swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 02f8c6aee8df3cdc935e9bdd4f2d020306035dbe authored by Linus Torvalds on 22 July 2011, 02:17:23 UTC
Linux 3.0
Linux 3.0
Tip revision: 02f8c6a
symbol.c
#define _GNU_SOURCE
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <libgen.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 "debug.h"
#include "symbol.h"
#include "strlist.h"
#include <libelf.h>
#include <gelf.h>
#include <elf.h>
#include <limits.h>
#include <sys/utsname.h>
#ifndef KSYM_NAME_LEN
#define KSYM_NAME_LEN 128
#endif
#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif
static bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
static int elf_read_build_id(Elf *elf, void *bf, size_t size);
static void dsos__add(struct list_head *head, struct dso *dso);
static struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
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);
static int vmlinux_path__nr_entries;
static char **vmlinux_path;
struct symbol_conf symbol_conf = {
.exclude_other = true,
.use_modules = true,
.try_vmlinux_path = true,
.symfs = "",
};
int dso__name_len(const struct dso *dso)
{
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);
}
static void dso__set_sorted_by_name(struct dso *dso, enum map_type type)
{
dso->sorted_by_name |= (1 << type);
}
bool symbol_type__is_a(char symbol_type, enum map_type map_type)
{
switch (map_type) {
case MAP__FUNCTION:
return symbol_type == 'T' || symbol_type == 'W';
case MAP__VARIABLE:
return symbol_type == 'D' || symbol_type == 'd';
default:
return false;
}
}
static 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);
}
static 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;
}
static void map_groups__fixup_end(struct map_groups *mg)
{
int i;
for (i = 0; i < MAP__NR_TYPES; ++i)
__map_groups__fixup_end(mg, i);
}
static 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);
}
static 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);
}
void dso__set_long_name(struct dso *dso, char *name)
{
if (name == NULL)
return;
dso->long_name = name;
dso->long_name_len = strlen(name);
}
static void dso__set_short_name(struct dso *dso, const char *name)
{
if (name == NULL)
return;
dso->short_name = name;
dso->short_name_len = strlen(name);
}
static void dso__set_basename(struct dso *dso)
{
dso__set_short_name(dso, basename(dso->long_name));
}
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);
dso__set_short_name(dso, dso->name);
for (i = 0; i < MAP__NR_TYPES; ++i)
dso->symbols[i] = dso->symbol_names[i] = RB_ROOT;
dso->symtab_type = SYMTAB__NOT_FOUND;
dso->loaded = 0;
dso->sorted_by_name = 0;
dso->has_build_id = 0;
dso->kernel = DSO_TYPE_USER;
INIT_LIST_HEAD(&dso->node);
}
return dso;
}
static 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 dso__delete(struct dso *dso)
{
int i;
for (i = 0; i < MAP__NR_TYPES; ++i)
symbols__delete(&dso->symbols[i]);
if (dso->sname_alloc)
free((char *)dso->short_name);
if (dso->lname_alloc)
free(dso->long_name);
free(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;
}
static 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;
}
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__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]);
}
int build_id__sprintf(const u8 *build_id, int len, char *bf)
{
char *bid = bf;
const u8 *raw = build_id;
int i;
for (i = 0; i < len; ++i) {
sprintf(bid, "%02x", *raw);
++raw;
bid += 2;
}
return raw - build_id;
}
size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
{
char sbuild_id[BUILD_ID_SIZE * 2 + 1];
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
return fprintf(fp, "%s", sbuild_id);
}
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;
}
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 ? "" : "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;
}
int kallsyms__parse(const char *filename, void *arg,
int (*process_symbol)(void *arg, const char *name,
char type, u64 start, u64 end))
{
char *line = NULL;
size_t n;
int err = -1;
u64 prev_start = 0;
char prev_symbol_type = 0;
char *prev_symbol_name;
FILE *file = fopen(filename, "r");
if (file == NULL)
goto out_failure;
prev_symbol_name = malloc(KSYM_NAME_LEN);
if (prev_symbol_name == NULL)
goto out_close;
err = 0;
while (!feof(file)) {
u64 start;
int line_len, len;
char symbol_type;
char *symbol_name;
line_len = getline(&line, &n, file);
if (line_len < 0 || !line)
break;
line[--line_len] = '\0'; /* \n */
len = hex2u64(line, &start);
len++;
if (len + 2 >= line_len)
continue;
symbol_type = toupper(line[len]);
len += 2;
symbol_name = line + len;
len = line_len - len;
if (len >= KSYM_NAME_LEN) {
err = -1;
break;
}
if (prev_symbol_type) {
u64 end = start;
if (end != prev_start)
--end;
err = process_symbol(arg, prev_symbol_name,
prev_symbol_type, prev_start, end);
if (err)
break;
}
memcpy(prev_symbol_name, symbol_name, len + 1);
prev_symbol_type = symbol_type;
prev_start = start;
}
free(prev_symbol_name);
free(line);
out_close:
fclose(file);
return err;
out_failure:
return -1;
}
struct process_kallsyms_args {
struct map *map;
struct dso *dso;
};
static u8 kallsyms2elf_type(char type)
{
if (type == 'W')
return STB_WEAK;
return isupper(type) ? STB_GLOBAL : STB_LOCAL;
}
static int map__process_kallsym_symbol(void *arg, const char *name,
char type, u64 start, u64 end)
{
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;
sym = symbol__new(start, end - start + 1,
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);
}
/*
* 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,
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 (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;
}
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;
}
