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linux/tools/perf/util/symbol.c
Namhyung Kim 98e9f03bbf perf symbols: Destroy unused symsrcs 
Stephane reported that perf report and annotate failed to process data
using lots of (> 500) shared libraries.  It was because of the limit on
number of open files (ulimit -n).

Currently when perf loads a DSO, it'll look for normal and dynamic
symbol tables.  And if it fails to find out both tables, it'll iterate
all of possible symtab types.  But many of them are useless since they
have no additional information and the problem is that it's not closing
those files even though they're not used.  Fix it.

Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1392859976-32760-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-02-24 11:13:08 -03:00

1837 lines
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#include <dirent.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>
#include <unistd.h>
#include <inttypes.h>
#include "build-id.h"
#include "util.h"
#include "debug.h"
#include "machine.h"
#include "symbol.h"
#include "strlist.h"
#include <elf.h>
#include <limits.h>
#include <symbol/kallsyms.h>
#include <sys/utsname.h>
static int dso__load_kernel_sym(struct dso *dso, struct map *map,
symbol_filter_t filter);
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
symbol_filter_t filter);
int vmlinux_path__nr_entries;
char **vmlinux_path;
struct symbol_conf symbol_conf = {
.use_modules = true,
.try_vmlinux_path = true,
.annotate_src = true,
.demangle = true,
.symfs = "",
};
static enum dso_binary_type binary_type_symtab[] = {
DSO_BINARY_TYPE__KALLSYMS,
DSO_BINARY_TYPE__GUEST_KALLSYMS,
DSO_BINARY_TYPE__JAVA_JIT,
DSO_BINARY_TYPE__DEBUGLINK,
DSO_BINARY_TYPE__BUILD_ID_CACHE,
DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
DSO_BINARY_TYPE__GUEST_KMODULE,
DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
DSO_BINARY_TYPE__NOT_FOUND,
};
#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
bool symbol_type__is_a(char symbol_type, enum map_type map_type)
{
symbol_type = toupper(symbol_type);
switch (map_type) {
case MAP__FUNCTION:
return symbol_type == 'T' || symbol_type == 'W';
case MAP__VARIABLE:
return symbol_type == 'D';
default:
return false;
}
}
static int prefix_underscores_count(const char *str)
{
const char *tail = str;
while (*tail == '_')
tail++;
return tail - str;
}
#define SYMBOL_A 0
#define SYMBOL_B 1
static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
{
s64 a;
s64 b;
size_t na, nb;
/* Prefer a symbol with non zero length */
a = syma->end - syma->start;
b = symb->end - symb->start;
if ((b == 0) && (a > 0))
return SYMBOL_A;
else if ((a == 0) && (b > 0))
return SYMBOL_B;
/* Prefer a non weak symbol over a weak one */
a = syma->binding == STB_WEAK;
b = symb->binding == STB_WEAK;
if (b && !a)
return SYMBOL_A;
if (a && !b)
return SYMBOL_B;
/* Prefer a global symbol over a non global one */
a = syma->binding == STB_GLOBAL;
b = symb->binding == STB_GLOBAL;
if (a && !b)
return SYMBOL_A;
if (b && !a)
return SYMBOL_B;
/* Prefer a symbol with less underscores */
a = prefix_underscores_count(syma->name);
b = prefix_underscores_count(symb->name);
if (b > a)
return SYMBOL_A;
else if (a > b)
return SYMBOL_B;
/* Choose the symbol with the longest name */
na = strlen(syma->name);
nb = strlen(symb->name);
if (na > nb)
return SYMBOL_A;
else if (na < nb)
return SYMBOL_B;
/* Avoid "SyS" kernel syscall aliases */
if (na >= 3 && !strncmp(syma->name, "SyS", 3))
return SYMBOL_B;
if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
return SYMBOL_B;
return SYMBOL_A;
}
void symbols__fixup_duplicate(struct rb_root *symbols)
{
struct rb_node *nd;
struct symbol *curr, *next;
nd = rb_first(symbols);
while (nd) {
curr = rb_entry(nd, struct symbol, rb_node);
again:
nd = rb_next(&curr->rb_node);
next = rb_entry(nd, struct symbol, rb_node);
if (!nd)
break;
if (curr->start != next->start)
continue;
if (choose_best_symbol(curr, next) == SYMBOL_A) {
rb_erase(&next->rb_node, symbols);
symbol__delete(next);
goto again;
} else {
nd = rb_next(&curr->rb_node);
rb_erase(&curr->rb_node, symbols);
symbol__delete(curr);
}
}
}
void symbols__fixup_end(struct rb_root *symbols)
{
struct rb_node *nd, *prevnd = rb_first(symbols);
struct symbol *curr, *prev;
if (prevnd == NULL)
return;
curr = rb_entry(prevnd, struct symbol, rb_node);
for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
prev = curr;
curr = rb_entry(nd, struct symbol, rb_node);
if (prev->end == prev->start && prev->end != curr->start)
prev->end = curr->start - 1;
}
/* Last entry */
if (curr->end == curr->start)
curr->end = roundup(curr->start, 4096);
}
void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
{
struct map *prev, *curr;
struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
if (prevnd == NULL)
return;
curr = rb_entry(prevnd, struct map, rb_node);
for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
prev = curr;
curr = rb_entry(nd, struct map, rb_node);
prev->end = curr->start - 1;
}
/*
* We still haven't the actual symbols, so guess the
* last map final address.
