1/*
2 * Common code for the sigreturn entry points on the vsyscall page.
3 * This code uses SYSCALL_ENTER_KERNEL (either syscall or int $0x80)
4 * to enter the kernel.
5 * This file is #include'd by vsyscall-*.S to define them after the
6 * vsyscall entry point.  The addresses we get for these entry points
7 * by doing ".balign 32" must match in both versions of the page.
8 */
9
10	.code32
11	.section .text.sigreturn,"ax"
12	.balign 32
13	.globl __kernel_sigreturn
14	.type __kernel_sigreturn,@function
15__kernel_sigreturn:
16.LSTART_sigreturn:
17	popl %eax
18	movl $__NR_ia32_sigreturn, %eax
19	SYSCALL_ENTER_KERNEL
20.LEND_sigreturn:
21	.size __kernel_sigreturn,.-.LSTART_sigreturn
22
23	.section .text.rtsigreturn,"ax"
24	.balign 32
25	.globl __kernel_rt_sigreturn
26	.type __kernel_rt_sigreturn,@function
27__kernel_rt_sigreturn:
28.LSTART_rt_sigreturn:
29	movl $__NR_ia32_rt_sigreturn, %eax
30	SYSCALL_ENTER_KERNEL
31.LEND_rt_sigreturn:
32	.size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
33
34	.section .eh_frame,"a",@progbits
35.LSTARTFRAMES:
36        .long .LENDCIES-.LSTARTCIES
37.LSTARTCIES:
38	.long 0			/* CIE ID */
39	.byte 1			/* Version number */
40	.string "zRS"		/* NUL-terminated augmentation string */
41	.uleb128 1		/* Code alignment factor */
42	.sleb128 -4		/* Data alignment factor */
43	.byte 8			/* Return address register column */
44	.uleb128 1		/* Augmentation value length */
45	.byte 0x1b		/* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
46	.byte 0x0c		/* DW_CFA_def_cfa */
47	.uleb128 4
48	.uleb128 4
49	.byte 0x88		/* DW_CFA_offset, column 0x8 */
50	.uleb128 1
51	.align 4
52.LENDCIES:
53
54	.long .LENDFDE2-.LSTARTFDE2	/* Length FDE */
55.LSTARTFDE2:
56	.long .LSTARTFDE2-.LSTARTFRAMES	/* CIE pointer */
57	/* HACK: The dwarf2 unwind routines will subtract 1 from the
58	   return address to get an address in the middle of the
59	   presumed call instruction.  Since we didn't get here via
60	   a call, we need to include the nop before the real start
61	   to make up for it.  */
62	.long .LSTART_sigreturn-1-.	/* PC-relative start address */
63	.long .LEND_sigreturn-.LSTART_sigreturn+1
64	.uleb128 0			/* Augmentation length */
65	/* What follows are the instructions for the table generation.
66	   We record the locations of each register saved.  This is
67	   complicated by the fact that the "CFA" is always assumed to
68	   be the value of the stack pointer in the caller.  This means
69	   that we must define the CFA of this body of code to be the
70	   saved value of the stack pointer in the sigcontext.  Which
71	   also means that there is no fixed relation to the other
72	   saved registers, which means that we must use DW_CFA_expression
73	   to compute their addresses.  It also means that when we
74	   adjust the stack with the popl, we have to do it all over again.  */
75
76#define do_cfa_expr(offset)						\
77	.byte 0x0f;			/* DW_CFA_def_cfa_expression */	\
78	.uleb128 1f-0f;			/*   length */			\
790:	.byte 0x74;			/*     DW_OP_breg4 */		\
80	.sleb128 offset;		/*      offset */		\
81	.byte 0x06;			/*     DW_OP_deref */		\
821:
83
84#define do_expr(regno, offset)						\
85	.byte 0x10;			/* DW_CFA_expression */		\
86	.uleb128 regno;			/*   regno */			\
87	.uleb128 1f-0f;			/*   length */			\
880:	.byte 0x74;			/*     DW_OP_breg4 */		\
89	.sleb128 offset;		/*       offset */		\
901:
91
92	do_cfa_expr(IA32_SIGCONTEXT_esp+4)
93	do_expr(0, IA32_SIGCONTEXT_eax+4)
94	do_expr(1, IA32_SIGCONTEXT_ecx+4)
95	do_expr(2, IA32_SIGCONTEXT_edx+4)
96	do_expr(3, IA32_SIGCONTEXT_ebx+4)
97	do_expr(5, IA32_SIGCONTEXT_ebp+4)
98	do_expr(6, IA32_SIGCONTEXT_esi+4)
99	do_expr(7, IA32_SIGCONTEXT_edi+4)
100	do_expr(8, IA32_SIGCONTEXT_eip+4)
101
102	.byte 0x42	/* DW_CFA_advance_loc 2 -- nop; popl eax. */
103
104	do_cfa_expr(IA32_SIGCONTEXT_esp)
105	do_expr(0, IA32_SIGCONTEXT_eax)
106	do_expr(1, IA32_SIGCONTEXT_ecx)
107	do_expr(2, IA32_SIGCONTEXT_edx)
108	do_expr(3, IA32_SIGCONTEXT_ebx)
109	do_expr(5, IA32_SIGCONTEXT_ebp)
110	do_expr(6, IA32_SIGCONTEXT_esi)
111	do_expr(7, IA32_SIGCONTEXT_edi)
112	do_expr(8, IA32_SIGCONTEXT_eip)
113
114	.align 4
115.LENDFDE2:
116
117	.long .LENDFDE3-.LSTARTFDE3	/* Length FDE */
118.LSTARTFDE3:
119	.long .LSTARTFDE3-.LSTARTFRAMES	/* CIE pointer */
120	/* HACK: See above wrt unwind library assumptions.  */
121	.long .LSTART_rt_sigreturn-1-.	/* PC-relative start address */
122	.long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1
123	.uleb128 0			/* Augmentation */
124	/* What follows are the instructions for the table generation.
125	   We record the locations of each register saved.  This is
126	   slightly less complicated than the above, since we don't
127	   modify the stack pointer in the process.  */
128
129	do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_esp)
130	do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_eax)
131	do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ecx)
132	do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_edx)
133	do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ebx)
134	do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ebp)
135	do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_esi)
136	do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_edi)
137	do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_eip)
138
139	.align 4
140.LENDFDE3:
141
142#include "../../i386/kernel/vsyscall-note.S"
143