static 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;
}
int dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map, symbol_filter_t filter)
{
if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return -1;
if (dso__load_all_kallsyms(dso, filename, map) < 0)
return -1;
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->symtab_type = SYMTAB__GUEST_KALLSYMS;
else
dso->symtab_type = SYMTAB__KALLSYMS;
return dso__split_kallsyms(dso, map, 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;
}
/**
* elf_symtab__for_each_symbol - iterate thru all the symbols
*
* @syms: struct elf_symtab instance to iterate
* @idx: uint32_t idx
* @sym: GElf_Sym iterator
*/
#define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
for (idx = 0, gelf_getsym(syms, idx, &sym);\
idx < nr_syms; \
idx++, gelf_getsym(syms, idx, &sym))
static inline uint8_t elf_sym__type(const GElf_Sym *sym)
{
return GELF_ST_TYPE(sym->st_info);
}
static inline int elf_sym__is_function(const GElf_Sym *sym)
{
return elf_sym__type(sym) == STT_FUNC &&
sym->st_name != 0 &&
sym->st_shndx != SHN_UNDEF;
}
static inline bool elf_sym__is_object(const GElf_Sym *sym)
{
return elf_sym__type(sym) == STT_OBJECT &&
sym->st_name != 0 &&
sym->st_shndx != SHN_UNDEF;
}
static inline int elf_sym__is_label(const GElf_Sym *sym)
{
return elf_sym__type(sym) == STT_NOTYPE &&
sym->st_name != 0 &&
sym->st_shndx != SHN_UNDEF &&
sym->st_shndx != SHN_ABS;
}
static inline const char *elf_sec__name(const GElf_Shdr *shdr,
const Elf_Data *secstrs)
{
return secstrs->d_buf + shdr->sh_name;
}
static inline int elf_sec__is_text(const GElf_Shdr *shdr,
const Elf_Data *secstrs)
{
return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
}
static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
const Elf_Data *secstrs)
{
return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
}
static inline const char *elf_sym__name(const GElf_Sym *sym,
const Elf_Data *symstrs)
{
return symstrs->d_buf + sym->st_name;
}
static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
GElf_Shdr *shp, const char *name,
size_t *idx)
{
Elf_Scn *sec = NULL;
size_t cnt = 1;
while ((sec = elf_nextscn(elf, sec)) != NULL) {
char *str;
gelf_getshdr(sec, shp);
str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
if (!strcmp(name, str)) {
if (idx)
*idx = cnt;
break;
}
++cnt;
}
return sec;
}
#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
idx < nr_entries; \
++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
idx < nr_entries; \
++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
/*
* We need to check if we have a .dynsym, so that we can handle the
* .plt, synthesizing its symbols, that aren't on the symtabs (be it
* .dynsym or .symtab).
* And always look at the original dso, not at debuginfo packages, that
* have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
*/
static int dso__synthesize_plt_symbols(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
uint32_t nr_rel_entries, idx;
GElf_Sym sym;
u64 plt_offset;
GElf_Shdr shdr_plt;
struct symbol *f;
GElf_Shdr shdr_rel_plt, shdr_dynsym;
Elf_Data *reldata, *syms, *symstrs;
Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
size_t dynsym_idx;
GElf_Ehdr ehdr;
char sympltname[1024];
Elf *elf;
int nr = 0, symidx, fd, err = 0;
char name[PATH_MAX];
snprintf(name, sizeof(name), "%s%s",
symbol_conf.symfs, dso->long_name);
fd = open(name, O_RDONLY);
if (fd < 0)
goto out;
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
if (elf == NULL)
goto out_close;
if (gelf_getehdr(elf, &ehdr) == NULL)
goto out_elf_end;
scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
".dynsym", &dynsym_idx);
if (scn_dynsym == NULL)
goto out_elf_end;
scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
".rela.plt", NULL);
if (scn_plt_rel == NULL) {
scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
".rel.plt", NULL);
if (scn_plt_rel == NULL)
goto out_elf_end;
}
err = -1;
if (shdr_rel_plt.sh_link != dynsym_idx)
goto out_elf_end;
if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
goto out_elf_end;
/*
* Fetch the relocation section to find the idxes to the GOT
* and the symbols in the .dynsym they refer to.
*/
reldata = elf_getdata(scn_plt_rel, NULL);
if (reldata == NULL)
goto out_elf_end;
syms = elf_getdata(scn_dynsym, NULL);
if (syms == NULL)
goto out_elf_end;
scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
if (scn_symstrs == NULL)
goto out_elf_end;
symstrs = elf_getdata(scn_symstrs, NULL);
if (symstrs == NULL)
goto out_elf_end;
nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
plt_offset = shdr_plt.sh_offset;
if (shdr_rel_plt.sh_type == SHT_RELA) {
GElf_Rela pos_mem, *pos;
elf_section__for_each_rela(reldata, pos, pos_mem, idx,
nr_rel_entries) {
symidx = GELF_R_SYM(pos->r_info);
plt_offset += shdr_plt.sh_entsize;
gelf_getsym(syms, symidx, &sym);
snprintf(sympltname, sizeof(sympltname),
"%s@plt", elf_sym__name(&sym, symstrs));
f = symbol__new(plt_offset, shdr_plt.sh_entsize,
STB_GLOBAL, sympltname);
if (!f)
goto out_elf_end;
if (filter && filter(map, f))
symbol__delete(f);
else {
symbols__insert(&dso->symbols[map->type], f);
++nr;
}
}
} else if (shdr_rel_plt.sh_type == SHT_REL) {
GElf_Rel pos_mem, *pos;
elf_section__for_each_rel(reldata, pos, pos_mem, idx,
nr_rel_entries) {
symidx = GELF_R_SYM(pos->r_info);
plt_offset += shdr_plt.sh_entsize;
gelf_getsym(syms, symidx, &sym);
snprintf(sympltname, sizeof(sympltname),
"%s@plt", elf_sym__name(&sym, symstrs));
f = symbol__new(plt_offset, shdr_plt.sh_entsize,
STB_GLOBAL, sympltname);
if (!f)
goto out_elf_end;
if (filter && filter(map, f))
symbol__delete(f);
else {
symbols__insert(&dso->symbols[map->type], f);
++nr;
}
}
}
err = 0;
out_elf_end:
elf_end(elf);
out_close:
