[apple/libc.git] / x86_64 / sys / _sigtramp.s

/*
 * Copyright (c) 2007 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include <sys/syscall.h>

#define UC_TRAD			1
#define UC_FLAVOR		30

/* Structure fields for ucontext and mcontext.  */
#define UCONTEXT_UC_MCONTEXT	48

#define MCONTEXT_ES_EXCEPTION	0
#define MCONTEXT_SS_RAX		16
#define MCONTEXT_SS_RBX		24
#define MCONTEXT_SS_RCX		32
#define MCONTEXT_SS_RDX		40
#define MCONTEXT_SS_RDI		48
#define MCONTEXT_SS_RSI		56
#define MCONTEXT_SS_RBP		64
#define MCONTEXT_SS_RSP		72
#define MCONTEXT_SS_R8		80
#define MCONTEXT_SS_RIP		144

/* register use:
	%rbx	uctx
	
void
_sigtramp(
	union __sigaction_u __sigaction_u,	%rdi
	int 			sigstyle,	%rsi
	int 			sig,		%rdx
	siginfo_t		*sinfo,		%rcx
	ucontext_t		*uctx		%r8
)
*/

	.globl __sigtramp
	.text
	.align 4,0x90
__sigtramp:
	/* Although this routine does not need any stack frame, various parts
	   of the OS can't analyse the stack without them.  */
	pushq	%rbp
	movq	%rsp, %rbp

	movq	%rdi, %rax	# set up address for call

#if defined(__DYNAMIC__)
	incl	___in_sigtramp(%rip)
#endif
	/* Save uctx in %rbx.  */
	movq	%r8, %rbx
	/* Call the signal handler.
	   Some variants are not supposed to get the last two parameters,
	   but the test to prevent this is more expensive than just passing
	   them.  */
	movl	%edx, %edi
	movq	%rcx, %rsi
	movq	%r8, %rdx
Lcall_start:
	call	*%rax
Lcall_end:
#if defined(__DYNAMIC__)
	decl	___in_sigtramp(%rip)
#endif
	movq	%rbx, %rdi
	movl	$ UC_FLAVOR, %esi
	jmp	___sigreturn

/* DWARF unwind table #defines.  */
#define DW_CFA_advance_loc_4 0x44
#define DW_CFA_def_cfa 0x0c
#define DW_CFA_def_cfa_expression 0x0F
#define DW_CFA_expression 0x10
#define DW_CFA_val_expression 0x16
#define DW_CFA_offset(column) 0x80+(column)

/* DWARF expression #defines.  */
#define DW_OP_deref 0x06
#define DW_OP_const1u 0x08
#define DW_OP_dup 0x12
#define DW_OP_drop 0x13
#define DW_OP_over 0x14
#define DW_OP_pick 0x15
#define DW_OP_swap 0x16
#define DW_OP_rot 0x17
#define DW_OP_abs 0x19
#define DW_OP_and 0x1a
#define DW_OP_div 0x1b
#define DW_OP_minus 0x1c
#define DW_OP_mod 0x1d
#define DW_OP_mul 0x1e
#define DW_OP_neg 0x1f
#define DW_OP_not 0x20
#define DW_OP_or 0x21
#define DW_OP_plus 0x22
#define DW_OP_plus_uconst 0x23
#define DW_OP_shl 0x24
#define DW_OP_shr 0x25
#define DW_OP_shra 0x26
#define DW_OP_xor 0x27
#define DW_OP_skip 0x2f
#define DW_OP_bra 0x28
#define DW_OP_eq 0x29
#define DW_OP_ge 0x2A
#define DW_OP_gt 0x2B
#define DW_OP_le 0x2C
#define DW_OP_lt 0x2D
#define DW_OP_ne 0x2E
#define DW_OP_lit(n) 0x30+(n)
#define DW_OP_breg(n) 0x70+(n)
#define DW_OP_deref_size 0x94

/* The location expression we'll use.  */

#define loc_expr_for_reg(regno, offs)				\
	.byte DW_CFA_expression, regno, 5 /* block length */,	\
	 DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref,	\
	 DW_OP_plus_uconst, offs

/* For r8 through r13 */
#define loc_expr_rN(regno) \
  loc_expr_for_reg(regno, MCONTEXT_SS_R8+(8*(regno-8)))

/* For r14 through r15 */
#define loc_expr_rN_long(regno)						\
	.byte DW_CFA_expression, regno, 6 /* block length */,		\
	 DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref,		\
	 DW_OP_plus_uconst, MCONTEXT_SS_R8+(8*(regno-8)), 1

