subr_syscall.c revision 184042
14Srgrimes/*- 21690Sdg * Copyright (C) 1994, David Greenman 31690Sdg * Copyright (c) 1990, 1993 41690Sdg * The Regents of the University of California. All rights reserved. 5174395Sjkoshy * Copyright (c) 2007 The FreeBSD Foundation 64Srgrimes * 74Srgrimes * This code is derived from software contributed to Berkeley by 84Srgrimes * the University of Utah, and William Jolitz. 94Srgrimes * 10174395Sjkoshy * Portions of this software were developed by A. Joseph Koshy under 11174395Sjkoshy * sponsorship from the FreeBSD Foundation and Google, Inc. 12174395Sjkoshy * 134Srgrimes * Redistribution and use in source and binary forms, with or without 144Srgrimes * modification, are permitted provided that the following conditions 154Srgrimes * are met: 164Srgrimes * 1. Redistributions of source code must retain the above copyright 174Srgrimes * notice, this list of conditions and the following disclaimer. 184Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 194Srgrimes * notice, this list of conditions and the following disclaimer in the 204Srgrimes * documentation and/or other materials provided with the distribution. 214Srgrimes * 3. All advertising materials mentioning features or use of this software 224Srgrimes * must display the following acknowledgement: 234Srgrimes * This product includes software developed by the University of 244Srgrimes * California, Berkeley and its contributors. 254Srgrimes * 4. Neither the name of the University nor the names of its contributors 264Srgrimes * may be used to endorse or promote products derived from this software 274Srgrimes * without specific prior written permission. 284Srgrimes * 294Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 304Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 314Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 324Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 334Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 344Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 354Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 364Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 374Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 384Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 394Srgrimes * SUCH DAMAGE. 404Srgrimes * 41608Srgrimes * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 424Srgrimes */ 434Srgrimes 44116182Sobrien#include <sys/cdefs.h> 45116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/subr_trap.c 184042 2008-10-19 01:35:27Z kmacy $"); 46116182Sobrien 47174395Sjkoshy#include "opt_hwpmc_hooks.h" 48118240Speter#include "opt_ktrace.h" 49104338Srwatson#include "opt_mac.h" 5078983Sjhb#ifdef __i386__ 5171257Speter#include "opt_npx.h" 5278983Sjhb#endif 53170640Sjeff#include "opt_sched.h" 5413203Swollman 551549Srgrimes#include <sys/param.h> 5665557Sjasone#include <sys/bus.h> 571549Srgrimes#include <sys/kernel.h> 5878983Sjhb#include <sys/lock.h> 5967365Sjhb#include <sys/mutex.h> 60174395Sjkoshy#include <sys/pmckern.h> 6178983Sjhb#include <sys/proc.h> 6299072Sjulian#include <sys/ktr.h> 6331389Sbde#include <sys/resourcevar.h> 64104964Sjeff#include <sys/sched.h> 6531389Sbde#include <sys/signalvar.h> 6678983Sjhb#include <sys/systm.h> 6712662Sdg#include <sys/vmmeter.h> 68118240Speter#ifdef KTRACE 69118240Speter#include <sys/uio.h> 70118240Speter#include <sys/ktrace.h> 71118240Speter#endif 72118240Speter 731549Srgrimes#include <machine/cpu.h> 7431389Sbde#include <machine/pcb.h> 751549Srgrimes 76184042Skmacy#ifdef XEN 77184042Skmacy#include <vm/vm.h> 78184042Skmacy#include <vm/vm_param.h> 79184042Skmacy#include <vm/pmap.h> 80184042Skmacy#endif 81184042Skmacy 82163606Srwatson#include <security/mac/mac_framework.h> 83163606Srwatson 8478983Sjhb/* 85167211Srwatson * Define the code needed before returning to user mode, for trap and 86167211Srwatson * syscall. 8778983Sjhb */ 8871527Sjhbvoid 89155455Sphkuserret(struct thread *td, struct trapframe *frame) 901690Sdg{ 9183366Sjulian struct proc *p = td->td_proc; 92757Sdg 9399072Sjulian CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid, 94173601Sjulian td->td_name); 95126661Srwatson#ifdef DIAGNOSTIC 96110190Sjulian /* Check that we called signotify() enough. */ 9778636Sjhb PROC_LOCK(p); 98170307Sjeff thread_lock(td); 99112888Sjeff if (SIGPENDING(td) && ((td->td_flags & TDF_NEEDSIGCHK) == 0 || 100111032Sjulian (td->td_flags & TDF_ASTPENDING) == 0)) 101102266Srwatson printf("failed to set signal flags properly for ast()\n"); 102170307Sjeff thread_unlock(td); 10382585Sdillon PROC_UNLOCK(p); 10493793Sbde#endif 105152376Srwatson#ifdef KTRACE 106152376Srwatson KTRUSERRET(td); 107152376Srwatson#endif 10893793Sbde /* 109136837Sphk * If this thread tickled GEOM, we need to wait for the giggling to 110136837Sphk * stop before we return to userland 111136837Sphk */ 112136837Sphk if (td->td_pflags & TDP_GEOM) 113136837Sphk g_waitidle(); 114136837Sphk 115136837Sphk /* 116110190Sjulian * Charge system time if profiling. 117110190Sjulian */ 118113874Sjhb if (p->p_flag & P_PROFIL) { 119155455Sphk addupc_task(td, TRAPF_PC(frame), td->td_pticks * psratio); 120110190Sjulian } 121139324Sjeff /* 122139324Sjeff * Let the scheduler adjust our priority etc. 123139324Sjeff */ 124139324Sjeff sched_userret(td); 125144061Sjeff KASSERT(td->td_locks == 0, 126144061Sjeff ("userret: Returning with %d locks held.", td->td_locks)); 127184042Skmacy#ifdef XEN 128184042Skmacy PT_UPDATES_FLUSH(); 129184042Skmacy#endif 1301690Sdg} 1311690Sdg 1324Srgrimes/* 13378983Sjhb * Process an asynchronous software trap. 13478983Sjhb * This is relatively easy. 13581493Sjhb * This function will return with preemption disabled. 1364Srgrimes */ 137798Swollmanvoid 13899072Sjulianast(struct trapframe *framep) 13965557Sjasone{ 140104297Sjhb struct thread *td; 141104297Sjhb struct proc *p; 14283366Sjulian int flags; 14393793Sbde int sig; 14477015Sbde#if defined(DEV_NPX) && !defined(SMP) 14577015Sbde int ucode; 146151316Sdavidxu ksiginfo_t ksi; 14777015Sbde#endif 14865557Sjasone 149104297Sjhb td = curthread; 150104297Sjhb p = td->td_proc; 151104378Sjmallett 15299072Sjulian CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid, 15399072Sjulian p->p_comm); 15472911Sjhb KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode")); 155111883Sjhb WITNESS_WARN(WARN_PANIC, NULL, "Returning to user mode"); 15681493Sjhb mtx_assert(&Giant, MA_NOTOWNED); 157170307Sjeff THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 15893390Sjake td->td_frame = framep; 159155455Sphk td->td_pticks = 0; 160104297Sjhb 16193390Sjake /* 162172207Sjeff * This updates the td_flag's for the checks below in one 16393390Sjake * "atomic" operation with turning off the astpending flag. 16493390Sjake * If another AST is triggered while we are handling the 165172207Sjeff * AST's saved in flags, the astpending flag will be set and 16693390Sjake * ast() will be called again. 