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freebsd
GitHub Repository: freebsd/freebsd-src
 Path: blob/main/sys/amd64/ia32/ia32_sigtramp.S
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/*-

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 * Copyright (c) 2003 Peter Wemm

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 * All rights reserved.

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 *

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 * Copyright (c) 2021 The FreeBSD Foundation

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 *

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 * Portions of this software were developed by Konstantin Belousov

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 * under sponsorship from the FreeBSD Foundation.

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 *

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 * Redistribution and use in source and binary forms, with or without

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 * modification, are permitted provided that the following conditions

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 * are met:

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 * 1. Redistributions of source code must retain the above copyright

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 *    notice, this list of conditions and the following disclaimer.

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 * 2. Redistributions in binary form must reproduce the above copyright

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 *    notice, this list of conditions and the following disclaimer in the

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 *    documentation and/or other materials provided with the distribution.

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 *

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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

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 * SUCH DAMAGE.

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 */

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#include <machine/asmacros.h>

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#include <sys/syscall.h>

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#include "ia32_assym.h"

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	.text

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/*

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 * Signal trampoline, mapped as vdso into shared page, or copied to

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 * top of user stack for old binaries.

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 */

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	ALIGN_TEXT

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	.globl	__vdso_ia32_sigcode

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__vdso_ia32_sigcode:

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	.cfi_startproc

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	.cfi_signal_frame

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	.cfi_def_cfa	%esp, 0

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#if 0

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	.cfi_offset	%gs,  IA32_SIGF_UC + IA32_UC_GS

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	.cfi_offset	%fs,  IA32_SIGF_UC + IA32_UC_FS

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	.cfi_offset	%es,  IA32_SIGF_UC + IA32_UC_ES

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	.cfi_offset	%ds,  IA32_SIGF_UC + IA32_UC_DS

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#endif

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	.cfi_offset	%edi, IA32_SIGF_UC + IA32_UC_EDI

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	.cfi_offset	%esi, IA32_SIGF_UC + IA32_UC_ESI

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	.cfi_offset	%ebp, IA32_SIGF_UC + IA32_UC_EBP

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	.cfi_offset	%ebx, IA32_SIGF_UC + IA32_UC_EBX

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	.cfi_offset	%edx, IA32_SIGF_UC + IA32_UC_EDX

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	.cfi_offset	%ecx, IA32_SIGF_UC + IA32_UC_ECX

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	.cfi_offset	%eax, IA32_SIGF_UC + IA32_UC_EAX

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	.cfi_offset	%eip, IA32_SIGF_UC + IA32_UC_EIP

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#if 0

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	.cfi_offset	%cs,  IA32_SIGF_UC + IA32_UC_CS

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	.cfi_offset	%flags, IA32_SIGF_UC + IA32_UC_EFLAGS

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#endif

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	.cfi_offset	%esp, IA32_SIGF_UC + IA32_UC_ESP

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#if 0

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	.cfi_offset	%ss,  IA32_SIGF_UC + IA32_UC_SS

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	.cfi_offset	93 /* %fs.base */, IA32_SIGF_UC + IA32_UC_FSBASE

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	.cfi_offset	94 /* %gs.base */, IA32_SIGF_UC + IA32_UC_GSBASE

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#endif

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	calll	*IA32_SIGF_HANDLER(%esp)

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	leal	IA32_SIGF_UC(%esp),%eax	/* get ucontext */

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	pushl	%eax

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	.cfi_def_cfa	%esp, 4

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	movl	$SYS_sigreturn,%eax

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	pushl	%eax			/* junk to fake return addr. */

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	.cfi_def_cfa	%esp, 8

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	int	$0x80			/* enter kernel with args */

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					/* on stack */

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1:

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	jmp	1b

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	.cfi_endproc

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	ALIGN_TEXT

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	.globl	__vdso_freebsd4_ia32_sigcode

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__vdso_freebsd4_ia32_sigcode:

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#ifdef COMPAT_FREEBSD4

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	calll	*IA32_SIGF_HANDLER(%esp)

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	leal	IA32_SIGF_UC4(%esp),%eax/* get ucontext */

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	pushl	%eax

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	movl	$344,%eax		/* 4.x SYS_sigreturn */

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	pushl	%eax			/* junk to fake return addr. */

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	int	$0x80			/* enter kernel with args */

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					/* on stack */

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1:

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	jmp	1b

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#else

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	ud2

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#endif

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	ALIGN_TEXT

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	.globl	__vdso_ia32_osigcode

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__vdso_ia32_osigcode:

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#ifdef COMPAT_43

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	calll	*IA32_SIGF_HANDLER(%esp)/* call signal handler */

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	leal	IA32_SIGF_SC(%esp),%eax	/* get sigcontext */

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	pushl	%eax

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	movl	$103,%eax		/* 3.x SYS_sigreturn */

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	pushl	%eax			/* junk to fake return addr. */

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	int	$0x80			/* enter kernel with args */

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1:

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	jmp	1b

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#else

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	ud2

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#endif

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/*

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 * Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls

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 * don't change the interrupt mask, so if this one went directly to the

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 * kernel then there would be a window with interrupts enabled in kernel

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 * mode, and all interrupt handlers would have to be almost as complicated

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 * as the NMI handler to support this.

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 *

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 * Instead, convert the lcall to an int0x80 call.  The kernel does most

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 * of the conversion by popping the lcall return values off the user

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 * stack and returning to them instead of to here, except when the

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 * conversion itself fails.  Adjusting the stack here is impossible for

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 * vfork() and harder for other syscalls.

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 */

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	ALIGN_TEXT

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	.globl	__vdso_lcall_tramp

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__vdso_lcall_tramp:

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#ifdef COMPAT_43

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	int	$0x80

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1:	jmp	1b

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#else

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	ud2

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#endif

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	.p2align 1

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