*/
curr->end = ~0ULL;
}
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
{
size_t namelen = strlen(name) + 1;
struct symbol *sym = calloc(1, (symbol_conf.priv_size +
sizeof(*sym) + namelen));
if (sym == NULL)
return NULL;
if (symbol_conf.priv_size)
sym = ((void *)sym) + symbol_conf.priv_size;
sym->start = start;
sym->end = len ? start + len - 1 : start;
sym->binding = binding;
sym->namelen = namelen - 1;
pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
__func__, name, start, sym->end);
memcpy(sym->name, name, namelen);
return sym;
}
void symbol__delete(struct symbol *sym)
{
free(((void *)sym) - symbol_conf.priv_size);
}
size_t symbol__fprintf(struct symbol *sym, FILE *fp)
{
return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
sym->start, sym->end,
sym->binding == STB_GLOBAL ? 'g' :
sym->binding == STB_LOCAL ? 'l' : 'w',
sym->name);
}
size_t symbol__fprintf_symname_offs(const struct symbol *sym,
const struct addr_location *al, FILE *fp)
{
unsigned long offset;
size_t length;
if (sym && sym->name) {
length = fprintf(fp, "%s", sym->name);
if (al) {
if (al->addr < sym->end)
offset = al->addr - sym->start;
else
offset = al->addr - al->map->start - sym->start;
length += fprintf(fp, "+0x%lx", offset);
}
return length;
} else
return fprintf(fp, "[unknown]");
}
size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
{
return symbol__fprintf_symname_offs(sym, NULL, fp);
}
void symbols__delete(struct rb_root *symbols)
{
struct symbol *pos;
struct rb_node *next = rb_first(symbols);
while (next) {
pos = rb_entry(next, struct symbol, rb_node);
next = rb_next(&pos->rb_node);
rb_erase(&pos->rb_node, symbols);
symbol__delete(pos);
}
}
void symbols__insert(struct rb_root *symbols, struct symbol *sym)
{
struct rb_node **p = &symbols->rb_node;
struct rb_node *parent = NULL;
const u64 ip = sym->start;
struct symbol *s;
while (*p != NULL) {
parent = *p;
s = rb_entry(parent, struct symbol, rb_node);
if (ip < s->start)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&sym->rb_node, parent, p);
rb_insert_color(&sym->rb_node, symbols);
}
static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
{
struct rb_node *n;
if (symbols == NULL)
return NULL;
n = symbols->rb_node;
while (n) {
struct symbol *s = rb_entry(n, struct symbol, rb_node);
if (ip < s->start)
n = n->rb_left;
else if (ip > s->end)
n = n->rb_right;
else
return s;
}
return NULL;
}
static struct symbol *symbols__first(struct rb_root *symbols)
{
struct rb_node *n = rb_first(symbols);
if (n)
return rb_entry(n, struct symbol, rb_node);
return NULL;
}
struct symbol_name_rb_node {
struct rb_node rb_node;
struct symbol sym;
};
static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
{
struct rb_node **p = &symbols->rb_node;
struct rb_node *parent = NULL;
struct symbol_name_rb_node *symn, *s;
symn = container_of(sym, struct symbol_name_rb_node, sym);
while (*p != NULL) {
parent = *p;
s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
if (strcmp(sym->name, s->sym.name) < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&symn->rb_node, parent, p);
rb_insert_color(&symn->rb_node, symbols);
}
static void symbols__sort_by_name(struct rb_root *symbols,
struct rb_root *source)
{
struct rb_node *nd;
for (nd = rb_first(source); nd; nd = rb_next(nd)) {
struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
symbols__insert_by_name(symbols, pos);
}
}
static struct symbol *symbols__find_by_name(struct rb_root *symbols,
const char *name)
{
struct rb_node *n;
if (symbols == NULL)
return NULL;
n = symbols->rb_node;
while (n) {
struct symbol_name_rb_node *s;
int cmp;
s = rb_entry(n, struct symbol_name_rb_node, rb_node);
cmp = strcmp(name, s->sym.name);
if (cmp < 0)
n = n->rb_left;
else if (cmp > 0)
n = n->rb_right;
else
return &s->sym;
}
return NULL;
}
struct symbol *dso__find_symbol(struct dso *dso,
enum map_type type, u64 addr)
{
return symbols__find(&dso->symbols[type], addr);
}
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
{
return symbols__first(&dso->symbols[type]);
}
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
const char *name)
{
return symbols__find_by_name(&dso->symbol_names[type], name);
}
void dso__sort_by_name(struct dso *dso, enum map_type type)
{
dso__set_sorted_by_name(dso, type);
return symbols__sort_by_name(&dso->symbol_names[type],
&dso->symbols[type]);
}
size_t dso__fprintf_symbols_by_name(struct dso *dso,
enum map_type type, FILE *fp)
{
size_t ret = 0;
struct rb_node *nd;
