1#include <linux/linkage.h> 2#include <asm/unistd_32.h> 3#include <asm/asm-offsets.h> 4 5#ifndef SYSCALL_ENTER_KERNEL 6#define SYSCALL_ENTER_KERNEL int $0x80 7#endif 8 9 .text 10 .globl __kernel_sigreturn 11 .type __kernel_sigreturn,@function 12 nop /* this guy is needed for .LSTARTFDEDLSI1 below (watch for HACK) */ 13 ALIGN 14__kernel_sigreturn: 15.LSTART_sigreturn: 16 popl %eax /* XXX does this mean it needs unwind info? */ 17 movl $__NR_sigreturn, %eax 18 SYSCALL_ENTER_KERNEL 19.LEND_sigreturn: 20 nop 21 .size __kernel_sigreturn,.-.LSTART_sigreturn 22 23 .globl __kernel_rt_sigreturn 24 .type __kernel_rt_sigreturn,@function 25 ALIGN 26__kernel_rt_sigreturn: 27.LSTART_rt_sigreturn: 28 movl $__NR_rt_sigreturn, %eax 29 SYSCALL_ENTER_KERNEL 30.LEND_rt_sigreturn: 31 nop 32 .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn 33 .previous 34 35 .section .eh_frame,"a",@progbits 36.LSTARTFRAMEDLSI1: 37 .long .LENDCIEDLSI1-.LSTARTCIEDLSI1 38.LSTARTCIEDLSI1: 39 .long 0 /* CIE ID */ 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 */ 48 .align 4 49.LENDCIEDLSI1: 50 .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */ 51.LSTARTFDEDLSI1: 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 57 to make up for it. */ 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. */ 71 72#define do_cfa_expr(offset) \ 73 .byte 0x0f; /* DW_CFA_def_cfa_expression */ \ 74 .uleb128 1f-0f; /* length */ \ 750: .byte 0x74; /* DW_OP_breg4 */ \ 76 .sleb128 offset; /* offset */ \ 77 .byte 0x06; /* DW_OP_deref */ \ 781: 79 80#define do_expr(regno, offset) \ 81 .byte 0x10; /* DW_CFA_expression */ \ 82 .uleb128 regno; /* regno */ \ 83 .uleb128 1f-0f; /* length */ \ 840: .byte 0x74; /* DW_OP_breg4 */ \ 85 .sleb128 offset; /* offset */ \ 861: 87 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) 97 98 .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */ 99 100 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) 109 110 .align 4 111.LENDFDEDLSI1: 112 113 .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */ 114.LSTARTFDEDLSI2: 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. */ 124 125 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) 134 135 .align 4 136.LENDFDEDLSI2: 137 .previous 138