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symbol.c
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/*
* symbol management routines for uftrace
*
* Copyright (C) 2014-2018, LG Electronics, Namhyung Kim <[email protected]>
*
* Released under the GPL v2.
*/
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
/* This should be defined before #include "utils.h" */
#define PR_FMT "symbol"
#define PR_DOMAIN DBG_SYMBOL
#include "uftrace.h"
#include "utils/filter.h"
#include "utils/rbtree.h"
#include "utils/symbol.h"
#include "utils/utils.h"
#ifndef EM_AARCH64
#define EM_AARCH64 183
#endif
#ifndef EM_RISCV
#define EM_RISCV 243
#endif
/* (global) symbol for kernel */
static struct uftrace_module kernel;
/* prevent duplicate symbols table loading */
static struct rb_root modules = RB_ROOT;
struct uftrace_symbol sched_sym = {
.addr = EVENT_ID_PERF_SCHED_BOTH,
.size = 1,
.type = ST_LOCAL_FUNC,
.name = "linux:schedule",
};
struct uftrace_symbol sched_preempt_sym = {
.addr = EVENT_ID_PERF_SCHED_BOTH_PREEMPT,
.size = 1,
.type = ST_LOCAL_FUNC,
.name = "linux:schedule (pre-empted)",
};
static int addrsort(const void *a, const void *b)
{
const struct uftrace_symbol *syma = a;
const struct uftrace_symbol *symb = b;
if (syma->addr > symb->addr)
return 1;
if (syma->addr < symb->addr)
return -1;
return 0;
}
static int addrfind(const void *a, const void *b)
{
uint64_t addr = *(uint64_t *)a;
const struct uftrace_symbol *sym = b;
if (sym->addr <= addr && addr < sym->addr + sym->size)
return 0;
if (sym->addr > addr)
return -1;
return 1;
}
static int namesort(const void *a, const void *b)
{
const struct uftrace_symbol *syma = *(const struct uftrace_symbol **)a;
const struct uftrace_symbol *symb = *(const struct uftrace_symbol **)b;
return strcmp(syma->name, symb->name);
}
static int namefind(const void *a, const void *b)
{
const char *name = a;
const struct uftrace_symbol *sym = *(const struct uftrace_symbol **)b;
return strcmp(name, sym->name);
}
char *get_soname(const char *filename)
{
struct uftrace_elf_data elf;
struct uftrace_elf_iter iter;
char *soname = NULL;
if (elf_init(filename, &elf) < 0) {
pr_dbg("error during open symbol file: %s: %m\n", filename);
return NULL;
}
elf_for_each_shdr(&elf, &iter) {
if (iter.shdr.sh_type == SHT_DYNAMIC)
break;
}
elf_for_each_dynamic(&elf, &iter) {
if (iter.dyn.d_tag != DT_SONAME)
continue;
soname = xstrdup(elf_get_name(&elf, &iter, iter.dyn.d_un.d_ptr));
break;
}
elf_finish(&elf);
return soname;
}
bool has_dependency(const char *filename, const char *libname)
{
bool ret = false;
struct uftrace_elf_data elf;
struct uftrace_elf_iter iter;
if (elf_init(filename, &elf) < 0) {
pr_dbg("error during open symbol file: %s: %m\n", filename);
return false;
}
elf_for_each_shdr(&elf, &iter) {
if (iter.shdr.sh_type == SHT_DYNAMIC)
break;
}
elf_for_each_dynamic(&elf, &iter) {
char *soname;
if (iter.dyn.d_tag != DT_NEEDED)
continue;
soname = elf_get_name(&elf, &iter, iter.dyn.d_un.d_ptr);
if (!strcmp(soname, libname)) {
ret = true;
break;
}
}
elf_finish(&elf);
return ret;
}
int check_static_binary(const char *filename)
{
int ret = 1;
struct uftrace_elf_data elf;
struct uftrace_elf_iter iter;
if (elf_init(filename, &elf) < 0) {
pr_dbg("error during open symbol file: %s: %m\n", filename);
return -1;
}
elf_for_each_phdr(&elf, &iter) {
if (iter.phdr.p_type == PT_DYNAMIC) {
ret = 0;
break;
}
}
elf_finish(&elf);
return ret;
}
bool check_script_file(const char *filename, char *buf, size_t len)
{
char magic[2];
int fd;
char *p;
bool ret = false;
fd = open(filename, O_RDONLY);
if (fd < 0)
return false;
if (read(fd, magic, sizeof(magic)) < 0)
goto out;
if (magic[0] != '#' || magic[1] != '!')
