2 * Copyright (C) 1994, David Greenman
3 * Copyright (c) 1990, 1993
4 * The Regents of the University of California. All rights reserved.
5 * Copyright (c) 2007 The FreeBSD Foundation
7 * This code is derived from software contributed to Berkeley by
8 * the University of Utah, and William Jolitz.
10 * Portions of this software were developed by A. Joseph Koshy under
11 * sponsorship from the FreeBSD Foundation and Google, Inc.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. All advertising materials mentioning features or use of this software
22 * must display the following acknowledgement:
23 * This product includes software developed by the University of
24 * California, Berkeley and its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
47 #include "opt_hwpmc_hooks.h"
48 #include "opt_ktrace.h"
53 #include "opt_sched.h"
55 #include <sys/param.h>
57 #include <sys/kernel.h>
59 #include <sys/mutex.h>
60 #include <sys/pmckern.h>
63 #include <sys/resourcevar.h>
64 #include <sys/sched.h>
65 #include <sys/signalvar.h>
66 #include <sys/systm.h>
67 #include <sys/vmmeter.h>
70 #include <sys/ktrace.h>
73 #include <machine/cpu.h>
74 #include <machine/pcb.h>
76 #include <security/mac/mac_framework.h>
79 * Define the code needed before returning to user mode, for trap and
83 userret(struct thread
*td
, struct trapframe
*frame
)
85 struct proc
*p
= td
->td_proc
;
87 CTR3(KTR_SYSC
, "userret: thread %p (pid %d, %s)", td
, p
->p_pid
,
90 /* Check that we called signotify() enough. */
93 if (SIGPENDING(td
) && ((td
->td_flags
& TDF_NEEDSIGCHK
) == 0 ||
94 (td
->td_flags
& TDF_ASTPENDING
) == 0))
95 printf("failed to set signal flags properly for ast()\n");
103 * If this thread tickled GEOM, we need to wait for the giggling to
104 * stop before we return to userland
106 if (td
->td_pflags
& TDP_GEOM
)
110 * Charge system time if profiling.
112 if (p
->p_flag
& P_PROFIL
) {
113 addupc_task(td
, TRAPF_PC(frame
), td
->td_pticks
* psratio
);
116 * Let the scheduler adjust our priority etc.
119 KASSERT(td
->td_locks
== 0,
120 ("userret: Returning with %d locks held.", td
->td_locks
));
124 * Process an asynchronous software trap.
125 * This is relatively easy.
126 * This function will return with preemption disabled.
129 ast(struct trapframe
*framep
)
135 #if defined(DEV_NPX) && !defined(SMP)
143 CTR3(KTR_SYSC
, "ast: thread %p (pid %d, %s)", td
, p
->p_pid
,
145 KASSERT(TRAPF_USERMODE(framep
), ("ast in kernel mode"));
146 WITNESS_WARN(WARN_PANIC
, NULL
, "Returning to user mode");
147 mtx_assert(&Giant
, MA_NOTOWNED
);
148 THREAD_LOCK_ASSERT(td
, MA_NOTOWNED
);
149 td
->td_frame
= framep
;
153 * This updates the td_flag's for the checks below in one
154 * "atomic" operation with turning off the astpending flag.
155 * If another AST is triggered while we are handling the
156 * AST's saved in flags, the astpending flag will be set and
157 * ast() will be called again.
160 flags
= td
->td_flags
;
161 td
->td_flags
&= ~(TDF_ASTPENDING
| TDF_NEEDSIGCHK
| TDF_NEEDSUSPCHK
|
162 TDF_NEEDRESCHED
| TDF_ALRMPEND
| TDF_PROFPEND
| TDF_MACPEND
);
164 PCPU_INC(cnt
.v_trap
);
166 if (td
->td_ucred
!= p
->p_ucred
)
167 cred_update_thread(td
);
168 if (td
->td_pflags
& TDP_OWEUPC
&& p
->p_flag
& P_PROFIL
) {
169 addupc_task(td
, td
->td_profil_addr
, td
->td_profil_ticks
);
170 td
->td_profil_ticks
= 0;
171 td
->td_pflags
&= ~TDP_OWEUPC
;
173 #if defined(HWPMC_HOOKS)
174 if (td
->td_pflags
& TDP_CALLCHAIN
) {
175 PMC_CALL_HOOK_UNLOCKED(td
, PMC_FN_USER_CALLCHAIN
,
177 td
->td_pflags
&= ~TDP_CALLCHAIN
;
180 if (flags
& TDF_ALRMPEND
) {
182 psignal(p
, SIGVTALRM
);
185 #if defined(DEV_NPX) && !defined(SMP)
186 if (PCPU_GET(curpcb
)->pcb_flags
& PCB_NPXTRAP
) {
187 atomic_clear_int(&PCPU_GET(curpcb
)->pcb_flags
,
191 ksiginfo_init_trap(&ksi
);
192 ksi
.ksi_signo
= SIGFPE
;
193 ksi
.ksi_code
= ucode
;
194 trapsignal(td
, &ksi
);
198 if (flags
& TDF_PROFPEND
) {
204 if (flags
& TDF_MACPEND
)
205 mac_thread_userret(td
);
207 if (flags
& TDF_NEEDRESCHED
) {
209 if (KTRPOINT(td
, KTR_CSW
))
213 sched_prio(td
, td
->td_user_pri
);
214 mi_switch(SW_INVOL
| SWT_NEEDRESCHED
, NULL
);
217 if (KTRPOINT(td
, KTR_CSW
))
221 if (flags
& TDF_NEEDSIGCHK
) {
223 mtx_lock(&p
->p_sigacts
->ps_mtx
);
224 while ((sig
= cursig(td
)) != 0)
226 mtx_unlock(&p
->p_sigacts
->ps_mtx
);
230 * We need to check to see if we have to exit or wait due to a
231 * single threading requirement or some other STOP condition.
233 if (flags
& TDF_NEEDSUSPCHK
) {
235 thread_suspend_check(0);
240 mtx_assert(&Giant
, MA_NOTOWNED
);