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when .symtab is null, use gdb info function

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This commit is contained in:
John Doe
2023-12-11 10:47:15 +00:00
parent fecaa06c79
commit fddda83a88
5 changed files with 110 additions and 38 deletions
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125
source/ucli/elf.cc
View File

@@ -163,7 +163,7 @@ static void __get_symbol_without_plt(std::set<symbol> &ss, sym_section_ctx *tab,
s.end = s.start + sym.st_size;
s.ip = s.start;
s.name = sym_name;
printf("name: %s, start: %lx, end: %lx\n", s.name.c_str(), s.start, s.end);
// printf("name: %s, start: 0x%lx, end: 0x%lx\n", s.name.c_str(), s.start, s.end);
ss.insert(s);
}
}
@@ -220,7 +220,7 @@ static void __get_plt_symbol(std::set<symbol> &ss, symbol_sections_ctx *si,
s.end = s.start + si->dynsymtab.plt_entsize;
s.ip = s.start;
s.name = sym_name;
printf("name: %s, start: %lx, end: %lx\n", s.name.c_str(), s.start, s.end);
// printf("plt name: %s, start: 0x%lx, end: 0x%lx\n", s.name.c_str(), s.start, s.end);
ss.insert(s);
}
}
@@ -282,7 +282,7 @@ static void get_all_symbols(std::set<symbol> &ss, symbol_sections_ctx *si,
bool is_stripped(const char* path) {
char command[256];
snprintf(command, sizeof(command), "file %s", path);
// snprintf(command, sizeof(command), "file %s", path);
FILE* fp = popen(command, "r");
if (fp == NULL) {
@@ -298,38 +298,92 @@ bool is_stripped(const char* path) {
}
#define MAX_LINE_LENGTH 1024
void get_symbol_from_elf_gdb(std::set<symbol> &ss, const char *path) {
void get_symbol_from_elf_gdb(std::set<symbol> &ss, const char *path, size_t file_base_addr = 0)
{
FILE *fp;
char cmd[MAX_LINE_LENGTH];
char line[MAX_LINE_LENGTH];
// 构建 GDB 命令
snprintf(cmd, sizeof(cmd),
"gdb -batch -ex \"file %s\" -ex \"info functions\"", path);
snprintf(cmd, sizeof(cmd), "gdb -batch -ex \"file %s\" -ex \"info functions\"", path);
// 执行 GDB 命令并获取输出
fp = popen(cmd, "r");
if (fp == NULL) {
perror("popen");
return ;
}
// 读取并解析 GDB 的输出
while (fgets(line, sizeof(line), fp) != NULL) {
unsigned long address;
char name[MAX_LINE_LENGTH];
// 解析函数名和地址
if (sscanf(line, "%lx %s", &address, name) == 2) {
printf("Name: %s, Address: %lx\n", name, address);
if (fp == NULL)
{
perror("popen");
return;
}
}
// 关闭 GDB 进程
pclose(fp);
//
bool non_debugging_symbols = false;
std::map<unsigned long long, std::string> symbol_map;
// 读取并解析 GDB 的输出
while (fgets(line, sizeof(line), fp) != NULL)
{
unsigned long long address;
char name[MAX_LINE_LENGTH];
// printf("line: %s", line);
if (!non_debugging_symbols)
{
if (strstr(line, "Non-debugging symbols:") != NULL)
{
non_debugging_symbols = true;
}
continue;
}
char *token = strtok(line, " ");
if (token != NULL)
{
sscanf(token, "%llx", &address);
token = strtok(NULL, "\n");
if (token != NULL)
{
strcpy(name, token);
}
// if name == ":", 跳过
if (name[0] == ':')
{
continue;
}
symbol_map[address] = std::string(name);
}
// 解析函数名和地址
// if (sscanf(line, "%llx %s", &address, name) == 2)
// {
// // if name == ":", 跳过
// if (name[0] == ':')
// {
// continue;
// }
// // printf("Name %s, Address %llx\n", name, address);
// // name -> std::string
// symbol_map[address] = std::string(name);
// }
}
symbol s;
// 插入范围到新的map
auto it = symbol_map.begin();
auto next_it = it;
++next_it;
for (; next_it != symbol_map.end(); ++it, ++next_it)
{
s.start = it->first - file_base_addr;
s.end = next_it->first - file_base_addr;
s.ip = s.start;
s.name = it->second;
// printf("gdb name: %s, start: 0x%lx, end: 0x%lx\n", s.name.c_str(), s.start, s.end);
ss.insert(s);
}
// 关闭 GDB 进程
pclose(fp);
//
}
bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
bool get_symbol_from_elf(std::set<symbol> &ss, const char *path, size_t file_base_addr) {
static int first_init = 0;
if (!first_init) {
@@ -340,12 +394,6 @@ bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
int is_reloc = 0;
elf_version(EV_CURRENT);
// Check if the file attribute contains "stripped"
if (is_stripped(path)){
get_symbol_from_elf_gdb(ss, path);
return true;
}
int fd = open(path, O_RDONLY);
Elf *elf = elf_begin(fd, ELF_C_READ, NULL); // 指向elf文件的指针
@@ -432,7 +480,22 @@ bool get_symbol_from_elf(std::set<symbol> &ss, const char *path) {
symbol_sections_ctx si;
memset(&si, 0, sizeof(si));
if (symtab_sec) {
get_symbols_in_section(&si.symtab, elf, symtab_sec, &symtab_shdr, is_reloc);
get_symbols_in_section(&si.symtab, elf, symtab_sec, &symtab_shdr, is_reloc);
} else {
if (hdr.e_type != ET_DYN) { // no shared object
// is_reloc = 1;
// printf("stripped, path: %s\n", path);
get_symbol_from_elf_gdb(ss, path, file_base_addr);
return true;
}
// Check if the file attribute contains "stripped"
// if (is_stripped(path))
// {
// printf("stripped, path: %s\n", path);
// get_symbol_from_elf_gdb(ss, path);
// return true;
// }
}
if (dynsym_sec) {
get_symbols_in_section(&si.symtab_in_dynsym, elf, dynsym_sec, &dynsym_shdr,

