[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / arm / sysdep-cancel.h

/* Copyright (C) 2003-2015 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
   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>
#include <tls.h>
#ifndef __ASSEMBLER__
# include <nptl/pthreadP.h>
#endif

#if IS_IN (libc) || IS_IN (libpthread) || IS_IN (librt)

/* NOTE: We do mark syscalls with unwind annotations, for the benefit of
   cancellation; but they're really only accurate at the point of the
   syscall.  The ARM unwind directives are not rich enough without adding
   a custom personality function.  */

# undef PSEUDO
# define PSEUDO(name, syscall_name, args)				\
	.text;								\
  ENTRY (__##syscall_name##_nocancel);					\
	CFI_SECTIONS;							\
	DO_CALL (syscall_name, args);					\
	cmn	r0, $4096;						\
	PSEUDO_RET;							\
  END (__##syscall_name##_nocancel);					\
  ENTRY (name);								\
	SINGLE_THREAD_P;						\
	DOARGS_##args;							\
	bne .Lpseudo_cancel;						\
	cfi_remember_state;						\
	ldr	r7, =SYS_ify (syscall_name);				\
	swi	0x0;							\
	UNDOARGS_##args;						\
	cmn	r0, $4096;						\
	PSEUDO_RET;							\
	cfi_restore_state;						\
  .Lpseudo_cancel:							\
	.fnstart;	/* matched by the .fnend in UNDOARGS below.  */	\
	DOCARGS_##args;	/* save syscall args etc. around CENABLE.  */	\
	CENABLE;							\
	mov ip, r0;		/* put mask in safe place.  */		\
	UNDOCARGS_##args;	/* restore syscall args.  */		\
	ldr	r7, =SYS_ify (syscall_name);				\
	swi	0x0;		/* do the call.  */			\
	mov	r7, r0;		/* save syscall return value.  */	\
	mov	r0, ip;		/* get mask back.  */			\
	CDISABLE;							\
	mov	r0, r7;		/* retrieve return value.  */		\
	RESTORE_LR_##args;						\
	UNDOARGS_##args;						\
	cmn	r0, $4096

/* DOARGS pushes eight bytes on the stack for five arguments, twelve bytes for
   six arguments, and four bytes for fewer.  In order to preserve doubleword
   alignment, sometimes we must save an extra register.  */

# define RESTART_UNWIND				\
	.fnend;					\
	.fnstart;				\
	.save	{r7};				\
	.save	{lr}

# define DOCARGS_0				\
	.save {r7};				\
	push	{lr};				\
	cfi_adjust_cfa_offset (4);		\
	cfi_rel_offset (lr, 0);			\
	.save	{lr}
# define UNDOCARGS_0
# define RESTORE_LR_0				\
	pop	{lr};				\
	cfi_adjust_cfa_offset (-4);		\
	cfi_restore (lr)

# define DOCARGS_1				\
	.save	{r7};				\
	push	{r0, r1, lr};			\
	cfi_adjust_cfa_offset (12);		\
	cfi_rel_offset (lr, 8);			\
	.save	{lr};				\
	.pad	#8
# define UNDOCARGS_1				\
	ldr r0, [sp], #8;			\
	cfi_adjust_cfa_offset (-8);		\
	RESTART_UNWIND
# define RESTORE_LR_1				\
	RESTORE_LR_0

# define DOCARGS_2				\
	.save	{r7};				\
	push	{r0, r1, lr};			\
	cfi_adjust_cfa_offset (12);		\
	cfi_rel_offset (lr, 8);			\
	.save	{lr};				\
	.pad	#8
# define UNDOCARGS_2				\
	pop	{r0, r1};			\
	cfi_adjust_cfa_offset (-8);		\
	RESTART_UNWIND
# define RESTORE_LR_2				\
	RESTORE_LR_0