goto out;
if (read(fd, buf, len) < 0) {
goto out;
}
buf[len - 1] = '\0';
p = strchr(buf, '\n');
if (p)
*p = '\0';
ret = true;
out:
close(fd);
return ret;
}
static bool is_symbol_end(const char *name)
{
if (!strcmp(name, "__sym_end") || !strcmp(name, "__dynsym_end") ||
!strcmp(name, "__func_end")) {
return true;
}
return false;
}
static void unload_symtab(struct uftrace_symtab *symtab)
{
size_t i;
for (i = 0; i < symtab->nr_sym; i++) {
struct uftrace_symbol *sym = symtab->sym + i;
free(sym->name);
}
free(symtab->sym_names);
free(symtab->sym);
symtab->nr_sym = 0;
symtab->sym = NULL;
symtab->sym_names = NULL;
}
static int load_symbol(struct uftrace_symtab *symtab, unsigned long prev_sym_value,
unsigned long long offset, unsigned long flags, struct uftrace_elf_data *elf,
struct uftrace_elf_iter *iter)
{
char *name;
struct uftrace_symbol *sym;
typeof(iter->sym) *elf_sym = &iter->sym;
if (elf_sym->st_shndx == STN_UNDEF)
return 0;
if (elf_sym->st_size == 0)
return 0;
if (elf_symbol_type(elf_sym) != STT_FUNC && elf_symbol_type(elf_sym) != STT_GNU_IFUNC &&
elf_symbol_type(elf_sym) != STT_OBJECT)
return 0;
/* skip aliases */
if (prev_sym_value == elf_sym->st_value)
return 0;
sym = &symtab->sym[symtab->nr_sym++];
sym->addr = elf_sym->st_value + offset;
sym->size = elf_sym->st_size;
switch (elf_symbol_bind(elf_sym)) {
case STB_LOCAL:
if (elf_symbol_type(elf_sym) == STT_OBJECT)
sym->type = ST_LOCAL_DATA;
else
sym->type = ST_LOCAL_FUNC;
break;
case STB_GLOBAL:
if (elf_symbol_type(elf_sym) == STT_OBJECT)
sym->type = ST_GLOBAL_DATA;
else
sym->type = ST_GLOBAL_FUNC;
break;
case STB_WEAK:
if (elf_symbol_type(elf_sym) == STT_OBJECT)
sym->type = ST_WEAK_DATA;
else
sym->type = ST_WEAK_FUNC;
break;
case STB_GNU_UNIQUE:
if (elf_symbol_type(elf_sym) == STT_OBJECT) {
sym->type = ST_UNIQUE_DATA;
break;
}
/* fall through */
default:
sym->type = ST_UNKNOWN;
break;
}
name = elf_get_name(elf, iter, elf_sym->st_name);
if (flags & SYMTAB_FL_DEMANGLE)
sym->name = demangle(name);
else
sym->name = xstrdup(name);
pr_dbg4("[%zd] %c %" PRIx64 " + %-5u %s\n", symtab->nr_sym, sym->type, sym->addr, sym->size,
sym->name);
return 1;
}
static void sort_symtab(struct uftrace_symtab *symtab)
{
unsigned i;
int dup_syms = 0;
qsort(symtab->sym, symtab->nr_sym, sizeof(*symtab->sym), addrsort);
/* remove duplicated (overlapped?) symbols */
for (i = 0; i < symtab->nr_sym - 1; i++) {
struct uftrace_symbol *curr = &symtab->sym[i];
struct uftrace_symbol *next = &symtab->sym[i + 1];
int count = 0;
char *bestname = curr->name;
while (curr->addr == next->addr && next < &symtab->sym[symtab->nr_sym]) {
/* prefer names not started by '_' (if not mangled) */
if (bestname[0] == '_' && bestname[1] != 'Z' && next->name[0] != '_')
bestname = next->name;
count++;
next++;
}
if (count) {
struct uftrace_symbol *tmp = curr;
bestname = xstrdup(bestname);
while (tmp < next - 1) {
free(tmp->name);
tmp++;
}
memmove(curr, next - 1, (symtab->nr_sym - i - count) * sizeof(*next));
free(curr->name);
curr->name = bestname;
