microsoft
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WSL2-Linux-Kernel
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perf symbols: Split out util/symbol-elf.c 

Factor out the dependency of ELF handling into separate symbol-elf.c
file. It is a preparation of building a minimalistic version perf tools
which doesn't depend on the elfutils.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344228082-15569-3-git-send-email-namhyung@kernel.org
[ committer note: removed blank line at symbol-elf.c EOF ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2012-08-06 13:41:20 +09:00 коммит произвёл Arnaldo Carvalho de Melo
Родитель 166ccc9c24
Коммит e5a1845fc0
6 изменённых файлов: 817 добавлений и 797 удалений
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1
tools/perf/Makefile
Просмотреть файл

@ -356,6 +356,7 @@ LIB_OBJS += $(OUTPUT)util/usage.o
LIB_OBJS += $(OUTPUT)util/wrapper.o LIB_OBJS += $(OUTPUT)util/wrapper.o
LIB_OBJS += $(OUTPUT)util/sigchain.o LIB_OBJS += $(OUTPUT)util/sigchain.o
LIB_OBJS += $(OUTPUT)util/symbol.o LIB_OBJS += $(OUTPUT)util/symbol.o
LIB_OBJS += $(OUTPUT)util/symbol-elf.o
LIB_OBJS += $(OUTPUT)util/dso-test-data.o LIB_OBJS += $(OUTPUT)util/dso-test-data.o
LIB_OBJS += $(OUTPUT)util/color.o LIB_OBJS += $(OUTPUT)util/color.o
LIB_OBJS += $(OUTPUT)util/pager.o LIB_OBJS += $(OUTPUT)util/pager.o

19
tools/perf/util/map.c
Просмотреть файл

@ -86,6 +86,25 @@ out_delete:
return NULL; return NULL;
} }
/*
* 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.
*/
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;
}
void map__delete(struct map *self) void map__delete(struct map *self)
{ {
free(self); free(self);

1
tools/perf/util/map.h
Просмотреть файл

@ -115,6 +115,7 @@ void map__init(struct map *self, enum map_type type,
struct map *map__new(struct list_head *dsos__list, u64 start, u64 len, struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
u64 pgoff, u32 pid, char *filename, u64 pgoff, u32 pid, char *filename,
enum map_type type); enum map_type type);
struct map *map__new2(u64 start, struct dso *dso, enum map_type type);
void map__delete(struct map *self); void map__delete(struct map *self);
struct map *map__clone(struct map *self); struct map *map__clone(struct map *self);
int map__overlap(struct map *l, struct map *r); int map__overlap(struct map *l, struct map *r);