2
source/ucli/elf.h
View File

@@ -6,6 +6,6 @@
#include "symbol.h"
bool get_symbol_from_elf(std::set<symbol> &ss, const char *path);
bool get_symbol_from_elf(std::set<symbol> &ss, const char *path, size_t file_base_addr);
#endif

12
source/ucli/symbol.cc
View File

@@ -145,6 +145,7 @@ bool symbol_parser::get_symbol_info(int pid, symbol &sym, elf_file &file) {
file.reset(area.name);
if (file.type != JIT_TYPE) {
sym.reset(area.map(sym.ip));
sym.base = area.start; // add base address
}
return true;
@@ -173,6 +174,7 @@ bool symbol_parser::putin_symbol_cache(int tgid, unsigned long addr,
}
bool search_symbol(const std::set<symbol> &ss, symbol &sym) {
// printf("search symbol2 0x%lx\n", sym.ip);
std::set<symbol>::const_iterator it = ss.find(sym);
if (it != ss.end()) {
@@ -186,7 +188,7 @@ bool search_symbol(const std::set<symbol> &ss, symbol &sym) {
return false;
}
bool symbol_parser::load_elf(pid_t pid, const elf_file &file) {
bool symbol_parser::load_elf(pid_t pid, const elf_file &file, size_t file_base_addr) {
std::map<elf_file, std::set<symbol> >::iterator it;
it = file_symbols.find(file);
std::set<symbol> tmp;
@@ -194,7 +196,8 @@ bool symbol_parser::load_elf(pid_t pid, const elf_file &file) {
if (it != file_symbols.end()) {
return true;
}
if (get_symbol_from_elf(syms, file.filename.c_str())) {
if (get_symbol_from_elf(syms, file.filename.c_str(), file_base_addr)) {
// printf("load elf %s\n", file.filename.c_str());
file_symbols.insert(make_pair(file, std::move(syms)));
return true;
}
@@ -206,10 +209,13 @@ bool symbol_parser::find_elf_symbol(symbol &sym, const elf_file &file, int pid,
std::map<elf_file, std::set<symbol> >::iterator it;
it = file_symbols.find(file);
std::set<symbol> ss;
// printf("search symbol1 0x%lx, base 0x%lx\n", sym.ip, sym.base);
if (it == file_symbols.end()) {
if (!load_elf(pid, file)) {
if (!load_elf(pid, file, sym.base)) {
// printf("load elf %s failed\n", file.filename.c_str());
return false;
}
// printf("load elf %s success\n", file.filename.c_str());
it = file_symbols.find(file);
return search_symbol(it->second, sym);
} else {

6
source/ucli/symbol.h
View File

@@ -57,6 +57,7 @@ struct vma {
};
size_t map(size_t pc) {
// printf("pc: %lx, start: %lx, offset: %lx\n", pc, start, offset);
return pc - start + offset;
}
@@ -89,9 +90,10 @@ struct symbol {
size_t start;
size_t end;
size_t ip;
size_t base;
std::string name;
symbol() :start(0), end(0), ip(0) {}
symbol() :start(0), end(0), ip(0) , base(0) {}
symbol(size_t pc) :start(0), end(0), ip(pc) {}
void reset(size_t va) { start = end = 0; ip = va; }
@@ -135,7 +137,7 @@ public:
void dump(void);
private:
bool load_pid_maps(int pid);
bool load_elf(pid_t pid, const elf_file& file);
bool load_elf(pid_t pid, const elf_file& file, size_t file_base_addr);
bool load_perf_map(int pid, int pid_ns);
public:
int java_only;

3
source/ucli/ucli-lib.cc
View File

@@ -103,8 +103,9 @@ static int unwind_frame_callback(struct unwind_entry *entry, void *arg) {
printf("#~ 0x%lx %s ([symbol])\n", entry->ip, symbol.c_str());
return 0;
}
// printf("#~ sym1 0x%lx\n", sym.ip);
if (g_symbol_parser.get_symbol_info(entry->pid, sym, file)) {
// printf("#~ sym2 0x%lx\n", sym.ip);
if (g_symbol_parser.find_elf_symbol(sym, file, entry->pid, entry->pid_ns)) {
printf("#~ 0x%lx %s ([symbol])\n", entry->ip, sym.name.c_str());
g_symbol_parser.putin_symbol_cache(entry->pid, entry->ip, sym.name);