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 #elif defined __sparc__
  50 # define __NR_set_tid_address   166
  51 #else
  52 # error "define __NR_set_tid_address"
  53 #endif
  54 #endif
  55
  56
  57 /* Default stack size.  */
  58 size_t __default_stacksize attribute_hidden;
  59
  60 /* Size and alignment of static TLS block.  */
  61 size_t __static_tls_size;
  62 size_t __static_tls_align_m1;
  63
  64 /* Version of the library, used in libthread_db to detect mismatches.  */
  65 static const char nptl_version[] = VERSION;
  66
  67
  68 #if defined USE_TLS && !defined SHARED
  69 extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
  70 #endif
  71
  72
  73 #ifdef SHARED
  74 static struct pthread_functions pthread_functions =
  75   {
  76     .ptr_pthread_attr_destroy = __pthread_attr_destroy,
  77 # if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
  78     .ptr___pthread_attr_init_2_0 = __pthread_attr_init_2_0,
  79 # endif
  80     .ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1,
  81     .ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate,
  82     .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate,
  83     .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched,
  84     .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched,
  85     .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam,
  86     .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam,
  87     .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy,
  88     .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy,
  89     .ptr_pthread_attr_getscope = __pthread_attr_getscope,
  90     .ptr_pthread_attr_setscope = __pthread_attr_setscope,
  91     .ptr_pthread_condattr_destroy = __pthread_condattr_destroy,
  92     .ptr_pthread_condattr_init = __pthread_condattr_init,
  93     .ptr___pthread_cond_broadcast = __pthread_cond_broadcast,
  94     .ptr___pthread_cond_destroy = __pthread_cond_destroy,
  95     .ptr___pthread_cond_init = __pthread_cond_init,
  96     .ptr___pthread_cond_signal = __pthread_cond_signal,
  97     .ptr___pthread_cond_wait = __pthread_cond_wait,
  98     .ptr___pthread_cond_timedwait = __pthread_cond_timedwait,
  99 # if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
 100     .ptr___pthread_cond_broadcast_2_0 = __pthread_cond_broadcast_2_0,
 101     .ptr___pthread_cond_destroy_2_0 = __pthread_cond_destroy_2_0,
 102     .ptr___pthread_cond_init_2_0 = __pthread_cond_init_2_0,
 103     .ptr___pthread_cond_signal_2_0 = __pthread_cond_signal_2_0,
 104     .ptr___pthread_cond_wait_2_0 = __pthread_cond_wait_2_0,
 105     .ptr___pthread_cond_timedwait_2_0 = __pthread_cond_timedwait_2_0,
 106 # endif
 107     .ptr_pthread_equal = __pthread_equal,
 108     .ptr___pthread_exit = __pthread_exit,
 109     .ptr_pthread_getschedparam = __pthread_getschedparam,
 110     .ptr_pthread_setschedparam = __pthread_setschedparam,
 111     .ptr_pthread_mutex_destroy = INTUSE(__pthread_mutex_destroy),
 112     .ptr_pthread_mutex_init = INTUSE(__pthread_mutex_init),
 113     .ptr_pthread_mutex_lock = INTUSE(__pthread_mutex_lock),
 114     .ptr_pthread_mutex_unlock = INTUSE(__pthread_mutex_unlock),
 115     .ptr_pthread_self = __pthread_self,
 116     .ptr_pthread_setcancelstate = __pthread_setcancelstate,
 117     .ptr_pthread_setcanceltype = __pthread_setcanceltype,
 118     .ptr___pthread_cleanup_upto = __pthread_cleanup_upto,
 119     .ptr___pthread_once = __pthread_once_internal,
 120     .ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock_internal,
 121     .ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock_internal,
 122     .ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock_internal,
 123     .ptr___pthread_key_create = __pthread_key_create_internal,
 124     .ptr___pthread_getspecific = __pthread_getspecific_internal,
 125     .ptr___pthread_setspecific = __pthread_setspecific_internal,
 126     .ptr__pthread_cleanup_push_defer = __pthread_cleanup_push_defer,
 127     .ptr__pthread_cleanup_pop_restore = __pthread_cleanup_pop_restore,
 128     .ptr_nthreads = &__nptl_nthreads,
 129     .ptr___pthread_unwind = &__pthread_unwind
 130   };
 131 # define ptr_pthread_functions &pthread_functions
 132 #else
 133 # define ptr_pthread_functions NULL
 134 #endif
 135
 136
 137 /* For asynchronous cancellation we use a signal.  This is the handler.  */
 138 static void
 139 sigcancel_handler (int sig, siginfo_t *si, void *ctx)
 140 {
 141   /* Safety check.  It would be possible to call this function for
 142      other signals and send a signal from another thread.  This is not
 143      correct and might even be a security problem.  Try to catch as
 144      many incorrect invocations as possible.  */
 145   if (sig != SIGCANCEL
 146 #ifdef __ASSUME_CORRECT_SI_PID
 147       /* Kernels before 2.5.75 stored the thread ID and not the process
 148          ID in si_pid so we skip this test.  */
 149       || si->si_pid != THREAD_GETMEM (THREAD_SELF, pid)
 150 #endif
 151       || si->si_code != SI_TKILL)
 152     return;
 153
 154   struct pthread *self = THREAD_SELF;
 155
 156   int oldval = THREAD_GETMEM (self, cancelhandling);
 157   while (1)
 158     {
 159       /* We are canceled now.  When canceled by another thread this flag
 160          is already set but if the signal is directly send (internally or
 161          from another process) is has to be done here.  */
 162       int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
 163
 164       if (oldval == newval || (oldval & EXITING_BITMASK) != 0)