# define DOCARGS_3				\
	.save	{r7};				\
	push	{r0, r1, r2, r3, lr};		\
	cfi_adjust_cfa_offset (20);		\
	cfi_rel_offset (lr, 16);		\
	.save	{lr};				\
	.pad	#16
# define UNDOCARGS_3				\
	pop	{r0, r1, r2, r3};		\
	cfi_adjust_cfa_offset (-16);		\
	RESTART_UNWIND
# define RESTORE_LR_3				\
	RESTORE_LR_0

# define DOCARGS_4				\
	.save	{r7};				\
	push	{r0, r1, r2, r3, lr};		\
	cfi_adjust_cfa_offset (20);		\
	cfi_rel_offset (lr, 16);		\
	.save	{lr};				\
	.pad	#16
# define UNDOCARGS_4				\
	pop	{r0, r1, r2, r3};		\
	cfi_adjust_cfa_offset (-16);		\
	RESTART_UNWIND
# define RESTORE_LR_4				\
	RESTORE_LR_0

/* r4 is only stmfd'ed for correct stack alignment.  */
# define DOCARGS_5				\
	.save	{r4, r7};			\
	push	{r0, r1, r2, r3, r4, lr};	\
	cfi_adjust_cfa_offset (24);		\
	cfi_rel_offset (lr, 20);		\
	.save	{lr};				\
	.pad	#20
# define UNDOCARGS_5				\
	pop	{r0, r1, r2, r3};		\
	cfi_adjust_cfa_offset (-16);		\
	.fnend;					\
	.fnstart;				\
	.save	{r4, r7};			\
	.save	{lr};				\
	.pad	#4
# define RESTORE_LR_5				\
	pop	{r4, lr};			\
	cfi_adjust_cfa_offset (-8);		\
	/* r4 will be marked as restored later.  */ \
	cfi_restore (lr)

# define DOCARGS_6				\
	.save	{r4, r5, r7};			\
	push	{r0, r1, r2, r3, lr};		\
	cfi_adjust_cfa_offset (20);		\
	cfi_rel_offset (lr, 16);		\
	.save	{lr};				\
	.pad	#16
# define UNDOCARGS_6				\
	pop	{r0, r1, r2, r3};		\
	cfi_adjust_cfa_offset (-16);		\
	.fnend;					\
	.fnstart;				\
	.save	{r4, r5, r7};			\
	.save	{lr};
# define RESTORE_LR_6				\
	RESTORE_LR_0

# if IS_IN (libpthread)
#  define CENABLE	bl PLTJMP(__pthread_enable_asynccancel)
#  define CDISABLE	bl PLTJMP(__pthread_disable_asynccancel)
#  define __local_multiple_threads __pthread_multiple_threads
# elif IS_IN (libc)
#  define CENABLE	bl PLTJMP(__libc_enable_asynccancel)
#  define CDISABLE	bl PLTJMP(__libc_disable_asynccancel)
#  define __local_multiple_threads __libc_multiple_threads
# elif IS_IN (librt)
#  define CENABLE	bl PLTJMP(__librt_enable_asynccancel)
#  define CDISABLE	bl PLTJMP(__librt_disable_asynccancel)
# else
#  error Unsupported library
# endif

# if IS_IN (libpthread) || IS_IN (libc)
#  ifndef __ASSEMBLER__
extern int __local_multiple_threads attribute_hidden;
#   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
#  else
#   define SINGLE_THREAD_P						\
	LDST_PCREL(ldr, ip, ip, __local_multiple_threads);		\
	teq ip, #0
#  endif
# else
/*  There is no __local_multiple_threads for librt, so use the TCB.  */
#  ifndef __ASSEMBLER__
#   define SINGLE_THREAD_P						\
  __builtin_expect (THREAD_GETMEM (THREAD_SELF,				\
				   header.multiple_threads) == 0, 1)
#  else
#   define SINGLE_THREAD_P						\
	push	{r0, lr};						\
	cfi_adjust_cfa_offset (8);					\
	cfi_rel_offset (lr, 4);						\
	GET_TLS (lr);							\
	NEGOFF_ADJ_BASE (r0, MULTIPLE_THREADS_OFFSET);			\
	ldr	ip, NEGOFF_OFF1 (r0, MULTIPLE_THREADS_OFFSET);		\
	pop	{r0, lr};						\
	cfi_adjust_cfa_offset (-8);					\
	cfi_restore (lr);						\
	teq	ip, #0
#  endif
# endif

