xref: /freebsd/sys/amd64/ia32/ia32_sigtramp.S (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1/*-
2 * Copyright (c) 2003 Peter Wemm
3 * All rights reserved.
4 *
5 * Copyright (c) 2021 The FreeBSD Foundation
6 *
7 * Portions of this software were developed by Konstantin Belousov
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <machine/asmacros.h>
33#include <sys/syscall.h>
34
35#include "ia32_assym.h"
36
37	.text
38/*
39 * Signal trampoline, mapped as vdso into shared page, or copied to
40 * top of user stack for old binaries.
41 */
42	ALIGN_TEXT
43	.globl	__vdso_ia32_sigcode
44__vdso_ia32_sigcode:
45	.cfi_startproc
46	.cfi_signal_frame
47	.cfi_def_cfa	%esp, 0
48#if 0
49	.cfi_offset	%gs,  IA32_SIGF_UC + IA32_UC_GS
50	.cfi_offset	%fs,  IA32_SIGF_UC + IA32_UC_FS
51	.cfi_offset	%es,  IA32_SIGF_UC + IA32_UC_ES
52	.cfi_offset	%ds,  IA32_SIGF_UC + IA32_UC_DS
53#endif
54	.cfi_offset	%edi, IA32_SIGF_UC + IA32_UC_EDI
55	.cfi_offset	%esi, IA32_SIGF_UC + IA32_UC_ESI
56	.cfi_offset	%ebp, IA32_SIGF_UC + IA32_UC_EBP
57	.cfi_offset	%ebx, IA32_SIGF_UC + IA32_UC_EBX
58	.cfi_offset	%edx, IA32_SIGF_UC + IA32_UC_EDX
59	.cfi_offset	%ecx, IA32_SIGF_UC + IA32_UC_ECX
60	.cfi_offset	%eax, IA32_SIGF_UC + IA32_UC_EAX
61	.cfi_offset	%eip, IA32_SIGF_UC + IA32_UC_EIP
62#if 0
63	.cfi_offset	%cs,  IA32_SIGF_UC + IA32_UC_CS
64	.cfi_offset	%flags, IA32_SIGF_UC + IA32_UC_EFLAGS
65#endif
66	.cfi_offset	%esp, IA32_SIGF_UC + IA32_UC_ESP
67#if 0
68	.cfi_offset	%ss,  IA32_SIGF_UC + IA32_UC_SS
69	.cfi_offset	93 /* %fs.base */, IA32_SIGF_UC + IA32_UC_FSBASE
70	.cfi_offset	94 /* %gs.base */, IA32_SIGF_UC + IA32_UC_GSBASE
71#endif
72	calll	*IA32_SIGF_HANDLER(%esp)
73	leal	IA32_SIGF_UC(%esp),%eax	/* get ucontext */
74	pushl	%eax
75	.cfi_def_cfa	%esp, 4
76	movl	$SYS_sigreturn,%eax
77	pushl	%eax			/* junk to fake return addr. */
78	.cfi_def_cfa	%esp, 8
79	int	$0x80			/* enter kernel with args */
80					/* on stack */
811:
82	jmp	1b
83	.cfi_endproc
84
85	ALIGN_TEXT
86	.globl	__vdso_freebsd4_ia32_sigcode
87__vdso_freebsd4_ia32_sigcode:
88#ifdef COMPAT_FREEBSD4
89	calll	*IA32_SIGF_HANDLER(%esp)
90	leal	IA32_SIGF_UC4(%esp),%eax/* get ucontext */
91	pushl	%eax
92	movl	$344,%eax		/* 4.x SYS_sigreturn */
93	pushl	%eax			/* junk to fake return addr. */
94	int	$0x80			/* enter kernel with args */
95					/* on stack */
961:
97	jmp	1b
98#else
99	ud2
100#endif
101
102	ALIGN_TEXT
103	.globl	__vdso_ia32_osigcode
104__vdso_ia32_osigcode:
105#ifdef COMPAT_43
106	calll	*IA32_SIGF_HANDLER(%esp)/* call signal handler */
107	leal	IA32_SIGF_SC(%esp),%eax	/* get sigcontext */
108	pushl	%eax
109	movl	$103,%eax		/* 3.x SYS_sigreturn */
110	pushl	%eax			/* junk to fake return addr. */
111	int	$0x80			/* enter kernel with args */
1121:
113	jmp	1b
114#else
115	ud2
116#endif
117
118/*
119 * Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls
120 * don't change the interrupt mask, so if this one went directly to the
121 * kernel then there would be a window with interrupts enabled in kernel
122 * mode, and all interrupt handlers would have to be almost as complicated
123 * as the NMI handler to support this.
124 *
125 * Instead, convert the lcall to an int0x80 call.  The kernel does most
126 * of the conversion by popping the lcall return values off the user
127 * stack and returning to them instead of to here, except when the
128 * conversion itself fails.  Adjusting the stack here is impossible for
129 * vfork() and harder for other syscalls.
130 */
131	ALIGN_TEXT
132	.globl	__vdso_lcall_tramp
133__vdso_lcall_tramp:
134#ifdef COMPAT_43
135	int	$0x80
1361:	jmp	1b
137#else
138	ud2
139#endif
140	.p2align 1
141