Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Andi Kleen | bb33421 | 2006-01-11 22:43:54 +0100 | [diff] [blame] | 10 | .code32 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
Jakub Jelinek | da2e9e1 | 2006-03-31 02:30:28 -0800 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | .long .LENDFDE2-.LSTARTFDE2 /* Length FDE */ |
| 55 | .LSTARTFDE2: |
Jakub Jelinek | da2e9e1 | 2006-03-31 02:30:28 -0800 | [diff] [blame] | 56 | .long .LSTARTFDE2-.LSTARTFRAMES /* CIE pointer */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 */ \ |
| 79 | 0: .byte 0x74; /* DW_OP_breg4 */ \ |
| 80 | .sleb128 offset; /* offset */ \ |
| 81 | .byte 0x06; /* DW_OP_deref */ \ |
| 82 | 1: |
| 83 | |
| 84 | #define do_expr(regno, offset) \ |
| 85 | .byte 0x10; /* DW_CFA_expression */ \ |
| 86 | .uleb128 regno; /* regno */ \ |
| 87 | .uleb128 1f-0f; /* length */ \ |
| 88 | 0: .byte 0x74; /* DW_OP_breg4 */ \ |
| 89 | .sleb128 offset; /* offset */ \ |
| 90 | 1: |
| 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: |
Jakub Jelinek | da2e9e1 | 2006-03-31 02:30:28 -0800 | [diff] [blame] | 119 | .long .LSTARTFDE3-.LSTARTFRAMES /* CIE pointer */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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: |
Roland McGrath | e09b8c0 | 2005-04-16 15:24:50 -0700 | [diff] [blame] | 141 | |
| 142 | #include "../../i386/kernel/vsyscall-note.S" |
| 143 | |