subr_syscall.c revision 106655
14Srgrimes/*- 21690Sdg * Copyright (C) 1994, David Greenman 31690Sdg * Copyright (c) 1990, 1993 41690Sdg * The Regents of the University of California. All rights reserved. 54Srgrimes * 64Srgrimes * This code is derived from software contributed to Berkeley by 74Srgrimes * the University of Utah, and William Jolitz. 84Srgrimes * 94Srgrimes * Redistribution and use in source and binary forms, with or without 104Srgrimes * modification, are permitted provided that the following conditions 114Srgrimes * are met: 124Srgrimes * 1. Redistributions of source code must retain the above copyright 134Srgrimes * notice, this list of conditions and the following disclaimer. 144Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 154Srgrimes * notice, this list of conditions and the following disclaimer in the 164Srgrimes * documentation and/or other materials provided with the distribution. 174Srgrimes * 3. All advertising materials mentioning features or use of this software 184Srgrimes * must display the following acknowledgement: 194Srgrimes * This product includes software developed by the University of 204Srgrimes * California, Berkeley and its contributors. 214Srgrimes * 4. Neither the name of the University nor the names of its contributors 224Srgrimes * may be used to endorse or promote products derived from this software 234Srgrimes * without specific prior written permission. 244Srgrimes * 254Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 264Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 274Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 284Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 294Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 304Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 314Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 324Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 334Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 344Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 354Srgrimes * SUCH DAMAGE. 364Srgrimes * 37608Srgrimes * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 3850477Speter * $FreeBSD: head/sys/kern/subr_trap.c 106655 2002-11-08 19:00:17Z rwatson $ 394Srgrimes */ 404Srgrimes 41104338Srwatson#include "opt_mac.h" 4278983Sjhb#ifdef __i386__ 4371257Speter#include "opt_npx.h" 4478983Sjhb#endif 4513203Swollman 461549Srgrimes#include <sys/param.h> 4765557Sjasone#include <sys/bus.h> 481549Srgrimes#include <sys/kernel.h> 4978983Sjhb#include <sys/lock.h> 50104338Srwatson#include <sys/mac.h> 5167365Sjhb#include <sys/mutex.h> 5278983Sjhb#include <sys/proc.h> 5399072Sjulian#include <sys/kse.h> 5499072Sjulian#include <sys/ktr.h> 5531389Sbde#include <sys/resourcevar.h> 56104964Sjeff#include <sys/sched.h> 5731389Sbde#include <sys/signalvar.h> 5878983Sjhb#include <sys/systm.h> 5912662Sdg#include <sys/vmmeter.h> 601549Srgrimes#include <machine/cpu.h> 6131389Sbde#include <machine/pcb.h> 621549Srgrimes 6378983Sjhb/* 6478983Sjhb * Define the code needed before returning to user mode, for 6578983Sjhb * trap and syscall. 