#elif !defined __ASSEMBLER__

/* For rtld, et cetera.  */
# define SINGLE_THREAD_P 1
# define NO_CANCELLATION 1

#endif

#ifndef __ASSEMBLER__
# define RTLD_SINGLE_THREAD_P \
  __builtin_expect (THREAD_GETMEM (THREAD_SELF, \
				   header.multiple_threads) == 0, 1)
#endif
Commit	Line	Data
b168057a	1	/* Copyright (C) 2003-2015 Free Software Foundation, Inc.
02a9f771 DJ	2	This file is part of the GNU C Library.
	3
	4	The GNU C Library is free software; you can redistribute it and/or
	5	modify it under the terms of the GNU Lesser General Public
	6	License as published by the Free Software Foundation; either
	7	version 2.1 of the License, or (at your option) any later version.
	8
	9	The GNU C Library is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	Lesser General Public License for more details.
	13
	14	You should have received a copy of the GNU Lesser General Public
ab84e3ff PE	15	License along with the GNU C Library. If not, see
ab84e3ff PE	16	<http://www.gnu.org/licenses/>. */
02a9f771 DJ	17
	18	#include <sysdep.h>
	19	#include <tls.h>
	20	#ifndef __ASSEMBLER__
	21	# include <nptl/pthreadP.h>
	22	#endif
	23
4f41c682	24	#if IS_IN (libc) \|\| IS_IN (libpthread) \|\| IS_IN (librt)
02a9f771 DJ	25
	26	/* NOTE: We do mark syscalls with unwind annotations, for the benefit of
	27	cancellation; but they're really only accurate at the point of the
	28	syscall. The ARM unwind directives are not rich enough without adding
	29	a custom personality function. */
	30
	31	# undef PSEUDO
	32	# define PSEUDO(name, syscall_name, args) \
63cc0e75	33	.text; \
63cc0e75 RH	34	ENTRY (__##syscall_name##_nocancel); \
	35	CFI_SECTIONS; \
	36	DO_CALL (syscall_name, args); \
	37	cmn r0, $4096; \
	38	PSEUDO_RET; \
	39	END (__##syscall_name##_nocancel); \
02a9f771	40	ENTRY (name); \
63cc0e75 RH	41	SINGLE_THREAD_P; \
	42	DOARGS_##args; \
	43	bne .Lpseudo_cancel; \
	44	cfi_remember_state; \
	45	ldr r7, =SYS_ify (syscall_name); \
	46	swi 0x0; \
	47	UNDOARGS_##args; \
	48	cmn r0, $4096; \
	49	PSEUDO_RET; \
	50	cfi_restore_state; \
02a9f771	51	.Lpseudo_cancel: \
63cc0e75 RH	52	.fnstart; /* matched by the .fnend in UNDOARGS below. */ \
	53	DOCARGS_##args; /* save syscall args etc. around CENABLE. */ \
	54	CENABLE; \
	55	mov ip, r0; /* put mask in safe place. */ \
	56	UNDOCARGS_##args; /* restore syscall args. */ \
	57	ldr r7, =SYS_ify (syscall_name); \
	58	swi 0x0; /* do the call. */ \
	59	mov r7, r0; /* save syscall return value. */ \
	60	mov r0, ip; /* get mask back. */ \
	61	CDISABLE; \
	62	mov r0, r7; /* retrieve return value. */ \
	63	RESTORE_LR_##args; \
	64	UNDOARGS_##args; \
	65	cmn r0, $4096
02a9f771	66
73886008 UW	67	/* DOARGS pushes eight bytes on the stack for five arguments, twelve bytes for