774
tools/perf/util/symbol-elf.c Normal file
Просмотреть файл

@ -0,0 +1,774 @@
#include <libelf.h>
#include <gelf.h>
#include <elf.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
#include "symbol.h"
#include "debug.h"
#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif
/**
* 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 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 inline const char *elf_sym__name(const GElf_Sym *sym,
const Elf_Data *symstrs)
{
return symstrs->d_buf + sym->st_name;
}
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 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 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).
*/
int dso__synthesize_plt_symbols(struct dso *dso, char *name, 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;
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;
}
/*
* 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;
}
/*
* Check following sections for notes:
* '.note.gnu.build-id'
* '.notes'
* '.note' (VDSO specific)
*/
do {
sec = elf_section_by_name(elf, &ehdr, &shdr,
".note.gnu.build-id", NULL);
if (sec)
break;
sec = elf_section_by_name(elf, &ehdr, &shdr,
".notes", NULL);
if (sec)
break;
sec = elf_section_by_name(elf, &ehdr, &shdr,
".note", NULL);
if (sec)
break;
return err;
} while (0);
data = elf_getdata(sec, NULL);
if (data == NULL)
goto out;
ptr = data->d_buf;
while (ptr < (data->d_buf + data->d_size)) {
GElf_Nhdr *nhdr = ptr;
size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
descsz = NOTE_ALIGN(nhdr->n_descsz);
const char *name;
ptr += sizeof(*nhdr);
name = ptr;
ptr += namesz;
if (nhdr->n_type == NT_GNU_BUILD_ID &&
nhdr->n_namesz == sizeof("GNU")) {
if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
size_t sz = min(size, descsz);
memcpy(bf, ptr, sz);
memset(bf + sz, 0, size - sz);
err = descsz;
break;
}
}
ptr += descsz;
}
out:
return err;
}
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;
size_t namesz, descsz;
if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
break;
namesz = NOTE_ALIGN(nhdr.n_namesz);
descsz = NOTE_ALIGN(nhdr.n_descsz);
if (nhdr.n_type == NT_GNU_BUILD_ID &&
nhdr.n_namesz == sizeof("GNU")) {
if (read(fd, bf, namesz) != (ssize_t)namesz)
break;
if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
size_t sz = min(descsz, size);
if (read(fd, build_id, sz) == (ssize_t)sz) {
memset(build_id + sz, 0, size - sz);
err = 0;
break;
}
} else if (read(fd, bf, descsz) != (ssize_t)descsz)
break;
} else {
int n = namesz + descsz;
if (read(fd, bf, n) != n)
break;
}
}
close(fd);
out:
return err;
}
int filename__read_debuglink(const char *filename, char *debuglink,
size_t size)
{
int fd, err = -1;
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf_Data *data;
Elf_Scn *sec;
Elf_Kind ek;
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;
}
ek = elf_kind(elf);
if (ek != ELF_K_ELF)
goto out_close;
if (gelf_getehdr(elf, &ehdr) == NULL) {
pr_err("%s: cannot get elf header.\n", __func__);
goto out_close;
}
sec = elf_section_by_name(elf, &ehdr, &shdr,
".gnu_debuglink", NULL);
if (sec == NULL)
goto out_close;
data = elf_getdata(sec, NULL);
if (data == NULL)
goto out_close;
/* the start of this section is a zero-terminated string */
strncpy(debuglink, data->d_buf, size);
elf_end(elf);
out_close:
close(fd);
out:
return err;
}
static int dso__swap_init(struct dso *dso, unsigned char eidata)
{
static unsigned int const endian = 1;
dso->needs_swap = DSO_SWAP__NO;
switch (eidata) {
case ELFDATA2LSB:
/* We are big endian, DSO is little endian. */
if (*(unsigned char const *)&endian != 1)
dso->needs_swap = DSO_SWAP__YES;
break;
case ELFDATA2MSB:
/* We are little endian, DSO is big endian. */
if (*(unsigned char const *)&endian != 0)
dso->needs_swap = DSO_SWAP__YES;
break;
default:
pr_err("unrecognized DSO data encoding %d\n", eidata);
return -EINVAL;
}
return 0;
}
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;
}
if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
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) < 0)
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 (opdshdr.sh_type != SHT_PROGBITS)
opdsec = NULL;
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 = DSO__SWAP(dso, u64, *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_duplicate(&dso->symbols[map->type]);
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;
}
void symbol__elf_init(void)
{
elf_version(EV_CURRENT);
}

