diff options
Diffstat (limited to 'nptl/sysdeps/i386/tls.h')
| -rw-r--r-- | nptl/sysdeps/i386/tls.h | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/nptl/sysdeps/i386/tls.h b/nptl/sysdeps/i386/tls.h new file mode 100644 index 0000000000..244a487bcb --- /dev/null +++ b/nptl/sysdeps/i386/tls.h @@ -0,0 +1,332 @@ +/* Definition for thread-local data handling. linuxthreads/i386 version. + Copyright (C) 2002 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _TLS_H +#define _TLS_H 1 + +#ifndef __ASSEMBLER__ +# include <stddef.h> +# include <stdint.h> + + +/* Type for the dtv. */ +typedef union dtv +{ + size_t counter; + void *pointer; +} dtv_t; + + +typedef struct +{ + void *tcb; /* Pointer to the TCB. Not necessary the + thread descriptor used by libpthread. */ + dtv_t *dtv; + void *self; /* Pointer to the thread descriptor. */ +} tcbhead_t; +#endif + + +/* We require TLS support in the tools. */ +#ifndef HAVE_TLS_SUPPORT +# error "TLS support is required." +#endif + +/* Signal that TLS support is available. */ +#define USE_TLS 1 + +/* Alignment requirement for the stack. For IA-32 this is govern by + the SSE memory functions. */ +#define STACK_ALIGN 16 + + +#ifndef __ASSEMBLER__ +/* Get system call information. */ +# include <sysdep.h> + +/* 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 <nptl/descr.h> + +/* This is the size of the initial TCB. */ +# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t) + +/* Alignment requirements for the initial TCB. */ +# define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t) + +/* 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(dtv) \ + ({ struct pthread *__pd; \ + THREAD_SETMEM (__pd, header.data.dtvp, dtv); }) + +/* Return dtv of given thread descriptor. */ +# define GET_DTV(descr) \ + (((tcbhead_t *) (descr))->dtv) + + +/* 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 + +/* 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; \ + \ + /* 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; }) + + +/* Return the address of the dtv for the current thread. */ +# define THREAD_DTV() \ + ({ struct pthread *__pd; \ + THREAD_GETMEM (__pd, header.data.dtvp); }) + + +/* 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.data.self))); \ + __self;}) + + +/* Read member of the thread descriptor directly. */ +# define THREAD_GETMEM(descr, member) \ + ({ __typeof (descr->member) __value; \ + if (sizeof (__value) == 1) \ + asm ("movb %%gs:%P2,%b0" \ + : "=q" (__value) \ + : "0" (0), "i" (offsetof (struct pthread, member))); \ + else if (sizeof (__value) == 4) \ + asm ("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 ("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) \ + ({ __typeof (descr->member) __value; \ + if (sizeof (__value) == 1) \ + asm ("movb %%gs:(%2),%b0" \ + : "=q" (__value) \ + : "0" (0), "r" (offsetof (struct pthread, member))); \ + else if (sizeof (__value) == 4) \ + asm ("movl %%gs:(%1),%0" \ + : "=r" (__value) \ + : "r" (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 ("movl %%gs:(%1),%%eax\n\t" \ + "movl %%gs:4(%1),%%edx" \ + : "=&A" (__value) \ + : "r" (offsetof (struct pthread, member))); \ + } \ + __value; }) + + +/* Same as THREAD_SETMEM, but the member offset can be non-constant. */ +# define THREAD_SETMEM(descr, member, value) \ + ({ if (sizeof (value) == 1) \ + asm volatile ("movb %0,%%gs:%P1" : \ + : "iq" (value), \ + "i" (offsetof (struct pthread, member))); \ + else if (sizeof (value) == 4) \ + asm volatile ("movl %0,%%gs:%P1" : \ + : "ir" (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 %%eax,%%gs:%P1\n\n" \ + "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, value) \ + ({ if (sizeof (value) == 1) \ + asm volatile ("movb %0,%%gs:(%1)" : \ + : "iq" (value), \ + "r" (offsetof (struct pthread, member))); \ + else if (sizeof (value) == 4) \ + asm volatile ("movl %0,%%gs:(%1)" : \ + : "ir" (value), \ + "r" (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 %%eax,%%gs:(%1)\n\t" \ + "movl %%edx,%%gs:4(%1)" : \ + : "A" (value), \ + "r" (offsetof (struct pthread, member))); \ + }}) + + +#endif /* __ASSEMBLER__ */ + +#endif /* tls.h */ |