nptl/init.c

   1 /* Copyright (C) 2002, 2003, 2004 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 #include <smp.h>
  35 #include <lowlevellock.h>
  36
  37
  38 #ifndef __NR_set_tid_address
  39 /* XXX For the time being...  Once we can rely on the kernel headers
  40    having the definition remove these lines.  */
  41 #if defined __s390__
  42 # define __NR_set_tid_address   252
  43 #elif defined __ia64__
  44 # define __NR_set_tid_address   1233
  45 #elif defined __i386__
  46 # define __NR_set_tid_address   258
  47 #elif defined __x86_64__
  48 # define __NR_set_tid_address   218
  49 #elif defined __powerpc__
  50 # define __NR_set_tid_address   232
  51 #elif defined __sparc__
  52 # define __NR_set_tid_address   166
  53 #else
  54 # error "define __NR_set_tid_address"
  55 #endif
  56 #endif
  57
  58
  59 /* Default stack size.  */
  60 size_t __default_stacksize attribute_hidden;
  61
  62 /* Size and alignment of static TLS block.  */
  63 size_t __static_tls_size;
  64 size_t __static_tls_align_m1;
  65
  66 /* Flag whether the machine is SMP or not.  */
  67 int __is_smp attribute_hidden;
  68
  69 /* Version of the library, used in libthread_db to detect mismatches.  */
  70 static const char nptl_version[] __attribute_used__ = VERSION;
  71
  72
  73 #if defined USE_TLS && !defined SHARED
  74 extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
  75 #endif
  76
  77
  78 #ifdef SHARED
  79 static const struct pthread_functions pthread_functions =
  80   {
  81     .ptr_pthread_attr_destroy = __pthread_attr_destroy,
  82 # if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
  83     .ptr___pthread_attr_init_2_0 = __pthread_attr_init_2_0,
  84 # endif
  85     .ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1,
  86     .ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate,
  87     .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate,
  88     .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched,
  89     .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched,
  90     .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam,
  91     .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam,
  92     .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy,
  93     .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy,
  94     .ptr_pthread_attr_getscope = __pthread_attr_getscope,
  95     .ptr_pthread_attr_setscope = __pthread_attr_setscope,
  96     .ptr_pthread_condattr_destroy = __pthread_condattr_destroy,
  97     .ptr_pthread_condattr_init = __pthread_condattr_init,
  98     .ptr___pthread_cond_broadcast = __pthread_cond_broadcast,
  99     .ptr___pthread_cond_destroy = __pthread_cond_destroy,
 100     .ptr___pthread_cond_init = __pthread_cond_init,
 101     .ptr___pthread_cond_signal = __pthread_cond_signal,
 102     .ptr___pthread_cond_wait = __pthread_cond_wait,
 103     .ptr___pthread_cond_timedwait = __pthread_cond_timedwait,
 104 # if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2)
 105     .ptr___pthread_cond_broadcast_2_0 = __pthread_cond_broadcast_2_0,
 106     .ptr___pthread_cond_destroy_2_0 = __pthread_cond_destroy_2_0,
 107     .ptr___pthread_cond_init_2_0 = __pthread_cond_init_2_0,
 108     .ptr___pthread_cond_signal_2_0 = __pthread_cond_signal_2_0,
 109     .ptr___pthread_cond_wait_2_0 = __pthread_cond_wait_2_0,
 110     .ptr___pthread_cond_timedwait_2_0 = __pthread_cond_timedwait_2_0,
 111 # endif
 112     .ptr_pthread_equal = __pthread_equal,
 113     .ptr___pthread_exit = __pthread_exit,
 114     .ptr_pthread_getschedparam = __pthread_getschedparam,
 115     .ptr_pthread_setschedparam = __pthread_setschedparam,
 116     .ptr_pthread_mutex_destroy = INTUSE(__pthread_mutex_destroy),
 117     .ptr_pthread_mutex_init = INTUSE(__pthread_mutex_init),
 118     .ptr_pthread_mutex_lock = INTUSE(__pthread_mutex_lock),
 119     .ptr_pthread_mutex_unlock = INTUSE(__pthread_mutex_unlock),
 120     .ptr_pthread_self = __pthread_self,
 121     .ptr_pthread_setcancelstate = __pthread_setcancelstate,
 122     .ptr_pthread_setcanceltype = __pthread_setcanceltype,
 123     .ptr___pthread_cleanup_upto = __pthread_cleanup_upto,
 124     .ptr___pthread_once = __pthread_once_internal,
 125     .ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock_internal,
 126     .ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock_internal,
 127     .ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock_internal,
 128     .ptr___pthread_key_create = __pthread_key_create_internal,
 129     .ptr___pthread_getspecific = __pthread_getspecific_internal,
 130     .ptr___pthread_setspecific = __pthread_setspecific_internal,
 131     .ptr__pthread_cleanup_push_defer = __pthread_cleanup_push_defer,
 132     .ptr__pthread_cleanup_pop_restore = __pthread_cleanup_pop_restore,