73886008 UW	68	six arguments, and four bytes for fewer. In order to preserve doubleword
e5b5ba47	69	alignment, sometimes we must save an extra register. */
02a9f771	70
63cc0e75 RH	71	# define RESTART_UNWIND \
	72	.fnend; \
	73	.fnstart; \
	74	.save {r7}; \
	75	.save {lr}
	76
	77	# define DOCARGS_0 \
	78	.save {r7}; \
55668624	79	push {lr}; \
63cc0e75 RH	80	cfi_adjust_cfa_offset (4); \
	81	cfi_rel_offset (lr, 0); \
	82	.save {lr}
02a9f771	83	# define UNDOCARGS_0
63cc0e75	84	# define RESTORE_LR_0 \
55668624	85	pop {lr}; \
63cc0e75 RH	86	cfi_adjust_cfa_offset (-4); \
	87	cfi_restore (lr)
	88
	89	# define DOCARGS_1 \
	90	.save {r7}; \
55668624	91	push {r0, r1, lr}; \
63cc0e75 RH	92	cfi_adjust_cfa_offset (12); \
	93	cfi_rel_offset (lr, 8); \
	94	.save {lr}; \
	95	.pad #8
	96	# define UNDOCARGS_1 \
	97	ldr r0, [sp], #8; \
	98	cfi_adjust_cfa_offset (-8); \
	99	RESTART_UNWIND
	100	# define RESTORE_LR_1 \
	101	RESTORE_LR_0
	102
	103	# define DOCARGS_2 \
	104	.save {r7}; \
55668624	105	push {r0, r1, lr}; \
63cc0e75 RH	106	cfi_adjust_cfa_offset (12); \
	107	cfi_rel_offset (lr, 8); \
	108	.save {lr}; \
	109	.pad #8
	110	# define UNDOCARGS_2 \
55668624	111	pop {r0, r1}; \
63cc0e75 RH	112	cfi_adjust_cfa_offset (-8); \
	113	RESTART_UNWIND
	114	# define RESTORE_LR_2 \
	115	RESTORE_LR_0
	116
	117	# define DOCARGS_3 \
	118	.save {r7}; \
55668624	119	push {r0, r1, r2, r3, lr}; \
63cc0e75 RH	120	cfi_adjust_cfa_offset (20); \
	121	cfi_rel_offset (lr, 16); \
	122	.save {lr}; \
	123	.pad #16
	124	# define UNDOCARGS_3 \
55668624	125	pop {r0, r1, r2, r3}; \
63cc0e75 RH	126	cfi_adjust_cfa_offset (-16); \
	127	RESTART_UNWIND
	128	# define RESTORE_LR_3 \
	129	RESTORE_LR_0
	130
	131	# define DOCARGS_4 \
	132	.save {r7}; \
55668624	133	push {r0, r1, r2, r3, lr}; \
63cc0e75 RH	134	cfi_adjust_cfa_offset (20); \
	135	cfi_rel_offset (lr, 16); \
	136	.save {lr}; \
	137	.pad #16
	138	# define UNDOCARGS_4 \
55668624	139	pop {r0, r1, r2, r3}; \
63cc0e75 RH	140	cfi_adjust_cfa_offset (-16); \
	141	RESTART_UNWIND
	142	# define RESTORE_LR_4 \
	143	RESTORE_LR_0
01b32e73 TS	144
01b32e73 TS	145	/* r4 is only stmfd'ed for correct stack alignment. */
63cc0e75 RH	146	# define DOCARGS_5 \
63cc0e75 RH	147	.save {r4, r7}; \
55668624	148	push {r0, r1, r2, r3, r4, lr}; \
63cc0e75 RH	149	cfi_adjust_cfa_offset (24); \
	150	cfi_rel_offset (lr, 20); \
	151	.save {lr}; \
	152	.pad #20
	153	# define UNDOCARGS_5 \
55668624	154	pop {r0, r1, r2, r3}; \
63cc0e75 RH	155	cfi_adjust_cfa_offset (-16); \
	156	.fnend; \
	157	.fnstart; \
	158	.save {r4, r7}; \
	159	.save {lr}; \
	160	.pad #4
	161	# define RESTORE_LR_5 \
55668624	162	pop {r4, lr}; \
63cc0e75 RH	163	cfi_adjust_cfa_offset (-8); \
