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