nptl/tst-setgetname.c

   1 /* Test pthread_setname_np and pthread_getname_np.
   2    Copyright (C) 2013-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <pthread.h>
  21 #include <string.h>
  22 #include <sys/syscall.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26
  27 /* New name of process.  */
  28 #define NEW_NAME "setname"
  29
  30 /* Name of process which is one byte too big
  31    e.g. 17 bytes including null-terminator  */
  32 #define BIG_NAME       "....V....X....XV"
  33
  34 /* Longest name of a process
  35    e.g. 16 bytes including null-terminator.  */
  36 #define LONGEST_NAME   "....V....X....X"
  37
  38 /* One less than longest name with unique
  39    characters to detect modification.  */
  40 #define CANARY_NAME    "abcdefghijklmn"
  41
  42 /* On Linux the maximum length of the name of a task *including* the null
  43    terminator.  */
  44 #define TASK_COMM_LEN 16
  45
  46 /* On Linux we can read this task's name from /proc.  */
  47 int
  48 get_self_comm (long tid, char *buf, size_t len)
  49 {
  50   int res = 0;
  51 #define FMT "/proc/self/task/%lu/comm"
  52   char fname[sizeof (FMT) + 32];
  53   sprintf (fname, FMT, (unsigned long) tid);
  54
  55   int fd = open (fname, O_RDONLY);
  56   if (fd == -1)
  57     return errno;
  58
  59   ssize_t n = read (fd, (void *) buf, len);
  60   if (n < 0)
  61     res = errno;
  62   else
  63     {
  64       if (buf[n - 1] == '\n')
  65         buf[n - 1] = '\0';
  66       else if (n == len)
  67         res = ERANGE;
  68       else
  69         buf[n] = '\0';
  70     }
  71
  72   close (fd);
  73   return res;
  74 }
  75
  76 int
  77 do_test (int argc, char **argv)
  78 {
  79   pthread_t self;
  80   int res;
  81   int ret = 0;
  82   char name[TASK_COMM_LEN];
  83   char name_check[TASK_COMM_LEN];
  84
  85   memset (name, '\0', TASK_COMM_LEN);
  86   memset (name_check, '\0', TASK_COMM_LEN);
  87
  88   /* Test 1: Get the name of the task via pthread_getname_np and /proc
  89      and verify that they both match.  */
  90   self = pthread_self ();
  91   res = pthread_getname_np (self, name, TASK_COMM_LEN);
  92
  93   if (res == 0)
  94     {
  95       res = get_self_comm (gettid (), name_check, TASK_COMM_LEN);
  96
  97       if (res == 0)
  98        {
  99          if (strncmp (name, name_check, strlen (BIG_NAME)) == 0)
 100            printf ("PASS: Test 1 - pthread_getname_np and /proc agree.\n");
 101          else
 102            {
 103              printf ("FAIL: Test 1 - pthread_getname_np and /proc differ"
 104                      " i.e. %s != %s\n", name, name_check);
 105              ret++;
 106            }
 107        }
 108       else
 109        {
 110          printf ("FAIL: Test 1 - unable read task name via proc.\n");
 111          ret++;
 112         }
 113     }
 114   else
 115     {
 116       printf ("FAIL: Test 1 - pthread_getname_np failed with error %d\n", res);
 117       ret++;
 118     }
 119
 120   /* Test 2: Test setting the name and then independently verify it
 121              was set.  */
 122   res = pthread_setname_np (self, NEW_NAME);
 123
 124   if (res == 0)
 125     {
 126       res = get_self_comm (gettid (), name_check, TASK_COMM_LEN);
 127       if (res == 0)
 128         {
 129          if (strncmp (NEW_NAME, name_check, strlen (BIG_NAME)) == 0)
 130            printf ("PASS: Test 2 - Value used in pthread_setname_np and"
 131                    " /proc agree.\n");
 132          else
 133            {
 134              printf ("FAIL: Test 2 - Value used in pthread_setname_np"
 135                      " and /proc differ i.e. %s != %s\n",
 136                      NEW_NAME, name_check);
 137              ret++;
 138            }
 139         }
 140       else
 141        {
 142          printf ("FAIL: Test 2 - unable to read task name via proc.\n");
 143          ret++;
 144         }
 145     }
 146   else
 147     {
 148       printf ("FAIL: Test 2 - pthread_setname_np failed with error %d\n", res);
 149       ret++;
 150     }
 151
 152   /* Test 3: Test setting a name that is one-byte too big.  */
 153   res = pthread_getname_np (self, name, TASK_COMM_LEN);
 154
 155   if (res == 0)
 156     {
 157       res = pthread_setname_np (self, BIG_NAME);
 158       if (res != 0)
 159         {
 160          if (res == ERANGE)
 161            {
 162              printf ("PASS: Test 3 - pthread_setname_np returned ERANGE"
 163                      " for a process name that was too long.\n");
