Remove upc_{control,register} syscalls and everything that has to do with it.
[dragonfly.git] / sys / platform / pc64 / x86_64 / trap.c
CommitLineData
d7f50089 1/*-
d7f50089
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2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
c8fe38ae
MD
4 * Copyright (C) 1994, David Greenman
5 * Copyright (c) 2008 The DragonFly Project.
6 * Copyright (c) 2008 Jordan Gordeev.
d7f50089
YY
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the University of Utah, and William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
c8fe38ae 39 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91
d7f50089 40 * $FreeBSD: src/sys/i386/i386/trap.c,v 1.147.2.11 2003/02/27 19:09:59 luoqi Exp $
d7f50089
YY
41 */
42
c8fe38ae 43/*
b2b3ffcd 44 * x86_64 Trap and System call handling
c8fe38ae
MD
45 */
46
775ce2da
SW
47#include "use_isa.h"
48
c8fe38ae
MD
49#include "opt_ddb.h"
50#include "opt_ktrace.h"
d7f50089
YY
51
52#include <machine/frame.h>
c8fe38ae
MD
53#include <sys/param.h>
54#include <sys/systm.h>
55#include <sys/kernel.h>
5ea440eb 56#include <sys/kerneldump.h>
c8fe38ae
MD
57#include <sys/proc.h>
58#include <sys/pioctl.h>
59#include <sys/types.h>
60#include <sys/signal2.h>
61#include <sys/syscall.h>
62#include <sys/sysctl.h>
63#include <sys/sysent.h>
64#include <sys/systm.h>
65#ifdef KTRACE
66#include <sys/ktrace.h>
67#endif
68#include <sys/ktr.h>
69#include <sys/sysmsg.h>
70#include <sys/sysproto.h>
71#include <sys/sysunion.h>
72
73#include <vm/pmap.h>
74#include <vm/vm.h>
75#include <vm/vm_extern.h>
76#include <vm/vm_kern.h>
77#include <vm/vm_param.h>
78#include <machine/cpu.h>
79#include <machine/pcb.h>
46d4e165 80#include <machine/smp.h>
c8fe38ae 81#include <machine/thread.h>
d2d8515b 82#include <machine/clock.h>
c8fe38ae
MD
83#include <machine/vmparam.h>
84#include <machine/md_var.h>
57a9c56b 85#include <machine_base/isa/isa_intr.h>
83c8d73e 86#include <machine_base/apic/lapic.h>
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MD
87
88#include <ddb/ddb.h>
684a93c4 89
46d4e165 90#include <sys/thread2.h>
684a93c4 91#include <sys/mplock2.h>
c8fe38ae 92
c8fe38ae
MD
93#define MAKEMPSAFE(have_mplock) \
94 if (have_mplock == 0) { \
95 get_mplock(); \
96 have_mplock = 1; \
97 }
98
c8fe38ae 99extern void trap(struct trapframe *frame);
c8fe38ae
MD
100
101static int trap_pfault(struct trapframe *, int);
102static void trap_fatal(struct trapframe *, vm_offset_t);
103void dblfault_handler(struct trapframe *frame);
104
c8fe38ae
MD
105#define MAX_TRAP_MSG 30
106static char *trap_msg[] = {
107 "", /* 0 unused */
108 "privileged instruction fault", /* 1 T_PRIVINFLT */
109 "", /* 2 unused */
110 "breakpoint instruction fault", /* 3 T_BPTFLT */
111 "", /* 4 unused */
112 "", /* 5 unused */
113 "arithmetic trap", /* 6 T_ARITHTRAP */
114 "system forced exception", /* 7 T_ASTFLT */
115 "", /* 8 unused */
116 "general protection fault", /* 9 T_PROTFLT */
117 "trace trap", /* 10 T_TRCTRAP */
118 "", /* 11 unused */
119 "page fault", /* 12 T_PAGEFLT */
120 "", /* 13 unused */
121 "alignment fault", /* 14 T_ALIGNFLT */
122 "", /* 15 unused */
123 "", /* 16 unused */
124 "", /* 17 unused */
125 "integer divide fault", /* 18 T_DIVIDE */
126 "non-maskable interrupt trap", /* 19 T_NMI */
127 "overflow trap", /* 20 T_OFLOW */