	164	/* r4 will be marked as restored later. */ \
	165	cfi_restore (lr)
	166
	167	# define DOCARGS_6 \
	168	.save {r4, r5, r7}; \
55668624	169	push {r0, r1, r2, r3, lr}; \
63cc0e75 RH	170	cfi_adjust_cfa_offset (20); \
	171	cfi_rel_offset (lr, 16); \
	172	.save {lr}; \
	173	.pad #16
	174	# define UNDOCARGS_6 \
55668624	175	pop {r0, r1, r2, r3}; \
63cc0e75 RH	176	cfi_adjust_cfa_offset (-16); \
	177	.fnend; \
	178	.fnstart; \
	179	.save {r4, r5, r7}; \
	180	.save {lr};
	181	# define RESTORE_LR_6 \
	182	RESTORE_LR_0
e5b5ba47	183
ce9f10f7	184	# if IS_IN (libpthread)
02a9f771 DJ	185	# define CENABLE bl PLTJMP(__pthread_enable_asynccancel)
	186	# define CDISABLE bl PLTJMP(__pthread_disable_asynccancel)
	187	# define __local_multiple_threads __pthread_multiple_threads
4f41c682	188	# elif IS_IN (libc)
02a9f771 DJ	189	# define CENABLE bl PLTJMP(__libc_enable_asynccancel)
	190	# define CDISABLE bl PLTJMP(__libc_disable_asynccancel)
	191	# define __local_multiple_threads __libc_multiple_threads
016afc75	192	# elif IS_IN (librt)
02a9f771 DJ	193	# define CENABLE bl PLTJMP(__librt_enable_asynccancel)
	194	# define CDISABLE bl PLTJMP(__librt_disable_asynccancel)
	195	# else
	196	# error Unsupported library
	197	# endif
	198
4f41c682	199	# if IS_IN (libpthread) \|\| IS_IN (libc)
02a9f771 DJ	200	# ifndef __ASSEMBLER__
	201	extern int __local_multiple_threads attribute_hidden;
	202	# define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)
	203	# else
	204	# define SINGLE_THREAD_P \
cd24e113 RH	205	LDST_PCREL(ldr, ip, ip, __local_multiple_threads); \
cd24e113 RH	206	teq ip, #0
02a9f771 DJ	207	# endif
	208	# else
	209	/* There is no __local_multiple_threads for librt, so use the TCB. */
	210	# ifndef __ASSEMBLER__
	211	# define SINGLE_THREAD_P \
	212	__builtin_expect (THREAD_GETMEM (THREAD_SELF, \
	213	header.multiple_threads) == 0, 1)
	214	# else
02a9f771	215	# define SINGLE_THREAD_P \
55668624	216	push {r0, lr}; \
63cc0e75 RH	217	cfi_adjust_cfa_offset (8); \
63cc0e75 RH	218	cfi_rel_offset (lr, 4); \
5232b909	219	GET_TLS (lr); \
3ae44082 RH	220	NEGOFF_ADJ_BASE (r0, MULTIPLE_THREADS_OFFSET); \
3ae44082 RH	221	ldr ip, NEGOFF_OFF1 (r0, MULTIPLE_THREADS_OFFSET); \
55668624	222	pop {r0, lr}; \
63cc0e75 RH	223	cfi_adjust_cfa_offset (-8); \
	224	cfi_restore (lr); \
	225	teq ip, #0
02a9f771 DJ	226	# endif
	227	# endif
	228
	229	#elif !defined __ASSEMBLER__
	230
	231	/* For rtld, et cetera. */
	232	# define SINGLE_THREAD_P 1
	233	# define NO_CANCELLATION 1
	234
	235	#endif
80d6637f DJ	236
	237	#ifndef __ASSEMBLER__
	238	# define RTLD_SINGLE_THREAD_P \
	239	__builtin_expect (THREAD_GETMEM (THREAD_SELF, \
	240	header.multiple_threads) == 0, 1)
	241	#endif