symtab->nr_sym -= count;
dup_syms += count;
}
}
if (dup_syms)
pr_dbg4("removed %d duplicates\n", dup_syms);
symtab->nr_alloc = symtab->nr_sym;
symtab->sym = xrealloc(symtab->sym, symtab->nr_sym * sizeof(*symtab->sym));
symtab->sym_names = xmalloc(sizeof(*symtab->sym_names) * symtab->nr_sym);
for (i = 0; i < symtab->nr_sym; i++)
symtab->sym_names[i] = &symtab->sym[i];
qsort(symtab->sym_names, symtab->nr_sym, sizeof(*symtab->sym_names), namesort);
symtab->name_sorted = true;
}
static int load_symtab(struct uftrace_symtab *symtab, const char *filename,
unsigned long long offset, unsigned long flags)
{
int ret = -1;
unsigned long prev_sym_value = -1;
struct uftrace_elf_data elf;
struct uftrace_elf_iter iter;
if (elf_init(filename, &elf) < 0) {
pr_dbg("error during open symbol file: %s: %m\n", filename);
return -1;
}
if (flags & SYMTAB_FL_ADJ_OFFSET) {
elf_for_each_phdr(&elf, &iter) {
if (iter.phdr.p_type == PT_LOAD) {
offset -= iter.phdr.p_vaddr;
break;
}
}
}
again:
elf_for_each_shdr(&elf, &iter) {
if (iter.shdr.sh_type == SHT_SYMTAB)
break;
}
if (iter.shdr.sh_type != SHT_SYMTAB) {
/* no symbol table, but it might have separate debug file */
if (elf_retry(filename, &elf))
goto again;
}
if (iter.shdr.sh_type != SHT_SYMTAB) {
/*
* fallback to dynamic symbol table when there's no symbol table
* (e.g. stripped binary built with -rdynamic option)
*/
elf_for_each_shdr(&elf, &iter) {
if (iter.shdr.sh_type == SHT_DYNSYM)
break;
}
if (iter.shdr.sh_type != SHT_DYNSYM) {
pr_dbg("no symbol table was found\n");
goto out;
}
pr_dbg4("no symtab, using dynsyms instead\n");
}
if (iter.shdr.sh_size == 0 || iter.shdr.sh_entsize == 0)
goto out;
/* pre-allocate enough symbol table entries */
symtab->nr_alloc = iter.shdr.sh_size / iter.shdr.sh_entsize;
symtab->sym = xmalloc(symtab->nr_alloc * sizeof(*symtab->sym));
pr_dbg3("loading symbols from %s (offset: %#llx)\n", filename, offset);
if (iter.shdr.sh_type == SHT_SYMTAB) {
elf_for_each_symbol(&elf, &iter) {
if (load_symbol(symtab, prev_sym_value, offset, flags, &elf, &iter))
prev_sym_value = iter.sym.st_value;
}
}
else {
elf_for_each_dynamic_symbol(&elf, &iter) {
if (load_symbol(symtab, prev_sym_value, offset, flags, &elf, &iter))
prev_sym_value = iter.sym.st_value;
}
}
pr_dbg4("loaded %zd symbols\n", symtab->nr_sym);
if (symtab->nr_sym == 0) {
free(symtab->sym);
symtab->sym = NULL;
goto out;
}
/* also fixup the size of symbol table */
sort_symtab(symtab);
ret = 0;
out:
elf_finish(&elf);
return ret;
}
static int load_dyn_symbol(struct uftrace_symtab *dsymtab, int sym_idx, unsigned long offset,
unsigned long flags, unsigned long plt_entsize, unsigned long prev_addr,
struct uftrace_elf_data *elf, struct uftrace_elf_iter *iter)
{
char *name;
struct uftrace_symbol *sym;
elf_get_symbol(elf, iter, sym_idx);
name = elf_get_name(elf, iter, iter->sym.st_name);
if (*name == '\0')
return 0;
sym = &dsymtab->sym[dsymtab->nr_sym++];
if (iter->sym.st_value && iter->sym.st_shndx == STN_UNDEF)
sym->addr = iter->sym.st_value + offset;
else