	/* Unwind tables.  */
	.section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support
EH_frame1:
	.set L$set$0,LECIE1-LSCIE1
	.long L$set$0	# Length of Common Information Entry
LSCIE1:
	.long	0	# CIE Identifier Tag
	.byte	0x3	# CIE Version
	.ascii "zR\0"	# CIE Augmentation
	.byte	0x1	# uleb128 0x1; CIE Code Alignment Factor
	.byte	0x78	# sleb128 -8; CIE Data Alignment Factor
	.byte	0x10	# CIE RA Column
	.byte	0x1	# uleb128 0x1; Augmentation size
	.byte	0x10	# FDE Encoding (pcrel)
	.byte	DW_CFA_def_cfa
	.byte	0x7	# uleb128 0x5
	.byte	0x8	# uleb128 0x4
	.byte	DW_CFA_offset(16)
	.byte	0x1	# uleb128 0x1
	.align 3
LECIE1:
	.globl _sigtramp.eh
_sigtramp.eh:
LSFDE1:
	.set L$set$1,LEFDE1-LASFDE1
	.long L$set$1	# FDE Length
LASFDE1:
	.long	LASFDE1-EH_frame1	# FDE CIE offset
	.quad	Lcall_start-.	# FDE initial location
	.set L$set$2,Lcall_end-Lcall_start
	.quad	L$set$2	# FDE address range
	.byte	0x0	# uleb128 0x0; Augmentation size

	/* Now for the expressions, which all compute
	   uctx->uc_mcontext->register
	   for each register.
	   
	   Describe even the registers that are not call-saved because they
	   might be being used in the prologue to save other registers.
	   Only integer registers are described at present.    */

	loc_expr_for_reg (0, MCONTEXT_SS_RAX)
	loc_expr_for_reg (1, MCONTEXT_SS_RBX)
	loc_expr_for_reg (2, MCONTEXT_SS_RCX)
	loc_expr_for_reg (3, MCONTEXT_SS_RDX)
	loc_expr_for_reg (4, MCONTEXT_SS_RSI)
	loc_expr_for_reg (5, MCONTEXT_SS_RDI)
	loc_expr_for_reg (6, MCONTEXT_SS_RBP)
	loc_expr_for_reg (7, MCONTEXT_SS_RSP)
	loc_expr_rN (8)
	loc_expr_rN (9)
	loc_expr_rN (10)
	loc_expr_rN (11)
	loc_expr_rN (12)
	loc_expr_rN (13)
	loc_expr_rN_long (14)
	loc_expr_rN_long (15)

	/* The Intel architecture classifies exceptions into three categories,
	   'faults' which put the address of the faulting instruction
	   in EIP, 'traps' which put the following instruction in EIP,
	   and 'aborts' which don't typically report the instruction
	   causing the exception.

	   The traps are #BP and #OF.  */

	.byte DW_CFA_val_expression, 16
	.set L$set$3,Lpc_end-Lpc_start
	.byte L$set$3
Lpc_start:
	/* Push the mcontext address twice.  */
	.byte DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref, DW_OP_dup
	/* Find the value of EIP.  */
	.byte   DW_OP_plus_uconst, MCONTEXT_SS_RIP, MCONTEXT_SS_RIP >> 7
	.byte   DW_OP_deref, DW_OP_swap
	/* Determine the exception type.  */
	.byte   DW_OP_plus_uconst, MCONTEXT_ES_EXCEPTION, DW_OP_deref_size, 4
	/* Check whether it is #BP (3) or #OF (4).  */
	.byte   DW_OP_dup, DW_OP_lit(3), DW_OP_ne
	.byte    DW_OP_swap, DW_OP_lit(4), DW_OP_ne, DW_OP_and
	/* If it is not, then add 1 to the instruction address, so as to point
	   within or past the faulting instruction.  */
	.byte   DW_OP_plus
Lpc_end:

	/* The CFA will have been saved as the value of RSP (it is not
	   RSP+8).  */
	.byte DW_CFA_def_cfa_expression
	.set L$set$4,Lcfa_end-Lcfa_start
	.byte L$set$4
Lcfa_start:
	.byte DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref
	.byte  DW_OP_plus_uconst, MCONTEXT_SS_RSP, DW_OP_deref
Lcfa_end:

	.align 3
LEFDE1:
		
