1/*- 2 * Copyright (c) 2003 Peter Wemm 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#include "opt_compat.h" 30 31#include <machine/asmacros.h> 32#include <sys/syscall.h> 33 34#include "ia32_assym.h" 35 36 .text 37 .code32 38/* 39 * Signal trampoline, copied to top of user stack 40 * XXX may need to be MD to match backend sendsig handoff protocol 41 */ 42 ALIGN_TEXT 43 .globl ia32_sigcode 44ia32_sigcode: 45 calll *IA32_SIGF_HANDLER(%esp) 46 leal IA32_SIGF_UC(%esp),%eax /* get ucontext */ 47 pushl %eax 48 movl $SYS_sigreturn,%eax 49 pushl %eax /* junk to fake return addr. */ 50 int $0x80 /* enter kernel with args */ 51 /* on stack */ 521: 53 jmp 1b 54 55#ifdef COMPAT_FREEBSD4 56 ALIGN_TEXT 57freebsd4_ia32_sigcode: 58 calll *IA32_SIGF_HANDLER(%esp) 59 leal IA32_SIGF_UC4(%esp),%eax/* get ucontext */ 60 pushl %eax 61 movl $344,%eax /* 4.x SYS_sigreturn */ 62 pushl %eax /* junk to fake return addr. */ 63 int $0x80 /* enter kernel with args */ 64 /* on stack */ 651: 66 jmp 1b 67#endif 68 69#ifdef COMPAT_43 70 ALIGN_TEXT 71ia32_osigcode: 72 calll *IA32_SIGF_HANDLER(%esp)/* call signal handler */ 73 leal IA32_SIGF_SC(%esp),%eax /* get sigcontext */ 74 pushl %eax 75 movl $103,%eax /* 3.x SYS_sigreturn */ 76 pushl %eax /* junk to fake return addr. */ 77 int $0x80 /* enter kernel with args */ 781: 79 jmp 1b 80 81/* 82 * Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls 83 * don't change the interrupt mask, so if this one went directly to the 84 * kernel then there would be a window with interrupts enabled in kernel 85 * mode, and all interrupt handlers would have to be almost as complicated 86 * as the NMI handler to support this. 87 * 88 * Instead, convert the lcall to an int0x80 call. The kernel does most 89 * of the conversion by popping the lcall return values off the user 90 * stack and returning to them instead of to here, except when the 91 * conversion itself fails. Adjusting the stack here is impossible for 92 * vfork() and harder for other syscalls. 93 */ 94 ALIGN_TEXT 95lcall_tramp: 96 int $0x80 971: jmp 1b 98#endif 99 100 ALIGN_TEXT 101esigcode: 102 103 .data 104 .globl sz_ia32_sigcode 105sz_ia32_sigcode: 106 .long esigcode-ia32_sigcode 107#ifdef COMPAT_FREEBSD4 108 .globl sz_freebsd4_ia32_sigcode 109sz_freebsd4_ia32_sigcode: 110 .long esigcode-freebsd4_ia32_sigcode 111#endif 112#ifdef COMPAT_43 113 .globl sz_ia32_osigcode 114sz_ia32_osigcode: 115 .long esigcode-ia32_osigcode 116 .globl sz_lcall_tramp 117sz_lcall_tramp: 118 .long esigcode-lcall_tramp 119#endif 120