diff options
Diffstat (limited to 'REORG.TODO/nptl/nptl-init.c')
| -rw-r--r-- | REORG.TODO/nptl/nptl-init.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/REORG.TODO/nptl/nptl-init.c b/REORG.TODO/nptl/nptl-init.c new file mode 100644 index 0000000000..29216077a2 --- /dev/null +++ b/REORG.TODO/nptl/nptl-init.c @@ -0,0 +1,480 @@ +/* Copyright (C) 2002-2017 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, see + <http://www.gnu.org/licenses/>. */ + +#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 <list.h> +#include <fork.h> +#include <version.h> +#include <shlib-compat.h> +#include <smp.h> +#include <lowlevellock.h> +#include <futex-internal.h> +#include <kernel-features.h> +#include <libc-pointer-arith.h> +#include <pthread-pids.h> + +#ifndef TLS_MULTIPLE_THREADS_IN_TCB +/* Pointer to the corresponding variable in libc. */ +int *__libc_multiple_threads_ptr attribute_hidden; +#endif + +/* 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; + + +#ifdef SHARED +static +#else +extern +#endif +void __nptl_set_robust (struct pthread *); + +#ifdef SHARED +static void nptl_freeres (void); + + +static const struct pthread_functions pthread_functions = + { + .ptr_pthread_attr_destroy = __pthread_attr_destroy, +# if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1) + .ptr___pthread_attr_init_2_0 = __pthread_attr_init_2_0, +# endif + .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, +# if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_3_2) + .ptr___pthread_cond_broadcast_2_0 = __pthread_cond_broadcast_2_0, + .ptr___pthread_cond_destroy_2_0 = __pthread_cond_destroy_2_0, + .ptr___pthread_cond_init_2_0 = __pthread_cond_init_2_0, + .ptr___pthread_cond_signal_2_0 = __pthread_cond_signal_2_0, + .ptr___pthread_cond_wait_2_0 = __pthread_cond_wait_2_0, + .ptr___pthread_cond_timedwait_2_0 = __pthread_cond_timedwait_2_0, +# endif + .ptr_pthread_equal = __pthread_equal, + .ptr___pthread_exit = __pthread_exit, + .ptr_pthread_getschedparam = __pthread_getschedparam, + .ptr_pthread_setschedparam = __pthread_setschedparam, + .ptr_pthread_mutex_destroy = __pthread_mutex_destroy, + .ptr_pthread_mutex_init = __pthread_mutex_init, + .ptr_pthread_mutex_lock = __pthread_mutex_lock, + .ptr_pthread_mutex_unlock = __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, + .ptr___pthread_rwlock_rdlock = __pthread_rwlock_rdlock, + .ptr___pthread_rwlock_wrlock = __pthread_rwlock_wrlock, + .ptr___pthread_rwlock_unlock = __pthread_rwlock_unlock, + .ptr___pthread_key_create = __pthread_key_create, + .ptr___pthread_getspecific = __pthread_getspecific, + .ptr___pthread_setspecific = __pthread_setspecific, + .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, +# ifdef SIGSETXID + .ptr__nptl_setxid = __nptl_setxid, +# endif + /* For now only the stack cache needs to be freed. */ + .ptr_freeres = nptl_freeres, + .ptr_set_robust = __nptl_set_robust + }; +# 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); +} + + +static +#endif +void +__nptl_set_robust (struct pthread *self) +{ +#ifdef __NR_set_robust_list + INTERNAL_SYSCALL_DECL (err); + INTERNAL_SYSCALL (set_robust_list, err, 2, &self->robust_head, + sizeof (struct robust_list_head)); +#endif +} + + +#ifdef SIGCANCEL +/* For asynchronous cancellation we use a signal. This is the handler. */ +static void +sigcancel_handler (int sig, siginfo_t *si, void *ctx) +{ + /* 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 + || si->si_pid != __getpid() + || 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; + } +} +#endif + + +#ifdef SIGSETXID +struct xid_command *__xidcmd attribute_hidden; + +/* We use the SIGSETXID signal in the setuid, setgid, etc. implementations to + tell each thread to call the respective setxid syscall on itself. This is + the handler. */ +static void +sighandler_setxid (int sig, siginfo_t *si, void *ctx) +{ + int result; + + /* 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 + || si->si_pid != __getpid () + || si->si_code != SI_TKILL) + return; + + INTERNAL_SYSCALL_DECL (err); + result = INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0], + __xidcmd->id[1], __xidcmd->id[2]); + int error = 0; + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err))) + error = INTERNAL_SYSCALL_ERRNO (result, err); + __nptl_setxid_error (__xidcmd, error); + + /* 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; + futex_wake (&self->setxid_futex, 1, FUTEX_PRIVATE); + + if (atomic_decrement_val (&__xidcmd->cntr) == 0) + futex_wake ((unsigned int *) &__xidcmd->cntr, 1, FUTEX_PRIVATE); +} +#endif + + +/* 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) +{ + /* Minimal initialization of the thread descriptor. */ + struct pthread *pd = THREAD_SELF; + __pthread_initialize_pids (pd); + 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)); + INTERNAL_SYSCALL_DECL (err); + 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 (); + } + +#ifdef __NR_futex +# 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; + INTERNAL_SYSCALL_DECL (err); + 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. */ + INTERNAL_SYSCALL_DECL (err); + 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 +#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); + +#if defined SIGCANCEL || defined SIGSETXID + struct sigaction sa; + __sigemptyset (&sa.sa_mask); + +# ifdef SIGCANCEL + /* 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. */ + sa.sa_sigaction = sigcancel_handler; + sa.sa_flags = SA_SIGINFO; + (void) __libc_sigaction (SIGCANCEL, &sa, NULL); +# endif + +# ifdef SIGSETXID + /* 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); +# endif + + /* 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. */ +# ifdef SIGCANCEL + __sigaddset (&sa.sa_mask, SIGCANCEL); +# endif +# ifdef SIGSETXID + __sigaddset (&sa.sa_mask, SIGSETXID); +# endif + { + INTERNAL_SYSCALL_DECL (err); + (void) INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_UNBLOCK, &sa.sa_mask, + NULL, _NSIG / 8); + } +#endif + + /* 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 = GLRO(dl_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 = ALIGN_UP (limit.rlim_cur, pagesz); + lll_lock (__default_pthread_attr_lock, LLL_PRIVATE); + __default_pthread_attr.stacksize = limit.rlim_cur; + __default_pthread_attr.guardsize = GLRO (dl_pagesize); + lll_unlock (__default_pthread_attr_lock, LLL_PRIVATE); + +#ifdef SHARED + /* Make __rtld_lock_{,un}lock_recursive use pthread_mutex_{,un}lock, + keep the lock count from the ld.so implementation. */ + GL(dl_rtld_lock_recursive) = (void *) __pthread_mutex_lock; + GL(dl_rtld_unlock_recursive) = (void *) __pthread_mutex_unlock; + unsigned int rtld_lock_count = GL(dl_load_lock).mutex.__data.__count; + GL(dl_load_lock).mutex.__data.__count = 0; + while (rtld_lock_count-- > 0) + __pthread_mutex_lock (&GL(dl_load_lock).mutex); + + GL(dl_make_stack_executable_hook) = &__make_stacks_executable; +#endif + + GL(dl_init_static_tls) = &__pthread_init_static_tls; + + GL(dl_wait_lookup_done) = &__wait_lookup_done; + + /* 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) + + +size_t +__pthread_get_minstack (const pthread_attr_t *attr) +{ + struct pthread_attr *iattr = (struct pthread_attr *) attr; + + return (GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN + + iattr->guardsize); +} |