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 * originally from: locore.s, by William F. Jolitz 33 * 34 * Substantially rewritten by David Greenman, Rod Grimes, 35 * Bruce Evans, Wolfgang Solfrank, Poul-Henning Kamp 36 * and many others. 37 */ 38 39#include <sys/syscall.h> 40#include <machine/asmacros.h> 41#include <machine/psl.h> 42 43#include "assym.inc" 44 45/* 46 * Signal trampoline, copied to top of user stack 47 */ 48ENTRY(sigcode) 49 calll *SIGF_HANDLER(%esp) 50 leal SIGF_UC(%esp),%eax /* get ucontext */ 51 pushl %eax 52 testl $PSL_VM,UC_EFLAGS(%eax) 53 jne 1f 54 mov UC_GS(%eax),%gs /* restore %gs */ 551: 56 movl $SYS_sigreturn,%eax 57 pushl %eax /* junk to fake return addr. */ 58 int $0x80 /* enter kernel with args */ 59 /* on stack */ 601: 61 jmp 1b 62 63#ifdef COMPAT_FREEBSD4 64 ALIGN_TEXT 65freebsd4_sigcode: 66 calll *SIGF_HANDLER(%esp) 67 leal SIGF_UC4(%esp),%eax /* get ucontext */ 68 pushl %eax 69 testl $PSL_VM,UC4_EFLAGS(%eax) 70 jne 1f 71 mov UC4_GS(%eax),%gs /* restore %gs */ 721: 73 movl $344,%eax /* 4.x SYS_sigreturn */ 74 pushl %eax /* junk to fake return addr. */ 75 int $0x80 /* enter kernel with args */ 76 /* on stack */ 771: 78 jmp 1b 79#endif 80 81#ifdef COMPAT_43 82 ALIGN_TEXT 83osigcode: 84 call *SIGF_HANDLER(%esp) /* call signal handler */ 85 lea SIGF_SC(%esp),%eax /* get sigcontext */ 86 pushl %eax 87 testl $PSL_VM,SC_PS(%eax) 88 jne 9f 89 mov SC_GS(%eax),%gs /* restore %gs */ 909: 91 movl $103,%eax /* 3.x SYS_sigreturn */ 92 pushl %eax /* junk to fake return addr. */ 93 int $0x80 /* enter kernel with args */ 940: jmp 0b 95 96/* 97 * Our lcall $7,$0 handler remains in user mode (ring 3), since lcalls 98 * don't change the interrupt mask, so if this one went directly to the 99 * kernel then there would be a window with interrupts enabled in kernel 100 * mode, and all interrupt handlers would have to be almost as complicated 101 * as the NMI handler to support this. 102 * 103 * Instead, convert the lcall to an int0x80 call. The kernel does most 104 * of the conversion by popping the lcall return values off the user 105 * stack and returning to them instead of to here, except when the 106 * conversion itself fails. Adjusting the stack here is impossible for 107 * vfork() and harder for other syscalls. 108 */ 109 ALIGN_TEXT 110lcall_tramp: 111 int $0x80 1121: jmp 1b 113 114#endif /* COMPAT_43 */ 115 116 ALIGN_TEXT 117esigcode: 118 119 .data 120 .globl szsigcode 121szsigcode: 122 .long esigcode-sigcode 123#ifdef COMPAT_FREEBSD4 124 .globl szfreebsd4_sigcode 125szfreebsd4_sigcode: 126 .long esigcode-freebsd4_sigcode 127#endif 128#ifdef COMPAT_43 129 .globl szosigcode 130szosigcode: 131 .long esigcode-osigcode 132 .globl sz_lcall_tramp 133sz_lcall_tramp: 134 .long esigcode-lcall_tramp 135#endif 136