subr_syscall.c revision 78983
1/*- 2 * Copyright (C) 1994, David Greenman 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the University of Utah, and William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 38 * $FreeBSD: head/sys/kern/subr_trap.c 78983 2001-06-29 19:51:37Z jhb $ 39 */ 40 41#ifdef __i386__ 42#include "opt_npx.h" 43#endif 44 45#include <sys/param.h> 46#include <sys/bus.h> 47#include <sys/kernel.h> 48#include <sys/lock.h> 49#include <sys/mutex.h> 50#include <sys/proc.h> 51#include <sys/resourcevar.h> 52#include <sys/signalvar.h> 53#include <sys/systm.h> 54#include <sys/vmmeter.h> 55#include <machine/cpu.h> 56#include <machine/pcb.h> 57 58/* 59 * Define the code needed before returning to user mode, for 60 * trap and syscall. 61 */ 62void 63userret(p, frame, oticks) 64 struct proc *p; 65 struct trapframe *frame; 66 u_quad_t oticks; 67{ 68 int sig; 69 70 PROC_LOCK(p); 71 while ((sig = CURSIG(p)) != 0) 72 postsig(sig); 73 74 mtx_lock_spin(&sched_lock); 75 PROC_UNLOCK_NOSWITCH(p); 76 p->p_pri.pri_level = p->p_pri.pri_user; 77 if (resched_wanted(p)) { 78 /* 79 * Since we are curproc, a clock interrupt could 80 * change our priority without changing run queues 81 * (the running process is not kept on a run queue). 82 * If this happened after we setrunqueue ourselves but 83 * before we switch()'ed, we might not be on the queue 84 * indicated by our priority. 85 */ 86 DROP_GIANT_NOSWITCH(); 87 setrunqueue(p); 88 p->p_stats->p_ru.ru_nivcsw++; 89 mi_switch(); 90 mtx_unlock_spin(&sched_lock); 91 PICKUP_GIANT(); 92 PROC_LOCK(p); 93 while ((sig = CURSIG(p)) != 0) 94 postsig(sig); 95 mtx_lock_spin(&sched_lock); 96 PROC_UNLOCK_NOSWITCH(p); 97 } 98 99 /* 100 * Charge system time if profiling. 101 */ 102 if (p->p_sflag & PS_PROFIL) { 103 mtx_unlock_spin(&sched_lock); 104 addupc_task(p, TRAPF_PC(frame), 105 (u_int)(p->p_sticks - oticks) * psratio); 106 } else 107 mtx_unlock_spin(&sched_lock); 108} 109 110/* 111 * Process an asynchronous software trap. 112 * This is relatively easy. 113 */ 114void 115ast(framep) 116 struct trapframe *framep; 117{ 118 struct proc *p = CURPROC; 119 u_quad_t sticks; 120#if defined(DEV_NPX) && !defined(SMP) 121 int ucode; 122#endif 123 124 KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode")); 125 126 /* 127 * We check for a pending AST here rather than in the assembly as 128 * acquiring and releasing mutexes in assembly is not fun. 129 */ 130 mtx_lock_spin(&sched_lock); 131 if (!(astpending(p) || resched_wanted(p))) { 132 mtx_unlock_spin(&sched_lock); 133 return; 134 } 135 136 sticks = p->p_sticks; 137 p->p_frame = framep; 138 139 astoff(p); 140 cnt.v_soft++; 141 mtx_intr_enable(&sched_lock); 142 if (p->p_sflag & PS_OWEUPC) { 143 p->p_sflag &= ~PS_OWEUPC; 144 mtx_unlock_spin(&sched_lock); 145 mtx_lock(&Giant); 146 addupc_task(p, p->p_stats->p_prof.pr_addr, 147 p->p_stats->p_prof.pr_ticks); 148 mtx_lock_spin(&sched_lock); 149 } 150 if (p->p_sflag & PS_ALRMPEND) { 151 p->p_sflag &= ~PS_ALRMPEND; 152 mtx_unlock_spin(&sched_lock); 153 PROC_LOCK(p); 154 psignal(p, SIGVTALRM); 155 PROC_UNLOCK(p); 156 mtx_lock_spin(&sched_lock); 157 } 158#if defined(DEV_NPX) && !defined(SMP) 159 if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) { 160 PCPU_GET(curpcb)->pcb_flags &= ~PCB_NPXTRAP; 161 mtx_unlock_spin(&sched_lock); 162 ucode = npxtrap(); 163 if (ucode != -1) { 164 if (!mtx_owned(&Giant)) 165 mtx_lock(&Giant); 166 trapsignal(p, SIGFPE, ucode); 167 } 168 mtx_lock_spin(&sched_lock); 169 } 170#endif 171 if (p->p_sflag & PS_PROFPEND) { 172 p->p_sflag &= ~PS_PROFPEND; 173 mtx_unlock_spin(&sched_lock); 174 PROC_LOCK(p); 175 psignal(p, SIGPROF); 176 PROC_UNLOCK(p); 177 } else 178 mtx_unlock_spin(&sched_lock); 179 180 userret(p, framep, sticks); 181 182 if (mtx_owned(&Giant)) 183 mtx_unlock(&Giant); 184} 185