/* Definition for thread-local data handling. nptl/i386 version. Copyright (C) 2002-2007, 2009 Free Software Foundation, Inc. This file is part of the GNU C Library. 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 . */ #ifndef _TLS_H #define _TLS_H 1 #ifndef __ASSEMBLER__ # include # include # include # include # include # include # include /* Type for the dtv. */ typedef union dtv { size_t counter; struct { void *val; bool is_static; } pointer; } dtv_t; typedef struct { void *tcb; /* Pointer to the TCB. Not necessarily the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ int multiple_threads; uintptr_t sysinfo; uintptr_t stack_guard; uintptr_t pointer_guard; int gscope_flag; #ifndef __ASSUME_PRIVATE_FUTEX int private_futex; #else int __unused1; #endif /* Reservation of some values for the TM ABI. */ void *__private_tm[5]; } tcbhead_t; # define TLS_MULTIPLE_THREADS_IN_TCB 1 #else /* __ASSEMBLER__ */ # include #endif /* We require TLS support in the tools. */ #define HAVE_TLS_SUPPORT #define HAVE___THREAD 1 #define HAVE_TLS_MODEL_ATTRIBUTE 1 /* Signal that TLS support is available. */ #define USE_TLS 1 /* Alignment requirement for the stack. For IA-32 this is governed by the SSE memory functions. */ #define STACK_ALIGN 16 #ifndef __ASSEMBLER__ /* Get system call information. */ # include /* The old way: using LDT. */ /* Structure passed to `modify_ldt', 'set_thread_area', and 'clone' calls. */ struct user_desc { unsigned int entry_number; unsigned long int base_addr; unsigned int limit; unsigned int seg_32bit:1; unsigned int contents:2; unsigned int read_exec_only:1; unsigned int limit_in_pages:1; unsigned int seg_not_present:1; unsigned int useable:1; unsigned int empty:25; }; /* Initializing bit fields is slow. We speed it up by using a union. */ union user_desc_init { struct user_desc desc; unsigned int vals[4]; }; /* Get the thread descriptor definition. */ # include /* This is the size of the initial TCB. Can't be just sizeof (tcbhead_t), because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole struct pthread even when not linked with -lpthread. */ # define TLS_INIT_TCB_SIZE sizeof (struct pthread) /* Alignment requirements for the initial TCB. */ # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread) /* This is the size of the TCB. */ # define TLS_TCB_SIZE sizeof (struct pthread) /* Alignment requirements for the TCB. */ # define TLS_TCB_ALIGN __alignof__ (struct pthread) /* The TCB can have any size and the memory following the address the thread pointer points to is unspecified. Allocate the TCB there. */ # define TLS_TCB_AT_TP 1 /* Install the dtv pointer. The pointer passed is to the element with index -1 which contain the length. */ # define INSTALL_DTV(descr, dtvp) \ ((tcbhead_t *) (descr))->dtv = (dtvp) + 1 /* Install new dtv for current thread. */ # define INSTALL_NEW_DTV(dtvp) \ ({ struct pthread *__pd; \ THREAD_SETMEM (__pd, header.dtv, (dtvp)); }) /* Return dtv of given thread descriptor. */ # define GET_DTV(descr) \ (((tcbhead_t *) (descr))->dtv) #define THREAD_SELF_SYSINFO THREAD_GETMEM (THREAD_SELF, header.sysinfo) #define THREAD_SYSINFO(pd) ((pd)->header.sysinfo) /* Macros to load from and store into segment registers. */ # ifndef TLS_GET_GS # define TLS_GET_GS() \ ({ int __seg; __asm__ ("movw %%gs, %w0" : "=q" (__seg)); __seg & 0xffff; }) # endif # ifndef TLS_SET_GS # define TLS_SET_GS(val) \ __asm__ ("movw %w0, %%gs" :: "q" (val)) # endif # ifndef __NR_set_thread_area # define __NR_set_thread_area 243 # endif # ifndef TLS_FLAG_WRITABLE # define TLS_FLAG_WRITABLE 0x00000001 # endif // XXX Enable for the real world. #if 0 # ifndef __ASSUME_SET_THREAD_AREA # error "we need set_thread_area" # endif #endif # ifdef __PIC__ # define TLS_EBX_ARG "r" # define TLS_LOAD_EBX "xchgl %3, %%ebx\n\t" # else # define TLS_EBX_ARG "b" # define TLS_LOAD_EBX # endif #if defined NEED_DL_SYSINFO # define INIT_SYSINFO \ _head->sysinfo = GLRO(dl_sysinfo) #else # define INIT_SYSINFO #endif #ifndef LOCK_PREFIX # ifdef UP # define LOCK_PREFIX /* nothing */ # else # define LOCK_PREFIX "lock;" # endif #endif /* Code to initially initialize the thread pointer. This might need special attention since 'errno' is not yet available and if the operation can cause a failure 'errno' must not be touched. */ # define TLS_INIT_TP(thrdescr, secondcall) \ ({ void *_thrdescr = (thrdescr); \ tcbhead_t *_head = _thrdescr; \ union user_desc_init _segdescr; \ int _result; \ \ _head->tcb = _thrdescr; \ /* For now the thread descriptor is at the same address. */ \ _head->self = _thrdescr; \ /* New syscall handling support. */ \ INIT_SYSINFO; \ \ /* The 'entry_number' field. Let the kernel pick a value. */ \ if (secondcall) \ _segdescr.vals[0] = TLS_GET_GS () >> 3; \ else \ _segdescr.vals[0] = -1; \ /* The 'base_addr' field. Pointer to the TCB. */ \ _segdescr.vals[1] = (unsigned long int) _thrdescr; \ /* The 'limit' field. We use 4GB which is 0xfffff pages. */ \ _segdescr.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 */ \ _segdescr.vals[3] = 0x51; \ \ /* Install the TLS. */ \ __asm__ __volatile__ (TLS_LOAD_EBX \ "int $0x80\n\t" \ TLS_LOAD_EBX \ : "=a" (_result), "=m" (_segdescr.desc.entry_number) \ : "0" (__NR_set_thread_area), \ TLS_EBX_ARG (&_segdescr.desc), "m" (_segdescr.desc)); \ \ if (_result == 0) \ /* We know the index in the GDT, now load the segment register. \ The use of the GDT is described by the value 3 in the lower \ three bits of the segment descriptor value. \ \ Note that we have to do this even if the numeric value of \ the descriptor does not change. Loading the segment register \ causes the segment information from the GDT to be loaded \ which is necessary since we have changed it. */ \ TLS_SET_GS (_segdescr.desc.entry_number * 8 + 3); \ \ _result == 0 ? NULL \ : "set_thread_area failed when setting up thread-local storage\n"; }) /* Return the address of the dtv for the current thread. */ # define THREAD_DTV() \ ({ struct pthread *__pd; \ THREAD_GETMEM (__pd, header.dtv); }) /* Return the thread descriptor for the current thread. The contained asm must *not* be marked __volatile__ since otherwise assignments like pthread_descr self = thread_self(); do not get optimized away. */ # define THREAD_SELF \ ({ struct pthread *__self; \ __asm__ ("movl %%gs:%c1,%0" : "=r" (__self) \ : "i" (offsetof (struct pthread, header.self))); \ __self;}) /* Magic for libthread_db to know how to do THREAD_SELF. */ # define DB_THREAD_SELF \ REGISTER_THREAD_AREA (32, offsetof (struct user_regs_struct, xgs), 3) \ REGISTER_THREAD_AREA (64, 26 * 8, 3) /* x86-64's user_regs_struct->gs */ /* Read member of the thread descriptor directly. */ # define THREAD_GETMEM(descr, member) \ ({ __typeof (descr->member) __value; \ if (sizeof (__value) == 1) \ __asm__ __volatile__ ("movb %%gs:%P2,%b0" \ : "=q" (__value) \ : "0" (0), "i" (offsetof (struct pthread, member))); \ else if (sizeof (__value) == 4) \ __asm__ __volatile__ ("movl %%gs:%P1,%0" \ : "=r" (__value) \ : "i" (offsetof (struct pthread, member))); \ else \ { \ if (sizeof (__value) != 8) \ /* There should not be any value with a size other than 1, \ 4 or 8. */ \ abort (); \ \ __asm__ __volatile__ ("movl %%gs:%P1,%%eax\n\t" \ "movl %%gs:%P2,%%edx" \ : "=A" (__value) \ : "i" (offsetof (struct pthread, member)), \ "i" (offsetof (struct pthread, member) + 4)); \ } \ __value; }) /* Same as THREAD_GETMEM, but the member offset can be non-constant. */ # define THREAD_GETMEM_NC(descr, member, idx) \ ({ __typeof (descr->member[0]) __value; \ if (sizeof (__value) == 1) \ __asm__ __volatile__ ("movb %%gs:%P2(%3),%b0" \ : "=q" (__value) \ : "0" (0), "i" (offsetof (struct pthread, member[0])), \ "r" (idx)); \ else if (sizeof (__value) == 4) \ __asm__ __volatile__ ("movl %%gs:%P1(,%2,4),%0" \ : "=r" (__value) \ : "i" (offsetof (struct pthread, member[0])), \ "r" (idx)); \ else \ { \ if (sizeof (__value) != 8) \ /* There should not be any value with a size other than 1, \ 4 or 8. */ \ abort (); \ \ __asm__ __volatile__ ("movl %%gs:%P1(,%2,8),%%eax\n\t" \ "movl %%gs:4+%P1(,%2,8),%%edx" \ : "=&A" (__value) \ : "i" (offsetof (struct pthread, member[0])), \ "r" (idx)); \ } \ __value; }) /* Same as THREAD_SETMEM, but the member offset can be non-constant. */ # define THREAD_SETMEM(descr, member, value) \ ({ if (sizeof (descr->member) == 1) \ __asm__ __volatile__ ("movb %b0,%%gs:%P1" : \ : "iq" (value), \ "i" (offsetof (struct pthread, member))); \ else if (sizeof (descr->member) == 4) \ __asm__ __volatile__ ("movl %0,%%gs:%P1" : \ : "ir" (value), \ "i" (offsetof (struct pthread, member))); \ else \ { \ if (sizeof (descr->member) != 8) \ /* There should not be any value with a size other than 1, \ 4 or 8. */ \ abort (); \ \ __asm__ __volatile__ ("movl %%eax,%%gs:%P1\n\t" \ "movl %%edx,%%gs:%P2" : \ : "A" (value), \ "i" (offsetof (struct pthread, member)), \ "i" (offsetof (struct pthread, member) + 4)); \ }}) /* Set member of the thread descriptor directly. */ # define THREAD_SETMEM_NC(descr, member, idx, value) \ ({ if (sizeof (descr->member[0]) == 1) \ __asm__ __volatile__ ("movb %b0,%%gs:%P1(%2)" : \ : "iq" (value), \ "i" (offsetof (struct pthread, member)), \ "r" (idx)); \ else if (sizeof (descr->member[0]) == 4) \ __asm__ __volatile__ ("movl %0,%%gs:%P1(,%2,4)" : \ : "ir" (value), \ "i" (offsetof (struct pthread, member)), \ "r" (idx)); \ else \ { \ if (sizeof (descr->member[0]) != 8) \ /* There should not be any value with a size other than 1, \ 4 or 8. */ \ abort (); \ \ __asm__ __volatile__ ("movl %%eax,%%gs:%P1(,%2,8)\n\t" \ "movl %%edx,%%gs:4+%P1(,%2,8)" : \ : "A" (value), \ "i" (offsetof (struct pthread, member)), \ "r" (idx)); \ }}) /* Atomic compare and exchange on TLS, returning old value. */ #define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \ ({ __typeof (descr->member) __ret; \ __typeof (oldval) __old = (oldval); \ if (sizeof (descr->member) == 4) \ __asm__ __volatile__ (LOCK_PREFIX "cmpxchgl %2, %%gs:%P3" \ : "=a" (__ret) \ : "0" (__old), "r" (newval), \ "i" (offsetof (struct pthread, member))); \ else \ /* Not necessary for other sizes in the moment. */ \ abort (); \ __ret; }) /* Atomic logical and. */ #define THREAD_ATOMIC_AND(descr, member, val) \ (void) ({ if (sizeof ((descr)->member) == 4) \ __asm__ __volatile__ (LOCK_PREFIX "andl %1, %%gs:%P0" \ :: "i" (offsetof (struct pthread, member)), \ "ir" (val)); \ else \ /* Not necessary for other sizes in the moment. */ \ abort (); }) /* Atomic set bit. */ #define THREAD_ATOMIC_BIT_SET(descr, member, bit) \ (void) ({ if (sizeof ((descr)->member) == 4) \ __asm__ __volatile__ (LOCK_PREFIX "orl %1, %%gs:%P0" \ :: "i" (offsetof (struct pthread, member)), \ "ir" (1 << (bit))); \ else \ /* Not necessary for other sizes in the moment. */ \ abort (); }) /* Set the stack guard field in TCB head. */ #define THREAD_SET_STACK_GUARD(value) \ THREAD_SETMEM (THREAD_SELF, header.stack_guard, value) #define THREAD_COPY_STACK_GUARD(descr) \ ((descr)->header.stack_guard \ = THREAD_GETMEM (THREAD_SELF, header.stack_guard)) /* Set the pointer guard field in the TCB head. */ #define THREAD_SET_POINTER_GUARD(value) \ THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value) #define THREAD_COPY_POINTER_GUARD(descr) \ ((descr)->header.pointer_guard \ = THREAD_GETMEM (THREAD_SELF, header.pointer_guard)) /* Get and set the global scope generation counter in the TCB head. */ #define THREAD_GSCOPE_FLAG_UNUSED 0 #define THREAD_GSCOPE_FLAG_USED 1 #define THREAD_GSCOPE_FLAG_WAIT 2 #define THREAD_GSCOPE_RESET_FLAG() \ do \ { int __res; \ __asm__ __volatile__ ("xchgl %0, %%gs:%P1" \ : "=r" (__res) \ : "i" (offsetof (struct pthread, header.gscope_flag)), \ "0" (THREAD_GSCOPE_FLAG_UNUSED)); \ if (__res == THREAD_GSCOPE_FLAG_WAIT) \ lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \ } \ while (0) #define THREAD_GSCOPE_SET_FLAG() \ THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED) #define THREAD_GSCOPE_WAIT() \ GL(dl_wait_lookup_done) () #endif /* __ASSEMBLER__ */ #endif /* tls.h */