struct symbol_name_rb_node *pos;
for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
fprintf(fp, "%s\n", pos->sym.name);
}
return ret;
}
int modules__parse(const char *filename, void *arg,
int (*process_module)(void *arg, const char *name,
u64 start))
{
char *line = NULL;
size_t n;
FILE *file;
int err = 0;
file = fopen(filename, "r");
if (file == NULL)
return -1;
while (1) {
char name[PATH_MAX];
u64 start;
char *sep;
ssize_t line_len;
line_len = getline(&line, &n, file);
if (line_len < 0) {
if (feof(file))
break;
err = -1;
goto out;
}
if (!line) {
err = -1;
goto out;
}
line[--line_len] = '\0'; /* \n */
sep = strrchr(line, 'x');
if (sep == NULL)
continue;
hex2u64(sep + 1, &start);
sep = strchr(line, ' ');
if (sep == NULL)
continue;
*sep = '\0';
scnprintf(name, sizeof(name), "[%s]", line);
err = process_module(arg, name, start);
if (err)
break;
}
out:
free(line);
fclose(file);
return err;
}
struct process_kallsyms_args {
struct map *map;
struct dso *dso;
};
bool symbol__is_idle(struct symbol *sym)
{
const char * const idle_symbols[] = {
"cpu_idle",
"intel_idle",
"default_idle",
"native_safe_halt",
"enter_idle",
"exit_idle",
"mwait_idle",
"mwait_idle_with_hints",
"poll_idle",
"ppc64_runlatch_off",
"pseries_dedicated_idle_sleep",
NULL
};
int i;
if (!sym)
return false;
for (i = 0; idle_symbols[i]; i++) {
if (!strcmp(idle_symbols[i], sym->name))
return true;
}
return false;
}
static int map__process_kallsym_symbol(void *arg, const char *name,
char type, u64 start)
{
struct symbol *sym;
struct process_kallsyms_args *a = arg;
struct rb_root *root = &a->dso->symbols[a->map->type];
if (!symbol_type__is_a(type, a->map->type))
return 0;
/*
* module symbols are not sorted so we add all
* symbols, setting length to 0, and rely on
* symbols__fixup_end() to fix it up.
*/
sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
if (sym == NULL)
return -ENOMEM;
/*
* We will pass the symbols to the filter later, in
* map__split_kallsyms, when we have split the maps per module
*/
symbols__insert(root, sym);
return 0;
}
/*
* Loads the function entries in /proc/kallsyms into kernel_map->dso,
* so that we can in the next step set the symbol ->end address and then
* call kernel_maps__split_kallsyms.
*/
static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
struct map *map)
{
struct process_kallsyms_args args = { .map = map, .dso = dso, };
return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
}
static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
struct map *curr_map;
struct symbol *pos;
int count = 0, moved = 0;
struct rb_root *root = &dso->symbols[map->type];
struct rb_node *next = rb_first(root);
while (next) {
char *module;
pos = rb_entry(next, struct symbol, rb_node);
next = rb_next(&pos->rb_node);
module = strchr(pos->name, '\t');
if (module)
*module = '\0';
curr_map = map_groups__find(kmaps, map->type, pos->start);
if (!curr_map || (filter && filter(curr_map, pos))) {
rb_erase(&pos->rb_node, root);
symbol__delete(pos);
} else {
pos->start -= curr_map->start - curr_map->pgoff;
if (pos->end)
pos->end -= curr_map->start - curr_map->pgoff;
if (curr_map != map) {
rb_erase(&pos->rb_node, root);
symbols__insert(
&curr_map->dso->symbols[curr_map->type],
pos);
++moved;
} else {
++count;
}
}
}
/* Symbols have been adjusted */
dso->adjust_symbols = 1;
return count + moved;
}
/*
* Split the symbols into maps, making sure there are no overlaps, i.e. the
* kernel range is broken in several maps, named [kernel].N, as we don't have
* the original ELF section names vmlinux have.
*/
static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
symbol_filter_t filter)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
struct machine *machine = kmaps->machine;
struct map *curr_map = map;
struct symbol *pos;
int count = 0, moved = 0;
struct rb_root *root = &dso->symbols[map->type];
struct rb_node *next = rb_first(root);
int kernel_range = 0;
while (next) {
char *module;
pos = rb_entry(next, struct symbol, rb_node);
next = rb_next(&pos->rb_node);
module = strchr(pos->name, '\t');
if (module) {
if (!symbol_conf.use_modules)
goto discard_symbol;
*module++ = '\0';
if (strcmp(curr_map->dso->short_name, module)) {
if (curr_map != map &&
dso->kernel == DSO_TYPE_GUEST_KERNEL &&
machine__is_default_guest(machine)) {
/*
* We assume all symbols of a module are
* continuous in * kallsyms, so curr_map
* points to a module and all its
* symbols are in its kmap. Mark it as
* loaded.
