diff options
Diffstat (limited to 'libpthread/nptl/init.c')
| -rw-r--r-- | libpthread/nptl/init.c | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/libpthread/nptl/init.c b/libpthread/nptl/init.c new file mode 100644 index 000000000..b651a3e62 --- /dev/null +++ b/libpthread/nptl/init.c @@ -0,0 +1,428 @@ +/* Copyright (C) 2002-2007, 2008, 2009 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <assert.h> +#include <errno.h> +#include <limits.h> +#include <signal.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/param.h> +#include <sys/resource.h> +#include <pthreadP.h> +#include <atomic.h> +#include <ldsodefs.h> +#include <tls.h> +#include <fork.h> +#include <version.h> +#include <smp.h> +#include <lowlevellock.h> +#include <bits/kernel-features.h> + + +/* Size and alignment of static TLS block. */ +size_t __static_tls_size; +size_t __static_tls_align_m1; + +#ifndef __ASSUME_SET_ROBUST_LIST +/* Negative if we do not have the system call and we can use it. */ +int __set_robust_list_avail; +# define set_robust_list_not_avail() \ + __set_robust_list_avail = -1 +#else +# define set_robust_list_not_avail() do { } while (0) +#endif + +#ifndef __ASSUME_FUTEX_CLOCK_REALTIME +/* Nonzero if we do not have FUTEX_CLOCK_REALTIME. */ +int __have_futex_clock_realtime; +# define __set_futex_clock_realtime() \ + __have_futex_clock_realtime = 1 +#else +#define __set_futex_clock_realtime() do { } while (0) +#endif + +/* Version of the library, used in libthread_db to detect mismatches. */ +static const char nptl_version[] __attribute_used__ = VERSION; + + +#ifndef SHARED +extern void __libc_setup_tls (size_t tcbsize, size_t tcbalign); +#endif + +#ifdef SHARED +static void nptl_freeres (void); + + +static const struct pthread_functions pthread_functions = + { + .ptr_pthread_attr_destroy = __pthread_attr_destroy, + .ptr___pthread_attr_init_2_1 = __pthread_attr_init_2_1, + .ptr_pthread_attr_getdetachstate = __pthread_attr_getdetachstate, + .ptr_pthread_attr_setdetachstate = __pthread_attr_setdetachstate, + .ptr_pthread_attr_getinheritsched = __pthread_attr_getinheritsched, + .ptr_pthread_attr_setinheritsched = __pthread_attr_setinheritsched, + .ptr_pthread_attr_getschedparam = __pthread_attr_getschedparam, + .ptr_pthread_attr_setschedparam = __pthread_attr_setschedparam, + .ptr_pthread_attr_getschedpolicy = __pthread_attr_getschedpolicy, + .ptr_pthread_attr_setschedpolicy = __pthread_attr_setschedpolicy, + .ptr_pthread_attr_getscope = __pthread_attr_getscope, + .ptr_pthread_attr_setscope = __pthread_attr_setscope, + .ptr_pthread_condattr_destroy = __pthread_condattr_destroy, + .ptr_pthread_condattr_init = __pthread_condattr_init, + .ptr___pthread_cond_broadcast = __pthread_cond_broadcast, + .ptr___pthread_cond_destroy = __pthread_cond_destroy, + .ptr___pthread_cond_init = __pthread_cond_init, + .ptr___pthread_cond_signal = __pthread_cond_signal, + .ptr___pthread_cond_wait = __pthread_cond_wait, + .ptr___pthread_cond_timedwait = __pthread_cond_timedwait, + .ptr_pthread_equal = __pthread_equal, + .ptr___pthread_exit = __pthread_exit, + .ptr_pthread_getschedparam = __pthread_getschedparam, + .ptr_pthread_setschedparam = __pthread_setschedparam, + .ptr_pthread_mutex_destroy = INTUSE(__pthread_mutex_destroy), + .ptr_pthread_mutex_init = INTUSE(__pthread_mutex_init), + .ptr_pthread_mutex_lock = INTUSE(__pthread_mutex_lock), + .ptr_pthread_mutex_unlock = INTUSE(__pthread_mutex_unlock), + .ptr_pthread_self = __pthread_self, + .ptr_pthread_setcancelstate = __pthread_setcancelstate, + .ptr_pthread_setcanceltype = __pthread_setcanceltype, + .ptr___pthread_cleanup_upto = __pthread_cleanup_upto, + .ptr___pthread_once = __pthread_once_internal, + .ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock_internal, + .ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock_internal, + .ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock_internal, + .ptr___pthread_key_create = __pthread_key_create_internal, + .ptr___pthread_getspecific = __pthread_getspecific_internal, + .ptr___pthread_setspecific = __pthread_setspecific_internal, + .ptr__pthread_cleanup_push_defer = __pthread_cleanup_push_defer, + .ptr__pthread_cleanup_pop_restore = __pthread_cleanup_pop_restore, + .ptr_nthreads = &__nptl_nthreads, + .ptr___pthread_unwind = &__pthread_unwind, + .ptr__nptl_deallocate_tsd = __nptl_deallocate_tsd, + .ptr__nptl_setxid = __nptl_setxid, + /* For now only the stack cache needs to be freed. */ + .ptr_freeres = nptl_freeres + }; +# define ptr_pthread_functions &pthread_functions +#else +# define ptr_pthread_functions NULL +#endif + + +#ifdef SHARED +/* This function is called indirectly from the freeres code in libc. */ +static void +__libc_freeres_fn_section +nptl_freeres (void) +{ + __unwind_freeres (); + __free_stacks (0); +} +#endif + + +/* For asynchronous cancellation we use a signal. This is the handler. */ +static void +sigcancel_handler (int sig, siginfo_t *si, void *ctx) +{ +#ifdef __ASSUME_CORRECT_SI_PID + /* Determine the process ID. It might be negative if the thread is + in the middle of a fork() call. */ + pid_t pid = THREAD_GETMEM (THREAD_SELF, pid); + if (__builtin_expect (pid < 0, 0)) + pid = -pid; +#endif + + /* Safety check. It would be possible to call this function for + other signals and send a signal from another process. This is not + correct and might even be a security problem. Try to catch as + many incorrect invocations as possible. */ + if (sig != SIGCANCEL +#ifdef __ASSUME_CORRECT_SI_PID + /* Kernels before 2.5.75 stored the thread ID and not the process + ID in si_pid so we skip this test. */ + || si->si_pid != pid +#endif + || si->si_code != SI_TKILL) + return; + + struct pthread *self = THREAD_SELF; + + int oldval = THREAD_GETMEM (self, cancelhandling); + while (1) + { + /* We are canceled now. When canceled by another thread this flag + is already set but if the signal is directly send (internally or + from another process) is has to be done here. */ + int newval = oldval | CANCELING_BITMASK | CANCELED_BITMASK; + + if (oldval == newval || (oldval & EXITING_BITMASK) != 0) + /* Already canceled or exiting. */ + break; + + int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, + oldval); + if (curval == oldval) + { + /* Set the return value. */ + THREAD_SETMEM (self, result, PTHREAD_CANCELED); + + /* Make sure asynchronous cancellation is still enabled. */ + if ((newval & CANCELTYPE_BITMASK) != 0) + /* Run the registered destructors and terminate the thread. */ + __do_cancel (); + + break; + } + + oldval = curval; + } +} + + +struct xid_command *__xidcmd attribute_hidden; + +/* For asynchronous cancellation we use a signal. This is the handler. */ +static void +sighandler_setxid (int sig, siginfo_t *si, void *ctx) +{ +#ifdef __ASSUME_CORRECT_SI_PID + /* Determine the process ID. It might be negative if the thread is + in the middle of a fork() call. */ + pid_t pid = THREAD_GETMEM (THREAD_SELF, pid); + if (__builtin_expect (pid < 0, 0)) + pid = -pid; +#endif + + /* Safety check. It would be possible to call this function for + other signals and send a signal from another process. This is not + correct and might even be a security problem. Try to catch as + many incorrect invocations as possible. */ + if (sig != SIGSETXID +#ifdef __ASSUME_CORRECT_SI_PID + /* Kernels before 2.5.75 stored the thread ID and not the process + ID in si_pid so we skip this test. */ + || si->si_pid != pid +#endif + || si->si_code != SI_TKILL) + return; + + INTERNAL_SYSCALL_DECL (err); + INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0], + __xidcmd->id[1], __xidcmd->id[2]); + + /* Reset the SETXID flag. */ + struct pthread *self = THREAD_SELF; + int flags, newval; + do + { + flags = THREAD_GETMEM (self, cancelhandling); + newval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, + flags & ~SETXID_BITMASK, flags); + } + while (flags != newval); + + /* And release the futex. */ + self->setxid_futex = 1; + lll_futex_wake (&self->setxid_futex, 1, LLL_PRIVATE); + + if (atomic_decrement_val (&__xidcmd->cntr) == 0) + lll_futex_wake (&__xidcmd->cntr, 1, LLL_PRIVATE); +} + + +/* When using __thread for this, we do it in libc so as not + to give libpthread its own TLS segment just for this. */ +extern void **__libc_dl_error_tsd (void) __attribute__ ((const)); + + +/* This can be set by the debugger before initialization is complete. */ +static bool __nptl_initial_report_events __attribute_used__; + +void +__pthread_initialize_minimal_internal (void) +{ +#ifndef SHARED + /* Unlike in the dynamically linked case the dynamic linker has not + taken care of initializing the TLS data structures. */ + __libc_setup_tls (TLS_TCB_SIZE, TLS_TCB_ALIGN); + + /* We must prevent gcc from being clever and move any of the + following code ahead of the __libc_setup_tls call. This function + will initialize the thread register which is subsequently + used. */ + __asm __volatile (""); +#endif + + /* Minimal initialization of the thread descriptor. */ + struct pthread *pd = THREAD_SELF; + INTERNAL_SYSCALL_DECL (err); + pd->pid = pd->tid = INTERNAL_SYSCALL (set_tid_address, err, 1, &pd->tid); + THREAD_SETMEM (pd, specific[0], &pd->specific_1stblock[0]); + THREAD_SETMEM (pd, user_stack, true); + if (LLL_LOCK_INITIALIZER != 0) + THREAD_SETMEM (pd, lock, LLL_LOCK_INITIALIZER); +#if HP_TIMING_AVAIL + THREAD_SETMEM (pd, cpuclock_offset, GL(dl_cpuclock_offset)); +#endif + + /* Initialize the robust mutex data. */ +#ifdef __PTHREAD_MUTEX_HAVE_PREV + pd->robust_prev = &pd->robust_head; +#endif + pd->robust_head.list = &pd->robust_head; +#ifdef __NR_set_robust_list + pd->robust_head.futex_offset = (offsetof (pthread_mutex_t, __data.__lock) + - offsetof (pthread_mutex_t, + __data.__list.__next)); + int res = INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head, + sizeof (struct robust_list_head)); + if (INTERNAL_SYSCALL_ERROR_P (res, err)) +#endif + set_robust_list_not_avail (); + +#ifndef __ASSUME_PRIVATE_FUTEX + /* Private futexes are always used (at least internally) so that + doing the test once this early is beneficial. */ + { + int word = 0; + word = INTERNAL_SYSCALL (futex, err, 3, &word, + FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1); + if (!INTERNAL_SYSCALL_ERROR_P (word, err)) + THREAD_SETMEM (pd, header.private_futex, FUTEX_PRIVATE_FLAG); + } + + /* Private futexes have been introduced earlier than the + FUTEX_CLOCK_REALTIME flag. We don't have to run the test if we + know the former are not supported. This also means we know the + kernel will return ENOSYS for unknown operations. */ + if (THREAD_GETMEM (pd, header.private_futex) != 0) +#endif +#ifndef __ASSUME_FUTEX_CLOCK_REALTIME + { + int word = 0; + /* NB: the syscall actually takes six parameters. The last is the + bit mask. But since we will not actually wait at all the value + is irrelevant. Given that passing six parameters is difficult + on some architectures we just pass whatever random value the + calling convention calls for to the kernel. It causes no harm. */ + word = INTERNAL_SYSCALL (futex, err, 5, &word, + FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME + | FUTEX_PRIVATE_FLAG, 1, NULL, 0); + assert (INTERNAL_SYSCALL_ERROR_P (word, err)); + if (INTERNAL_SYSCALL_ERRNO (word, err) != ENOSYS) + __set_futex_clock_realtime (); + } +#endif + + /* Set initial thread's stack block from 0 up to __libc_stack_end. + It will be bigger than it actually is, but for unwind.c/pt-longjmp.c + purposes this is good enough. */ + THREAD_SETMEM (pd, stackblock_size, (size_t) __libc_stack_end); + + /* Initialize the list of all running threads with the main thread. */ + INIT_LIST_HEAD (&__stack_user); + list_add (&pd->list, &__stack_user); + + /* Before initializing __stack_user, the debugger could not find us and + had to set __nptl_initial_report_events. Propagate its setting. */ + THREAD_SETMEM (pd, report_events, __nptl_initial_report_events); + + /* Install the cancellation signal handler. If for some reason we + cannot install the handler we do not abort. Maybe we should, but + it is only asynchronous cancellation which is affected. */ + struct sigaction sa; + sa.sa_sigaction = sigcancel_handler; + sa.sa_flags = SA_SIGINFO; + __sigemptyset (&sa.sa_mask); + + (void) __libc_sigaction (SIGCANCEL, &sa, NULL); + + /* Install the handle to change the threads' uid/gid. */ + sa.sa_sigaction = sighandler_setxid; + sa.sa_flags = SA_SIGINFO | SA_RESTART; + + (void) __libc_sigaction (SIGSETXID, &sa, NULL); + + /* The parent process might have left the signals blocked. Just in + case, unblock it. We reuse the signal mask in the sigaction + structure. It is already cleared. */ + __sigaddset (&sa.sa_mask, SIGCANCEL); + __sigaddset (&sa.sa_mask, SIGSETXID); + (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask, + NULL, _NSIG / 8); + + /* Get the size of the static and alignment requirements for the TLS + block. */ + size_t static_tls_align; + _dl_get_tls_static_info (&__static_tls_size, &static_tls_align); + + /* Make sure the size takes all the alignments into account. */ + if (STACK_ALIGN > static_tls_align) + static_tls_align = STACK_ALIGN; + __static_tls_align_m1 = static_tls_align - 1; + + __static_tls_size = roundup (__static_tls_size, static_tls_align); + + /* Determine the default allowed stack size. This is the size used + in case the user does not specify one. */ + struct rlimit limit; + if (getrlimit (RLIMIT_STACK, &limit) != 0 + || limit.rlim_cur == RLIM_INFINITY) + /* The system limit is not usable. Use an architecture-specific + default. */ + limit.rlim_cur = ARCH_STACK_DEFAULT_SIZE; + else if (limit.rlim_cur < PTHREAD_STACK_MIN) + /* The system limit is unusably small. + Use the minimal size acceptable. */ + limit.rlim_cur = PTHREAD_STACK_MIN; + + /* Make sure it meets the minimum size that allocate_stack + (allocatestack.c) will demand, which depends on the page size. */ + const uintptr_t pagesz = sysconf (_SC_PAGESIZE); + const size_t minstack = pagesz + __static_tls_size + MINIMAL_REST_STACK; + if (limit.rlim_cur < minstack) + limit.rlim_cur = minstack; + + /* Round the resource limit up to page size. */ + limit.rlim_cur = (limit.rlim_cur + pagesz - 1) & -pagesz; + __default_stacksize = limit.rlim_cur; + +#ifdef SHARED + /* Transfer the old value from the dynamic linker's internal location. */ + *__libc_dl_error_tsd () = *(*GL(dl_error_catch_tsd)) (); + GL(dl_error_catch_tsd) = &__libc_dl_error_tsd; + +#endif + + GL(dl_init_static_tls) = &__pthread_init_static_tls; + + /* Register the fork generation counter with the libc. */ +#ifndef TLS_MULTIPLE_THREADS_IN_TCB + __libc_multiple_threads_ptr = +#endif + __libc_pthread_init (&__fork_generation, __reclaim_stacks, + ptr_pthread_functions); + + /* Determine whether the machine is SMP or not. */ + __is_smp = is_smp_system (); +} +strong_alias (__pthread_initialize_minimal_internal, + __pthread_initialize_minimal) |