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, set LDT descriptor 0 as code segment, which reflects
90 * the lcall $7,$0 back to ring 3 trampoline. The trampoline sets up
91 * the frame for int $0x80.
99 pushl 0x24(%ebp) /* arg 6 */
104 pushl 0x10(%ebp) /* arg 1 */
105 subl $4,%esp /* gap */
111 * vfork handling is special and relies on the libc stub saving
112 * the return ip in %ecx. Also, we assume that the call was done
113 * with ucode32 selector in %cs.
116 movl $0x33,4(%esp) /* GUCODE32_SEL | SEL_UPL */
125 .globl sz_ia32_sigcode
127 .long esigcode-ia32_sigcode
128 #ifdef COMPAT_FREEBSD4
129 .globl sz_freebsd4_ia32_sigcode
130 sz_freebsd4_ia32_sigcode:
131 .long esigcode-freebsd4_ia32_sigcode
134 .globl sz_ia32_osigcode
136 .long esigcode-ia32_osigcode
137 .globl sz_lcall_tramp
139 .long esigcode-lcall_tramp