 164
 165              /* Verify the old name didn't change.  */
 166              res = get_self_comm (gettid (), name_check, TASK_COMM_LEN);
 167              if (res == 0)
 168                {
 169                  if (strncmp (name, name_check, strlen (BIG_NAME)) == 0)
 170                    printf ("PASS: Test 3 - Original name unchanged after"
 171                            " pthread_setname_np returned ERANGE.\n");
 172                  else
 173                    {
 174                      printf ("FAIL: Test 3 - Original name changed after"
 175                              " pthread_setname_np returned ERANGE"
 176                              " i.e. %s != %s\n",
 177                              name, name_check);
 178                      ret++;
 179                    }
 180                }
 181              else
 182                {
 183                  printf ("FAIL: Test 3 - unable to read task name.\n");
 184                  ret++;
 185                }
 186            }
 187          else
 188            {
 189              printf ("FAIL: Test 3 - Wrong error returned"
 190                      " i.e. ERANGE != %d\n", res);
 191              ret++;
 192            }
 193         }
 194       else
 195         {
 196          printf ("FAIL: Test 3 - Too-long name accepted by"
 197                  " pthread_setname_np.\n");
 198          ret++;
 199         }
 200     }
 201   else
 202     {
 203       printf ("FAIL: Test 3 - Unable to get original name.\n");
 204       ret++;
 205     }
 206
 207   /* Test 4: Verify that setting the longest name works.  */
 208   res = pthread_setname_np (self, LONGEST_NAME);
 209
 210   if (res == 0)
 211     {
 212       res = get_self_comm (gettid (), name_check, TASK_COMM_LEN);
 213       if (res == 0)
 214         {
 215          if (strncmp (LONGEST_NAME, name_check, strlen (BIG_NAME)) == 0)
 216            printf ("PASS: Test 4 - Longest name set via pthread_setname_np"
 217                    " agrees with /proc.\n");
 218          else
 219            {
 220              printf ("FAIL: Test 4 - Value used in pthread_setname_np and /proc"
 221                      " differ i.e. %s != %s\n", LONGEST_NAME, name_check);
 222              ret++;
 223            }
 224         }
 225       else
 226        {
 227          printf ("FAIL: Test 4 - unable to read task name via proc.\n");
 228          ret++;
 229         }
 230     }
 231   else
 232     {
 233       printf ("FAIL: Test 4 - pthread_setname_np failed with error %d\n", res);
 234       ret++;
 235     }
 236
 237   /* Test 5: Verify that getting a long name into a small buffer fails.  */
 238   strncpy (name, CANARY_NAME, strlen (CANARY_NAME) + 1);
 239
 240   /* Claim the buffer length is strlen (LONGEST_NAME).  This is one character
 241      too small to hold LONGEST_NAME *and* the null terminator.  We should get
 242      back ERANGE and name should be unmodified.  */
 243   res = pthread_getname_np (self, name, strlen (LONGEST_NAME));
 244
 245   if (res != 0)
 246     {
 247       if (res == ERANGE)
 248         {
 249           if (strncmp (CANARY_NAME, name, strlen (BIG_NAME)) == 0)
 250             {
 251               printf ("PASS: Test 5 - ERANGE and buffer unmodified.\n");
 252             }
 253           else
 254             {
 255               printf ("FAIL: Test 5 - Original buffer modified.\n");
 256               ret++;
 257             }
 258         }
 259       else
 260         {
 261           printf ("FAIL: Test 5 - Did not return ERANGE for small buffer.\n");
 262           ret++;
 263         }
 264     }
 265   else
 266     {
 267       printf ("FAIL: Test 5 - Returned name longer than buffer.\n");
 268       ret++;
 269     }
 270
 271   /* Test 6: Lastly make sure we can read back the longest name.  */
 272   res = pthread_getname_np (self, name, strlen (LONGEST_NAME) + 1);
 273
 274   if (res == 0)
 275     {
 276       if (strncmp (LONGEST_NAME, name, strlen (BIG_NAME)) == 0)
 277         {
 278           printf ("PASS: Test 6 - Read back longest name correctly.\n");
 279         }
 280       else
 281         {
 282           printf ("FAIL: Test 6 - Read \"%s\" instead of longest name.\n",
 283                   name);
 284           ret++;
 285         }
 286     }
 287   else
 288     {
 289       printf ("FAIL: Test 6 - pthread_getname_np failed with error %d\n", res);
 290       ret++;
 291     }
 292
 293   return ret;
 294 }
 295
 296 #include <test-skeleton.c>