1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * William Jolitz. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)locore.s 7.3 (Berkeley) 5/13/91 33 * $FreeBSD$ 34 * 35 * originally from: locore.s, by William F. Jolitz 36 * 37 * Substantially rewritten by David Greenman, Rod Grimes, 38 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 39 * and many others. 40 */ 41 42#include <sys/syscall.h> 43#include <machine/asmacros.h> 44#include <machine/psl.h> 45 46#include "assym.inc" 47 48/* 49 * Signal trampoline, copied to top of user stack 50 */ 51ENTRY(sigcode) 52 calll *SIGF_HANDLER(%esp) 53 leal SIGF_UC(%esp),%eax /* get ucontext */ 54 pushl %eax 55 testl $PSL_VM,UC_EFLAGS(%eax) 56 jne 1f 57 mov UC_GS(%eax),%gs /* restore %gs */ 581: 59 movl $SYS_sigreturn,%eax 60 pushl %eax /* junk to fake return addr. */ 61 int $0x80 /* enter kernel with args */ 62 /* on stack */ 631: 64 jmp 1b 65 66#ifdef COMPAT_FREEBSD4 67 ALIGN_TEXT 68freebsd4_sigcode: 69 calll *SIGF_HANDLER(%esp) 70 leal SIGF_UC4(%esp),%eax /* get ucontext */ 71 pushl %eax 72 testl $PSL_VM,UC4_EFLAGS(%eax) 73 jne 1f 74 mov UC4_GS(%eax),%gs /* restore %gs */ 751: 76 movl $344,%eax /* 4.x SYS_sigreturn */ 77 pushl %eax /* junk to fake return addr. */ 78 int $0x80 /* enter kernel with args */ 79 /* on stack */ 801: 81 jmp 1b 82#endif 83 84#ifdef COMPAT_43 85 ALIGN_TEXT 86osigcode: 87 call *SIGF_HANDLER(%esp) /* call signal handler */ 88 lea SIGF_SC(%esp),%eax /* get sigcontext */ 89 pushl %eax 90 testl $PSL_VM,SC_PS(%eax) 91 jne 9f 92 mov SC_GS(%eax),%gs /* restore %gs */ 939: 94 movl $103,%eax /* 3.x SYS_sigreturn */ 95 pushl %eax /* junk to fake return addr. */ 96 int $0x80 /* enter kernel with args */ 970: jmp 0b 98 99/* 100 * Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls 101 * don't change the interrupt mask, so if this one went directly to the 102 * kernel then there would be a window with interrupts enabled in kernel 103 * mode, and all interrupt handlers would have to be almost as complicated 104 * as the NMI handler to support this. 105 * 106 * Instead, convert the lcall to an int0x80 call. The kernel does most 107 * of the conversion by popping the lcall return values off the user 108 * stack and returning to them instead of to here, except when the 109 * conversion itself fails. Adjusting the stack here is impossible for 110 * vfork() and harder for other syscalls. 111 */ 112 ALIGN_TEXT 113lcall_tramp: 114 int $0x80 1151: jmp 1b 116 117#endif /* COMPAT_43 */ 118 119 ALIGN_TEXT 120esigcode: 121 122 .data 123 .globl szsigcode 124szsigcode: 125 .long esigcode-sigcode 126#ifdef COMPAT_FREEBSD4 127 .globl szfreebsd4_sigcode 128szfreebsd4_sigcode: 129 .long esigcode-freebsd4_sigcode 130#endif 131#ifdef COMPAT_43 132 .globl szosigcode 133szosigcode: 134 .long esigcode-osigcode 135 .globl sz_lcall_tramp 136sz_lcall_tramp: 137 .long esigcode-lcall_tramp 138#endif 139