nptl/init.c

   1 /* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
   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
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <assert.h>
  21 #include <limits.h>
  22 #include <signal.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <sys/param.h>
  26 #include <sys/resource.h>
  27 #include <pthreadP.h>
  28 #include <atomic.h>
  29 #include <ldsodefs.h>
  30 #include <tls.h>
  31 #include <fork.h>
  32 #include <version.h>
  33 #include <shlib-compat.h>
  34
  35
  36 #ifndef __NR_set_tid_address
  37 /* XXX For the time being...  Once we can rely on the kernel headers
  38    having the definition remove these lines.  */
  39 #if defined __s390__
  40 # define __NR_set_tid_address   252
  41 #elif defined __ia64__
  42 # define __NR_set_tid_address   1233
  43 #elif defined __i386__
  44 # define __NR_set_tid_address   258
  45 #elif defined __x86_64__
  46 # define __NR_set_tid_address   218
  47 #elif defined __powerpc__
  48 # define __NR_set_tid_address   232
  49 #else
  50 # error "define __NR_set_tid_address"
  51 #endif
  52 #endif
  53
  54
  55 /* Default stack size.  */
  56 size_t __default_stacksize attribute_hidden;
  57
  58 /* Size and alignment of static TLS block.  */
  59 size_t __static_tls_size;
  60 size_t __static_tls_align_m1;
  61
  62 /* Version of the library, used in libthread_db to detect mismatches.  */
  63 static const char nptl_version[] = VERSION;
  64
  65
  66 #if defined USE_TLS && !defined SHARED
  67 extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
  68 #endif
  69
  70
  71 #ifdef SHARED
  72 static struct pthread_functions pthread_functions =
  73   {
  74     .ptr_pthread_attr_destroy = __pthread_attr_destroy,
  75 # if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
  76     .ptr___pthread_attr_init_2_0 = __pthread_attr_init_2_0,
  77 # endif
  78     .ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1,
  79     .ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate,
  80     .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate,
  81     .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched,
  82     .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched,
  83     .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam,
  84     .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam,
  85     .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy,
  86     .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy,
  87     .ptr_pthread_attr_getscope = __pthread_attr_getscope,
  88     .ptr_pthread_attr_setscope = __pthread_attr_setscope,
  89     .ptr_pthread_condattr_destroy = __pthread_condattr_destroy,
  90     .ptr_pthread_condattr_init = __pthread_condattr_init,
  91     .ptr___pthread_cond_broadcast = __pthread_cond_broadcast,
  92     .ptr___pthread_cond_destroy = __pthread_cond_destroy,
  93     .ptr___pthread_cond_init = __pthread_cond_init,
  94     .ptr___pthread_cond_signal = __pthread_cond_signal,
  95     .ptr___pthread_cond_wait = __pthread_cond_wait,
  96 # if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
  97     .ptr___pthread_cond_broadcast_2_0 = __pthread_cond_broadcast_2_0,
  98     .ptr___pthread_cond_destroy_2_0 = __pthread_cond_destroy_2_0,
  99     .ptr___pthread_cond_init_2_0 = __pthread_cond_init_2_0,
 100     .ptr___pthread_cond_signal_2_0 = __pthread_cond_signal_2_0,
 101     .ptr___pthread_cond_wait_2_0 = __pthread_cond_wait_2_0,
 102 # endif
 103     .ptr_pthread_equal = __pthread_equal,
 104     .ptr___pthread_exit = __pthread_exit,
 105     .ptr_pthread_getschedparam = __pthread_getschedparam,
 106     .ptr_pthread_setschedparam = __pthread_setschedparam,
 107     .ptr_pthread_mutex_destroy = INTUSE(__pthread_mutex_destroy),
 108     .ptr_pthread_mutex_init = INTUSE(__pthread_mutex_init),
 109     .ptr_pthread_mutex_lock = INTUSE(__pthread_mutex_lock),
 110     .ptr_pthread_mutex_unlock = INTUSE(__pthread_mutex_unlock),
 111     .ptr_pthread_self = __pthread_self,
 112     .ptr_pthread_setcancelstate = __pthread_setcancelstate,
 113     .ptr_pthread_setcanceltype = __pthread_setcanceltype,
 114     .ptr___pthread_cleanup_upto = __pthread_cleanup_upto,
 115     .ptr___pthread_once = __pthread_once_internal,
 116     .ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock_internal,
 117     .ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock_internal,
 118     .ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock_internal,
 119     .ptr___pthread_key_create = __pthread_key_create_internal,
 120     .ptr___pthread_getspecific = __pthread_getspecific_internal,
 121     .ptr___pthread_setspecific = __pthread_setspecific_internal,
 122     .ptr__pthread_cleanup_push_defer = __pthread_cleanup_push_defer,
 123     .ptr__pthread_cleanup_pop_restore = __pthread_cleanup_pop_restore,
 124     .ptr_nthreads = &__nptl_nthreads,
 125     .ptr___pthread_unwind = &__pthread_unwind
 126   };
 127 # define ptr_pthread_functions &pthread_functions
 128 #else
 129 # define ptr_pthread_functions NULL
 130 #endif
 131
 132
 133 /* For asynchronous cancellation we use a signal.  This is the handler.  */
 134 static void
 135 sigcancel_handler (int sig, siginfo_t *si, void *ctx)
 136 {
 137   /* Safety check.  It would be possible to call this function for
 138      other signals and send a signal from another thread.  This is not
 139      correct and might even be a security problem.  Try to catch as
 140      many incorrect invocations as possible.  */
 141   if (sig != SIGCANCEL
 142 #ifdef __ASSUME_CORRECT_SI_PID
 143       /* Kernels before 2.5.75 stored the thread ID and not the process