	.subsections_via_symbols
Commit	Line	Data
224c7076 A	1	/*
	2	* Copyright (c) 2007 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. Please obtain a copy of the License at
	10	* http://www.opensource.apple.com/apsl/ and read it before using this
	11	* file.
	12	*
	13	* The Original Code and all software distributed under the License are
	14	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	15	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	16	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	* Please see the License for the specific language governing rights and
	19	* limitations under the License.
	20	*
	21	* @APPLE_LICENSE_HEADER_END@
	22	*/
	23
	24	#include <sys/syscall.h>
	25
	26	#define UC_TRAD 1
	27	#define UC_FLAVOR 30
	28
	29	/* Structure fields for ucontext and mcontext. */
	30	#define UCONTEXT_UC_MCONTEXT 48
	31
	32	#define MCONTEXT_ES_EXCEPTION 0
	33	#define MCONTEXT_SS_RAX 16
	34	#define MCONTEXT_SS_RBX 24
	35	#define MCONTEXT_SS_RCX 32
	36	#define MCONTEXT_SS_RDX 40
	37	#define MCONTEXT_SS_RDI 48
	38	#define MCONTEXT_SS_RSI 56
	39	#define MCONTEXT_SS_RBP 64
	40	#define MCONTEXT_SS_RSP 72
	41	#define MCONTEXT_SS_R8 80
	42	#define MCONTEXT_SS_RIP 144
	43
	44	/* register use:
	45	%rbx uctx
	46
	47	void
	48	_sigtramp(
	49	union __sigaction_u __sigaction_u, %rdi
	50	int sigstyle, %rsi
	51	int sig, %rdx
	52	siginfo_t *sinfo, %rcx
	53	ucontext_t *uctx %r8
	54	)
	55	*/
	56
	57	.globl __sigtramp
	58	.text
	59	.align 4,0x90
	60	__sigtramp:
	61	/* Although this routine does not need any stack frame, various parts
	62	of the OS can't analyse the stack without them. */
	63	pushq %rbp
	64	movq %rsp, %rbp
65
66	movq %rdi, %rax # set up address for call
67
68	#if defined(__DYNAMIC__)
69	incl ___in_sigtramp(%rip)
70	#endif
71	/* Save uctx in %rbx. */
72	movq %r8, %rbx
73	/* Call the signal handler.
74	Some variants are not supposed to get the last two parameters,
75	but the test to prevent this is more expensive than just passing
76	them. */
77	movl %edx, %edi
78	movq %rcx, %rsi
79	movq %r8, %rdx
80	Lcall_start:
81	call *%rax
82	Lcall_end:
83	#if defined(__DYNAMIC__)
84	decl ___in_sigtramp(%rip)
85	#endif
86	movq %rbx, %rdi
87	movl $ UC_FLAVOR, %esi
88	jmp ___sigreturn
89
90	/* DWARF unwind table #defines. */
91	#define DW_CFA_advance_loc_4 0x44
92	#define DW_CFA_def_cfa 0x0c
93	#define DW_CFA_def_cfa_expression 0x0F
94	#define DW_CFA_expression 0x10
95	#define DW_CFA_val_expression 0x16
96	#define DW_CFA_offset(column) 0x80+(column)
97
98	/* DWARF expression #defines. */
99	#define DW_OP_deref 0x06
100	#define DW_OP_const1u 0x08
101	#define DW_OP_dup 0x12
102	#define DW_OP_drop 0x13
103	#define DW_OP_over 0x14
104	#define DW_OP_pick 0x15
105	#define DW_OP_swap 0x16
106	#define DW_OP_rot 0x17
107	#define DW_OP_abs 0x19
108	#define DW_OP_and 0x1a
109	#define DW_OP_div 0x1b
110	#define DW_OP_minus 0x1c
111	#define DW_OP_mod 0x1d
112	#define DW_OP_mul 0x1e
113	#define DW_OP_neg 0x1f
114	#define DW_OP_not 0x20
115	#define DW_OP_or 0x21
116	#define DW_OP_plus 0x22
117	#define DW_OP_plus_uconst 0x23
118	#define DW_OP_shl 0x24
119	#define DW_OP_shr 0x25
120	#define DW_OP_shra 0x26
121	#define DW_OP_xor 0x27
122	#define DW_OP_skip 0x2f
123	#define DW_OP_bra 0x28
124	#define DW_OP_eq 0x29
125	#define DW_OP_ge 0x2A
126	#define DW_OP_gt 0x2B
127	#define DW_OP_le 0x2C
128	#define DW_OP_lt 0x2D
129	#define DW_OP_ne 0x2E
130	#define DW_OP_lit(n) 0x30+(n)
131	#define DW_OP_breg(n) 0x70+(n)
132	#define DW_OP_deref_size 0x94
133
134	/* The location expression we'll use. */
135
136	#define loc_expr_for_reg(regno, offs) \
137	.byte DW_CFA_expression, regno, 5 /* block length */, \
138	DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref, \
139	DW_OP_plus_uconst, offs
140