sym->addr = prev_addr + plt_entsize;
sym->size = plt_entsize;
sym->type = ST_PLT_FUNC;
if (flags & SYMTAB_FL_DEMANGLE)
sym->name = demangle(name);
else
sym->name = xstrdup(name);
pr_dbg4("[%zd] %c %" PRIx64 " + %-5u %s\n", dsymtab->nr_sym, sym->type, sym->addr,
sym->size, sym->name);
return 1;
}
void sort_dynsymtab(struct uftrace_symtab *dsymtab)
{
unsigned i, k;
if (dsymtab->nr_sym == 0)
return;
dsymtab->nr_alloc = dsymtab->nr_sym;
dsymtab->sym = xrealloc(dsymtab->sym, dsymtab->nr_sym * sizeof(*dsymtab->sym));
/*
* abuse ->sym_names[] to save original index
*/
dsymtab->sym_names = xmalloc(sizeof(*dsymtab->sym_names) * dsymtab->nr_sym);
/* save current address for each symbol */
for (i = 0; i < dsymtab->nr_sym; i++)
dsymtab->sym_names[i] = (void *)(long)dsymtab->sym[i].addr;
/* sort ->sym by address now */
qsort(dsymtab->sym, dsymtab->nr_sym, sizeof(*dsymtab->sym), addrsort);
/* find position of sorted symbol */
for (i = 0; i < dsymtab->nr_sym; i++) {
for (k = 0; k < dsymtab->nr_sym; k++) {
if (dsymtab->sym_names[i] == (void *)(long)dsymtab->sym[k].addr) {
dsymtab->sym_names[i] = &dsymtab->sym[k];
break;
}
}
}
dsymtab->name_sorted = false;
}
__weak int arch_load_dynsymtab_noplt(struct uftrace_symtab *dsymtab, struct uftrace_elf_data *elf,
unsigned long offset, unsigned long flags)
{
return 0;
}
int load_elf_dynsymtab(struct uftrace_symtab *dsymtab, struct uftrace_elf_data *elf,
unsigned long offset, unsigned long flags)
{
int ret = -1;
char *shstr;
unsigned long plt_addr = 0;
unsigned long prev_addr;
size_t plt_entsize = 1;
int rel_type = SHT_NULL;
bool found_dynamic = false;
bool found_dynsym = false;
bool found_pltsec = false;
struct uftrace_elf_iter sec_iter;
struct uftrace_elf_iter dyn_iter;
struct uftrace_elf_iter rel_iter;
unsigned symidx;
struct uftrace_symbol *sym;
if (flags & SYMTAB_FL_ADJ_OFFSET) {
elf_for_each_phdr(elf, &sec_iter) {
if (sec_iter.phdr.p_type == PT_LOAD) {
offset -= sec_iter.phdr.p_vaddr;
break;
}
}
}
elf_for_each_shdr(elf, &sec_iter) {
typeof(sec_iter.shdr) *shdr = &sec_iter.shdr;
shstr = elf_get_name(elf, &sec_iter, shdr->sh_name);
if (strcmp(shstr, ".dynsym") == 0) {
memcpy(&dyn_iter, &sec_iter, sizeof(sec_iter));
elf_get_strtab(elf, &dyn_iter, shdr->sh_link);
elf_get_secdata(elf, &dyn_iter);
found_dynsym = true;
}
else if (strcmp(shstr, ".rela.plt") == 0) {
memcpy(&rel_iter, &sec_iter, sizeof(sec_iter));
rel_type = SHT_RELA;
}
else if (strcmp(shstr, ".rel.plt") == 0) {
memcpy(&rel_iter, &sec_iter, sizeof(sec_iter));
rel_type = SHT_REL;
}
else if (strcmp(shstr, ".plt") == 0) {
plt_addr = shdr->sh_addr + offset;
plt_entsize = shdr->sh_entsize;
}
else if (strcmp(shstr, ".plt.sec") == 0) {
plt_addr = shdr->sh_addr + offset;
plt_entsize = shdr->sh_entsize;
found_pltsec = true;
}
else if (strcmp(shstr, ".dynamic") == 0) {
found_dynamic = true;
}
}
if (!found_dynsym || !found_dynamic) {
pr_dbg3("cannot find dynamic symbols.. skipping\n");
ret = 0;
goto out;
}
if (rel_type == SHT_NULL) {
arch_load_dynsymtab_noplt(dsymtab, elf, offset, flags);