close(fd);
if (err == 0)
return nr;
out:
pr_debug("%s: problems reading %s PLT info.\n",
__func__, dso->long_name);
return 0;
}
static bool elf_sym__is_a(GElf_Sym *sym, enum map_type type)
{
switch (type) {
case MAP__FUNCTION:
return elf_sym__is_function(sym);
case MAP__VARIABLE:
return elf_sym__is_object(sym);
default:
return false;
}
}
static bool elf_sec__is_a(GElf_Shdr *shdr, Elf_Data *secstrs,
enum map_type type)
{
switch (type) {
case MAP__FUNCTION:
return elf_sec__is_text(shdr, secstrs);
case MAP__VARIABLE:
return elf_sec__is_data(shdr, secstrs);
default:
return false;
}
}
static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
{
Elf_Scn *sec = NULL;
GElf_Shdr shdr;
size_t cnt = 1;
while ((sec = elf_nextscn(elf, sec)) != NULL) {
gelf_getshdr(sec, &shdr);
if ((addr >= shdr.sh_addr) &&
(addr < (shdr.sh_addr + shdr.sh_size)))
return cnt;
++cnt;
}
return -1;
}
static int dso__load_sym(struct dso *dso, struct map *map, const char *name,
int fd, symbol_filter_t filter, int kmodule,
int want_symtab)
{
struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
struct map *curr_map = map;
struct dso *curr_dso = dso;
Elf_Data *symstrs, *secstrs;
uint32_t nr_syms;
int err = -1;
uint32_t idx;
GElf_Ehdr ehdr;
GElf_Shdr shdr, opdshdr;
Elf_Data *syms, *opddata = NULL;
GElf_Sym sym;
Elf_Scn *sec, *sec_strndx, *opdsec;
Elf *elf;
int nr = 0;
size_t opdidx = 0;
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
if (elf == NULL) {
pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
goto out_close;
}
if (gelf_getehdr(elf, &ehdr) == NULL) {
pr_debug("%s: cannot get elf header.\n", __func__);
goto out_elf_end;
}
/* Always reject images with a mismatched build-id: */
if (dso->has_build_id) {
u8 build_id[BUILD_ID_SIZE];
if (elf_read_build_id(elf, build_id,
BUILD_ID_SIZE) != BUILD_ID_SIZE)
goto out_elf_end;
if (!dso__build_id_equal(dso, build_id))
goto out_elf_end;
}
sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
if (sec == NULL) {
if (want_symtab)
goto out_elf_end;
sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
if (sec == NULL)
goto out_elf_end;
}
opdsec = elf_section_by_name(elf, &ehdr, &opdshdr, ".opd", &opdidx);
if (opdsec)
opddata = elf_rawdata(opdsec, NULL);
syms = elf_getdata(sec, NULL);
if (syms == NULL)
goto out_elf_end;
sec = elf_getscn(elf, shdr.sh_link);
if (sec == NULL)
goto out_elf_end;
symstrs = elf_getdata(sec, NULL);
if (symstrs == NULL)
goto out_elf_end;
sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
if (sec_strndx == NULL)
goto out_elf_end;
secstrs = elf_getdata(sec_strndx, NULL);
if (secstrs == NULL)
goto out_elf_end;
nr_syms = shdr.sh_size / shdr.sh_entsize;
memset(&sym, 0, sizeof(sym));
if (dso->kernel == DSO_TYPE_USER) {
dso->adjust_symbols = (ehdr.e_type == ET_EXEC ||
elf_section_by_name(elf, &ehdr, &shdr,
".gnu.prelink_undo",
NULL) != NULL);
} else {
dso->adjust_symbols = 0;
}
elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
struct symbol *f;
const char *elf_name = elf_sym__name(&sym, symstrs);
char *demangled = NULL;
int is_label = elf_sym__is_label(&sym);
const char *section_name;
if (kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
strcmp(elf_name, kmap->ref_reloc_sym->name) == 0)
kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
if (!is_label && !elf_sym__is_a(&sym, map->type))
continue;
/* Reject ARM ELF "mapping symbols": these aren't unique and
* don't identify functions, so will confuse the profile
* output: */
if (ehdr.e_machine == EM_ARM) {
if (!strcmp(elf_name, "$a") ||
!strcmp(elf_name, "$d") ||
!strcmp(elf_name, "$t"))
continue;
}
if (opdsec && sym.st_shndx == opdidx) {
u32 offset = sym.st_value - opdshdr.sh_addr;
u64 *opd = opddata->d_buf + offset;
sym.st_value = *opd;
sym.st_shndx = elf_addr_to_index(elf, sym.st_value);
}
sec = elf_getscn(elf, sym.st_shndx);
if (!sec)
goto out_elf_end;
gelf_getshdr(sec, &shdr);
if (is_label && !elf_sec__is_a(&shdr, secstrs, map->type))
continue;
section_name = elf_sec__name(&shdr, secstrs);
/* On ARM, symbols for thumb functions have 1 added to
* the symbol address as a flag - remove it */
if ((ehdr.e_machine == EM_ARM) &&
(map->type == MAP__FUNCTION) &&
(sym.st_value & 1))
--sym.st_value;
if (dso->kernel != DSO_TYPE_USER || kmodule) {
char dso_name[PATH_MAX];
if (strcmp(section_name,
(curr_dso->short_name +
dso->short_name_len)) == 0)
goto new_symbol;
if (strcmp(section_name, ".text") == 0) {
curr_map = map;
curr_dso = dso;
goto new_symbol;
}
snprintf(dso_name, sizeof(dso_name),
"%s%s", dso->short_name, section_name);
curr_map = map_groups__find_by_name(kmap->kmaps, map->type, dso_name);
if (curr_map == NULL) {
u64 start = sym.st_value;
if (kmodule)
start += map->start + shdr.sh_offset;
curr_dso = dso__new(dso_name);
if (curr_dso == NULL)
goto out_elf_end;
curr_dso->kernel = dso->kernel;
curr_dso->long_name = dso->long_name;
curr_dso->long_name_len = dso->long_name_len;
curr_map = map__new2(start, curr_dso,
map->type);
if (curr_map == NULL) {
dso__delete(curr_dso);
goto out_elf_end;
}
curr_map->map_ip = identity__map_ip;
curr_map->unmap_ip = identity__map_ip;
curr_dso->symtab_type = dso->symtab_type;
map_groups__insert(kmap->kmaps, curr_map);
dsos__add(&dso->node, curr_dso);
dso__set_loaded(curr_dso, map->type);
} else
curr_dso = curr_map->dso;
goto new_symbol;
}
if (curr_dso->adjust_symbols) {
pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
"sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n", __func__,
(u64)sym.st_value, (u64)shdr.sh_addr,
(u64)shdr.sh_offset);
sym.st_value -= shdr.sh_addr - shdr.sh_offset;
}
/*
* We need to figure out if the object was created from C++ sources
* DWARF DW_compile_unit has this, but we don't always have access
* to it...
