freebsd-dev/sys/i386/linux/linux_locore.s
Dmitry Chagin 437c43c1cb Being exported through vdso the note.Linux section used by glibc
to determine the kernel version (this saves one uname call).
Temporarily disable the export of a note.Linux section until I figured
out how to change the kernel version in the note.Linux on the fly.

Differential Revision:	https://reviews.freebsd.org/D1081
Reviewed by:	trasz
2015-05-24 16:25:44 +00:00

150 lines
3.8 KiB
ArmAsm

/* $FreeBSD$ */
#include "linux_assym.h" /* system definitions */
#include <machine/asmacros.h> /* miscellaneous asm macros */
#include <i386/linux/linux_syscall.h> /* system call numbers */
#include "assym.s"
/*
* To avoid excess stack frame the signal trampoline code emulates
* the 'call' instruction.
*/
NON_GPROF_ENTRY(linux_sigcode)
movl %esp, %ebx /* preserve sigframe */
call .getip0
.getip0:
popl %eax
add $.startsigcode-.getip0, %eax /* ret address */
push %eax
jmp *LINUX_SIGF_HANDLER(%ebx)
.startsigcode:
popl %eax /* gcc unwind code need this */
movl $LINUX_SYS_linux_sigreturn,%eax /* linux_sigreturn() */
int $0x80 /* enter kernel with args */
.endsigcode:
0: jmp 0b
NON_GPROF_ENTRY(linux_rt_sigcode)
leal LINUX_RT_SIGF_UC(%esp),%ebx /* linux ucp */
leal LINUX_RT_SIGF_SC(%ebx),%ecx /* linux sigcontext */
movl %esp, %edi
call .getip1
.getip1:
popl %eax
add $.startrtsigcode-.getip1, %eax /* ret address */
push %eax
jmp *LINUX_RT_SIGF_HANDLER(%edi)
.startrtsigcode:
movl $LINUX_SYS_linux_rt_sigreturn,%eax /* linux_rt_sigreturn() */
int $0x80 /* enter kernel with args */
.endrtsigcode:
0: jmp 0b
NON_GPROF_ENTRY(linux_vsyscall)
.startvsyscall:
int $0x80
ret
.endvsyscall:
#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
#define do_cfa_expr(offset) \
.byte 0x0f; /* DW_CFA_def_cfa_expression */ \
.uleb128 11f-10f; /* length */ \
10: .byte 0x74; /* DW_OP_breg4 */ \
.sleb128 offset; /* offset */ \
.byte 0x06; /* DW_OP_deref */ \
11:
/* CIE */
.section .eh_frame,"a",@progbits
.LSTARTFRAMEDLSI1:
.long .LENDCIEDLSI1-.LSTARTCIEDLSI1
.LSTARTCIEDLSI1:
.long 0 /* CIE ID */
.byte 1 /* Version number */
.string "zRS" /* 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 0 /* DW_CFA_nop */
.align 4
.LENDCIEDLSI1:
/* FDE */
.long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */
.LSTARTFDEDLSI1:
.long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */
.long .startsigcode-. /* PC-relative start address */
.long .endsigcode-.startsigcode
.uleb128 0 /* Augmentation */
do_cfa_expr(LINUX_SIGF_SC-8)
.align 4
.LENDFDEDLSI1:
.long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */
.LSTARTFDEDLSI2:
.long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */
.long .startrtsigcode-. /* PC-relative start address */
.long .endrtsigcode-.startrtsigcode
.uleb128 0 /* Augmentation */
do_cfa_expr(LINUX_RT_SIGF_SC-4+LINUX_SC_ESP)
.align 4
.LENDFDEDLSI2:
.previous
.section .eh_frame,"a",@progbits
.LSTARTFRAMEDLSI2:
.long .LENDCIEDLSI2-.LSTARTCIEDLSI2
.LSTARTCIEDLSI2:
.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
.LENDCIEDLSI2:
.long .LENDFDEDLSI3-.LSTARTFDEDLSI3 /* Length FDE */
.LSTARTFDEDLSI3:
.long .LSTARTFDEDLSI3-.LSTARTFRAMEDLSI2 /* CIE pointer */
.long .startvsyscall-. /* PC-relative start address */
.long .endvsyscall-.startvsyscall
.uleb128 0
.align 4
.LENDFDEDLSI3:
.previous