*/
dso__set_loaded(curr_map->dso,
curr_map->type);
}
curr_map = map_groups__find_by_name(kmaps,
map->type, module);
if (curr_map == NULL) {
pr_debug("%s/proc/{kallsyms,modules} "
"inconsistency while looking "
"for \"%s\" module!\n",
machine->root_dir, module);
curr_map = map;
goto discard_symbol;
}
if (curr_map->dso->loaded &&
!machine__is_default_guest(machine))
goto discard_symbol;
}
/*
* So that we look just like we get from .ko files,
* i.e. not prelinked, relative to map->start.
*/
pos->start = curr_map->map_ip(curr_map, pos->start);
pos->end = curr_map->map_ip(curr_map, pos->end);
} else if (curr_map != map) {
char dso_name[PATH_MAX];
struct dso *ndso;
if (delta) {
/* Kernel was relocated at boot time */
pos->start -= delta;
pos->end -= delta;
}
if (count == 0) {
curr_map = map;
goto filter_symbol;
}
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
snprintf(dso_name, sizeof(dso_name),
"[guest.kernel].%d",
kernel_range++);
else
snprintf(dso_name, sizeof(dso_name),
"[kernel].%d",
kernel_range++);
ndso = dso__new(dso_name);
if (ndso == NULL)
return -1;
ndso->kernel = dso->kernel;
curr_map = map__new2(pos->start, ndso, map->type);
if (curr_map == NULL) {
dso__delete(ndso);
return -1;
}
curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
map_groups__insert(kmaps, curr_map);
++kernel_range;
} else if (delta) {
/* Kernel was relocated at boot time */
pos->start -= delta;
pos->end -= delta;
}
filter_symbol:
if (filter && filter(curr_map, pos)) {
discard_symbol: rb_erase(&pos->rb_node, root);
symbol__delete(pos);
} else {
if (curr_map != map) {
rb_erase(&pos->rb_node, root);
symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
++moved;
} else
++count;
}
}
if (curr_map != map &&
dso->kernel == DSO_TYPE_GUEST_KERNEL &&
machine__is_default_guest(kmaps->machine)) {
dso__set_loaded(curr_map->dso, curr_map->type);
}
return count + moved;
}
bool symbol__restricted_filename(const char *filename,
const char *restricted_filename)
{
bool restricted = false;
if (symbol_conf.kptr_restrict) {
char *r = realpath(filename, NULL);
if (r != NULL) {
restricted = strcmp(r, restricted_filename) == 0;
free(r);
return restricted;
}
}
return restricted;
}
struct module_info {
struct rb_node rb_node;
char *name;
u64 start;
};
static void add_module(struct module_info *mi, struct rb_root *modules)
{
struct rb_node **p = &modules->rb_node;
struct rb_node *parent = NULL;
struct module_info *m;
while (*p != NULL) {
parent = *p;
m = rb_entry(parent, struct module_info, rb_node);
if (strcmp(mi->name, m->name) < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&mi->rb_node, parent, p);
rb_insert_color(&mi->rb_node, modules);
}
static void delete_modules(struct rb_root *modules)
{
struct module_info *mi;
struct rb_node *next = rb_first(modules);
while (next) {
mi = rb_entry(next, struct module_info, rb_node);
next = rb_next(&mi->rb_node);
rb_erase(&mi->rb_node, modules);
zfree(&mi->name);
free(mi);
}
}
static struct module_info *find_module(const char *name,
struct rb_root *modules)
{
struct rb_node *n = modules->rb_node;
while (n) {
struct module_info *m;
int cmp;
m = rb_entry(n, struct module_info, rb_node);
cmp = strcmp(name, m->name);
if (cmp < 0)
n = n->rb_left;
else if (cmp > 0)
n = n->rb_right;
else
return m;
}
return NULL;
}
static int __read_proc_modules(void *arg, const char *name, u64 start)
{
struct rb_root *modules = arg;
struct module_info *mi;
mi = zalloc(sizeof(struct module_info));
if (!mi)
return -ENOMEM;
mi->name = strdup(name);
mi->start = start;
if (!mi->name) {
free(mi);
return -ENOMEM;
}
add_module(mi, modules);
return 0;
}
static int read_proc_modules(const char *filename, struct rb_root *modules)
{
if (symbol__restricted_filename(filename, "/proc/modules"))
return -1;
if (modules__parse(filename, modules, __read_proc_modules)) {
delete_modules(modules);
return -1;
}
return 0;
}
int compare_proc_modules(const char *from, const char *to)
{
struct rb_root from_modules = RB_ROOT;
struct rb_root to_modules = RB_ROOT;
struct rb_node *from_node, *to_node;
struct module_info *from_m, *to_m;
int ret = -1;
if (read_proc_modules(from, &from_modules))
return -1;
if (read_proc_modules(to, &to_modules))
goto out_delete_from;
from_node = rb_first(&from_modules);
to_node = rb_first(&to_modules);
while (from_node) {
if (!to_node)
break;
from_m = rb_entry(from_node, struct module_info, rb_node);
to_m = rb_entry(to_node, struct module_info, rb_node);
if (from_m->start != to_m->start ||
strcmp(from_m->name, to_m->name))
break;
from_node = rb_next(from_node);
to_node = rb_next(to_node);
}
if (!from_node && !to_node)
ret = 0;
delete_modules(&to_modules);
out_delete_from:
delete_modules(&from_modules);
return ret;
}
static int do_validate_kcore_modules(const char *filename, struct map *map,
struct map_groups *kmaps)
{
struct rb_root modules = RB_ROOT;
struct map *old_map;
int err;
err = read_proc_modules(filename, &modules);
if (err)
return err;
old_map = map_groups__first(kmaps, map->type);
while (old_map) {
struct map *next = map_groups__next(old_map);
struct module_info *mi;
if (old_map == map || old_map->start == map->start) {
/* The kernel map */
old_map = next;
continue;
}
/* Module must be in memory at the same address */
mi = find_module(old_map->dso->short_name, &modules);
if (!mi || mi->start != old_map->start) {
err = -EINVAL;
goto out;
}
old_map = next;
}
out:
delete_modules(&modules);
return err;
}
/*
* If kallsyms is referenced by name then we look for filename in the same
* directory.