804
tools/perf/util/symbol.c
Просмотреть файл

@ -15,8 +15,6 @@
#include "symbol.h" #include "symbol.h"
#include "strlist.h" #include "strlist.h"
#include <libelf.h>
#include <gelf.h>
#include <elf.h> #include <elf.h>
#include <limits.h> #include <limits.h>
#include <sys/utsname.h> #include <sys/utsname.h>
@ -25,15 +23,7 @@
#define KSYM_NAME_LEN 256 #define KSYM_NAME_LEN 256
#endif #endif
#ifndef NT_GNU_BUILD_ID
#define NT_GNU_BUILD_ID 3
#endif
static void dso_cache__free(struct rb_root *root); static void dso_cache__free(struct rb_root *root);
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, static int dso__load_kernel_sym(struct dso *dso, struct map *map,
symbol_filter_t filter); symbol_filter_t filter);
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map, static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
@ -170,7 +160,7 @@ static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
return SYMBOL_B; return SYMBOL_B;
} }
static void symbols__fixup_duplicate(struct rb_root *symbols) void symbols__fixup_duplicate(struct rb_root *symbols)
{ {
struct rb_node *nd; struct rb_node *nd;
struct symbol *curr, *next; struct symbol *curr, *next;
@ -199,7 +189,7 @@ again:
} }
} }
static void symbols__fixup_end(struct rb_root *symbols) void symbols__fixup_end(struct rb_root *symbols)
{ {
struct rb_node *nd, *prevnd = rb_first(symbols); struct rb_node *nd, *prevnd = rb_first(symbols);
struct symbol *curr, *prev; struct symbol *curr, *prev;
@ -222,7 +212,7 @@ static void symbols__fixup_end(struct rb_root *symbols)
curr->end = roundup(curr->start, 4096); curr->end = roundup(curr->start, 4096);
} }
static void __map_groups__fixup_end(struct map_groups *mg, enum map_type type) void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
{ {
struct map *prev, *curr; struct map *prev, *curr;
struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]); struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
@ -252,8 +242,7 @@ static void map_groups__fixup_end(struct map_groups *mg)
__map_groups__fixup_end(mg, i); __map_groups__fixup_end(mg, i);
} }
static struct symbol *symbol__new(u64 start, u64 len, u8 binding, struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
const char *name)
{ {
size_t namelen = strlen(name) + 1; size_t namelen = strlen(name) + 1;
struct symbol *sym = calloc(1, (symbol_conf.priv_size + struct symbol *sym = calloc(1, (symbol_conf.priv_size +
@ -390,7 +379,7 @@ void dso__set_build_id(struct dso *dso, void *build_id)
dso->has_build_id = 1; dso->has_build_id = 1;
} }
static void symbols__insert(struct rb_root *symbols, struct symbol *sym) void symbols__insert(struct rb_root *symbols, struct symbol *sym)
{ {
struct rb_node **p = &symbols->rb_node; struct rb_node **p = &symbols->rb_node;
struct rb_node *parent = NULL; struct rb_node *parent = NULL;
@ -904,561 +893,7 @@ out_failure:
return -1; return -1;
} }
/** bool dso__build_id_equal(const struct dso *dso, u8 *build_id)
* 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, char *name, 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;
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__swap_init(struct dso *dso, unsigned char eidata)
{
static unsigned int const endian = 1;
dso->needs_swap = DSO_SWAP__NO;
switch (eidata) {
case ELFDATA2LSB:
/* We are big endian, DSO is little endian. */
if (*(unsigned char const *)&endian != 1)
dso->needs_swap = DSO_SWAP__YES;
break;
case ELFDATA2MSB:
/* We are little endian, DSO is big endian. */
if (*(unsigned char const *)&endian != 0)
dso->needs_swap = DSO_SWAP__YES;
break;
default:
pr_err("unrecognized DSO data encoding %d\n", eidata);
return -EINVAL;
}
return 0;
}
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;
}
if (dso__swap_init(dso, ehdr.e_ident[EI_DATA]))
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) < 0)
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 (opdshdr.sh_type != SHT_PROGBITS)
opdsec = NULL;
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 = DSO__SWAP(dso, u64, *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_duplicate(&dso->symbols[map->type]);
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;
}
void symbol__elf_init(void)
{
elf_version(EV_CURRENT);
}
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; return memcmp(dso->build_id, build_id, sizeof(dso->build_id)) == 0;
} }
@ -1485,212 +920,6 @@ bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
return have_build_id; 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;
}
/*
* Check following sections for notes:
* '.note.gnu.build-id'
* '.notes'
* '.note' (VDSO specific)
*/
do {
sec = elf_section_by_name(elf, &ehdr, &shdr,
".note.gnu.build-id", NULL);
if (sec)
break;
sec = elf_section_by_name(elf, &ehdr, &shdr,
".notes", NULL);
if (sec)
break;
sec = elf_section_by_name(elf, &ehdr, &shdr,
".note", NULL);
if (sec)
break;
return err;
} while (0);
data = elf_getdata(sec, NULL);
if (data == NULL)
goto out;
ptr = data->d_buf;
while (ptr < (data->d_buf + data->d_size)) {
GElf_Nhdr *nhdr = ptr;
size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
descsz = NOTE_ALIGN(nhdr->n_descsz);
const char *name;
ptr += sizeof(*nhdr);
name = ptr;
ptr += namesz;
if (nhdr->n_type == NT_GNU_BUILD_ID &&
nhdr->n_namesz == sizeof("GNU")) {
if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
size_t sz = min(size, descsz);
memcpy(bf, ptr, sz);
memset(bf + sz, 0, size - sz);
err = descsz;
break;
}
}
ptr += descsz;
}
out:
return err;
}
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;
size_t namesz, descsz;
if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
break;
namesz = NOTE_ALIGN(nhdr.n_namesz);
descsz = NOTE_ALIGN(nhdr.n_descsz);
if (nhdr.n_type == NT_GNU_BUILD_ID &&
nhdr.n_namesz == sizeof("GNU")) {
if (read(fd, bf, namesz) != (ssize_t)namesz)
break;
if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
size_t sz = min(descsz, size);
if (read(fd, build_id, sz) == (ssize_t)sz) {
memset(build_id + sz, 0, size - sz);
err = 0;
break;
}
} else if (read(fd, bf, descsz) != (ssize_t)descsz)
break;
} else {
int n = namesz + descsz;
if (read(fd, bf, n) != n)
break;
}
}
close(fd);
out:
return err;
}
static int filename__read_debuglink(const char *filename,
char *debuglink, size_t size)
{
int fd, err = -1;
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf_Data *data;
Elf_Scn *sec;
Elf_Kind ek;
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;
}
ek = elf_kind(elf);
if (ek != ELF_K_ELF)
goto out_close;
if (gelf_getehdr(elf, &ehdr) == NULL) {
pr_err("%s: cannot get elf header.\n", __func__);
goto out_close;
}
sec = elf_section_by_name(elf, &ehdr, &shdr,
".gnu_debuglink", NULL);
if (sec == NULL)
goto out_close;
data = elf_getdata(sec, NULL);
if (data == NULL)
goto out_close;
/* the start of this section is a zero-terminated string */
strncpy(debuglink, data->d_buf, size);
elf_end(elf);
out_close:
close(fd);
out:
return err;
}
char dso__symtab_origin(const struct dso *dso) char dso__symtab_origin(const struct dso *dso)
{ {
static const char origin[] = { static const char origin[] = {
@ -2035,25 +1264,6 @@ static int machine__set_modules_path(struct machine *machine)
return map_groups__set_modules_path_dir(&machine->kmaps, modules_path); 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, struct map *machine__new_module(struct machine *machine, u64 start,
const char *filename) const char *filename)
{ {
@ -2357,7 +1567,7 @@ out_try_fixup:
return err; return err;
} }
static void dsos__add(struct list_head *head, struct dso *dso) void dsos__add(struct list_head *head, struct dso *dso)
{ {
list_add_tail(&dso->node, head); list_add_tail(&dso->node, head);
} }

