如何撤消strip - 即将符号添加回剥离的二进制文件

Question

I have a stripped binary and symbol-file. Is it possible to add the symbols back to binary and create an unstripped binary.

My use-case is using this binary w/ valgrind.

Answer 1

For those tools that do not support separate files for debug information, you can glue the debug sections back to the original binary .

You can do something along these lines, for example:

• First build a small program that efficiently extracts an arbitrary chunk from a file

  (note that dd will not do this efficiently as we'd have to use bs=1 to support an arbitrary offset and length, and objcopy -O binary does not copy sections that are not ALLOC, LOAD ※ )

   cat <<EOF | gcc -xc -o ./mydd - #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <sys/stat.h> #include <unistd.h> #include <macros.h> char buf[1024*1024]; int main(int argc, char** argv) { char *fin, *fout; int fdin, fdout; off_t off; size_t len; ssize_t rd; int status; if (argc != 5) { fprintf(stderr, "Usage: %s fin skip count fout\\n", argv[0]); return 1; } fin = argv[1]; off = strtoul(argv[2], NULL, 0); len = strtoul(argv[3], NULL, 0); fout = argv[4]; fdin = -1; fdout = -1; if ((fdin = open(fin, O_RDONLY)) < 0) { status = errno; perror(fin); } else if ((fdout = open(fout, O_WRONLY|O_TRUNC|O_CREAT, 0660)) < 0) { status = errno; perror(fout); } else if (lseek(fdin, off, SEEK_SET) == (off_t)-1) { status = errno; perror("Seeking input"); } else { while (len > 0 && (rd = read(fdin, buf, min(len, sizeof(buf)))) > 0) { if (write(fdout, buf, rd) != rd) { /*don't bother with partial writes or EINTR/EAGAIN*/ status = errno; perror(fin); break; } len -= rd; } if (rd < 0) { status = errno; perror(fin); } } if (fdin >= 0) close(fdin); if (fdout >= 0) close(fdout); return status; } EOF 

• Finally, extract the .debug sections and glue them to the stripped binary.

   objcopy ` objdump -h program.dbg | awk '$2~/^\\.debug/' | while read idx name size vma lma off algn ; do echo "$name" >&2 echo " --add-section=$name=$name.raw" ./mydd program.dbg 0x$off 0x$size $name".raw" done ` program program_with_dbg 

Answer 2

Valgrind支持单独的调试文件 ，因此您应该在这里使用答案 ，并且valgrind应该与外部化调试文件一起正常工作。

Answer 3

elfutils comes with the tool eu-unstrip which can be used to merge symbol files with executables. The result can then be used in place of the stripped version.