*/
static bool filename_from_kallsyms_filename(char *filename,
const char *base_name,
const char *kallsyms_filename)
{
char *name;
strcpy(filename, kallsyms_filename);
name = strrchr(filename, '/');
if (!name)
return false;
name += 1;
if (!strcmp(name, "kallsyms")) {
strcpy(name, base_name);
return true;
}
return false;
}
static int validate_kcore_modules(const char *kallsyms_filename,
struct map *map)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
char modules_filename[PATH_MAX];
if (!filename_from_kallsyms_filename(modules_filename, "modules",
kallsyms_filename))
return -EINVAL;
if (do_validate_kcore_modules(modules_filename, map, kmaps))
return -EINVAL;
return 0;
}
static int validate_kcore_addresses(const char *kallsyms_filename,
struct map *map)
{
struct kmap *kmap = map__kmap(map);
if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
u64 start;
start = kallsyms__get_function_start(kallsyms_filename,
kmap->ref_reloc_sym->name);
if (start != kmap->ref_reloc_sym->addr)
return -EINVAL;
}
return validate_kcore_modules(kallsyms_filename, map);
}
struct kcore_mapfn_data {
struct dso *dso;
enum map_type type;
struct list_head maps;
};
static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
{
struct kcore_mapfn_data *md = data;
struct map *map;
map = map__new2(start, md->dso, md->type);
if (map == NULL)
return -ENOMEM;
map->end = map->start + len;
map->pgoff = pgoff;
list_add(&map->node, &md->maps);
return 0;
}
static int dso__load_kcore(struct dso *dso, struct map *map,
const char *kallsyms_filename)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
struct machine *machine = kmaps->machine;
struct kcore_mapfn_data md;
struct map *old_map, *new_map, *replacement_map = NULL;
bool is_64_bit;
int err, fd;
char kcore_filename[PATH_MAX];
struct symbol *sym;
/* This function requires that the map is the kernel map */
if (map != machine->vmlinux_maps[map->type])
return -EINVAL;
if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
kallsyms_filename))
return -EINVAL;
/* Modules and kernel must be present at their original addresses */
if (validate_kcore_addresses(kallsyms_filename, map))
return -EINVAL;
md.dso = dso;
md.type = map->type;
INIT_LIST_HEAD(&md.maps);
fd = open(kcore_filename, O_RDONLY);
if (fd < 0)
return -EINVAL;
/* Read new maps into temporary lists */
err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
&is_64_bit);
if (err)
goto out_err;
if (list_empty(&md.maps)) {
err = -EINVAL;
goto out_err;
}
/* Remove old maps */
old_map = map_groups__first(kmaps, map->type);
while (old_map) {
struct map *next = map_groups__next(old_map);
if (old_map != map)
map_groups__remove(kmaps, old_map);
old_map = next;
}
/* Find the kernel map using the first symbol */
sym = dso__first_symbol(dso, map->type);
list_for_each_entry(new_map, &md.maps, node) {
if (sym && sym->start >= new_map->start &&
sym->start < new_map->end) {
replacement_map = new_map;
break;
}
}
if (!replacement_map)
replacement_map = list_entry(md.maps.next, struct map, node);
/* Add new maps */
while (!list_empty(&md.maps)) {
new_map = list_entry(md.maps.next, struct map, node);
list_del(&new_map->node);
if (new_map == replacement_map) {
map->start = new_map->start;
map->end = new_map->end;
map->pgoff = new_map->pgoff;
map->map_ip = new_map->map_ip;
map->unmap_ip = new_map->unmap_ip;
map__delete(new_map);
/* Ensure maps are correctly ordered */
map_groups__remove(kmaps, map);
map_groups__insert(kmaps, map);
} else {
map_groups__insert(kmaps, new_map);
}
}
/*
* Set the data type and long name so that kcore can be read via
* dso__data_read_addr().