15
tools/perf/util/symbol.h
Просмотреть файл

@ -254,6 +254,7 @@ static inline void dso__set_loaded(struct dso *dso, enum map_type type)
void dso__sort_by_name(struct dso *dso, enum map_type type); void dso__sort_by_name(struct dso *dso, enum map_type type);
void dsos__add(struct list_head *head, struct dso *dso);
struct dso *__dsos__findnew(struct list_head *head, const char *name); struct dso *__dsos__findnew(struct list_head *head, const char *name);
int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter); int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter);
@ -283,6 +284,7 @@ size_t dso__fprintf(struct dso *dso, enum map_type type, FILE *fp);
char dso__symtab_origin(const struct dso *dso); char dso__symtab_origin(const struct dso *dso);
void dso__set_long_name(struct dso *dso, char *name); void dso__set_long_name(struct dso *dso, char *name);
void dso__set_build_id(struct dso *dso, void *build_id); void dso__set_build_id(struct dso *dso, void *build_id);
bool dso__build_id_equal(const struct dso *dso, u8 *build_id);
void dso__read_running_kernel_build_id(struct dso *dso, void dso__read_running_kernel_build_id(struct dso *dso,
struct machine *machine); struct machine *machine);
struct map *dso__new_map(const char *name); struct map *dso__new_map(const char *name);
@ -298,6 +300,8 @@ int build_id__sprintf(const u8 *build_id, int len, char *bf);
int kallsyms__parse(const char *filename, void *arg, int kallsyms__parse(const char *filename, void *arg,
int (*process_symbol)(void *arg, const char *name, int (*process_symbol)(void *arg, const char *name,
char type, u64 start, u64 end)); char type, u64 start, u64 end));
int filename__read_debuglink(const char *filename, char *debuglink,
size_t size);
void machine__destroy_kernel_maps(struct machine *machine); void machine__destroy_kernel_maps(struct machine *machine);
int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel); int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel);
@ -310,6 +314,7 @@ void machines__destroy_guest_kernel_maps(struct rb_root *machines);
int symbol__init(void); int symbol__init(void);
void symbol__exit(void); void symbol__exit(void);
void symbol__elf_init(void); void symbol__elf_init(void);
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
size_t symbol__fprintf_symname_offs(const struct symbol *sym, size_t symbol__fprintf_symname_offs(const struct symbol *sym,
const struct addr_location *al, FILE *fp); const struct addr_location *al, FILE *fp);
size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp); size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);
@ -327,4 +332,14 @@ ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr, struct machine *machine, u64 addr,
u8 *data, ssize_t size); u8 *data, ssize_t size);
int dso__test_data(void); int dso__test_data(void);
int dso__load_sym(struct dso *dso, struct map *map, const char *name, int fd,
symbol_filter_t filter, int kmodule, int want_symtab);
int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
symbol_filter_t filter);
void symbols__insert(struct rb_root *symbols, struct symbol *sym);
void symbols__fixup_duplicate(struct rb_root *symbols);
void symbols__fixup_end(struct rb_root *symbols);
void __map_groups__fixup_end(struct map_groups *mg, enum map_type type);
#endif /* __PERF_SYMBOL */ #endif /* __PERF_SYMBOL */