diff options
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/i386/createthread.c')
| -rw-r--r-- | nptl/sysdeps/unix/sysv/linux/i386/createthread.c | 170 |
1 files changed, 31 insertions, 139 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/i386/createthread.c b/nptl/sysdeps/unix/sysv/linux/i386/createthread.c index def163350f..37e3d94996 100644 --- a/nptl/sysdeps/unix/sysv/linux/i386/createthread.c +++ b/nptl/sysdeps/unix/sysv/linux/i386/createthread.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2002 Free Software Foundation, Inc. +/* Copyright (C) 2002, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. @@ -17,141 +17,33 @@ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ -#include <sched.h> -#include <setjmp.h> -#include <signal.h> -#include <stdlib.h> -#include <atomic.h> -#include <ldsodefs.h> -#include <tls.h> - - -#define CLONE_SIGNAL (CLONE_SIGHAND | CLONE_THREAD) - - -static int -create_thread (struct pthread *pd, STACK_VARIABLES_PARMS) -{ - union user_desc_init desc; - - /* Describe the thread-local storage segment. */ - - /* The 'entry_number' field. The first three bits of the segment - register value select the GDT, ignore them. We get the index - from the value of the %gs register in the current thread. */ - desc.vals[0] = TLS_GET_GS () >> 3; - /* The 'base_addr' field. Pointer to the TCB. */ - desc.vals[1] = (unsigned long int) pd; - /* The 'limit' field. We use 4GB which is 0xfffff pages. */ - desc.vals[2] = 0xfffff; - /* Collapsed value of the bitfield: - .seg_32bit = 1 - .contents = 0 - .read_exec_only = 0 - .limit_in_pages = 1 - .seg_not_present = 0 - .useable = 1 */ - desc.vals[3] = 0x51; - - - assert (pd->header.data.tcb != NULL); - - - if (__builtin_expect (THREAD_GETMEM (THREAD_SELF, report_events), 0)) - { - /* The parent thread is supposed to report events. Check whether - the TD_CREATE event is needed, too. */ - const int _idx = __td_eventword (TD_CREATE); - const uint32_t _mask = __td_eventmask (TD_CREATE); - - if ((_mask & (__nptl_threads_events.event_bits[_idx] - | pd->eventbuf.eventmask.event_bits[_idx])) != 0) - { - /* We have to report the new thread. Make sure the thread - does not run far by forcing it to get a lock. We lock it - here too so that the new thread cannot continue until we - tell it to. */ - lll_lock (pd->lock); - - /* Create the thread. */ - if (__clone (start_thread_debug, STACK_VARIABLES_ARGS, - CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGNAL | - CLONE_SETTLS | CLONE_PARENT_SETTID | - CLONE_CHILD_CLEARTID | CLONE_DETACHED | 0, - pd, &pd->tid, &desc.desc, &pd->tid) == -1) - /* Failed. */ - return errno; - - /* We now have for sure more than one thread. */ - pd->header.data.multiple_threads = 1; - - /* Now fill in the information about the new thread in - the newly created thread's data structure. We cannot let - the new thread do this since we don't know whether it was - already scheduled when we send the event. */ - pd->eventbuf.eventnum = TD_CREATE; - pd->eventbuf.eventdata = pd; - - /* Enqueue the descriptor. */ - do - pd->nextevent = __nptl_last_event; - while (atomic_compare_and_exchange_acq (&__nptl_last_event, pd, - pd->nextevent) != 0); - - /* Now call the function which signals the event. */ - __nptl_create_event (); - - /* And finally restart the new thread. */ - lll_unlock (pd->lock); - - return 0; - } - } - -#ifdef NEED_DL_SYSINFO - assert (THREAD_GETMEM (THREAD_SELF, header.data.sysinfo) - == pd->header.data.sysinfo); -#endif - - /* We rely heavily on various flags the CLONE function understands: - - CLONE_VM, CLONE_FS, CLONE_FILES - These flags select semantics with shared address space and - file descriptors according to what POSIX requires. - - CLONE_SIGNAL - This flag selects the POSIX signal semantics. - - CLONE_SETTLS - The sixth parameter to CLONE determines the TLS area for the - new thread. - - CLONE_PARENT_SETTID - The kernels writes the thread ID of the newly created thread - into the location pointed to by the fifth parameters to CLONE. - - Note that it would be semantically equivalent to use - CLONE_CHILD_SETTID but it is be more expensive in the kernel. - - CLONE_CHILD_CLEARTID - The kernels clears the thread ID of a thread that has called - sys_exit() - using the same parameter as CLONE_SETTID. - - CLONE_DETACHED - No signal is generated if the thread exists and it is - automatically reaped. - - The termination signal is chosen to be zero which means no signal - is sent. */ - if (__clone (start_thread, STACK_VARIABLES_ARGS, - CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGNAL | - CLONE_SETTLS | CLONE_PARENT_SETTID | CLONE_CHILD_CLEARTID | - CLONE_DETACHED | 0, pd, &pd->tid, &desc.desc, &pd->tid) == -1) - /* Failed. */ - return errno; - - /* We now have for sure more than one thread. */ - THREAD_SETMEM (THREAD_SELF, header.data.multiple_threads, 1); - - return 0; -} +/* The "thread register" gets initialized from a segment descriptor. + Initialize such a descriptor first. */ +#define PREPARE_CREATE \ + union user_desc_init desc; \ + \ + /* Describe the thread-local storage segment. */ \ + \ + /* The 'entry_number' field. The first three bits of the segment \ + register value select the GDT, ignore them. We get the index \ + from the value of the %gs register in the current thread. */ \ + desc.vals[0] = TLS_GET_GS () >> 3; \ + /* The 'base_addr' field. Pointer to the TCB. */ \ + desc.vals[1] = (unsigned long int) pd; \ + /* The 'limit' field. We use 4GB which is 0xfffff pages. */ \ + desc.vals[2] = 0xfffff; \ + /* Collapsed value of the bitfield: \ + .seg_32bit = 1 \ + .contents = 0 \ + .read_exec_only = 0 \ + .limit_in_pages = 1 \ + .seg_not_present = 0 \ + .useable = 1 */ \ + desc.vals[3] = 0x51 + +/* Value passed to 'clone' for initialization of the thread register. */ +#define TLS_VALUE &desc.desc + + +/* Get the real implementation. */ +#include <nptl/sysdeps/pthread/createthread.c> |