __dso__findlink_by_longname() isn't guaranteed to add it
* back, so a clean removal is required here.
*/
RB_CLEAR_NODE(&dso->rb_node);
dso->root = NULL;
}
dso->long_name = name;
dso->long_name_len = strlen(name);
dso->long_name_allocated = name_allocated;
if (root)
__dso__findlink_by_longname(root, dso, NULL);
}
void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
{
if (name == NULL)
return;
if (dso->short_name_allocated)
free((char *)dso->short_name);
dso->short_name = name;
dso->short_name_len = strlen(name);
dso->short_name_allocated = name_allocated;
}
static void dso__set_basename(struct dso *dso)
{
/*
* basename() may modify path buffer, so we must pass
* a copy.
*/
char *base, *lname = strdup(dso->long_name);
if (!lname)
return;
/*
* basename() may return a pointer to internal
* storage which is reused in subsequent calls
* so copy the result.
*/
base = strdup(basename(lname));
free(lname);
if (!base)
return;
dso__set_short_name(dso, base, true);
}
int dso__name_len(const struct dso *dso)
{
if (!dso)
return strlen("[unknown]");
if (verbose)
return dso->long_name_len;
return dso->short_name_len;
}
bool dso__loaded(const struct dso *dso, enum map_type type)
{
return dso->loaded & (1 << type);
}
bool dso__sorted_by_name(const struct dso *dso, enum map_type type)
{
return dso->sorted_by_name & (1 << type);
}
void dso__set_sorted_by_name(struct dso *dso, enum map_type type)
{
dso->sorted_by_name |= (1 << type);
}
struct dso *dso__new(const char *name)
{
struct dso *dso = calloc(1, sizeof(*dso) + strlen(name) + 1);
if (dso != NULL) {
int i;
strcpy(dso->name, name);
dso__set_long_name(dso, dso->name, false);
dso__set_short_name(dso, dso->name, false);
for (i = 0; i < MAP__NR_TYPES; ++i)
dso->symbols[i] = dso->symbol_names[i] = RB_ROOT;
dso->data.cache = 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_TYPE_USER;
dso->needs_swap = DSO_SWAP__UNSET;
RB_CLEAR_NODE(&dso->rb_node);
dso->root = NULL;
INIT_LIST_HEAD(&dso->node);
INIT_LIST_HEAD(&dso->data.open_entry);
pthread_mutex_init(&dso->lock, NULL);
atomic_set(&dso->refcnt, 1);
}
return dso;
}
void dso__delete(struct dso *dso)
{
int i;
if (!RB_EMPTY_NODE(&dso->rb_node))
pr_err("DSO %s is still in rbtree when being deleted!\n",
dso->long_name);
for (i = 0; i < MAP__NR_TYPES; ++i)
symbols__delete(&dso->symbols[i]);
if (dso->short_name_allocated) {
zfree((char **)&dso->short_name);
dso->short_name_allocated = false;
}
if (dso->long_name_allocated) {
zfree((char **)&dso->long_name);
dso->long_name_allocated = false;
}
dso__data_close(dso);
auxtrace_cache__free(dso->auxtrace_cache);
dso_cache__free(dso);
dso__free_a2l(dso);
zfree(&dso->symsrc_filename);
pthread_mutex_destroy(&dso->lock);
free(dso);
}
struct dso *dso__get(struct dso *dso)
{
if (dso)
atomic_inc(&dso->refcnt);
return dso;
}
void dso__put(struct dso *dso)
{
if (dso && atomic_dec_and_test(&dso->refcnt))
dso__delete(dso);
}
void dso__set_build_id(struct dso *dso, void *build_id)
{
memcpy(dso->build_id, build_id, sizeof(dso->build_id));
dso->has_build_id = 1;
}
bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
{
return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 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->build_id,
sizeof(dso->build_id)) == 0)
dso->has_build_id = true;
}
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 + 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->build_id,
sizeof(dso->build_id)) == 0)
dso->has_build_id = true;
return 0;
}
bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
{
bool have_build_id = false;
struct dso *pos;
list_for_each_entry(pos, head, node) {
if (with_hits && !pos->hit && !dso__is_vdso(pos))
continue;
if (pos->has_build_id) {
have_build_id = true;
continue;
}
if (filename__read_build_id(pos->long_name, pos->build_id,
sizeof(pos->build_id)) > 0) {
have_build_id = true;
pos->has_build_id = true;
}
}
return have_build_id;
}
void __dsos__add(struct dsos *dsos, struct dso *dso)
{
list_add_tail(&dso->node, &dsos->head);
__dso__findlink_by_longname(&dsos->root, dso, NULL);
/*
* It is now in the linked list, grab a reference, then garbage collect
* this when needing memory, by looking at LRU dso instances in the
* list with atomic_read(&dso->refcnt) == 1, i.e. no references
* anywhere besides the one for the list, do, under a lock for the
* list: remove it from the list, then a dso__put(), that probably will
* be the last and will then call dso__delete(), end of life.
