2 * Copyright (c) 2003 Peter Wemm
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include "opt_compat.h"
31 #include <machine/asmacros.h>
32 #include <sys/syscall.h>
34 #include "ia32_assym.h"
39 * Signal trampoline, copied to top of user stack
40 * XXX may need to be MD to match backend sendsig handoff protocol
45 calll *IA32_SIGF_HANDLER(%esp)
46 leal IA32_SIGF_UC(%esp),%eax /* get ucontext */
48 movl $SYS_sigreturn,%eax
49 pushl %eax /* junk to fake return addr. */
50 int $0x80 /* enter kernel with args */
55 #ifdef COMPAT_FREEBSD4
57 freebsd4_ia32_sigcode:
58 calll *IA32_SIGF_HANDLER(%esp)
59 leal IA32_SIGF_UC4(%esp),%eax/* get ucontext */
61 movl $344,%eax /* 4.x SYS_sigreturn */
62 pushl %eax /* junk to fake return addr. */
63 int $0x80 /* enter kernel with args */
72 calll *IA32_SIGF_HANDLER(%esp)/* call signal handler */
73 leal IA32_SIGF_SC(%esp),%eax /* get sigcontext */
75 movl $103,%eax /* 3.x SYS_sigreturn */
76 pushl %eax /* junk to fake return addr. */
77 int $0x80 /* enter kernel with args */
83 * The lcall $7,$0 emulator cannot use the call gate that does an
84 * inter-privilege transition. The reason is that the call gate
85 * does not disable interrupts, and, before the swapgs is
86 * executed, we would have a window where the ring 0 code is
87 * executed with the wrong gsbase.
89 * Instead, reflect the lcall $7,$0 back to ring 3 trampoline
90 * which sets up the frame for int $0x80.
96 * There, we are in 64bit mode and need to return to 32bit.
97 * First, convert call frame from 64 to 32 bit format.
101 movl %eax,20(%rsp) /* ret %cs */
103 movl %eax,16(%rsp) /* ret %rip -> %eip */
106 /* Now return to 32bit */
107 pushq $0x33 /* _ucode32sel UPL */
113 /* Back in 32bit mode */
119 pushl 0x24(%ebp) /* arg 6 */
124 pushl 0x10(%ebp) /* arg 1 */
125 pushl 0xc(%ebp) /* gap */
132 * vfork handling is special and relies on the libc stub saving
133 * the return ip in %ecx. If vfork failed, then there is no
134 * child which can corrupt the frame created by call gate.
146 .globl sz_ia32_sigcode
148 .long esigcode-ia32_sigcode
149 #ifdef COMPAT_FREEBSD4
150 .globl sz_freebsd4_ia32_sigcode
151 sz_freebsd4_ia32_sigcode:
152 .long esigcode-freebsd4_ia32_sigcode
155 .globl sz_ia32_osigcode
157 .long esigcode-ia32_osigcode
158 .globl sz_lcall_tramp
160 .long esigcode-lcall_tramp