freebsd-nq/sys/amd64/linux/linux_locore.asm
Dmitry Chagin 815165be20 linux(4): Remove function prototypes from the vDSO.
In preparation for vDSO code revision get rid of incomplete vDSO methods
from locore, but leave .note.Linux section commented out.
.note.Linux section is used by glibc rtld to get the kernel version, that
saves one system call call. I'll try to implement it later, if figure out
how to use it with jails.

MFC after:	2 weeks
2021-07-20 09:52:08 +03:00

83 lines
1.8 KiB
NASM

/* $FreeBSD$ */
#include "linux_assym.h" /* system definitions */
#include <machine/asmacros.h> /* miscellaneous asm macros */
#include <amd64/linux/linux_syscall.h> /* system call numbers */
.data
.globl linux_platform
linux_platform:
.asciz "x86_64"
.text
/*
* To avoid excess stack frame the signal trampoline code emulates
* the 'call' instruction.
*/
ENTRY(linux_rt_sigcode)
movq %rsp, %rbx /* preserve sigframe */
call .getip
.getip:
popq %rax
add $.startrtsigcode-.getip, %rax /* ret address */
pushq %rax
jmp *LINUX_RT_SIGF_HANDLER(%rbx)
.startrtsigcode:
movq $LINUX_SYS_linux_rt_sigreturn,%rax /* linux_rt_sigreturn() */
syscall /* enter kernel with args */
hlt
.endrtsigcode:
0: jmp 0b
#if 0
.section .note.Linux, "a",@note
.long 2f - 1f /* namesz */
.balign 4
.long 4f - 3f /* descsz */
.long 0
1:
.asciz "Linux"
2:
.balign 4
3:
.long LINUX_VERSION_CODE
4:
.balign 4
.previous
#endif
.section .eh_frame,"a",@progbits
.LSTARTFRAMEDLSI0:
.long .LENDCIEDLSI0-.LSTARTCIEDLSI0
.LSTARTCIEDLSI0:
.long 0 /* CIE ID */
.byte 1 /* Version number */
.string "zR" /* NULL-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 0x0c /* DW_CFA_def_cfa */
.uleb128 4
.uleb128 4
.byte 0x88 /* DW_CFA_offset, column 0x8 */
.uleb128 1
.align 4
.LENDCIEDLSI0:
.long .LENDFDEDLSI0-.LSTARTFDEDLSI0 /* Length FDE */
.LSTARTFDEDLSI0:
.long .LSTARTFDEDLSI0-.LSTARTFRAMEDLSI0 /* CIE pointer */
.long .startrtsigcode-. /* PC-relative start address */
.long .endrtsigcode-.startrtsigcode
.uleb128 0
.align 4
.LENDFDEDLSI0:
.previous