 144          ID in si_pid so we skip this test.  */
 145       || si->si_pid != THREAD_GETMEM (THREAD_SELF, pid)
 146 #endif
 147       || si->si_code != SI_TKILL)
 148     return;
 149
 150   struct pthread *self = THREAD_SELF;
 151
 152   int oldval = THREAD_GETMEM (self, cancelhandling);
 153   while (1)
 154     {
 155       /* We are canceled now.  When canceled by another thread this flag
 156          is already set but if the signal is directly send (internally or
 157          from another process) is has to be done here.  */
 158       int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
 159
 160       if (oldval == newval || (oldval & EXITING_BITMASK) != 0)
 161         /* Already canceled or exiting.  */
 162         break;
 163
 164       int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
 165                                               oldval);
 166       if (curval == oldval)
 167         {
 168           /* Set the return value.  */
 169           THREAD_SETMEM (self, result, PTHREAD_CANCELED);
 170
 171           /* Make sure asynchronous cancellation is still enabled.  */
 172           if ((newval & CANCELTYPE_BITMASK) != 0)
 173             /* Run the registered destructors and terminate the thread.  */
 174             __do_cancel ();
 175
 176           break;
 177         }
 178
 179       oldval = curval;
 180     }
 181 }
 182
 183
 184 /* When using __thread for this, we do it in libc so as not
 185    to give libpthread its own TLS segment just for this.  */
 186 extern void **__libc_dl_error_tsd (void) __attribute__ ((const));
 187
 188
 189 void
 190 __pthread_initialize_minimal_internal (void)
 191 {
 192 #ifndef SHARED
 193   /* Unlike in the dynamically linked case the dynamic linker has not
 194      taken care of initializing the TLS data structures.  */
 195   __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
 196
 197   /* We must prevent gcc from being clever and move any of the
 198      following code ahead of the __libc_setup_tls call.  This function
 199      will initialize the thread register which is subsequently
 200      used.  */
 201   __asm __volatile ("");
 202 #endif
 203
 204   /* Minimal initialization of the thread descriptor.  */
 205   struct pthread *pd = THREAD_SELF;
 206   INTERNAL_SYSCALL_DECL (err);
 207   pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid);
 208   THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
 209   THREAD_SETMEM (pd, user_stack, true);
 210   if (LLL_LOCK_INITIALIZER != 0)
 211     THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
 212 #if HP_TIMING_AVAIL
 213   THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
 214 #endif
 215
 216   /* Initialize the list of all running threads with the main thread.  */
 217   INIT_LIST_HEAD (&__stack_user);
 218   list_add (&pd->list, &__stack_user);
 219
 220
 221   /* Install the cancellation signal handler.  If for some reason we
 222      cannot install the handler we do not abort.  Maybe we should, but
 223      it is only asynchronous cancellation which is affected.  */
 224   struct sigaction sa;
 225   sa.sa_sigaction = sigcancel_handler;
 226   sa.sa_flags = SA_SIGINFO;
 227   sigemptyset (&sa.sa_mask);
 228
 229   (void) __libc_sigaction (SIGCANCEL, &sa, NULL);
 230
 231   /* The parent process might have left the signal blocked.  Just in
 232      case, unblock it.  We reuse the signal mask in the sigaction
 233      structure.  It is already cleared.  */
 234   __sigaddset (&sa.sa_mask, SIGCANCEL);
 235   (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
 236                            NULL, _NSIG / 8);
 237
 238
 239   /* Determine the default allowed stack size.  This is the size used
 240      in case the user does not specify one.  */
 241   struct rlimit limit;
 242   if (getrlimit (RLIMIT_STACK, &limit) != 0
 243       || limit.rlim_cur == RLIM_INFINITY)
 244     /* The system limit is not usable.  Use an architecture-specific
 245        default.  */
 246     limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
 247
 248 #ifdef NEED_SEPARATE_REGISTER_STACK
 249   __default_stacksize = MAX (limit.rlim_cur / 2, PTHREAD_STACK_MIN);
 250 #else
 251   __default_stacksize = MAX (limit.rlim_cur, PTHREAD_STACK_MIN);
 252 #endif
 253   /* The maximum page size better should be a multiple of the page
 254      size.  */
 255   assert (__default_stacksize % __sysconf (_SC_PAGESIZE) == 0);
 256
 257   /* Get the size of the static and alignment requirements for the TLS
 258      block.  */
 259   size_t static_tls_align;
 260   _dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
 261
 262   /* Make sure the size takes all the alignments into account.  */
 263   if (STACK_ALIGN > static_tls_align)
 264     static_tls_align = STACK_ALIGN;
 265   __static_tls_align_m1 = static_tls_align - 1;
 266
 267   __static_tls_size = roundup (__static_tls_size, static_tls_align);
 268
 269 #ifdef SHARED
 270   /* Transfer the old value from the dynamic linker's internal location.  */
 271   *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
 272   GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
 273 #endif
 274
 275   GL(dl_init_static_tls) = &__pthread_init_static_tls;
 276
 277   /* Register the fork generation counter with the libc.  */
 278 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
 279   __libc_multiple_threads_ptr =
 280 #endif
 281     __libc_pthread_init (&__fork_generation, __reclaim_stacks,
 282                          ptr_pthread_functions);
 283 }
 284 strong_alias (__pthread_initialize_minimal_internal,
 285               __pthread_initialize_minimal)