none/tests/procfs-cmdline-exe.c

   1 /*
   2  * Read /proc/self/cmdline and /proc/self/exe such that it can be tested
   3  * whether Valgrind intercepts the system calls that access these pseudo-files
   4  * properly on Linux and whether Valgrind does not modify the behavior of
   5  * accessing these files on other operating systems.
   6  */
   7
   8 #define _ATFILE_SOURCE
   9
  10 #include <ctype.h>
  11 #include <errno.h>
  12 #include <fcntl.h>
  13 #include <stdio.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16 #include <string.h>
  17 #include <unistd.h>
  18 #include "../../config.h"
  19
  20 static void test_cmdline(const char* const cwd, const char* const label,
  21                          const char* const path)
  22 {
  23   int fd, n;
  24   char ch;
  25
  26   fprintf(stderr, "%s:\n", label);
  27   fd = open(path, 0);
  28   if (fd >= 0)
  29   {
  30     while ((n = read(fd, &ch, 1)) > 0)
  31     {
  32       if (ch == '\\')
  33         fprintf(stderr, "\\\\");
  34       else if (ch == 0)
  35         fprintf(stderr, "\\0");
  36       else if (isprint((unsigned)ch))
  37         fprintf(stderr, "%c", ch);
  38       else
  39         fprintf(stderr, "\\0%o", ch);
  40     }
  41     fprintf(stderr, "\n");
  42     close(fd);
  43   }
  44   else
  45     perror("open()");
  46 }
  47
  48 static void test_readlink(const char* const cwd, const char* const label,
  49                           const char* const path)
  50 {
  51   char buf[512];
  52   const char* p;
  53   int n;
  54
  55   if ((n = readlink(path, buf, sizeof(buf) - 1)) >= 0)
  56   {
  57     buf[n] = 0;
  58     p = buf;
  59     if (strncmp(buf, cwd, strlen(cwd)) == 0)
  60       p += strlen(cwd);
  61     fprintf(stderr, "Result of readlink(\"%s\"): %s\n", label, p);
  62   }
  63   else
  64     perror("readlink");
  65 }
  66
  67 static void test_readlinkat(const char* const cwd, const char* const label,
  68                             const char* const path)
  69 {
  70 #if HAVE_READLINKAT
  71   char buf[512];
  72   const char* p;
  73   int n;
  74
  75   if ((n = readlinkat(AT_FDCWD, path, buf, sizeof(buf) - 1)) >= 0)
  76   {
  77     buf[n] = 0;
  78     p = buf;
  79     if (strncmp(buf, cwd, strlen(cwd)) == 0)
  80       p += strlen(cwd);
  81     fprintf(stderr, "Result of readlinkat(\"%s\"): %s\n", label, p);
  82   }
  83   else
  84     perror("readlinkat");
  85 #else
  86   errno = ENOSYS;
  87   perror("readlinkat");
  88 #endif
  89 }
  90
  91 int main(int argc, char** argv)
  92 {
  93   char cwd[512];
  94   char path[512];
  95
  96   cwd[0] = 0;
  97   if (! getcwd(cwd, sizeof(cwd)))
  98     perror("getcwd");
  99   strcat(cwd, "/");
 100
 101   snprintf(path, sizeof(path), "/proc/%ld/cmdline", (long) getpid());
 102
 103   test_cmdline(cwd, "/proc/self/cmdline", "/proc/self/cmdline");
 104   test_cmdline(cwd, "/proc/<pid>/cmdline", path);
 105
 106   snprintf(path, sizeof(path), "/proc/%ld/exe", (long) getpid());
 107
 108   test_readlink(cwd, "/proc/self/exe", "/proc/self/exe");
 109   test_readlink(cwd, "/proc/<pid>/exe", path);
 110
 111   test_readlinkat(cwd, "/proc/self/exe", "/proc/self/exe");
 112   test_readlinkat(cwd, "/proc/<pid>/exe", path);
 113
 114   return 0;
 115 }