*/
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
else
dso->binary_type = DSO_BINARY_TYPE__KCORE;
dso__set_long_name(dso, strdup(kcore_filename), true);
close(fd);
if (map->type == MAP__FUNCTION)
pr_debug("Using %s for kernel object code\n", kcore_filename);
else
pr_debug("Using %s for kernel data\n", kcore_filename);
return 0;
out_err:
while (!list_empty(&md.maps)) {
map = list_entry(md.maps.next, struct map, node);
list_del(&map->node);
map__delete(map);
}
close(fd);
return -EINVAL;
}
/*
* If the kernel is relocated at boot time, kallsyms won't match. Compute the
* delta based on the relocation reference symbol.
*/
static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
{
struct kmap *kmap = map__kmap(map);
u64 addr;
if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
return 0;
addr = kallsyms__get_function_start(filename,
kmap->ref_reloc_sym->name);
if (!addr)
return -1;
*delta = addr - kmap->ref_reloc_sym->addr;
return 0;
}
int dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map, symbol_filter_t filter)
{
u64 delta = 0;
if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return -1;
if (dso__load_all_kallsyms(dso, filename, map) < 0)
return -1;
if (kallsyms__delta(map, filename, &delta))
return -1;
symbols__fixup_duplicate(&dso->symbols[map->type]);
symbols__fixup_end(&dso->symbols[map->type]);
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
else
dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
if (!dso__load_kcore(dso, map, filename))
return dso__split_kallsyms_for_kcore(dso, map, filter);
else
return dso__split_kallsyms(dso, map, delta, filter);
}
static int dso__load_perf_map(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
char *line = NULL;
size_t n;
FILE *file;
int nr_syms = 0;
file = fopen(dso->long_name, "r");
if (file == NULL)
goto out_failure;
while (!feof(file)) {
u64 start, size;
struct symbol *sym;
int line_len, len;
line_len = getline(&line, &n, file);
if (line_len < 0)
break;
if (!line)
goto out_failure;
line[--line_len] = '\0'; /* \n */
len = hex2u64(line, &start);
len++;
if (len + 2 >= line_len)
continue;
len += hex2u64(line + len, &size);
len++;
if (len + 2 >= line_len)
continue;
sym = symbol__new(start, size, STB_GLOBAL, line + len);
if (sym == NULL)
goto out_delete_line;
if (filter && filter(map, sym))
symbol__delete(sym);
else {
symbols__insert(&dso->symbols[map->type], sym);
nr_syms++;
}
}
free(line);
fclose(file);
return nr_syms;
out_delete_line:
free(line);
out_failure:
return -1;
}
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
{
char *name;
int ret = -1;
u_int i;
struct machine *machine;
char *root_dir = (char *) "";
int ss_pos = 0;
struct symsrc ss_[2];
struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
dso__set_loaded(dso, map->type);
if (dso->kernel == DSO_TYPE_KERNEL)
return dso__load_kernel_sym(dso, map, filter);
else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
return dso__load_guest_kernel_sym(dso, map, filter);
if (map->groups && map->groups->machine)
machine = map->groups->machine;
else
machine = NULL;
dso->adjust_symbols = 0;
if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
struct stat st;
if (lstat(dso->name, &st) < 0)
return -1;
if (st.st_uid && (st.st_uid != geteuid())) {
pr_warning("File %s not owned by current user or root, "
"ignoring it.\n", dso->name);
return -1;
}
ret = dso__load_perf_map(dso, map, filter);
dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
DSO_BINARY_TYPE__NOT_FOUND;
return ret;
}
if (machine)
root_dir = machine->root_dir;
name = malloc(PATH_MAX);
if (!name)
return -1;
/* Iterate over candidate debug images.
* Keep track of "interesting" ones (those which have a symtab, dynsym,
* and/or opd section) for processing.