16793390Sjake */ 168170307Sjeff thread_lock(td); 169170307Sjeff flags = td->td_flags; 170177471Sjeff td->td_flags &= ~(TDF_ASTPENDING | TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK | 171177471Sjeff TDF_NEEDRESCHED | TDF_ALRMPEND | TDF_PROFPEND | TDF_MACPEND); 172170307Sjeff thread_unlock(td); 173170292Sattilio PCPU_INC(cnt.v_trap); 174135573Sjhb 17593390Sjake if (td->td_ucred != p->p_ucred) 17693390Sjake cred_update_thread(td); 177132266Sjhb if (td->td_pflags & TDP_OWEUPC && p->p_flag & P_PROFIL) { 178132266Sjhb addupc_task(td, td->td_profil_addr, td->td_profil_ticks); 179132266Sjhb td->td_profil_ticks = 0; 180132266Sjhb td->td_pflags &= ~TDP_OWEUPC; 181131437Sjhb } 182174395Sjkoshy#if defined(HWPMC_HOOKS) 183174395Sjkoshy if (td->td_pflags & TDP_CALLCHAIN) { 184174395Sjkoshy PMC_CALL_HOOK_UNLOCKED(td, PMC_FN_USER_CALLCHAIN, 185174395Sjkoshy (void *) framep); 186174395Sjkoshy td->td_pflags &= ~TDP_CALLCHAIN; 187174395Sjkoshy } 188174395Sjkoshy#endif 189172207Sjeff if (flags & TDF_ALRMPEND) { 19093390Sjake PROC_LOCK(p); 19193390Sjake psignal(p, SIGVTALRM); 19293390Sjake PROC_UNLOCK(p); 19393390Sjake } 19477015Sbde#if defined(DEV_NPX) && !defined(SMP) 19593390Sjake if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) { 19693390Sjake atomic_clear_int(&PCPU_GET(curpcb)->pcb_flags, 19793390Sjake PCB_NPXTRAP); 19893390Sjake ucode = npxtrap(); 19993390Sjake if (ucode != -1) { 200151316Sdavidxu ksiginfo_init_trap(&ksi); 201151316Sdavidxu ksi.ksi_signo = SIGFPE; 202151316Sdavidxu ksi.ksi_code = ucode; 203151316Sdavidxu trapsignal(td, &ksi); 20477015Sbde } 20593390Sjake } 20677015Sbde#endif 207172207Sjeff if (flags & TDF_PROFPEND) { 20893390Sjake PROC_LOCK(p); 20993390Sjake psignal(p, SIGPROF); 21093390Sjake PROC_UNLOCK(p); 21193390Sjake } 212106655Srwatson#ifdef MAC 213172207Sjeff if (flags & TDF_MACPEND) 214106655Srwatson mac_thread_userret(td); 215106655Srwatson#endif 216111032Sjulian if (flags & TDF_NEEDRESCHED) { 217118240Speter#ifdef KTRACE 218118240Speter if (KTRPOINT(td, KTR_CSW)) 219119781Speter ktrcsw(1, 1); 220118240Speter#endif 221170307Sjeff thread_lock(td); 222163709Sjb sched_prio(td, td->td_user_pri); 223178272Sjeff mi_switch(SW_INVOL | SWT_NEEDRESCHED, NULL); 224170307Sjeff thread_unlock(td); 225118240Speter#ifdef KTRACE 226118240Speter if (KTRPOINT(td, KTR_CSW)) 227119781Speter ktrcsw(0, 1); 228118240Speter#endif 22993793Sbde } 230112888Sjeff if (flags & TDF_NEEDSIGCHK) { 23193793Sbde PROC_LOCK(p); 232114983Sjhb mtx_lock(&p->p_sigacts->ps_mtx); 233116963Sdavidxu while ((sig = cursig(td)) != 0) 23493793Sbde postsig(sig); 235114983Sjhb mtx_unlock(&p->p_sigacts->ps_mtx); 23693793Sbde PROC_UNLOCK(p); 23793793Sbde } 238177471Sjeff /* 239177471Sjeff * We need to check to see if we have to exit or wait due to a 240177471Sjeff * single threading requirement or some other STOP condition. 241177471Sjeff */ 242177471Sjeff if (flags & TDF_NEEDSUSPCHK) { 243177471Sjeff PROC_LOCK(p); 244177471Sjeff thread_suspend_check(0); 245177471Sjeff PROC_UNLOCK(p); 246177471Sjeff } 24765557Sjasone 248155455Sphk userret(td, framep); 24981493Sjhb mtx_assert(&Giant, MA_NOTOWNED); 25024691Speter} 251