 133     .ptr_nthreads = &__nptl_nthreads,
 134     .ptr___pthread_unwind = &__pthread_unwind,
 135     .ptr__nptl_deallocate_tsd = __nptl_deallocate_tsd,
 136     .ptr__nptl_setxid = __nptl_setxid
 137   };
 138 # define ptr_pthread_functions &pthread_functions
 139 #else
 140 # define ptr_pthread_functions NULL
 141 #endif
 142
 143
 144 /* For asynchronous cancellation we use a signal.  This is the handler.  */
 145 static void
 146 sigcancel_handler (int sig, siginfo_t *si, void *ctx)
 147 {
 148   /* Safety check.  It would be possible to call this function for
 149      other signals and send a signal from another process.  This is not
 150      correct and might even be a security problem.  Try to catch as
 151      many incorrect invocations as possible.  */
 152   if (sig != SIGCANCEL
 153 #ifdef __ASSUME_CORRECT_SI_PID
 154       /* Kernels before 2.5.75 stored the thread ID and not the process
 155          ID in si_pid so we skip this test.  */
 156       || si->si_pid != THREAD_GETMEM (THREAD_SELF, pid)
 157 #endif
 158       || si->si_code != SI_TKILL)
 159     return;
 160
 161   struct pthread *self = THREAD_SELF;
 162
 163   int oldval = THREAD_GETMEM (self, cancelhandling);
 164   while (1)
 165     {
 166       /* We are canceled now.  When canceled by another thread this flag
 167          is already set but if the signal is directly send (internally or
 168          from another process) is has to be done here.  */
 169       int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK;
 170
 171       if (oldval == newval || (oldval & EXITING_BITMASK) != 0)
 172         /* Already canceled or exiting.  */
 173         break;
 174
 175       int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval,
 176                                               oldval);
 177       if (curval == oldval)
 178         {
 179           /* Set the return value.  */
 180           THREAD_SETMEM (self, result, PTHREAD_CANCELED);
 181
 182           /* Make sure asynchronous cancellation is still enabled.  */
 183           if ((newval & CANCELTYPE_BITMASK) != 0)
 184             /* Run the registered destructors and terminate the thread.  */
 185             __do_cancel ();
 186
 187           break;
 188         }
 189
 190       oldval = curval;
 191     }
 192 }
 193
 194
 195 struct xid_command *__xidcmd attribute_hidden;
 196
 197 /* For asynchronous cancellation we use a signal.  This is the handler.  */
 198 static void
 199 sighandler_setxid (int sig, siginfo_t *si, void *ctx)
 200 {
 201   /* Safety check.  It would be possible to call this function for
 202      other signals and send a signal from another process.  This is not
 203      correct and might even be a security problem.  Try to catch as
 204      many incorrect invocations as possible.  */
 205   if (sig != SIGSETXID
 206 #ifdef __ASSUME_CORRECT_SI_PID
 207       /* Kernels before 2.5.75 stored the thread ID and not the process
 208          ID in si_pid so we skip this test.  */
 209       || si->si_pid != THREAD_GETMEM (THREAD_SELF, pid)
 210 #endif
 211       || si->si_code != SI_TKILL)
 212     return;
 213
 214   INTERNAL_SYSCALL_DECL (err);
 215   INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0],
 216                         __xidcmd->id[1], __xidcmd->id[2]);
 217
 218   if (atomic_decrement_val (&__xidcmd->cntr) == 0)
 219     lll_futex_wake (&__xidcmd->cntr, 1);
 220 }
 221
 222
 223 /* When using __thread for this, we do it in libc so as not
 224    to give libpthread its own TLS segment just for this.  */
 225 extern void **__libc_dl_error_tsd (void) __attribute__ ((const));
 226
 227
 228 void
 229 __pthread_initialize_minimal_internal (void)
 230 {
 231 #ifndef SHARED
 232   /* Unlike in the dynamically linked case the dynamic linker has not
 233      taken care of initializing the TLS data structures.  */
 234   __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN);
 235
 236   /* We must prevent gcc from being clever and move any of the
 237      following code ahead of the __libc_setup_tls call.  This function
 238      will initialize the thread register which is subsequently
 239      used.  */
 240   __asm __volatile ("");
 241 #endif
 242
 243   /* Minimal initialization of the thread descriptor.  */
 244   struct pthread *pd = THREAD_SELF;
 245   INTERNAL_SYSCALL_DECL (err);
 246   pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid);
 247   THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]);
 248   THREAD_SETMEM (pd, user_stack, true);
 249   if (LLL_LOCK_INITIALIZER != 0)
 250     THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER);
 251 #if HP_TIMING_AVAIL
 252   THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset));
 253 #endif
 254
 255   /* Set initial thread's stack block from 0 up to __libc_stack_end.
