/*-
* Copyright (c) 2003 Peter Wemm
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include "opt_compat.h"
#include <machine/asmacros.h>
#include <sys/syscall.h>
#include "ia32_assym.h"
.text
.code32
/*
* Signal trampoline, copied to top of user stack
* XXX may need to be MD to match backend sendsig handoff protocol
*/
ALIGN_TEXT
.globl ia32_sigcode
ia32_sigcode:
calll *IA32_SIGF_HANDLER(%esp)
leal IA32_SIGF_UC(%esp),%eax /* get ucontext */
pushl %eax
movl $SYS_sigreturn,%eax
pushl %eax /* junk to fake return addr. */
int $0x80 /* enter kernel with args */
/* on stack */
1:
jmp 1b
#ifdef COMPAT_FREEBSD4
ALIGN_TEXT
freebsd4_ia32_sigcode:
calll *IA32_SIGF_HANDLER(%esp)
leal IA32_SIGF_UC4(%esp),%eax/* get ucontext */
pushl %eax
movl $344,%eax /* 4.x SYS_sigreturn */
pushl %eax /* junk to fake return addr. */
int $0x80 /* enter kernel with args */
/* on stack */
1:
jmp 1b
#endif
#ifdef COMPAT_43
ALIGN_TEXT
ia32_osigcode:
calll *IA32_SIGF_HANDLER(%esp)/* call signal handler */
leal IA32_SIGF_SC(%esp),%eax /* get sigcontext */
pushl %eax
movl $103,%eax /* 3.x SYS_sigreturn */
pushl %eax /* junk to fake return addr. */
int $0x80 /* enter kernel with args */
1:
jmp 1b
/*
* The lcall $7,$0 emulator cannot use the call gate that does an
* inter-privilege transition. The reason is that the call gate
* does not disable interrupts, and, before the swapgs is
* executed, we would have a window where the ring 0 code is
* executed with the wrong gsbase.
*
* Instead, reflect the lcall $7,$0 back to ring 3 trampoline
* which sets up the frame for int $0x80.
*/
ALIGN_TEXT
lcall_tramp:
.code64
/*
* There, we are in 64bit mode and need to return to 32bit.
* First, convert call frame from 64 to 32 bit format.
*/
pushq %rax
movl 16(%rsp),%eax
movl %eax,20(%rsp) /* ret %cs */
movl 8(%rsp),%eax
movl %eax,16(%rsp) /* ret %rip -> %eip */
popq %rax
addq $8,%rsp
/* Now return to 32bit */
pushq $0x33 /* _ucode32sel UPL */
callq 1f
1:
addq $2f-1b,(%rsp)
lretq
2:
/* Back in 32bit mode */
.code32
cmpl $SYS_vfork,%eax
je 4f
pushl %ebp
movl %esp,%ebp
pushl 0x24(%ebp) /* arg 6 */
pushl 0x20(%ebp)
pushl 0x1c(%ebp)
pushl 0x18(%ebp)
pushl 0x14(%ebp)
pushl 0x10(%ebp) /* arg 1 */
pushl 0xc(%ebp) /* gap */
int $0x80
leavel
3:
lretl
4:
/*
* vfork handling is special and relies on the libc stub saving
* the return ip in %ecx. If vfork failed, then there is no
* child which can corrupt the frame created by call gate.
*/
int $0x80
jb 3b
addl $8,%esp
jmpl *%ecx
#endif
ALIGN_TEXT
esigcode:
.data
.globl sz_ia32_sigcode
sz_ia32_sigcode:
.long esigcode-ia32_sigcode
#ifdef COMPAT_FREEBSD4
.globl sz_freebsd4_ia32_sigcode
sz_freebsd4_ia32_sigcode:
.long esigcode-freebsd4_ia32_sigcode
#endif
#ifdef COMPAT_43
.globl sz_ia32_osigcode
sz_ia32_osigcode:
.long esigcode-ia32_osigcode
.globl sz_lcall_tramp
sz_lcall_tramp:
.long esigcode-lcall_tramp
#endif
