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
46 #include <sys/param.h>
48 #include <sys/kernel.h>
51 #include <sys/mutex.h>
55 #include <sys/resourcevar.h>
56 #include <sys/sched.h>
57 #include <sys/signalvar.h>
58 #include <sys/systm.h>
59 #include <sys/vmmeter.h>
60 #include <machine/cpu.h>
61 #include <machine/pcb.h>
64 * Define the code needed before returning to user mode, for
70 userret(td, frame, oticks)
72 struct trapframe *frame;
75 struct proc *p = td->td_proc;
76 struct kse *ke = td->td_kse;
78 CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid,
81 /* Check that we called signotify() enough. */
84 mtx_lock_spin(&sched_lock);
85 if (SIGPENDING(p) && ((p->p_sflag & PS_NEEDSIGCHK) == 0 ||
86 (td->td_kse->ke_flags & KEF_ASTPENDING) == 0))
87 printf("failed to set signal flags properly for ast()\n");
88 mtx_unlock_spin(&sched_lock);
94 * Let the scheduler adjust our priority etc.
99 * We need to check to see if we have to exit or wait due to a
100 * single threading requirement or some other STOP condition.
101 * Don't bother doing all the work if the stop bits are not set
102 * at this time.. If we miss it, we miss it.. no big deal.
104 if (P_SHOULDSTOP(p)) {
106 thread_suspend_check(0); /* Can suspend or kill */
111 * Do special thread processing, e.g. upcall tweaking and such.
113 if (p->p_flag & P_KSES) {
114 thread_userret(td, frame);
115 /* printf("KSE thread returned"); */
119 * Charge system time if profiling.
121 * XXX should move PS_PROFIL to a place that can obviously be
122 * accessed safely without sched_lock.
124 if (p->p_sflag & PS_PROFIL) {
127 mtx_lock_spin(&sched_lock);
128 ticks = ke->ke_sticks - oticks;
129 mtx_unlock_spin(&sched_lock);
130 addupc_task(ke, TRAPF_PC(frame), (u_int)ticks * psratio);
135 * Process an asynchronous software trap.
136 * This is relatively easy.
137 * This function will return with preemption disabled.
140 ast(struct trapframe *framep)
147 u_int prticks, sticks;
151 #if defined(DEV_NPX) && !defined(SMP)
159 CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid,
161 KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode"));
163 if (witness_list(td))
164 panic("Returning to user mode with mutex(s) held");
166 mtx_assert(&Giant, MA_NOTOWNED);
167 mtx_assert(&sched_lock, MA_NOTOWNED);
168 td->td_frame = framep;
171 * This updates the p_sflag's for the checks below in one
172 * "atomic" operation with turning off the astpending flag.
173 * If another AST is triggered while we are handling the
174 * AST's saved in sflag, the astpending flag will be set and
175 * ast() will be called again.
177 mtx_lock_spin(&sched_lock);
179 sticks = ke->ke_sticks;
180 flags = ke->ke_flags;
182 p->p_sflag &= ~(PS_ALRMPEND | PS_NEEDSIGCHK | PS_PROFPEND | PS_XCPU);
184 p->p_sflag &= ~PS_MACPEND;
186 ke->ke_flags &= ~(KEF_ASTPENDING | KEF_NEEDRESCHED | KEF_OWEUPC);
189 if (flags & KEF_OWEUPC && sflag & PS_PROFIL) {
190 prticks = p->p_stats->p_prof.pr_ticks;
191 p->p_stats->p_prof.pr_ticks = 0;
193 mtx_unlock_spin(&sched_lock);
195 * XXXKSE While the fact that we owe a user profiling
196 * tick is stored per KSE in this code, the statistics
197 * themselves are still stored per process.
198 * This should probably change, by which I mean that
199 * possibly the location of both might change.
202 if (td->td_ucred != p->p_ucred)
203 cred_update_thread(td);
204 if (flags & KEF_OWEUPC && sflag & PS_PROFIL)
205 addupc_task(ke, p->p_stats->p_prof.pr_addr, prticks);
206 if (sflag & PS_ALRMPEND) {
208 psignal(p, SIGVTALRM);
211 #if defined(DEV_NPX) && !defined(SMP)
212 if (PCPU_GET(curpcb)->pcb_flags & PCB_NPXTRAP) {
213 atomic_clear_int(&PCPU_GET(curpcb)->pcb_flags,
217 trapsignal(p, SIGFPE, ucode);
221 if (sflag & PS_PROFPEND) {
226 if (sflag & PS_XCPU) {
228 rlim = &p->p_rlimit[RLIMIT_CPU];
229 if (p->p_runtime.sec >= rlim->rlim_max)
230 killproc(p, "exceeded maximum CPU limit");
233 mtx_lock_spin(&sched_lock);
234 if (p->p_cpulimit < rlim->rlim_max)
236 mtx_unlock_spin(&sched_lock);
241 if (sflag & PS_MACPEND)
242 mac_thread_userret(td);
244 if (flags & KEF_NEEDRESCHED) {
245 mtx_lock_spin(&sched_lock);
246 sched_prio(td, kg->kg_user_pri);
247 p->p_stats->p_ru.ru_nivcsw++;
249 mtx_unlock_spin(&sched_lock);
251 if (sflag & PS_NEEDSIGCHK) {
253 while ((sig = cursig(td)) != 0)
258 userret(td, framep, sticks);
260 cred_free_thread(td);
262 mtx_assert(&Giant, MA_NOTOWNED);