subr_syscall.c revision 79222
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 79222 2001-07-04 15:36:30Z dillon $ 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 mtx_lock(&Giant); 71 PROC_LOCK(p); 72 while ((sig = CURSIG(p)) != 0) 73 postsig(sig); 74 mtx_unlock(&Giant); 75 76 mtx_lock_spin(&sched_lock); 77 PROC_UNLOCK_NOSWITCH(p); 78 p->p_pri.pri_level = p->p_pri.pri_user; 79 if (resched_wanted(p)) { 80 /* 81 * Since we are curproc, a clock interrupt could 82 * change our priority without changing run queues 83 * (the running process is not kept on a run queue). 84 * If this happened after we setrunqueue ourselves but 85 * before we switch()'ed, we might not be on the queue 86 * indicated by our priority. 87 */ 88 DROP_GIANT_NOSWITCH(); 89 setrunqueue(p); 90 p->p_stats->p_ru.ru_nivcsw++; 91 mi_switch(); 92 mtx_unlock_spin(&sched_lock); 93 PICKUP_GIANT(); 94 mtx_lock(&Giant); 95 PROC_LOCK(p); 96 while ((sig = CURSIG(p)) != 0) 97 postsig(sig); 98 mtx_unlock(&Giant); 99 mtx_lock_spin(&sched_lock); 100 PROC_UNLOCK_NOSWITCH(p); 101 } 102 103 /* 104 * Charge system time if profiling. 105 */ 106 if (p->p_sflag & PS_PROFIL) { 107 mtx_unlock_spin(&sched_lock); 108 addupc_task(p, TRAPF_PC(frame), 109 (u_int)(p->p_sticks - oticks) * psratio); 110 } else 111 mtx_unlock_spin(&sched_lock); 112} 113 114/* 115 * Process an asynchronous software trap. 116 * This is relatively easy. 117 */ 118void 119ast(framep) 120 struct trapframe *framep; 121{ 122 struct proc *p = CURPROC; 123 u_quad_t sticks; 124#if defined(DEV_NPX) && !defined(SMP) 125 int ucode; 126#endif 127 128 KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode")); 129 130 /* 131 * We check for a pending AST here rather than in the assembly as 132 * acquiring and releasing mutexes in assembly is not fun. 133 */ 134 mtx_lock_spin(&sched_lock); 135 if (!(astpending(p) || resched_wanted(p))) { 136 mtx_unlock_spin(&sched_lock); 137 return; 138 } 139 140 sticks = p->p_sticks; 141 p->p_frame = framep; 142 143 astoff(p); 144 cnt.v_soft++; 145 mtx_intr_enable(&sched_lock); 146 if (p->p_sflag & PS_OWEUPC) { 147 p->p_sflag &= ~PS_OWEUPC; 148 mtx_unlock_spin(&sched_lock); 149 mtx_lock(&Giant); 150 addupc_task(p, p->p_stats->p_prof.pr_addr, 151 p->p_stats->p_prof.pr_ticks); 152 mtx_lock_spin(&sched_lock); 153 } 154 if (p->p_sflag & PS_ALRMPEND) { 155 p->p_sflag &= ~PS_ALRMPEND; 156 mtx_unlock_spin(&sched_lock); 157 PROC_LOCK(p); 158 psignal(p, SIGVTALRM); 159 PROC_UNLOCK(p); 160 mtx_lock_spin(&sched_lock); 161 } 162#if defined(DEV_NPX) && !defined(SMP) 163 if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) { 164 PCPU_GET(curpcb)->pcb_flags &= ~PCB_NPXTRAP; 165 mtx_unlock_spin(&sched_lock); 166 ucode = npxtrap(); 167 if (ucode != -1) { 168 if (!mtx_owned(&Giant)) 169 mtx_lock(&Giant); 170 trapsignal(p, SIGFPE, ucode); 171 } 172 mtx_lock_spin(&sched_lock); 173 } 174#endif 175 if (p->p_sflag & PS_PROFPEND) { 176 p->p_sflag &= ~PS_PROFPEND; 177 mtx_unlock_spin(&sched_lock); 178 PROC_LOCK(p); 179 psignal(p, SIGPROF); 180 PROC_UNLOCK(p); 181 } else 182 mtx_unlock_spin(&sched_lock); 183 184 userret(p, framep, sticks); 185 186 if (mtx_owned(&Giant)) 187 mtx_unlock(&Giant); 188} 189