6682585Sdillon * 6782585Sdillon * MPSAFE 6878983Sjhb */ 6971527Sjhbvoid 7083366Sjulianuserret(td, frame, oticks) 7183366Sjulian struct thread *td; 721690Sdg struct trapframe *frame; 7381493Sjhb u_int oticks; 741690Sdg{ 7583366Sjulian struct proc *p = td->td_proc; 7683366Sjulian struct kse *ke = td->td_kse; 77757Sdg 7899072Sjulian CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid, 7999072Sjulian p->p_comm); 8093793Sbde#ifdef INVARIANTS 8193793Sbde /* Check that we called signotify() enough. */ 8279125Sjhb mtx_lock(&Giant); 8378636Sjhb PROC_LOCK(p); 8493793Sbde mtx_lock_spin(&sched_lock); 85104306Sjmallett if (SIGPENDING(p) && ((p->p_sflag & PS_NEEDSIGCHK) == 0 || 86104383Sjmallett (td->td_kse->ke_flags & KEF_ASTPENDING) == 0)) 87102266Srwatson printf("failed to set signal flags properly for ast()\n"); 8893793Sbde mtx_unlock_spin(&sched_lock); 8982585Sdillon PROC_UNLOCK(p); 9079125Sjhb mtx_unlock(&Giant); 9193793Sbde#endif 9228013Sdyson 9393793Sbde /* 94104964Sjeff * Let the scheduler adjust our priority etc. 9593793Sbde */ 96104964Sjeff sched_userret(td); 9771527Sjhb 986296Sdg /* 99105974Sjulian * We need to check to see if we have to exit or wait due to a 100105974Sjulian * single threading requirement or some other STOP condition. 101105974Sjulian * Don't bother doing all the work if the stop bits are not set 102105974Sjulian * at this time.. If we miss it, we miss it.. no big deal. 10399072Sjulian */ 104105974Sjulian if (P_SHOULDSTOP(p)) { 105105974Sjulian PROC_LOCK(p); 106105974Sjulian thread_suspend_check(0); /* Can suspend or kill */ 107105974Sjulian PROC_UNLOCK(p); 108105974Sjulian } 109105974Sjulian 110105974Sjulian /* 111105974Sjulian * Do special thread processing, e.g. upcall tweaking and such. 112105974Sjulian */ 11399072Sjulian if (p->p_flag & P_KSES) { 114103838Sjulian thread_userret(td, frame); 11599072Sjulian /* printf("KSE thread returned"); */ 11699072Sjulian } 11799072Sjulian 11899072Sjulian /* 1196296Sdg * Charge system time if profiling. 12093793Sbde * 12193793Sbde * XXX should move PS_PROFIL to a place that can obviously be 12293793Sbde * accessed safely without sched_lock. 1236296Sdg */ 12483366Sjulian if (p->p_sflag & PS_PROFIL) { 12588119Sjhb quad_t ticks; 12688119Sjhb 12793793Sbde mtx_lock_spin(&sched_lock); 12888119Sjhb ticks = ke->ke_sticks - oticks; 12988119Sjhb mtx_unlock_spin(&sched_lock); 13088119Sjhb addupc_task(ke, TRAPF_PC(frame), (u_int)ticks * psratio); 13193793Sbde } 1321690Sdg} 1331690Sdg 1344Srgrimes/* 13578983Sjhb * Process an asynchronous software trap. 13678983Sjhb * This is relatively easy. 13781493Sjhb * This function will return with preemption disabled. 1384Srgrimes */ 139798Swollmanvoid 14099072Sjulianast(struct trapframe *framep) 14165557Sjasone{ 142104297Sjhb struct thread *td; 143104297Sjhb struct proc *p; 144103838Sjulian struct kse *ke; 145104297Sjhb struct ksegrp *kg; 146104240Sjhb struct rlimit *rlim; 14781493Sjhb u_int prticks, sticks; 14881493Sjhb int sflag; 14983366Sjulian int flags; 15093793Sbde int sig; 15177015Sbde#if defined(DEV_NPX) && !defined(SMP) 15277015Sbde int ucode; 15377015Sbde#endif 15465557Sjasone 155104297Sjhb td = curthread; 156104297Sjhb p = td->td_proc; 157104378Sjmallett kg = td->td_ksegrp; 158104378Sjmallett 15999072Sjulian CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid, 16099072Sjulian p->p_comm); 16172911Sjhb KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode")); 16281493Sjhb#ifdef WITNESS 16383366Sjulian if (witness_list(td)) 16481493Sjhb panic("Returning to user mode with mutex(s) held"); 16581493Sjhb#endif 16681493Sjhb mtx_assert(&Giant, MA_NOTOWNED); 16793793Sbde mtx_assert(&sched_lock, MA_NOTOWNED); 16893390Sjake td->td_frame = framep; 169104297Sjhb 17093390Sjake /* 17193390Sjake * This updates the p_sflag's for the checks below in one 17293390Sjake * "atomic" operation with turning off the astpending flag. 17393390Sjake * If another AST is triggered while we are handling the 17493390Sjake * AST's saved in sflag, the astpending flag will be set and 17593390Sjake * ast() will be called again. 