*/
demangled = bfd_demangle(NULL, elf_name, DMGL_PARAMS | DMGL_ANSI);
if (demangled != NULL)
elf_name = demangled;
new_symbol:
f = symbol__new(sym.st_value, sym.st_size,
GELF_ST_BIND(sym.st_info), elf_name);
free(demangled);
if (!f)
goto out_elf_end;
if (filter && filter(curr_map, f))
symbol__delete(f);
else {
symbols__insert(&curr_dso->symbols[curr_map->type], f);
nr++;
}
}
/*
* For misannotated, zeroed, ASM function sizes.
*/
if (nr > 0) {
symbols__fixup_end(&dso->symbols[map->type]);
if (kmap) {
/*
* We need to fixup this here too because we create new
* maps here, for things like vsyscall sections.
*/
__map_groups__fixup_end(kmap->kmaps, map->type);
}
}
err = nr;
out_elf_end:
elf_end(elf);
out_close:
return err;
}
static bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
{
return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 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)
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;
}
/*
* Align offset to 4 bytes as needed for note name and descriptor data.
*/
#define NOTE_ALIGN(n) (((n) + 3) & -4U)
static int elf_read_build_id(Elf *elf, void *bf, size_t size)
{
int err = -1;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf_Data *data;
Elf_Scn *sec;
Elf_Kind ek;
void *ptr;
if (size < BUILD_ID_SIZE)
goto out;
ek = elf_kind(elf);
if (ek != ELF_K_ELF)
goto out;
if (gelf_getehdr(elf, &ehdr) == NULL) {
pr_err("%s: cannot get elf header.\n", __func__);
goto out;
}
sec = elf_section_by_name(elf, &ehdr, &shdr,
".note.gnu.build-id", NULL);
if (sec == NULL) {
sec = elf_section_by_name(elf, &ehdr, &shdr,
".notes", NULL);
if (sec == NULL)
goto out;
}
data = elf_getdata(sec, NULL);
if (data == NULL)
goto out;
ptr = data->d_buf;
while (ptr < (data->d_buf + data->d_size)) {
GElf_Nhdr *nhdr = ptr;
int namesz = NOTE_ALIGN(nhdr->n_namesz),
descsz = NOTE_ALIGN(nhdr->n_descsz);
const char *name;
ptr += sizeof(*nhdr);
name = ptr;
ptr += namesz;
if (nhdr->n_type == NT_GNU_BUILD_ID &&
nhdr->n_namesz == sizeof("GNU")) {
if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
memcpy(bf, ptr, BUILD_ID_SIZE);
err = BUILD_ID_SIZE;
break;
}
}
ptr += descsz;
}
out:
return err;
}
int filename__read_build_id(const char *filename, void *bf, size_t size)
{
int fd, err = -1;
Elf *elf;
if (size < BUILD_ID_SIZE)
goto out;
fd = open(filename, O_RDONLY);
if (fd < 0)
goto out;
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
if (elf == NULL) {
pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
goto out_close;
}
err = elf_read_build_id(elf, bf, size);
elf_end(elf);
out_close:
close(fd);
out:
return err;
}
int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
{
int fd, err = -1;
if (size < BUILD_ID_SIZE)
goto out;
fd = open(filename, O_RDONLY);
if (fd < 0)
goto out;
while (1) {
char bf[BUFSIZ];
GElf_Nhdr nhdr;
int namesz, descsz;
if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
break;
namesz = NOTE_ALIGN(nhdr.n_namesz);
descsz = NOTE_ALIGN(nhdr.n_descsz);
if (nhdr.n_type == NT_GNU_BUILD_ID &&
nhdr.n_namesz == sizeof("GNU")) {
if (read(fd, bf, namesz) != namesz)
break;
if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
if (read(fd, build_id,
BUILD_ID_SIZE) == BUILD_ID_SIZE) {
err = 0;
break;
}
} else if (read(fd, bf, descsz) != descsz)
break;
} else {
int n = namesz + descsz;
if (read(fd, bf, n) != n)
break;
}
}
close(fd);
out:
return err;
}
char dso__symtab_origin(const struct dso *dso)
{
static const char origin[] = {
[SYMTAB__KALLSYMS] = 'k',
[SYMTAB__JAVA_JIT] = 'j',
[SYMTAB__BUILD_ID_CACHE] = 'B',
[SYMTAB__FEDORA_DEBUGINFO] = 'f',
[SYMTAB__UBUNTU_DEBUGINFO] = 'u',
[SYMTAB__BUILDID_DEBUGINFO] = 'b',
[SYMTAB__SYSTEM_PATH_DSO] = 'd',
[SYMTAB__SYSTEM_PATH_KMODULE] = 'K',
[SYMTAB__GUEST_KALLSYMS] = 'g',
[SYMTAB__GUEST_KMODULE] = 'G',
};
if (dso == NULL || dso->symtab_type == SYMTAB__NOT_FOUND)
return '!';
return origin[dso->symtab_type];
}
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
{
int size = PATH_MAX;
char *name;
int ret = -1;
int fd;
struct machine *machine;
const char *root_dir;
int want_symtab;
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;
name = malloc(size);
if (!name)
return -1;
dso->adjust_symbols = 0;
if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
ret = dso__load_perf_map(dso, map, filter);
dso->symtab_type = ret > 0 ? SYMTAB__JAVA_JIT :
SYMTAB__NOT_FOUND;
return ret;
}
/* Iterate over candidate debug images.