*
* That, or at the end of the 'struct machine' lifetime, when all
* 'struct dso' instances will be removed from the list, in
* dsos__exit(), if they have no other reference from some other data
* structure.
*
* E.g.: after processing a 'perf.data' file and storing references
* to objects instantiated while processing events, we will have
* references to the 'thread', 'map', 'dso' structs all from 'struct
* hist_entry' instances, but we may not need anything not referenced,
* so we might as well call machines__exit()/machines__delete() and
* garbage collect it.
*/
dso__get(dso);
}
void dsos__add(struct dsos *dsos, struct dso *dso)
{
pthread_rwlock_wrlock(&dsos->lock);
__dsos__add(dsos, dso);
pthread_rwlock_unlock(&dsos->lock);
}
struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
{
struct dso *pos;
if (cmp_short) {
list_for_each_entry(pos, &dsos->head, node)
if (strcmp(pos->short_name, name) == 0)
return pos;
return NULL;
}
return __dso__find_by_longname(&dsos->root, name);
}
struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
{
struct dso *dso;
pthread_rwlock_rdlock(&dsos->lock);
dso = __dsos__find(dsos, name, cmp_short);
pthread_rwlock_unlock(&dsos->lock);
return dso;
}
struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
{
struct dso *dso = dso__new(name);
if (dso != NULL) {
__dsos__add(dsos, dso);
dso__set_basename(dso);
/* Put dso here because __dsos_add already got it */
dso__put(dso);
}
return dso;
}
struct dso *__dsos__findnew(struct dsos *dsos, const char *name)
{
struct dso *dso = __dsos__find(dsos, name, false);
return dso ? dso : __dsos__addnew(dsos, name);
}
struct dso *dsos__findnew(struct dsos *dsos, const char *name)
{
struct dso *dso;
pthread_rwlock_wrlock(&dsos->lock);
dso = dso__get(__dsos__findnew(dsos, name));
pthread_rwlock_unlock(&dsos->lock);
return dso;
}
size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
bool (skip)(struct dso *dso, int parm), int parm)
{
struct dso *pos;
size_t ret = 0;
list_for_each_entry(pos, head, node) {
if (skip && skip(pos, parm))
continue;
ret += dso__fprintf_buildid(pos, fp);
ret += fprintf(fp, " %s\n", pos->long_name);
}
return ret;
}
size_t __dsos__fprintf(struct list_head *head, FILE *fp)
{
struct dso *pos;
size_t ret = 0;
list_for_each_entry(pos, head, node) {
int i;
for (i = 0; i < MAP__NR_TYPES; ++i)
ret += dso__fprintf(pos, i, fp);
}
return ret;
}
size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
{
char sbuild_id[SBUILD_ID_SIZE];
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
return fprintf(fp, "%s", sbuild_id);
}
size_t dso__fprintf(struct dso *dso, enum map_type type, FILE *fp)
{
struct rb_node *nd;
size_t ret = fprintf(fp, "dso: %s (", dso->short_name);
if (dso->short_name != dso->long_name)
ret += fprintf(fp, "%s, ", dso->long_name);
ret += fprintf(fp, "%s, %sloaded, ", map_type__name[type],
dso__loaded(dso, type) ? "" : "NOT ");
ret += dso__fprintf_buildid(dso, fp);
ret += fprintf(fp, ")\n");
for (nd = rb_first(&dso->symbols[type]); 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;
/*
* 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;
}