goto out_sort;
}
if (elf->ehdr.e_machine == EM_ARM) {
plt_addr += 8; /* ARM PLT0 size is 20 */
plt_entsize = 12; /* size of R_ARM_JUMP_SLOT */
}
else if (elf->ehdr.e_machine == EM_AARCH64) {
plt_addr += 16; /* AARCH64 PLT0 size is 32 */
if (plt_entsize == 0)
plt_entsize = 16;
}
else if (elf->ehdr.e_machine == EM_386) {
plt_entsize += 12;
}
else if (elf->ehdr.e_machine == EM_X86_64) {
plt_entsize = 16; /* lld (of LLVM) seems to miss setting it */
}
else if (elf->ehdr.e_machine == EM_RISCV) {
plt_addr += 16; /* RISCV64 PLT0 size is 32 */
}
prev_addr = plt_addr;
if (found_pltsec)
prev_addr -= plt_entsize;
/* pre-allocate enough symbol table entries */
dsymtab->nr_alloc = rel_iter.shdr.sh_size / rel_iter.shdr.sh_entsize;
dsymtab->sym = xmalloc(dsymtab->nr_alloc * sizeof(*dsymtab->sym));
if (rel_type == SHT_REL) {
elf_for_each_rel(elf, &rel_iter) {
symidx = elf_rel_symbol(&rel_iter.rel);
elf_get_symbol(elf, &dyn_iter, symidx);
if (load_dyn_symbol(dsymtab, symidx, offset, flags, plt_entsize, prev_addr,
elf, &dyn_iter)) {
sym = &dsymtab->sym[dsymtab->nr_sym - 1];
prev_addr = sym->addr;
}
}
}
else {
elf_for_each_rela(elf, &rel_iter) {
symidx = elf_rel_symbol(&rel_iter.rela);
elf_get_symbol(elf, &dyn_iter, symidx);
if (load_dyn_symbol(dsymtab, symidx, offset, flags, plt_entsize, prev_addr,
elf, &dyn_iter)) {
sym = &dsymtab->sym[dsymtab->nr_sym - 1];
prev_addr = sym->addr;
}
}
}
out_sort:
pr_dbg4("loaded %zd symbols\n", dsymtab->nr_sym);
if (dsymtab->nr_sym == 0)
goto out;
/* also fixup the size of symbol table */
sort_dynsymtab(dsymtab);
ret = 0;
out:
return ret;
}
static void merge_symtabs(struct uftrace_symtab *left, struct uftrace_symtab *right)
{
size_t nr_sym = left->nr_sym + right->nr_sym;
struct uftrace_symbol *syms;
size_t i;
if (right->nr_sym == 0)
return;
if (left->nr_sym == 0) {
*left = *right;
right->nr_sym = 0;
right->sym = NULL;
right->sym_names = NULL;
return;
}
pr_dbg4("merge two symbol tables (left = %lu, right = %lu)\n", left->nr_sym, right->nr_sym);
syms = xmalloc(nr_sym * sizeof(*syms));
if (left->sym[0].addr < right->sym[0].addr) {
memcpy(&syms[0], left->sym, left->nr_sym * sizeof(*syms));
memcpy(&syms[left->nr_sym], right->sym, right->nr_sym * sizeof(*syms));
}
else {
memcpy(&syms[0], right->sym, right->nr_sym * sizeof(*syms));
memcpy(&syms[right->nr_sym], left->sym, left->nr_sym * sizeof(*syms));
}
free(left->sym);
free(right->sym);
left->sym = NULL;
right->sym = NULL;
free(left->sym_names);
free(right->sym_names);
left->sym_names = NULL;
right->sym_names = NULL;
left->nr_sym = left->nr_alloc = nr_sym;
left->sym = syms;
left->sym_names = xmalloc(nr_sym * sizeof(*left->sym_names));
qsort(left->sym, left->nr_sym, sizeof(*left->sym), addrsort);
for (i = 0; i < left->nr_sym; i++)
left->sym_names[i] = &left->sym[i];
qsort(left->sym_names, left->nr_sym, sizeof(*left->sym_names), namesort);
left->name_sorted = true;
}
static int load_dynsymtab(struct uftrace_symtab *dsymtab, const char *filename,
unsigned long offset, unsigned long flags)