* On the first pass, only load images if they have a full symtab.
* Failing that, do a second pass where we accept .dynsym also
*/
want_symtab = 1;
restart:
for (dso->symtab_type = SYMTAB__BUILD_ID_CACHE;
dso->symtab_type != SYMTAB__NOT_FOUND;
dso->symtab_type++) {
switch (dso->symtab_type) {
case SYMTAB__BUILD_ID_CACHE:
/* skip the locally configured cache if a symfs is given */
if (symbol_conf.symfs[0] ||
(dso__build_id_filename(dso, name, size) == NULL)) {
continue;
}
break;
case SYMTAB__FEDORA_DEBUGINFO:
snprintf(name, size, "%s/usr/lib/debug%s.debug",
symbol_conf.symfs, dso->long_name);
break;
case SYMTAB__UBUNTU_DEBUGINFO:
snprintf(name, size, "%s/usr/lib/debug%s",
symbol_conf.symfs, dso->long_name);
break;
case SYMTAB__BUILDID_DEBUGINFO: {
char build_id_hex[BUILD_ID_SIZE * 2 + 1];
if (!dso->has_build_id)
continue;
build_id__sprintf(dso->build_id,
sizeof(dso->build_id),
build_id_hex);
snprintf(name, size,
"%s/usr/lib/debug/.build-id/%.2s/%s.debug",
symbol_conf.symfs, build_id_hex, build_id_hex + 2);
}
break;
case SYMTAB__SYSTEM_PATH_DSO:
snprintf(name, size, "%s%s",
symbol_conf.symfs, dso->long_name);
break;
case SYMTAB__GUEST_KMODULE:
if (map->groups && machine)
root_dir = machine->root_dir;
else
root_dir = "";
snprintf(name, size, "%s%s%s", symbol_conf.symfs,
root_dir, dso->long_name);
break;
case SYMTAB__SYSTEM_PATH_KMODULE:
snprintf(name, size, "%s%s", symbol_conf.symfs,
dso->long_name);
break;
default:;
}
/* Name is now the name of the next image to try */
fd = open(name, O_RDONLY);
if (fd < 0)
continue;
ret = dso__load_sym(dso, map, name, fd, filter, 0,
want_symtab);
close(fd);
/*
* Some people seem to have debuginfo files _WITHOUT_ debug
* info!?!?
*/
if (!ret)
continue;
if (ret > 0) {
int nr_plt = dso__synthesize_plt_symbols(dso, map,
filter);
if (nr_plt > 0)
ret += nr_plt;
break;
}
}
/*
* If we wanted a full symtab but no image had one,
* relax our requirements and repeat the search.
*/
if (ret <= 0 && want_symtab) {
want_symtab = 0;
goto restart;
}
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;
}
static 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;
}
static int map_groups__set_modules_path_dir(struct map_groups *mg,
const char *dir_name)
{
struct dirent *dent;
DIR *dir = opendir(dir_name);
int ret = 0;
if (!dir) {
pr_debug("%s: cannot open %s dir\n", __func__, dir_name);
return -1;
}
while ((dent = readdir(dir)) != NULL) {
char path[PATH_MAX];
struct stat st;
/*sshfs might return bad dent->d_type, so we have to stat*/
sprintf(path, "%s/%s", dir_name, dent->d_name);
if (stat(path, &st))
continue;
if (S_ISDIR(st.st_mode)) {
if (!strcmp(dent->d_name, ".") ||
!strcmp(dent->d_name, ".."))
continue;
snprintf(path, sizeof(path), "%s/%s",
dir_name, dent->d_name);
ret = map_groups__set_modules_path_dir(mg, path);
if (ret < 0)
goto out;
} else {
char *dot = strrchr(dent->d_name, '.'),
dso_name[PATH_MAX];
struct map *map;
char *long_name;
if (dot == NULL || strcmp(dot, ".ko"))
continue;
snprintf(dso_name, sizeof(dso_name), "[%.*s]",
(int)(dot - dent->d_name), dent->d_name);
strxfrchar(dso_name, '-', '_');
map = map_groups__find_by_name(mg, MAP__FUNCTION,
dso_name);
if (map == NULL)
continue;
snprintf(path, sizeof(path), "%s/%s",
dir_name, dent->d_name);
long_name = strdup(path);
if (long_name == NULL) {
ret = -1;
goto out;
}
dso__set_long_name(map->dso, long_name);
map->dso->lname_alloc = 1;
dso__kernel_module_get_build_id(map->dso, "");
}
}
out:
closedir(dir);
return ret;
}
static char *get_kernel_version(const char *root_dir)
{
char version[PATH_MAX];
FILE *file;
char *name, *tmp;
const char *prefix = "Linux version ";
sprintf(version, "%s/proc/version", root_dir);
file = fopen(version, "r");
if (!file)
return NULL;
version[0] = '\0';
tmp = fgets(version, sizeof(version), file);
fclose(file);
name = strstr(version, prefix);
if (!name)
return NULL;
name += strlen(prefix);
tmp = strchr(name, ' ');
if (tmp)
*tmp = '\0';
return strdup(name);
}
static int machine__set_modules_path(struct machine *machine)
{
char *version;
char modules_path[PATH_MAX];
version = get_kernel_version(machine->root_dir);
if (!version)
return -1;
snprintf(modules_path, sizeof(modules_path), "%s/lib/modules/%s/kernel",
machine->root_dir, version);
free(version);
return map_groups__set_modules_path_dir(&machine->kmaps, modules_path);
}
/*
* Constructor variant for modules (where we know from /proc/modules where
* they are loaded) and for vmlinux, where only after we load all the
* symbols we'll know where it starts and ends.
