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 <machine/asmacros.h> 30#include <sys/syscall.h> 31 32#include "ia32_assym.h" 33 34 .text 35 .code32 36/* 37 * Signal trampoline, copied to top of user stack 38 * XXX may need to be MD to match backend sendsig handoff protocol 39 */ 40 ALIGN_TEXT 41 .globl ia32_sigcode 42ia32_sigcode: 43 calll *IA32_SIGF_HANDLER(%esp) 44 leal IA32_SIGF_UC(%esp),%eax /* get ucontext */ 45 pushl %eax 46 movl $SYS_sigreturn,%eax 47 pushl %eax /* junk to fake return addr. */ 48 int $0x80 /* enter kernel with args */ 49 /* on stack */ 501: 51 jmp 1b 52 53#ifdef COMPAT_FREEBSD4 54 ALIGN_TEXT 55freebsd4_ia32_sigcode: 56 calll *IA32_SIGF_HANDLER(%esp) 57 leal IA32_SIGF_UC4(%esp),%eax/* get ucontext */ 58 pushl %eax 59 movl $344,%eax /* 4.x SYS_sigreturn */ 60 pushl %eax /* junk to fake return addr. */ 61 int $0x80 /* enter kernel with args */ 62 /* on stack */ 631: 64 jmp 1b 65#endif 66 67#ifdef COMPAT_43 68 ALIGN_TEXT 69ia32_osigcode: 70 calll *IA32_SIGF_HANDLER(%esp)/* call signal handler */ 71 leal IA32_SIGF_SC(%esp),%eax /* get sigcontext */ 72 pushl %eax 73 movl $103,%eax /* 3.x SYS_sigreturn */ 74 pushl %eax /* junk to fake return addr. */ 75 int $0x80 /* enter kernel with args */ 761: 77 jmp 1b 78 79/* 80 * Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls 81 * don't change the interrupt mask, so if this one went directly to the 82 * kernel then there would be a window with interrupts enabled in kernel 83 * mode, and all interrupt handlers would have to be almost as complicated 84 * as the NMI handler to support this. 85 * 86 * Instead, convert the lcall to an int0x80 call. The kernel does most 87 * of the conversion by popping the lcall return values off the user 88 * stack and returning to them instead of to here, except when the 89 * conversion itself fails. Adjusting the stack here is impossible for 90 * vfork() and harder for other syscalls. 91 */ 92 ALIGN_TEXT 93lcall_tramp: 94 int $0x80 951: jmp 1b 96#endif 97 98 ALIGN_TEXT 99esigcode: 100 101 .data 102 .globl sz_ia32_sigcode 103sz_ia32_sigcode: 104 .long esigcode-ia32_sigcode 105#ifdef COMPAT_FREEBSD4 106 .globl sz_freebsd4_ia32_sigcode 107sz_freebsd4_ia32_sigcode: 108 .long esigcode-freebsd4_ia32_sigcode 109#endif 110#ifdef COMPAT_43 111 .globl sz_ia32_osigcode 112sz_ia32_osigcode: 113 .long esigcode-ia32_osigcode 114 .globl sz_lcall_tramp 115sz_lcall_tramp: 116 .long esigcode-lcall_tramp 117#endif 118