2 * Copyright (C) 1994, David Greenman
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
7 * the University of Utah, and William Jolitz.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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.
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
37 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include "opt_ktrace.h"
49 #include <sys/param.h>
51 #include <sys/kernel.h>
54 #include <sys/mutex.h>
57 #include <sys/resourcevar.h>
58 #include <sys/sched.h>
59 #include <sys/signalvar.h>
60 #include <sys/systm.h>
61 #include <sys/vmmeter.h>
64 #include <sys/ktrace.h>
67 #include <machine/cpu.h>
68 #include <machine/pcb.h>
72 #include <vm/vm_param.h>
77 * Define the code needed before returning to user mode, for
83 userret(td, frame, oticks)
85 struct trapframe *frame;
88 struct proc *p = td->td_proc;
90 CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid,
93 /* Check that we called signotify() enough. */
95 mtx_lock_spin(&sched_lock);
96 if (SIGPENDING(td) && ((td->td_flags & TDF_NEEDSIGCHK) == 0 ||
97 (td->td_flags & TDF_ASTPENDING) == 0))
98 printf("failed to set signal flags properly for ast()\n");
99 mtx_unlock_spin(&sched_lock);
108 * If this thread tickled GEOM, we need to wait for the giggling to
109 * stop before we return to userland
111 if (td->td_pflags & TDP_GEOM)
115 * We need to check to see if we have to exit or wait due to a
116 * single threading requirement or some other STOP condition.
117 * Don't bother doing all the work if the stop bits are not set
118 * at this time.. If we miss it, we miss it.. no big deal.
120 if (P_SHOULDSTOP(p)) {
122 thread_suspend_check(0); /* Can suspend or kill */
127 * Do special thread processing, e.g. upcall tweaking and such.
129 if (p->p_flag & P_SA)
130 thread_userret(td, frame);
133 * Charge system time if profiling.
135 if (p->p_flag & P_PROFIL) {
138 ticks = td->td_sticks - oticks;
139 addupc_task(td, TRAPF_PC(frame), (u_int)ticks * psratio);
143 * Let the scheduler adjust our priority etc.
146 KASSERT(td->td_locks == 0,
147 ("userret: Returning with %d locks held.", td->td_locks));
154 * Process an asynchronous software trap.
155 * This is relatively easy.
156 * This function will return with preemption disabled.
159 ast(struct trapframe *framep)
169 #if defined(DEV_NPX) && !defined(SMP)
177 CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid,
179 KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode"));
180 WITNESS_WARN(WARN_PANIC, NULL, "Returning to user mode");
181 mtx_assert(&Giant, MA_NOTOWNED);
182 mtx_assert(&sched_lock, MA_NOTOWNED);
183 td->td_frame = framep;
184 sticks = td->td_sticks;
186 if ((p->p_flag & P_SA) && (td->td_mailbox == NULL))
187 thread_user_enter(td);
190 * This updates the p_sflag's for the checks below in one
191 * "atomic" operation with turning off the astpending flag.
192 * If another AST is triggered while we are handling the
193 * AST's saved in sflag, the astpending flag will be set and
194 * ast() will be called again.
196 mtx_lock_spin(&sched_lock);
197 flags = td->td_flags;
199 p->p_sflag &= ~(PS_ALRMPEND | PS_PROFPEND | PS_XCPU);
201 p->p_sflag &= ~PS_MACPEND;
203 td->td_flags &= ~(TDF_ASTPENDING | TDF_NEEDSIGCHK |
204 TDF_NEEDRESCHED | TDF_INTERRUPT);
206 mtx_unlock_spin(&sched_lock);
209 * XXXKSE While the fact that we owe a user profiling
210 * tick is stored per KSE in this code, the statistics
211 * themselves are still stored per process.
212 * This should probably change, by which I mean that
213 * possibly the location of both might change.
215 if (td->td_ucred != p->p_ucred)
216 cred_update_thread(td);
217 if (td->td_pflags & TDP_OWEUPC && p->p_flag & P_PROFIL) {
218 addupc_task(td, td->td_profil_addr, td->td_profil_ticks);
219 td->td_profil_ticks = 0;
220 td->td_pflags &= ~TDP_OWEUPC;
222 if (sflag & PS_ALRMPEND) {
224 psignal(p, SIGVTALRM);
227 #if defined(DEV_NPX) && !defined(SMP)
228 if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) {
229 atomic_clear_int(&PCPU_GET(curpcb)->pcb_flags,
233 trapsignal(td, SIGFPE, ucode);
237 if (sflag & PS_PROFPEND) {
242 if (sflag & PS_XCPU) {
244 lim_rlimit(p, RLIMIT_CPU, &rlim);
245 mtx_lock_spin(&sched_lock);
246 if (p->p_rux.rux_runtime.sec >= rlim.rlim_max) {
247 mtx_unlock_spin(&sched_lock);
248 killproc(p, "exceeded maximum CPU limit");
250 if (p->p_cpulimit < rlim.rlim_max)
252 mtx_unlock_spin(&sched_lock);
258 if (sflag & PS_MACPEND)
259 mac_thread_userret(td);
261 if (flags & TDF_NEEDRESCHED) {
263 if (KTRPOINT(td, KTR_CSW))
266 mtx_lock_spin(&sched_lock);
267 sched_prio(td, kg->kg_user_pri);
268 mi_switch(SW_INVOL, NULL);
269 mtx_unlock_spin(&sched_lock);
271 if (KTRPOINT(td, KTR_CSW))
275 if (flags & TDF_NEEDSIGCHK) {
277 mtx_lock(&p->p_sigacts->ps_mtx);
278 while ((sig = cursig(td)) != 0)
280 mtx_unlock(&p->p_sigacts->ps_mtx);
284 userret(td, framep, sticks);
285 mtx_assert(&Giant, MA_NOTOWNED);