 256      It will be bigger than it actually is, but for unwind.c/pt-longjmp.c
 257      purposes this is good enough.  */
 258   THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end);
 259
 260   /* Initialize the list of all running threads with the main thread.  */
 261   INIT_LIST_HEAD (&__stack_user);
 262   list_add (&pd->list, &__stack_user);
 263
 264
 265   /* Install the cancellation signal handler.  If for some reason we
 266      cannot install the handler we do not abort.  Maybe we should, but
 267      it is only asynchronous cancellation which is affected.  */
 268   struct sigaction sa;
 269   sa.sa_sigaction = sigcancel_handler;
 270   sa.sa_flags = SA_SIGINFO;
 271   sigemptyset (&sa.sa_mask);
 272
 273   (void) __libc_sigaction (SIGCANCEL, &sa, NULL);
 274
 275   /* Install the handle to change the threads' uid/gid.  */
 276   sa.sa_sigaction = sighandler_setxid;
 277   sa.sa_flags = SA_SIGINFO | SA_RESTART;
 278
 279   (void) __libc_sigaction (SIGSETXID, &sa, NULL);
 280
 281   /* The parent process might have left the signal blocked.  Just in
 282      case, unblock it.  We reuse the signal mask in the sigaction
 283      structure.  It is already cleared.  */
 284   __sigaddset (&sa.sa_mask, SIGCANCEL);
 285   (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask,
 286                            NULL, _NSIG / 8);
 287
 288
 289   /* Determine the default allowed stack size.  This is the size used
 290      in case the user does not specify one.  */
 291   struct rlimit limit;
 292   if (getrlimit (RLIMIT_STACK, &limit) != 0
 293       || limit.rlim_cur == RLIM_INFINITY)
 294     /* The system limit is not usable.  Use an architecture-specific
 295        default.  */
 296     __default_stacksize = ARCH_STACK_DEFAULT_SIZE;
 297   else if (limit.rlim_cur < PTHREAD_STACK_MIN)
 298     /* The system limit is unusably small.
 299        Use the minimal size acceptable.  */
 300     __default_stacksize = PTHREAD_STACK_MIN;
 301   else
 302     {
 303       /* Round the resource limit up to page size.  */
 304       const uintptr_t pagesz = __sysconf (_SC_PAGESIZE);
 305       __default_stacksize = (limit.rlim_cur + pagesz - 1) & -pagesz;
 306     }
 307
 308   /* Get the size of the static and alignment requirements for the TLS
 309      block.  */
 310   size_t static_tls_align;
 311   _dl_get_tls_static_info (&__static_tls_size, &static_tls_align);
 312
 313   /* Make sure the size takes all the alignments into account.  */
 314   if (STACK_ALIGN > static_tls_align)
 315     static_tls_align = STACK_ALIGN;
 316   __static_tls_align_m1 = static_tls_align - 1;
 317
 318   __static_tls_size = roundup (__static_tls_size, static_tls_align);
 319
 320 #ifdef SHARED
 321   /* Transfer the old value from the dynamic linker's internal location.  */
 322   *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) ();
 323   GL(dl_error_catch_tsd) = &__libc_dl_error_tsd;
 324
 325   /* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock,
 326      keep the lock count from the ld.so implementation.  */
 327   GL(dl_rtld_lock_recursive) = (void *) INTUSE (__pthread_mutex_lock);
 328   GL(dl_rtld_unlock_recursive) = (void *) INTUSE (__pthread_mutex_unlock);
 329   unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__data.__count;
 330   GL(dl_load_lock).mutex.__data.__count = 0;
 331   while (rtld_lock_count-- > 0)
 332     INTUSE (__pthread_mutex_lock) (&GL(dl_load_lock).mutex);
 333
 334   GL(dl_make_stack_executable_hook) = &__make_stacks_executable;
 335 #endif
 336
 337   GL(dl_init_static_tls) = &__pthread_init_static_tls;
 338
 339   /* Register the fork generation counter with the libc.  */
 340 #ifndef TLS_MULTIPLE_THREADS_IN_TCB
 341   __libc_multiple_threads_ptr =
 342 #endif
 343     __libc_pthread_init (&__fork_generation, __reclaim_stacks,
 344                          ptr_pthread_functions);
 345
 346   /* Determine whether the machine is SMP or not.  */
 347   __is_smp = is_smp_system ();
 348 }
 349 strong_alias (__pthread_initialize_minimal_internal,
 350               __pthread_initialize_minimal)