*/
static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
{
struct map *map = calloc(1, (sizeof(*map) +
(dso->kernel ? sizeof(struct kmap) : 0)));
if (map != NULL) {
/*
* ->end will be filled after we load all the symbols
*/
map__init(map, type, start, 0, 0, dso);
}
return map;
}
struct map *machine__new_module(struct machine *machine, u64 start,
const char *filename)
{
struct map *map;
struct dso *dso = __dsos__findnew(&machine->kernel_dsos, filename);
if (dso == NULL)
return NULL;
map = map__new2(start, dso, MAP__FUNCTION);
if (map == NULL)
return NULL;
if (machine__is_host(machine))
dso->symtab_type = SYMTAB__SYSTEM_PATH_KMODULE;
else
dso->symtab_type = SYMTAB__GUEST_KMODULE;
map_groups__insert(&machine->kmaps, map);
return map;
}
static int machine__create_modules(struct machine *machine)
{
char *line = NULL;
size_t n;
FILE *file;
struct map *map;
const char *modules;
char path[PATH_MAX];
if (machine__is_default_guest(machine))
modules = symbol_conf.default_guest_modules;
else {
sprintf(path, "%s/proc/modules", machine->root_dir);
modules = path;
}
if (symbol__restricted_filename(path, "/proc/modules"))
return -1;
file = fopen(modules, "r");
if (file == NULL)
return -1;
while (!feof(file)) {
char name[PATH_MAX];
u64 start;
char *sep;
int line_len;
line_len = getline(&line, &n, file);
if (line_len < 0)
break;
if (!line)
goto out_failure;
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';
snprintf(name, sizeof(name), "[%s]", line);
map = machine__new_module(machine, start, name);
if (map == NULL)
goto out_delete_line;
dso__kernel_module_get_build_id(map->dso, machine->root_dir);
}
free(line);
fclose(file);
return machine__set_modules_path(machine);
out_delete_line:
free(line);
out_failure:
return -1;
}
int dso__load_vmlinux(struct dso *dso, struct map *map,
const char *vmlinux, symbol_filter_t filter)
{
int err = -1, fd;
char symfs_vmlinux[PATH_MAX];
snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
symbol_conf.symfs, vmlinux);
fd = open(symfs_vmlinux, O_RDONLY);
if (fd < 0)
return -1;
dso__set_long_name(dso, (char *)vmlinux);
dso__set_loaded(dso, map->type);
err = dso__load_sym(dso, map, symfs_vmlinux, fd, filter, 0, 0);
close(fd);
if (err > 0)
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, filter);
if (err > 0) {
dso__set_long_name(dso, filename);
goto out;
}
free(filename);
}
for (i = 0; i < vmlinux_path__nr_entries; ++i) {
err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
if (err > 0) {
dso__set_long_name(dso, strdup(vmlinux_path[i]));
break;
}
}
out:
return err;
}
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.vmlinux_name != NULL) {
err = dso__load_vmlinux(dso, map,
symbol_conf.vmlinux_name, filter);
if (err > 0) {
dso__set_long_name(dso,
strdup(symbol_conf.vmlinux_name));
goto out_fixup;
}
return err;
}
if (vmlinux_path != NULL) {
err = dso__load_vmlinux_path(dso, map, filter);
if (err > 0)
goto out_fixup;
}
/* do not try local files if a symfs was given */
if (symbol_conf.symfs[0] != 0)
return -1;
/*
* Say the kernel DSO was created when processing the build-id header table,
* we have a build-id, so check if it is the same as the running kernel,
* using it if it is.
*/
if (dso->has_build_id) {
u8 kallsyms_build_id[BUILD_ID_SIZE];
char sbuild_id[BUILD_ID_SIZE * 2 + 1];
if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
sizeof(kallsyms_build_id)) == 0) {
if (dso__build_id_equal(dso, kallsyms_build_id)) {
kallsyms_filename = "/proc/kallsyms";
goto do_kallsyms;
}
}
/*
* Now look if we have it on the build-id cache in
* $HOME/.debug/[kernel.kallsyms].
*/
build_id__sprintf(dso->build_id, sizeof(dso->build_id),
sbuild_id);
if (asprintf(&kallsyms_allocated_filename,
"%s/.debug/[kernel.kallsyms]/%s",
getenv("HOME"), sbuild_id) == -1) {
pr_err("Not enough memory for kallsyms file lookup\n");
return -1;
}
kallsyms_filename = kallsyms_allocated_filename;
if (access(kallsyms_filename, F_OK)) {
pr_err("No kallsyms or vmlinux with build-id %s "
"was found\n", sbuild_id);
free(kallsyms_allocated_filename);
return -1;
}
} else {
/*
* Last resort, if we don't have a build-id and couldn't find
* any vmlinux file, try the running kernel kallsyms table.
