glibc/sysdeps/i386/nptl/tcb-access.h
Florian Weimer 8d1927d8dc nptl: Introduce THREAD_GETMEM_VOLATILE
This will be needed for rseq TCB access.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00

126 lines
5.3 KiB
C

/* THREAD_* accessors. i386 version.
Copyright (C) 2002-2021 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
<https://www.gnu.org/licenses/>. */
/* Read member of the thread descriptor directly. */
#define THREAD_GETMEM(descr, member) \
({ __typeof (descr->member) __value; \
_Static_assert (sizeof (__value) == 1 \
|| sizeof (__value) == 4 \
|| sizeof (__value) == 8, \
"size of per-thread data"); \
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 /* 8 */ \
{ \
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; })
/* THREAD_GETMEM already forces a read. */
#define THREAD_GETMEM_VOLATILE(descr, member) THREAD_GETMEM (descr, member)
/* Same as THREAD_GETMEM, but the member offset can be non-constant. */
#define THREAD_GETMEM_NC(descr, member, idx) \
({ __typeof (descr->member[0]) __value; \
_Static_assert (sizeof (__value) == 1 \
|| sizeof (__value) == 4 \
|| sizeof (__value) == 8, \
"size of per-thread data"); \
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 /* 8 */ \
{ \
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; })
/* Set member of the thread descriptor directly. */
#define THREAD_SETMEM(descr, member, value) \
({ \
_Static_assert (sizeof (descr->member) == 1 \
|| sizeof (descr->member) == 4 \
|| sizeof (descr->member) == 8, \
"size of per-thread data"); \
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 /* 8 */ \
{ \
asm volatile ("movl %%eax,%%gs:%P1\n\t" \
"movl %%edx,%%gs:%P2" : \
: "A" ((uint64_t) cast_to_integer (value)), \
"i" (offsetof (struct pthread, member)), \
"i" (offsetof (struct pthread, member) + 4)); \
}})
/* Same as THREAD_SETMEM, but the member offset can be non-constant. */
#define THREAD_SETMEM_NC(descr, member, idx, value) \
({ \
_Static_assert (sizeof (descr->member[0]) == 1 \
|| sizeof (descr->member[0]) == 4 \
|| sizeof (descr->member[0]) == 8, \
"size of per-thread data"); \
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 /* 8 */ \
{ \
asm volatile ("movl %%eax,%%gs:%P1(,%2,8)\n\t" \
"movl %%edx,%%gs:4+%P1(,%2,8)" : \
: "A" ((uint64_t) cast_to_integer (value)), \
"i" (offsetof (struct pthread, member)), \
"r" (idx)); \
}})