*/
for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
struct symsrc *ss = &ss_[ss_pos];
bool next_slot = false;
enum dso_binary_type symtab_type = binary_type_symtab[i];
if (dso__read_binary_type_filename(dso, symtab_type,
root_dir, name, PATH_MAX))
continue;
/* Name is now the name of the next image to try */
if (symsrc__init(ss, dso, name, symtab_type) < 0)
continue;
if (!syms_ss && symsrc__has_symtab(ss)) {
syms_ss = ss;
next_slot = true;
if (!dso->symsrc_filename)
dso->symsrc_filename = strdup(name);
}
if (!runtime_ss && symsrc__possibly_runtime(ss)) {
runtime_ss = ss;
next_slot = true;
}
if (next_slot) {
ss_pos++;
if (syms_ss && runtime_ss)
break;
} else {
symsrc__destroy(ss);
}
}
if (!runtime_ss && !syms_ss)
goto out_free;
if (runtime_ss && !syms_ss) {
syms_ss = runtime_ss;
}
/* We'll have to hope for the best */
if (!runtime_ss && syms_ss)
runtime_ss = syms_ss;
if (syms_ss) {
int km;
km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
} else {
ret = -1;
}
if (ret > 0) {
int nr_plt;
nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
if (nr_plt > 0)
ret += nr_plt;
}
for (; ss_pos > 0; ss_pos--)
symsrc__destroy(&ss_[ss_pos - 1]);
out_free:
free(name);
if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
return 0;
return ret;
}
struct map *map_groups__find_by_name(struct map_groups *mg,
enum map_type type, const char *name)
{
struct rb_node *nd;
for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
struct map *map = rb_entry(nd, struct map, rb_node);
if (map->dso && strcmp(map->dso->short_name, name) == 0)
return map;
}
return NULL;
}
int dso__load_vmlinux(struct dso *dso, struct map *map,
const char *vmlinux, bool vmlinux_allocated,
symbol_filter_t filter)
{
int err = -1;
struct symsrc ss;
char symfs_vmlinux[PATH_MAX];
enum dso_binary_type symtab_type;
if (vmlinux[0] == '/')
snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
else
snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
symbol_conf.symfs, vmlinux);
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
else
symtab_type = DSO_BINARY_TYPE__VMLINUX;
if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
return -1;
err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
symsrc__destroy(&ss);
if (err > 0) {
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
else
dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
dso__set_long_name(dso, vmlinux, vmlinux_allocated);
dso__set_loaded(dso, map->type);
pr_debug("Using %s for symbols\n", symfs_vmlinux);
}
return err;
}
int dso__load_vmlinux_path(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
int i, err = 0;
char *filename;
pr_debug("Looking at the vmlinux_path (%d entries long)\n",
vmlinux_path__nr_entries + 1);
filename = dso__build_id_filename(dso, NULL, 0);
if (filename != NULL) {
err = dso__load_vmlinux(dso, map, filename, true, filter);
if (err > 0)
goto out;
free(filename);
}
for (i = 0; i < vmlinux_path__nr_entries; ++i) {
err = dso__load_vmlinux(dso, map, vmlinux_path[i], false, filter);
if (err > 0)
break;
}
out:
return err;
}
static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
{
char kallsyms_filename[PATH_MAX];
struct dirent *dent;
int ret = -1;
DIR *d;
d = opendir(dir);
if (!d)
return -1;
while (1) {
dent = readdir(d);
if (!dent)
break;
if (dent->d_type != DT_DIR)
continue;
scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
"%s/%s/kallsyms", dir, dent->d_name);
if (!validate_kcore_addresses(kallsyms_filename, map)) {
strlcpy(dir, kallsyms_filename, dir_sz);
ret = 0;
break;
}
}
closedir(d);
return ret;
}
static char *dso__find_kallsyms(struct dso *dso, struct map *map)
{
u8 host_build_id[BUILD_ID_SIZE];
char sbuild_id[BUILD_ID_SIZE * 2 + 1];
bool is_host = false;
char path[PATH_MAX];
if (!dso->has_build_id) {
/*
* Last resort, if we don't have a build-id and couldn't find
* any vmlinux file, try the running kernel kallsyms table.
*/
goto proc_kallsyms;
}
if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
sizeof(host_build_id)) == 0)
is_host = dso__build_id_equal(dso, host_build_id);
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
sbuild_id);
/* Use /proc/kallsyms if possible */
if (is_host) {
DIR *d;
int fd;
/* If no cached kcore go with /proc/kallsyms */
d = opendir(path);
if (!d)
goto proc_kallsyms;
closedir(d);
/*
* Do not check the build-id cache, until we know we cannot use
* /proc/kcore.
*/
fd = open("/proc/kcore", O_RDONLY);
if (fd != -1) {
close(fd);
/* If module maps match go with /proc/kallsyms */
if (!validate_kcore_addresses("/proc/kallsyms", map))
goto proc_kallsyms;
}
/* Find kallsyms in build-id cache with kcore */
if (!find_matching_kcore(map, path, sizeof(path)))
return strdup(path);
goto proc_kallsyms;
}
/* Find kallsyms in build-id cache with kcore */
if (!find_matching_kcore(map, path, sizeof(path)))
return strdup(path);
scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
buildid_dir, sbuild_id);
if (access(path, F_OK)) {
pr_err("No kallsyms or vmlinux with build-id %s was found\n",
sbuild_id);
return NULL;
}
return strdup(path);
proc_kallsyms:
return strdup("/proc/kallsyms");
}
static int dso__load_kernel_sym(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
int err;
const char *kallsyms_filename = NULL;
char *kallsyms_allocated_filename = NULL;
/*
* Step 1: if the user specified a kallsyms or vmlinux filename, use
* it and only it, reporting errors to the user if it cannot be used.
*
* For instance, try to analyse an ARM perf.data file _without_ a
* build-id, or if the user specifies the wrong path to the right
* vmlinux file, obviously we can't fallback to another vmlinux (a
* x86_86 one, on the machine where analysis is being performed, say),
* or worse, /proc/kallsyms.
*
* If the specified file _has_ a build-id and there is a build-id
* section in the perf.data file, we will still do the expected
* validation in dso__load_vmlinux and will bail out if they don't
* match.