*/
kallsyms_filename = "/proc/kallsyms";
}
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) {
out_fixup:
if (kallsyms_filename != NULL)
dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
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, filter);
goto out_try_fixup;
}
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);
out_try_fixup:
if (err > 0) {
if (kallsyms_filename != NULL) {
machine__mmap_name(machine, path, sizeof(path));
dso__set_long_name(dso, strdup(path));
}
map__fixup_start(map);
map__fixup_end(map);
}
return err;
}
static void dsos__add(struct list_head *head, struct dso *dso)
{
list_add_tail(&dso->node, head);
}
static struct dso *dsos__find(struct list_head *head, const char *name)
{
struct dso *pos;
list_for_each_entry(pos, head, node)
if (strcmp(pos->long_name, name) == 0)
return pos;
return NULL;
}
struct dso *__dsos__findnew(struct list_head *head, const char *name)
{
struct dso *dso = dsos__find(head, name);
if (!dso) {
dso = dso__new(name);
if (dso != NULL) {
dsos__add(head, dso);
dso__set_basename(dso);
}
}
return dso;
}
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 machines__fprintf_dsos(struct rb_root *machines, FILE *fp)
{
struct rb_node *nd;
size_t ret = 0;
for (nd = rb_first(machines); nd; nd = rb_next(nd)) {
struct machine *pos = rb_entry(nd, struct machine, rb_node);
ret += __dsos__fprintf(&pos->kernel_dsos, fp);
ret += __dsos__fprintf(&pos->user_dsos, fp);
}
return ret;
}
static size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
bool with_hits)
{
struct dso *pos;
size_t ret = 0;
list_for_each_entry(pos, head, node) {
if (with_hits && !pos->hit)
continue;
ret += dso__fprintf_buildid(pos, fp);
ret += fprintf(fp, " %s\n", pos->long_name);
}
return ret;
}
size_t machine__fprintf_dsos_buildid(struct machine *machine, FILE *fp,
bool with_hits)
{
return __dsos__fprintf_buildid(&machine->kernel_dsos, fp, with_hits) +
__dsos__fprintf_buildid(&machine->user_dsos, fp, with_hits);
}
size_t machines__fprintf_dsos_buildid(struct rb_root *machines,
FILE *fp, bool with_hits)
{
struct rb_node *nd;
size_t ret = 0;
for (nd = rb_first(machines); nd; nd = rb_next(nd)) {
struct machine *pos = rb_entry(nd, struct machine, rb_node);
ret += machine__fprintf_dsos_buildid(pos, fp, with_hits);
}
return ret;
}
struct dso *dso__new_kernel(const char *name)
{
struct dso *dso = dso__new(name ?: "[kernel.kallsyms]");
if (dso != NULL) {
dso__set_short_name(dso, "[kernel]");
dso->kernel = DSO_TYPE_KERNEL;
}
return dso;
}
static struct dso *dso__new_guest_kernel(struct machine *machine,
const char *name)
{
char bf[PATH_MAX];
struct dso *dso = dso__new(name ?: machine__mmap_name(machine, bf,
sizeof(bf)));
if (dso != NULL) {
dso__set_short_name(dso, "[guest.kernel]");
dso->kernel = DSO_TYPE_GUEST_KERNEL;
}
return dso;
}
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;
}
static struct dso *machine__create_kernel(struct machine *machine)
{
const char *vmlinux_name = NULL;
struct dso *kernel;
if (machine__is_host(machine)) {
vmlinux_name = symbol_conf.vmlinux_name;
kernel = dso__new_kernel(vmlinux_name);
} else {
if (machine__is_default_guest(machine))
vmlinux_name = symbol_conf.default_guest_vmlinux_name;
kernel = dso__new_guest_kernel(machine, vmlinux_name);
}
if (kernel != NULL) {
dso__read_running_kernel_build_id(kernel, machine);
dsos__add(&machine->kernel_dsos, kernel);
}
return kernel;
}
struct process_args {
u64 start;
};
static int symbol__in_kernel(void *arg, const char *name,
char type __used, u64 start, u64 end __used)
{
struct process_args *args = arg;
if (strchr(name, '['))
return 0;
args->start = start;
return 1;
}
/* Figure out the start address of kernel map from /proc/kallsyms */
static u64 machine__get_kernel_start_addr(struct machine *machine)
{
const char *filename;
char path[PATH_MAX];
struct process_args args;
if (machine__is_host(machine)) {
filename = "/proc/kallsyms";
} else {
if (machine__is_default_guest(machine))
filename = (char *)symbol_conf.default_guest_kallsyms;
else {
sprintf(path, "%s/proc/kallsyms", machine->root_dir);
filename = path;
}
}
if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return 0;
if (kallsyms__parse(filename, &args, symbol__in_kernel) <= 0)
return 0;
return args.start;
}
int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
{
enum map_type type;
u64 start = machine__get_kernel_start_addr(machine);
for (type = 0; type < MAP__NR_TYPES; ++type) {
struct kmap *kmap;
machine->vmlinux_maps[type] = map__new2(start, kernel, type);
if (machine->vmlinux_maps[type] == NULL)
return -1;
machine->vmlinux_maps[type]->map_ip =
machine->vmlinux_maps[type]->unmap_ip =
identity__map_ip;
kmap = map__kmap(machine->vmlinux_maps[type]);
kmap->kmaps = &machine->kmaps;
map_groups__insert(&machine->kmaps,
machine->vmlinux_maps[type]);
}
return 0;
}
void machine__destroy_kernel_maps(struct machine *machine)
{
enum map_type type;
for (type = 0; type < MAP__NR_TYPES; ++type) {
struct kmap *kmap;
if (machine->vmlinux_maps[type] == NULL)
continue;
kmap = map__kmap(machine->vmlinux_maps[type]);
map_groups__remove(&machine->kmaps,
machine->vmlinux_maps[type]);
if (kmap->ref_reloc_sym) {
/*
* ref_reloc_sym is shared among all maps, so free just
* on one of them.