{
struct uftrace_symtab dsymtab_noplt = {};
struct uftrace_elf_data elf;
if (elf_init(filename, &elf) < 0) {
pr_dbg("error during open symbol file: %s: %m\n", filename);
return -1;
}
pr_dbg3("loading dynamic symbols from %s (offset: %#lx)\n", filename, offset);
load_elf_dynsymtab(dsymtab, &elf, offset, flags);
arch_load_dynsymtab_noplt(&dsymtab_noplt, &elf, offset, flags);
merge_symtabs(dsymtab, &dsymtab_noplt);
elf_finish(&elf);
return dsymtab->nr_sym;
}
static int update_symtab_using_dynsym(struct uftrace_symtab *symtab, const char *filename,
unsigned long offset, unsigned long flags)
{
int ret = -1;
int count = 0;
struct uftrace_elf_data elf;
struct uftrace_elf_iter iter;
if (elf_init(filename, &elf) < 0)
return -1;
if (flags & SYMTAB_FL_ADJ_OFFSET) {
elf_for_each_phdr(&elf, &iter) {
if (iter.phdr.p_type == PT_LOAD) {
offset -= iter.phdr.p_vaddr;
break;
}
}
}
elf_for_each_shdr(&elf, &iter) {
if (iter.shdr.sh_type == SHT_DYNSYM)
break;
}
if (iter.shdr.sh_type != SHT_DYNSYM) {
ret = 0;
goto out;
}
pr_dbg4("updating symbol name using dynamic symbols\n");
elf_for_each_dynamic_symbol(&elf, &iter) {
struct uftrace_symbol *sym;
char *name;
uint64_t addr;
if (iter.sym.st_shndx == SHN_UNDEF)
continue;
if (elf_symbol_type(&iter.sym) != STT_FUNC &&
elf_symbol_type(&iter.sym) != STT_GNU_IFUNC &&
elf_symbol_type(&iter.sym) != STT_OBJECT)
continue;
addr = iter.sym.st_value + offset;
sym = bsearch(&addr, symtab->sym, symtab->nr_sym, sizeof(*sym), addrfind);
if (sym == NULL)
continue;
name = elf_get_name(&elf, &iter, iter.sym.st_name);
if (sym->name[0] != '_' && name[0] == '_')
continue;
if (sym->name[1] == 'Z')
continue;
pr_dbg4("update symbol name to %s\n", name);
free(sym->name);
count++;
if (flags & SYMTAB_FL_DEMANGLE)
sym->name = demangle(name);
else
sym->name = xstrdup(name);
}
ret = 1;
if (count)
pr_dbg4("updated %d symbols\n", count);
qsort(symtab->sym_names, symtab->nr_sym, sizeof(*symtab->sym_names), namesort);
symtab->name_sorted = true;
out:
elf_finish(&elf);
return ret;
}
static void load_python_symtab(struct uftrace_sym_info *sinfo)
{
char *symfile = NULL;
struct uftrace_mmap *map;
/* try to load python symtab (if exists) */
xasprintf(&symfile, "%s/%s.sym", sinfo->dirname, UFTRACE_PYTHON_SYMTAB_NAME);
if (access(symfile, R_OK) < 0) {
free(symfile);
return;
}
/* add a fake map for python script */
map = xzalloc(sizeof(*map) + sizeof(UFTRACE_PYTHON_SYMTAB_NAME));
memcpy(map->prot, "rwxp", 4);
strcpy(map->libname, UFTRACE_PYTHON_SYMTAB_NAME);
map->len = sizeof(UFTRACE_PYTHON_SYMTAB_NAME) - 1;
map->mod = load_module_symtab(sinfo, UFTRACE_PYTHON_SYMTAB_NAME, "no-buildid");
map->start = 0;
map->end = ALIGN(map->mod->symtab.nr_sym, 4096);
memset(&map->mod->dinfo, 0, sizeof(map->mod->dinfo));
/* add new map to symtabs */
map->next = sinfo->maps;
sinfo->maps = map;
free(symfile);
}
enum uftrace_trace_type check_trace_functions(const char *filename)
{
struct uftrace_elf_data elf;
struct uftrace_elf_iter iter;
enum uftrace_trace_type ret = TRACE_ERROR;