 165         /* Already canceled or exiting.  */
 166         break;
 167
 168       int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
 169                                               oldval);
 170       if (curval == oldval)
 171         {
 172           /* Set the return value.  */
 173           THREAD_SETMEM (self, result, PTHREAD_CANCELED);
 174
 175           /* Make sure asynchronous cancellation is still enabled.  */
 176           if ((newval & CANCELTYPE_BITMASK) != 0)
 177             /* Run the registered destructors and terminate the thread.  */
 178             __do_cancel ();
 179
 180           break;
 181         }
 182
 183       oldval = curval;
 184     }
 185 }
 186
 187
 188 /* When using __thread for this, we do it in libc so as not
 189    to give libpthread its own TLS segment just for this.  */
 190 extern void **__libc_dl_error_tsd (void) __attribute__ ((const));
 191
 192
 193 void
 194 __pthread_initialize_minimal_internal (void)
 195 {
 196 #ifndef SHARED
 197   /* Unlike in the dynamically linked case the dynamic linker has not
 198      taken care of initializing the TLS data structures.  */
 199   __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
 200
 201   /* We must prevent gcc from being clever and move any of the
 202      following code ahead of the __libc_setup_tls call.  This function
 203      will initialize the thread register which is subsequently
 204      used.  */
 205   __asm __volatile ("");
 206 #endif
 207
 208   /* Minimal initialization of the thread descriptor.  */
 209   struct pthread *pd = THREAD_SELF;
 210   INTERNAL_SYSCALL_DECL (err);
 211   pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid);
 212   THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
 213   THREAD_SETMEM (pd, user_stack, true);
 214   if (LLL_LOCK_INITIALIZER != 0)
 215     THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
 216 #if HP_TIMING_AVAIL
 217   THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
 218 #endif
 219
 220   /* Initialize the list of all running threads with the main thread.  */
 221   INIT_LIST_HEAD (&__stack_user);
 222   list_add (&pd->list, &__stack_user);
 223
 224
 225   /* Install the cancellation signal handler.  If for some reason we
 226      cannot install the handler we do not abort.  Maybe we should, but
 227      it is only asynchronous cancellation which is affected.  */
 228   struct sigaction sa;
 229   sa.sa_sigaction = sigcancel_handler;
 230   sa.sa_flags = SA_SIGINFO;
 231   sigemptyset (&sa.sa_mask);
 232
 233   (void) __libc_sigaction (SIGCANCEL, &sa, NULL);
 234
 235   /* The parent process might have left the signal blocked.  Just in
 236      case, unblock it.  We reuse the signal mask in the sigaction
 237      structure.  It is already cleared.  */
 238   __sigaddset (&sa.sa_mask, SIGCANCEL);
 239   (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
 240                            NULL, _NSIG / 8);
 241
 242
 243   /* Determine the default allowed stack size.  This is the size used
 244      in case the user does not specify one.  */
 245   struct rlimit limit;
 246   if (getrlimit (RLIMIT_STACK, &limit) != 0
 247       || limit.rlim_cur == RLIM_INFINITY)
 248     /* The system limit is not usable.  Use an architecture-specific
 249        default.  */
 250     limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE;
 251
 252 #ifdef NEED_SEPARATE_REGISTER_STACK
 253   __default_stacksize = MAX (limit.rlim_cur / 2, PTHREAD_STACK_MIN);
 254 #else
 255   __default_stacksize = MAX (limit.rlim_cur, PTHREAD_STACK_MIN);
 256 #endif
 257   /* The maximum page size better should be a multiple of the page
 258      size.  */
 259   assert (__default_stacksize % __sysconf (_SC_PAGESIZE) == 0);
 260
 261   /* Get the size of the static and alignment requirements for the TLS
 262      block.  */
 263   size_t static_tls_align;
 264   _dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
 265
 266   /* Make sure the size takes all the alignments into account.  */
 267   if (STACK_ALIGN > static_tls_align)
 268     static_tls_align = STACK_ALIGN;
 269   __static_tls_align_m1 = static_tls_align - 1;
 270
 271   __static_tls_size = roundup (__static_tls_size, static_tls_align);
 272
 273 #ifdef SHARED
 274   /* Transfer the old value from the dynamic linker's internal location.  */
 275   *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
 276   GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
 277
 278   /* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock,
 279      keep the lock count from the ld.so implementation.  */
 280   GL(dl_rtld_lock_recursive) = (void *) INTUSE (__pthread_mutex_lock);
 281   GL(dl_rtld_unlock_recursive) = (void *) INTUSE (__pthread_mutex_unlock);
 282   unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__data.__count;
 283   GL(dl_load_lock).mutex.__data.__count = 0;
 284   while (rtld_lock_count-- > 0)
 285     INTUSE (__pthread_mutex_lock) (&GL(dl_load_lock).mutex);
 286
 287   GL(dl_make_stack_executable_hook) = &__make_stacks_executable;
 288 #endif
 289
 290   GL(dl_init_static_tls) = &__pthread_init_static_tls;
 291
 292   /* Register the fork generation counter with the libc.  */
 293 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
 294   __libc_multiple_threads_ptr =
 295 #endif
 296     __libc_pthread_init (&__fork_generation, __reclaim_stacks,
 297                          ptr_pthread_functions);
 298 }
 299 strong_alias (__pthread_initialize_minimal_internal,
 300               __pthread_initialize_minimal)