141	/* For r8 through r13 */
142	#define loc_expr_rN(regno) \
143	loc_expr_for_reg(regno, MCONTEXT_SS_R8+(8*(regno-8)))
144
145	/* For r14 through r15 */
146	#define loc_expr_rN_long(regno) \
147	.byte DW_CFA_expression, regno, 6 /* block length */, \
148	DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref, \
149	DW_OP_plus_uconst, MCONTEXT_SS_R8+(8*(regno-8)), 1
150
151	/* Unwind tables. */
152	.section __TEXT,__eh_frame,coalesced,no_toc+strip_static_syms+live_support
153	EH_frame1:
154	.set L$set$0,LECIE1-LSCIE1
155	.long L$set$0 # Length of Common Information Entry
156	LSCIE1:
157	.long 0 # CIE Identifier Tag
158	.byte 0x3 # CIE Version
159	.ascii "zR\0" # CIE Augmentation
160	.byte 0x1 # uleb128 0x1; CIE Code Alignment Factor
161	.byte 0x78 # sleb128 -8; CIE Data Alignment Factor
162	.byte 0x10 # CIE RA Column
163	.byte 0x1 # uleb128 0x1; Augmentation size
164	.byte 0x10 # FDE Encoding (pcrel)
165	.byte DW_CFA_def_cfa
166	.byte 0x7 # uleb128 0x5
167	.byte 0x8 # uleb128 0x4
168	.byte DW_CFA_offset(16)
169	.byte 0x1 # uleb128 0x1
170	.align 3
171	LECIE1:
172	.globl _sigtramp.eh
173	_sigtramp.eh:
174	LSFDE1:
175	.set L$set$1,LEFDE1-LASFDE1
176	.long L$set$1 # FDE Length
177	LASFDE1:
178	.long LASFDE1-EH_frame1 # FDE CIE offset
179	.quad Lcall_start-. # FDE initial location
180	.set L$set$2,Lcall_end-Lcall_start
181	.quad L$set$2 # FDE address range
182	.byte 0x0 # uleb128 0x0; Augmentation size
183
184	/* Now for the expressions, which all compute
185	uctx->uc_mcontext->register
186	for each register.
187
188	Describe even the registers that are not call-saved because they
189	might be being used in the prologue to save other registers.
190	Only integer registers are described at present. */
191
192	loc_expr_for_reg (0, MCONTEXT_SS_RAX)
193	loc_expr_for_reg (1, MCONTEXT_SS_RBX)
194	loc_expr_for_reg (2, MCONTEXT_SS_RCX)
195	loc_expr_for_reg (3, MCONTEXT_SS_RDX)
196	loc_expr_for_reg (4, MCONTEXT_SS_RSI)
197	loc_expr_for_reg (5, MCONTEXT_SS_RDI)
198	loc_expr_for_reg (6, MCONTEXT_SS_RBP)
199	loc_expr_for_reg (7, MCONTEXT_SS_RSP)
200	loc_expr_rN (8)
201	loc_expr_rN (9)
202	loc_expr_rN (10)
203	loc_expr_rN (11)
204	loc_expr_rN (12)
205	loc_expr_rN (13)
206	loc_expr_rN_long (14)
207	loc_expr_rN_long (15)
208
209	/* The Intel architecture classifies exceptions into three categories,
210	'faults' which put the address of the faulting instruction
211	in EIP, 'traps' which put the following instruction in EIP,
212	and 'aborts' which don't typically report the instruction
213	causing the exception.
214
215	The traps are #BP and #OF. */
216
217	.byte DW_CFA_val_expression, 16
218	.set L$set$3,Lpc_end-Lpc_start
219	.byte L$set$3
220	Lpc_start:
221	/* Push the mcontext address twice. */
222	.byte DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref, DW_OP_dup
223	/* Find the value of EIP. */
224	.byte DW_OP_plus_uconst, MCONTEXT_SS_RIP, MCONTEXT_SS_RIP >> 7
225	.byte DW_OP_deref, DW_OP_swap
226	/* Determine the exception type. */
227	.byte DW_OP_plus_uconst, MCONTEXT_ES_EXCEPTION, DW_OP_deref_size, 4
228	/* Check whether it is #BP (3) or #OF (4). */
229	.byte DW_OP_dup, DW_OP_lit(3), DW_OP_ne
230	.byte DW_OP_swap, DW_OP_lit(4), DW_OP_ne, DW_OP_and
231	/* If it is not, then add 1 to the instruction address, so as to point
232	within or past the faulting instruction. */
233	.byte DW_OP_plus
234	Lpc_end:
235
236	/* The CFA will have been saved as the value of RSP (it is not
237	RSP+8). */
238	.byte DW_CFA_def_cfa_expression
239	.set L$set$4,Lcfa_end-Lcfa_start
240	.byte L$set$4
241	Lcfa_start:
242	.byte DW_OP_breg(3), UCONTEXT_UC_MCONTEXT, DW_OP_deref
243	.byte DW_OP_plus_uconst, MCONTEXT_SS_RSP, DW_OP_deref
244	Lcfa_end:
245
246	.align 3
247	LEFDE1:
248
249	.subsections_via_symbols