95 lines
2.7 KiB
C
Executable file
95 lines
2.7 KiB
C
Executable file
/*
|
|
* Copyright (C) 2008 The Android Open Source Project
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
#include <pthread.h>
|
|
|
|
|
|
struct user_desc {
|
|
unsigned int entry_number;
|
|
unsigned long 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;
|
|
};
|
|
|
|
extern int __set_thread_area(struct user_desc *u_info);
|
|
|
|
/* the following can't be const, since the first call will
|
|
* update the 'entry_number' field
|
|
*/
|
|
static struct user_desc _tls_desc =
|
|
{
|
|
-1,
|
|
0,
|
|
0x1000,
|
|
1,
|
|
0,
|
|
0,
|
|
1,
|
|
0,
|
|
1,
|
|
0
|
|
};
|
|
|
|
struct _thread_area_head {
|
|
void *self;
|
|
};
|
|
|
|
/* we implement thread local storage through the gs: segment descriptor
|
|
* we create a segment descriptor for the tls
|
|
*/
|
|
int __set_tls(void *ptr)
|
|
{
|
|
int rc, segment;
|
|
|
|
_tls_desc.base_addr = (unsigned long)ptr;
|
|
|
|
/* We also need to write the location of the tls to ptr[0] */
|
|
((struct _thread_area_head *)ptr)->self = ptr;
|
|
|
|
rc = __set_thread_area( &_tls_desc );
|
|
if (rc != 0)
|
|
{
|
|
/* could not set thread local area */
|
|
return -1;
|
|
}
|
|
|
|
/* this weird computation comes from GLibc */
|
|
segment = _tls_desc.entry_number*8 + 3;
|
|
asm __volatile__ (
|
|
" movw %w0, %%gs" :: "q"(segment)
|
|
);
|
|
return 0;
|
|
}
|
|
|
|
|
|
|