1 #include <linux/linkage.h>
2 #include <asm/unistd_32.h>
3 #include <asm/asm-offsets.h>
5 #ifndef SYSCALL_ENTER_KERNEL
6 #define SYSCALL_ENTER_KERNEL int $0x80
10 .globl __kernel_sigreturn
11 .type __kernel_sigreturn,@function
12 nop /* this guy is needed for .LSTARTFDEDLSI1 below (watch for HACK) */
16 popl %eax /* XXX does this mean it needs unwind info? */
17 movl $__NR_sigreturn, %eax
21 .size __kernel_sigreturn,.-.LSTART_sigreturn
23 .globl __kernel_rt_sigreturn
24 .type __kernel_rt_sigreturn,@function
26 __kernel_rt_sigreturn:
28 movl $__NR_rt_sigreturn, %eax
32 .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
35 .section .eh_frame,"a",@progbits
37 .long .LENDCIEDLSI1-.LSTARTCIEDLSI1
40 .byte 1 /* Version number */
41 .string "zRS" /* NUL-terminated augmentation string */
42 .uleb128 1 /* Code alignment factor */
43 .sleb128 -4 /* Data alignment factor */
44 .byte 8 /* Return address register column */
45 .uleb128 1 /* Augmentation value length */
46 .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
47 .byte 0 /* DW_CFA_nop */
50 .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */
52 .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */
53 /* HACK: The dwarf2 unwind routines will subtract 1 from the
54 return address to get an address in the middle of the
55 presumed call instruction. Since we didn't get here via
56 a call, we need to include the nop before the real start
58 .long .LSTART_sigreturn-1-. /* PC-relative start address */
59 .long .LEND_sigreturn-.LSTART_sigreturn+1
60 .uleb128 0 /* Augmentation */
61 /* What follows are the instructions for the table generation.
62 We record the locations of each register saved. This is
63 complicated by the fact that the "CFA" is always assumed to
64 be the value of the stack pointer in the caller. This means
65 that we must define the CFA of this body of code to be the
66 saved value of the stack pointer in the sigcontext. Which
67 also means that there is no fixed relation to the other
68 saved registers, which means that we must use DW_CFA_expression
69 to compute their addresses. It also means that when we
70 adjust the stack with the popl, we have to do it all over again. */
72 #define do_cfa_expr(offset) \
73 .byte 0x0f; /* DW_CFA_def_cfa_expression */ \
74 .uleb128 1f-0f; /* length */ \
75 0: .byte 0x74; /* DW_OP_breg4 */ \
76 .sleb128 offset; /* offset */ \
77 .byte 0x06; /* DW_OP_deref */ \
80 #define do_expr(regno, offset) \
81 .byte 0x10; /* DW_CFA_expression */ \
82 .uleb128 regno; /* regno */ \
83 .uleb128 1f-0f; /* length */ \
84 0: .byte 0x74; /* DW_OP_breg4 */ \
85 .sleb128 offset; /* offset */ \
88 do_cfa_expr(IA32_SIGCONTEXT_sp+4)
89 do_expr(0, IA32_SIGCONTEXT_ax+4)
90 do_expr(1, IA32_SIGCONTEXT_cx+4)
91 do_expr(2, IA32_SIGCONTEXT_dx+4)
92 do_expr(3, IA32_SIGCONTEXT_bx+4)
93 do_expr(5, IA32_SIGCONTEXT_bp+4)
94 do_expr(6, IA32_SIGCONTEXT_si+4)
95 do_expr(7, IA32_SIGCONTEXT_di+4)
96 do_expr(8, IA32_SIGCONTEXT_ip+4)
98 .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */
100 do_cfa_expr(IA32_SIGCONTEXT_sp)
101 do_expr(0, IA32_SIGCONTEXT_ax)
102 do_expr(1, IA32_SIGCONTEXT_cx)
103 do_expr(2, IA32_SIGCONTEXT_dx)
104 do_expr(3, IA32_SIGCONTEXT_bx)
105 do_expr(5, IA32_SIGCONTEXT_bp)
106 do_expr(6, IA32_SIGCONTEXT_si)
107 do_expr(7, IA32_SIGCONTEXT_di)
108 do_expr(8, IA32_SIGCONTEXT_ip)
113 .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */
115 .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */
116 /* HACK: See above wrt unwind library assumptions. */
117 .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */
118 .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1
119 .uleb128 0 /* Augmentation */
120 /* What follows are the instructions for the table generation.
121 We record the locations of each register saved. This is
122 slightly less complicated than the above, since we don't
123 modify the stack pointer in the process. */
125 do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_sp)
126 do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ax)
127 do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_cx)
128 do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_dx)
129 do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bx)
130 do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bp)
131 do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_si)
132 do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_di)
133 do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ip)