addr2line.c

   1 /*
   2  * Copyright (C) 2008 Eduard - Gabriel Munteanu
   3  *
   4  * This file is released under GPL version 2.
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11 #include <errno.h>
  12
  13 #include <addr2line.h>
  14 #include <config.h>
  15
  16 static int our_pipe[2], a2l_pipe[2]; /* "Ownership" defined by who reads. */
  17 static int addr2line_running;
  18
  19 int addr2line_init(const char *vmlinux_path)
  20 {
  21         char tmp[500];
  22
  23         pid_t pid;
  24
  25         if (addr2line_running)
  26                 return -EEXIST;
  27
  28         if (pipe(our_pipe) < 0)
  29                 goto err;
  30         if (pipe(a2l_pipe) < 0)
  31                 goto err;
  32
  33         pid = fork();
  34         if (pid < 0)
  35                 goto err;
  36         else if (!pid) {
  37                 close(0);
  38                 dup(a2l_pipe[0]);
  39                 close(1);
  40                 dup(our_pipe[1]);
  41                 sprintf(tmp, "--exe=%s", vmlinux_path);
  42                 exit(execl(ADDR2LINE_PATH, ADDR2LINE_PATH,
  43                            "-i", tmp, (char *) NULL));
  44         } else {
  45                 addr2line_running = 1;
  46         }
  47
  48         return 0;
  49
  50 err:
  51         return -1;
  52 }
  53
  54 void addr2line_exit(void)
  55 {
  56         close(a2l_pipe[1]);
  57         close(our_pipe[0]);
  58 }
  59
  60 ssize_t addr2line_query(void *addr, char *result, size_t len)
  61 {
  62         char ptr_str[32];
  63         size_t ptr_str_len;
  64         ssize_t count;
  65
  66         sprintf(ptr_str, "%p\n", addr);
  67         ptr_str_len = strlen(ptr_str);
  68         count = write(a2l_pipe[1], ptr_str, ptr_str_len);
  69         if (count < ptr_str_len)
  70                 return -EIO;
  71
  72         count = read(our_pipe[0], result, len - 1);
  73         result[count - 1] = '\0'; /* addr2line terminates lines with '\n' */
  74
  75         return count;
  76 }
  77