17693390Sjake */ 17793390Sjake mtx_lock_spin(&sched_lock); 178104383Sjmallett ke = td->td_kse; 17993390Sjake sticks = ke->ke_sticks; 180104297Sjhb flags = ke->ke_flags; 18193390Sjake sflag = p->p_sflag; 182104296Sjhb p->p_sflag &= ~(PS_ALRMPEND | PS_NEEDSIGCHK | PS_PROFPEND | PS_XCPU); 183106655Srwatson#ifdef MAC 184106655Srwatson p->p_sflag &= ~PS_MACPEND; 185106655Srwatson#endif 18693793Sbde ke->ke_flags &= ~(KEF_ASTPENDING | KEF_NEEDRESCHED | KEF_OWEUPC); 18793390Sjake cnt.v_soft++; 188104297Sjhb prticks = 0; 18993390Sjake if (flags & KEF_OWEUPC && sflag & PS_PROFIL) { 19093390Sjake prticks = p->p_stats->p_prof.pr_ticks; 19193390Sjake p->p_stats->p_prof.pr_ticks = 0; 19293390Sjake } 19393390Sjake mtx_unlock_spin(&sched_lock); 19499072Sjulian /* 19599072Sjulian * XXXKSE While the fact that we owe a user profiling 19699072Sjulian * tick is stored per KSE in this code, the statistics 19799072Sjulian * themselves are still stored per process. 19899072Sjulian * This should probably change, by which I mean that 19999072Sjulian * possibly the location of both might change. 20099072Sjulian */ 20191090Sjulian 20293390Sjake if (td->td_ucred != p->p_ucred) 20393390Sjake cred_update_thread(td); 20493390Sjake if (flags & KEF_OWEUPC && sflag & PS_PROFIL) 20593390Sjake addupc_task(ke, p->p_stats->p_prof.pr_addr, prticks); 20693390Sjake if (sflag & PS_ALRMPEND) { 20793390Sjake PROC_LOCK(p); 20893390Sjake psignal(p, SIGVTALRM); 20993390Sjake PROC_UNLOCK(p); 21093390Sjake } 21177015Sbde#if defined(DEV_NPX) && !defined(SMP) 21293390Sjake if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) { 21393390Sjake atomic_clear_int(&PCPU_GET(curpcb)->pcb_flags, 21493390Sjake PCB_NPXTRAP); 21593390Sjake ucode = npxtrap(); 21693390Sjake if (ucode != -1) { 21793390Sjake trapsignal(p, SIGFPE, ucode); 21877015Sbde } 21993390Sjake } 22077015Sbde#endif 22193390Sjake if (sflag & PS_PROFPEND) { 22293390Sjake PROC_LOCK(p); 22393390Sjake psignal(p, SIGPROF); 22493390Sjake PROC_UNLOCK(p); 22593390Sjake } 226104240Sjhb if (sflag & PS_XCPU) { 227104240Sjhb PROC_LOCK(p); 228104240Sjhb rlim = &p->p_rlimit[RLIMIT_CPU]; 229104240Sjhb if (p->p_runtime.sec >= rlim->rlim_max) 230104240Sjhb killproc(p, "exceeded maximum CPU limit"); 231104240Sjhb else { 232104240Sjhb psignal(p, SIGXCPU); 233104719Sjhb mtx_lock_spin(&sched_lock); 234104719Sjhb if (p->p_cpulimit < rlim->rlim_max) 235104719Sjhb p->p_cpulimit += 5; 236104719Sjhb mtx_unlock_spin(&sched_lock); 237104240Sjhb } 238104240Sjhb PROC_UNLOCK(p); 239104240Sjhb } 240106655Srwatson#ifdef MAC 241106655Srwatson if (sflag & PS_MACPEND) 242106655Srwatson mac_thread_userret(td); 243106655Srwatson#endif 24493793Sbde if (flags & KEF_NEEDRESCHED) { 24593793Sbde mtx_lock_spin(&sched_lock); 246104964Sjeff sched_prio(td, kg->kg_user_pri); 24793793Sbde p->p_stats->p_ru.ru_nivcsw++; 24893793Sbde mi_switch(); 24993793Sbde mtx_unlock_spin(&sched_lock); 25093793Sbde } 25193793Sbde if (sflag & PS_NEEDSIGCHK) { 25293793Sbde PROC_LOCK(p); 25399072Sjulian while ((sig = cursig(td)) != 0) 25493793Sbde postsig(sig); 25593793Sbde PROC_UNLOCK(p); 25693793Sbde } 25765557Sjasone 25893390Sjake userret(td, framep, sticks); 25999753Smini#ifdef DIAGNOSTIC 26099753Smini cred_free_thread(td); 26199753Smini#endif 26281493Sjhb mtx_assert(&Giant, MA_NOTOWNED); 26324691Speter} 264