*/
if (symbol_conf.kallsyms_name != NULL) {
kallsyms_filename = symbol_conf.kallsyms_name;
goto do_kallsyms;
}
if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name,
false, filter);
}
if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
err = dso__load_vmlinux_path(dso, map, filter);
if (err > 0)
return err;
}
/* do not try local files if a symfs was given */
if (symbol_conf.symfs[0] != 0)
return -1;
kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
if (!kallsyms_allocated_filename)
return -1;
kallsyms_filename = kallsyms_allocated_filename;
do_kallsyms:
err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
if (err > 0)
pr_debug("Using %s for symbols\n", kallsyms_filename);
free(kallsyms_allocated_filename);
if (err > 0 && !dso__is_kcore(dso)) {
dso__set_long_name(dso, "[kernel.kallsyms]", false);
map__fixup_start(map);
map__fixup_end(map);
}
return err;
}
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
int err;
const char *kallsyms_filename = NULL;
struct machine *machine;
char path[PATH_MAX];
if (!map->groups) {
pr_debug("Guest kernel map hasn't the point to groups\n");
return -1;
}
machine = map->groups->machine;
if (machine__is_default_guest(machine)) {
/*
* if the user specified a vmlinux filename, use it and only
* it, reporting errors to the user if it cannot be used.
* Or use file guest_kallsyms inputted by user on commandline
*/
if (symbol_conf.default_guest_vmlinux_name != NULL) {
err = dso__load_vmlinux(dso, map,
symbol_conf.default_guest_vmlinux_name,
false, filter);
return err;
}
kallsyms_filename = symbol_conf.default_guest_kallsyms;
if (!kallsyms_filename)
return -1;
} else {
sprintf(path, "%s/proc/kallsyms", machine->root_dir);
kallsyms_filename = path;
}
err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
if (err > 0)
pr_debug("Using %s for symbols\n", kallsyms_filename);
if (err > 0 && !dso__is_kcore(dso)) {
machine__mmap_name(machine, path, sizeof(path));
dso__set_long_name(dso, strdup(path), true);
map__fixup_start(map);
map__fixup_end(map);
}
return err;
}
static void vmlinux_path__exit(void)
{
while (--vmlinux_path__nr_entries >= 0)
zfree(&vmlinux_path[vmlinux_path__nr_entries]);
zfree(&vmlinux_path);
}
static int vmlinux_path__init(void)
{
struct utsname uts;
char bf[PATH_MAX];
vmlinux_path = malloc(sizeof(char *) * 5);
if (vmlinux_path == NULL)
return -1;
vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
goto out_fail;
++vmlinux_path__nr_entries;
vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
goto out_fail;
++vmlinux_path__nr_entries;
/* only try running kernel version if no symfs was given */
if (symbol_conf.symfs[0] != 0)
return 0;
if (uname(&uts) < 0)
return -1;
snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
goto out_fail;
++vmlinux_path__nr_entries;
snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
goto out_fail;
++vmlinux_path__nr_entries;
snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
uts.release);
vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
goto out_fail;
++vmlinux_path__nr_entries;
return 0;
out_fail:
vmlinux_path__exit();
return -1;
}
int setup_list(struct strlist **list, const char *list_str,
const char *list_name)
{
if (list_str == NULL)
return 0;
*list = strlist__new(true, list_str);
if (!*list) {
pr_err("problems parsing %s list\n", list_name);
return -1;
}
return 0;
}
static bool symbol__read_kptr_restrict(void)
{
bool value = false;
if (geteuid() != 0) {
FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
if (fp != NULL) {
char line[8];
if (fgets(line, sizeof(line), fp) != NULL)
value = atoi(line) != 0;
fclose(fp);
}
}
return value;
}
int symbol__init(void)
{
const char *symfs;
if (symbol_conf.initialized)
return 0;
symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
symbol__elf_init();
if (symbol_conf.sort_by_name)
symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
sizeof(struct symbol));
if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
return -1;
if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
pr_err("'.' is the only non valid --field-separator argument\n");
return -1;
}
if (setup_list(&symbol_conf.dso_list,
symbol_conf.dso_list_str, "dso") < 0)
return -1;
if (setup_list(&symbol_conf.comm_list,
symbol_conf.comm_list_str, "comm") < 0)
goto out_free_dso_list;
if (setup_list(&symbol_conf.sym_list,
symbol_conf.sym_list_str, "symbol") < 0)
goto out_free_comm_list;
/*
* A path to symbols of "/" is identical to ""
* reset here for simplicity.
*/
symfs = realpath(symbol_conf.symfs, NULL);
if (symfs == NULL)
symfs = symbol_conf.symfs;
if (strcmp(symfs, "/") == 0)
symbol_conf.symfs = "";
if (symfs != symbol_conf.symfs)
free((void *)symfs);
symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
symbol_conf.initialized = true;
return 0;
out_free_comm_list:
strlist__delete(symbol_conf.comm_list);
out_free_dso_list:
strlist__delete(symbol_conf.dso_list);
return -1;
}
void symbol__exit(void)
{
if (!symbol_conf.initialized)
return;
strlist__delete(symbol_conf.sym_list);
strlist__delete(symbol_conf.dso_list);
strlist__delete(symbol_conf.comm_list);
vmlinux_path__exit();
symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
symbol_conf.initialized = false;
}
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