const char *trace_funcs[] = {
"__cyg_profile_func_enter", "__fentry__", "mcount", "_mcount", "__gnu_mcount_nc",
};
char *name;
unsigned i;
if (elf_init(filename, &elf) < 0) {
pr_dbg("error during open symbol file: %s: %m\n", filename);
return ret;
}
elf_for_each_shdr(&elf, &iter) {
if (iter.shdr.sh_type == SHT_DYNSYM) {
elf_get_secdata(&elf, &iter);
break;
}
}
if (iter.shdr.sh_type != SHT_DYNSYM) {
pr_dbg3("cannot find dynamic symbols.. skipping\n");
ret = TRACE_NONE;
goto out;
}
pr_dbg4("check trace functions in %s\n", filename);
elf_for_each_dynamic_symbol(&elf, &iter) {
elf_get_symbol(&elf, &iter, iter.i);
name = elf_get_name(&elf, &iter, iter.sym.st_name);
/* undefined function is ok here */
if (elf_symbol_type(&iter.sym) != STT_FUNC &&
#ifdef __ANDROID__
// Profiling functions are undefined on Android
elf_symbol_type(&iter.sym) != STT_NOTYPE &&
#endif
elf_symbol_type(&iter.sym) != STT_GNU_IFUNC)
continue;
for (i = 0; i < ARRAY_SIZE(trace_funcs); i++) {
if (!strcmp(name, trace_funcs[i])) {
if (i == 0)
ret = TRACE_CYGPROF;
else if (i == 1)
ret = TRACE_FENTRY;
else
ret = TRACE_MCOUNT;
goto out;
}
}
}
ret = TRACE_NONE;
out:
elf_finish(&elf);
return ret;
}
struct uftrace_mmap *find_map_by_name(struct uftrace_sym_info *sinfo, const char *prefix)
{
struct uftrace_mmap *map;
char *mod_name;
for_each_map(sinfo, map) {
mod_name = strrchr(map->libname, '/');
if (mod_name == NULL)
mod_name = map->libname;
else
mod_name++;
if (!strncmp(mod_name, prefix, strlen(prefix)))
return map;
}
return NULL;
}
static int load_module_symbol_file(struct uftrace_symtab *symtab, const char *symfile,
uint64_t offset)
{
FILE *fp;
char *line = NULL;
size_t len = 0;
unsigned int i;
unsigned int grow = SYMTAB_GROW;
char allowed_types[] = "?TtwPKDdvu";
uint64_t prev_addr = -1;
char prev_type = 'X';
fp = fopen(symfile, "r");
if (fp == NULL) {
pr_dbg("reading %s failed: %m\n", symfile);
return -1;
}
pr_dbg2("loading symbols from %s: offset = %lx\n", symfile, offset);
while (getline(&line, &len, fp) > 0) {
struct uftrace_symbol *sym;
uint64_t addr;
uint32_t size;
char type;
char *name;
char *pos;
if (*line == '#') {
if (!strncmp(line, "# symbols: ", 11)) {
size_t nr_syms = strtoul(line + 11, &pos, 10);
size_t size_syms = nr_syms * sizeof(*sym);
symtab->nr_alloc = nr_syms;
symtab->sym = xrealloc(symtab->sym, size_syms);
}
continue;
}
pos = strchr(line, '\n');
if (pos)
*pos = '\0';
addr = strtoull(line, &pos, 16);
size = 0;
if (*pos++ != ' ') {
pr_dbg4("invalid symbol file format before type\n");
continue;
}
type = *pos++;
if (isdigit(type)) {
/* new symbol file has size info */
size = strtoul(pos - 1, &pos, 16);
if (*pos++ != ' ') {
pr_dbg4("invalid symbol file format for size\n");
continue;
}
type = *pos++;
}
if (*pos++ != ' ') {
pr_dbg4("invalid symbol file format after type\n");
continue;
}
name = pos;
/*
* remove kernel module if any.
* ex) btrfs_end_transaction_throttle [btrfs]
*/
pos = strchr(name, '\t');
if (pos)
*pos = '\0';
if (addr == prev_addr && type == prev_type) {