| /* |
| * Common code for the sigreturn entry points in vDSO images. |
| * So far this code is the same for both int80 and sysenter versions. |
| * This file is #include'd by int80.S et al to define them first thing. |
| * The kernel assumes that the addresses of these routines are constant |
| * for all vDSO implementations. |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/unistd_32.h> |
| #include <asm/asm-offsets.h> |
| |
| #ifndef SYSCALL_ENTER_KERNEL |
| #define SYSCALL_ENTER_KERNEL int $0x80 |
| #endif |
| |
| .text |
| .globl __kernel_sigreturn |
| .type __kernel_sigreturn,@function |
| ALIGN |
| __kernel_sigreturn: |
| .LSTART_sigreturn: |
| popl %eax /* XXX does this mean it needs unwind info? */ |
| movl $__NR_sigreturn, %eax |
| SYSCALL_ENTER_KERNEL |
| .LEND_sigreturn: |
| nop |
| .size __kernel_sigreturn,.-.LSTART_sigreturn |
| |
| .globl __kernel_rt_sigreturn |
| .type __kernel_rt_sigreturn,@function |
| ALIGN |
| __kernel_rt_sigreturn: |
| .LSTART_rt_sigreturn: |
| movl $__NR_rt_sigreturn, %eax |
| SYSCALL_ENTER_KERNEL |
| .LEND_rt_sigreturn: |
| nop |
| .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn |
| .previous |
| |
| .section .eh_frame,"a",@progbits |
| .LSTARTFRAMEDLSI1: |
| .long .LENDCIEDLSI1-.LSTARTCIEDLSI1 |
| .LSTARTCIEDLSI1: |
| .long 0 /* CIE ID */ |
| .byte 1 /* Version number */ |
| .string "zRS" /* NUL-terminated augmentation string */ |
| .uleb128 1 /* Code alignment factor */ |
| .sleb128 -4 /* Data alignment factor */ |
| .byte 8 /* Return address register column */ |
| .uleb128 1 /* Augmentation value length */ |
| .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */ |
| .byte 0 /* DW_CFA_nop */ |
| .align 4 |
| .LENDCIEDLSI1: |
| .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */ |
| .LSTARTFDEDLSI1: |
| .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */ |
| /* HACK: The dwarf2 unwind routines will subtract 1 from the |
| return address to get an address in the middle of the |
| presumed call instruction. Since we didn't get here via |
| a call, we need to include the nop before the real start |
| to make up for it. */ |
| .long .LSTART_sigreturn-1-. /* PC-relative start address */ |
| .long .LEND_sigreturn-.LSTART_sigreturn+1 |
| .uleb128 0 /* Augmentation */ |
| /* What follows are the instructions for the table generation. |
| We record the locations of each register saved. This is |
| complicated by the fact that the "CFA" is always assumed to |
| be the value of the stack pointer in the caller. This means |
| that we must define the CFA of this body of code to be the |
| saved value of the stack pointer in the sigcontext. Which |
| also means that there is no fixed relation to the other |
| saved registers, which means that we must use DW_CFA_expression |
| to compute their addresses. It also means that when we |
| adjust the stack with the popl, we have to do it all over again. */ |
| |
| #define do_cfa_expr(offset) \ |
| .byte 0x0f; /* DW_CFA_def_cfa_expression */ \ |
| .uleb128 1f-0f; /* length */ \ |
| 0: .byte 0x74; /* DW_OP_breg4 */ \ |
| .sleb128 offset; /* offset */ \ |
| .byte 0x06; /* DW_OP_deref */ \ |
| 1: |
| |
| #define do_expr(regno, offset) \ |
| .byte 0x10; /* DW_CFA_expression */ \ |
| .uleb128 regno; /* regno */ \ |
| .uleb128 1f-0f; /* length */ \ |
| 0: .byte 0x74; /* DW_OP_breg4 */ \ |
| .sleb128 offset; /* offset */ \ |
| 1: |
| |
| do_cfa_expr(IA32_SIGCONTEXT_sp+4) |
| do_expr(0, IA32_SIGCONTEXT_ax+4) |
| do_expr(1, IA32_SIGCONTEXT_cx+4) |
| do_expr(2, IA32_SIGCONTEXT_dx+4) |
| do_expr(3, IA32_SIGCONTEXT_bx+4) |
| do_expr(5, IA32_SIGCONTEXT_bp+4) |
| do_expr(6, IA32_SIGCONTEXT_si+4) |
| do_expr(7, IA32_SIGCONTEXT_di+4) |
| do_expr(8, IA32_SIGCONTEXT_ip+4) |
| |
| .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */ |
| |
| do_cfa_expr(IA32_SIGCONTEXT_sp) |
| do_expr(0, IA32_SIGCONTEXT_ax) |
| do_expr(1, IA32_SIGCONTEXT_cx) |
| do_expr(2, IA32_SIGCONTEXT_dx) |
| do_expr(3, IA32_SIGCONTEXT_bx) |
| do_expr(5, IA32_SIGCONTEXT_bp) |
| do_expr(6, IA32_SIGCONTEXT_si) |
| do_expr(7, IA32_SIGCONTEXT_di) |
| do_expr(8, IA32_SIGCONTEXT_ip) |
| |
| .align 4 |
| .LENDFDEDLSI1: |
| |
| .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */ |
| .LSTARTFDEDLSI2: |
| .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */ |
| /* HACK: See above wrt unwind library assumptions. */ |
| .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */ |
| .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1 |
| .uleb128 0 /* Augmentation */ |
| /* What follows are the instructions for the table generation. |
| We record the locations of each register saved. This is |
| slightly less complicated than the above, since we don't |
| modify the stack pointer in the process. */ |
| |
| do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_sp) |
| do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ax) |
| do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_cx) |
| do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_dx) |
| do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bx) |
| do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bp) |
| do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_si) |
| do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_di) |
| do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ip) |
| |
| .align 4 |
| .LENDFDEDLSI2: |
| .previous |
