gdb/testsuite/gdb.threads/clone-new-thread-event.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2009-2024 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program 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
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18    Test that GDB doesn't lose an event for a thread it didn't know
  19    about, until an event is reported for it.  */
  20
  21 #define _GNU_SOURCE
  22 #include <sched.h>
  23 #include <assert.h>
  24 #include <stdlib.h>
  25 #include <signal.h>
  26 #include <sys/types.h>
  27 #include <unistd.h>
  28 #include <sys/syscall.h>
  29 #include <sys/wait.h>
  30
  31 #include <features.h>
  32 #ifdef __UCLIBC__
  33 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
  34 #define HAS_NOMMU
  35 #endif
  36 #endif
  37
  38 #define STACK_SIZE 0x1000
  39
  40 static int
  41 tkill (int lwpid, int signo)
  42 {
  43   return syscall (__NR_tkill, lwpid, signo);
  44 }
  45
  46 static pid_t
  47 local_gettid (void)
  48 {
  49   return syscall (__NR_gettid);
  50 }
  51
  52 static int
  53 fn (void *unused)
  54 {
  55   tkill (local_gettid (), SIGUSR1);
  56   return 0;
  57 }
  58
  59 int
  60 main (int argc, char **argv)
  61 {
  62   unsigned char *stack;
  63   int new_pid, status, ret;
  64
  65   stack = malloc (STACK_SIZE);
  66   assert (stack != NULL);
  67
  68   new_pid = clone (fn, stack + STACK_SIZE, CLONE_FILES
  69 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
  70                    | CLONE_VM
  71 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
  72                    , NULL, NULL, NULL, NULL);
  73   assert (new_pid > 0);
  74
  75   /* Note the clone call above didn't use CLONE_THREAD, so it actually
  76      put the new thread in a new thread group.  However, the new clone
  77      is still reported with PTRACE_EVENT_CLONE to GDB, since we didn't
  78      use CLONE_VFORK (results in PTRACE_EVENT_VFORK) nor set the
  79      termination signal to SIGCHLD (results in PTRACE_EVENT_FORK), so
  80      GDB thinks of it as a new thread of the same inferior.  It's a
  81      bit of an odd setup, but it's not important for what we're
  82      testing, and, it let's us conveniently use waitpid to wait for
  83      the clone, which you can't with CLONE_THREAD.  */
  84   ret = waitpid (new_pid, &status, __WALL);
  85   assert (ret == new_pid);
  86   assert (WIFSIGNALED (status) && WTERMSIG (status) == SIGUSR1);
  87
  88   return 0;
  89 }