*/
if (type == MAP__FUNCTION) {
free((char *)kmap->ref_reloc_sym->name);
kmap->ref_reloc_sym->name = NULL;
free(kmap->ref_reloc_sym);
}
kmap->ref_reloc_sym = NULL;
}
map__delete(machine->vmlinux_maps[type]);
machine->vmlinux_maps[type] = NULL;
}
}
int machine__create_kernel_maps(struct machine *machine)
{
struct dso *kernel = machine__create_kernel(machine);
if (kernel == NULL ||
__machine__create_kernel_maps(machine, kernel) < 0)
return -1;
if (symbol_conf.use_modules && machine__create_modules(machine) < 0)
pr_debug("Problems creating module maps, continuing anyway...\n");
/*
* Now that we have all the maps created, just set the ->end of them:
*/
map_groups__fixup_end(&machine->kmaps);
return 0;
}
static void vmlinux_path__exit(void)
{
while (--vmlinux_path__nr_entries >= 0) {
free(vmlinux_path[vmlinux_path__nr_entries]);
vmlinux_path[vmlinux_path__nr_entries] = NULL;
}
free(vmlinux_path);
vmlinux_path = NULL;
}
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;
}
size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
{
int i;
size_t printed = 0;
struct dso *kdso = machine->vmlinux_maps[MAP__FUNCTION]->dso;
if (kdso->has_build_id) {
char filename[PATH_MAX];
if (dso__build_id_filename(kdso, filename, sizeof(filename)))
printed += fprintf(fp, "[0] %s\n", filename);
}
for (i = 0; i < vmlinux_path__nr_entries; ++i)
printed += fprintf(fp, "[%d] %s\n",
i + kdso->has_build_id, vmlinux_path[i]);
return printed;
}
static 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 = ALIGN(symbol_conf.priv_size, sizeof(u64));
elf_version(EV_CURRENT);
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_dso_list:
strlist__delete(symbol_conf.dso_list);
out_free_comm_list:
strlist__delete(symbol_conf.comm_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;
}
int machines__create_kernel_maps(struct rb_root *machines, pid_t pid)
{
struct machine *machine = machines__findnew(machines, pid);
if (machine == NULL)
return -1;
return machine__create_kernel_maps(machine);
}
static int hex(char ch)
{
if ((ch >= '0') && (ch <= '9'))
return ch - '0';
if ((ch >= 'a') && (ch <= 'f'))
return ch - 'a' + 10;
if ((ch >= 'A') && (ch <= 'F'))
return ch - 'A' + 10;
return -1;
}
/*
* While we find nice hex chars, build a long_val.
* Return number of chars processed.
*/
int hex2u64(const char *ptr, u64 *long_val)
{
const char *p = ptr;
*long_val = 0;
while (*p) {
const int hex_val = hex(*p);
if (hex_val < 0)
break;
*long_val = (*long_val << 4) | hex_val;
p++;
}
return p - ptr;
}
char *strxfrchar(char *s, char from, char to)
{
char *p = s;
while ((p = strchr(p, from)) != NULL)
*p++ = to;
return s;
}
int machines__create_guest_kernel_maps(struct rb_root *machines)
{
int ret = 0;
struct dirent **namelist = NULL;
int i, items = 0;
char path[PATH_MAX];
pid_t pid;
if (symbol_conf.default_guest_vmlinux_name ||
symbol_conf.default_guest_modules ||
symbol_conf.default_guest_kallsyms) {
machines__create_kernel_maps(machines, DEFAULT_GUEST_KERNEL_ID);
}
if (symbol_conf.guestmount) {
items = scandir(symbol_conf.guestmount, &namelist, NULL, NULL);
if (items <= 0)
return -ENOENT;
for (i = 0; i < items; i++) {
if (!isdigit(namelist[i]->d_name[0])) {
/* Filter out . and .. */
continue;
}
pid = atoi(namelist[i]->d_name);
sprintf(path, "%s/%s/proc/kallsyms",
symbol_conf.guestmount,
namelist[i]->d_name);
ret = access(path, R_OK);
if (ret) {
pr_debug("Can't access file %s\n", path);
goto failure;
}
machines__create_kernel_maps(machines, pid);
}
failure:
free(namelist);
}
return ret;
}
void machines__destroy_guest_kernel_maps(struct rb_root *machines)
{
struct rb_node *next = rb_first(machines);
while (next) {
struct machine *pos = rb_entry(next, struct machine, rb_node);
next = rb_next(&pos->rb_node);
rb_erase(&pos->rb_node, machines);
machine__delete(pos);
}
}
int machine__load_kallsyms(struct machine *machine, const char *filename,
enum map_type type, symbol_filter_t filter)
{
struct map *map = machine->vmlinux_maps[type];
int ret = dso__load_kallsyms(map->dso, filename, map, filter);
if (ret > 0) {
dso__set_loaded(map->dso, type);
/*
* Since /proc/kallsyms will have multiple sessions for the
* kernel, with modules between them, fixup the end of all
* sections.
*/
__map_groups__fixup_end(&machine->kmaps, type);
}
return ret;
}
int machine__load_vmlinux_path(struct machine *machine, enum map_type type,
symbol_filter_t filter)
{
struct map *map = machine->vmlinux_maps[type];
int ret = dso__load_vmlinux_path(map->dso, map, filter);
if (ret > 0) {
dso__set_loaded(map->dso, type);
map__reloc_vmlinux(map);
}
return ret;
}