128 "FPU bounds check fault", /* 21 T_BOUND */
129 "FPU device not available", /* 22 T_DNA */
130 "double fault", /* 23 T_DOUBLEFLT */
131 "FPU operand fetch fault", /* 24 T_FPOPFLT */
132 "invalid TSS fault", /* 25 T_TSSFLT */
133 "segment not present fault", /* 26 T_SEGNPFLT */
134 "stack fault", /* 27 T_STKFLT */
135 "machine check trap", /* 28 T_MCHK */
136 "SIMD floating-point exception", /* 29 T_XMMFLT */
137 "reserved (unknown) fault", /* 30 T_RESERVED */
138};
139
140#ifdef DDB
141static int ddb_on_nmi = 1;
142SYSCTL_INT(_machdep, OID_AUTO, ddb_on_nmi, CTLFLAG_RW,
143 &ddb_on_nmi, 0, "Go to DDB on NMI");
2883d2d8
MD
144static int ddb_on_seg_fault = 0;
145SYSCTL_INT(_machdep, OID_AUTO, ddb_on_seg_fault, CTLFLAG_RW,
146 &ddb_on_seg_fault, 0, "Go to DDB on user seg-fault");
d2d8515b
MD
147static int freeze_on_seg_fault = 0;
148SYSCTL_INT(_machdep, OID_AUTO, freeze_on_seg_fault, CTLFLAG_RW,
149 &freeze_on_seg_fault, 0, "Go to DDB on user seg-fault");
c8fe38ae
MD
150#endif
151static int panic_on_nmi = 1;
152SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
153 &panic_on_nmi, 0, "Panic on NMI");
154static int fast_release;
155SYSCTL_INT(_machdep, OID_AUTO, fast_release, CTLFLAG_RW,
156 &fast_release, 0, "Passive Release was optimal");
157static int slow_release;
158SYSCTL_INT(_machdep, OID_AUTO, slow_release, CTLFLAG_RW,
159 &slow_release, 0, "Passive Release was nonoptimal");
c8fe38ae 160
c8fe38ae 161/*
d2d8515b
MD
162 * System call debugging records the worst-case system call
163 * overhead (inclusive of blocking), but may be inaccurate.
164 */
165/*#define SYSCALL_DEBUG*/
166#ifdef SYSCALL_DEBUG
167uint64_t SysCallsWorstCase[SYS_MAXSYSCALL];
168#endif
169
170/*
7bd858e5 171 * Passively intercepts the thread switch function to increase
c8fe38ae
MD
172 * the thread priority from a user priority to a kernel priority, reducing
173 * syscall and trap overhead for the case where no switch occurs.
7bd858e5 174 *
d86a23e0 175 * Synchronizes td_ucred with p_ucred. This is used by system calls,
7bd858e5
MD
176 * signal handling, faults, AST traps, and anything else that enters the
177 * kernel from userland and provides the kernel with a stable read-only
178 * copy of the process ucred.
c8fe38ae 179 */
c8fe38ae 180static __inline void
d86a23e0 181userenter(struct thread *curtd, struct proc *curp)
c8fe38ae 182{
7bd858e5
MD
183 struct ucred *ocred;
184 struct ucred *ncred;
185
3824f392 186 curtd->td_release = lwkt_passive_release;
7bd858e5 187
d86a23e0
MD
188 if (curtd->td_ucred != curp->p_ucred) {
189 ncred = crhold(curp->p_ucred);
190 ocred = curtd->td_ucred;
191 curtd->td_ucred = ncred;
7bd858e5
MD
192 if (ocred)
193 crfree(ocred);
194 }
4643740a 195
1fdd109e 196#ifdef DDB
4643740a
MD
197 /*
198 * Debugging, remove top two user stack pages to catch kernel faults
199 */
200 if (freeze_on_seg_fault > 1 && curtd->td_lwp) {
201 pmap_remove(vmspace_pmap(curtd->td_lwp->lwp_vmspace),
202 0x00007FFFFFFFD000LU,
203 0x0000800000000000LU);
204 }
1fdd109e 205#endif
c8fe38ae
MD
206}
207
208/*
209 * Handle signals, upcalls, profiling, and other AST's and/or tasks that
210 * must be completed before we can return to or try to return to userland.
211 *
212 * Note that td_sticks is a 64 bit quantity, but there's no point doing 64
213 * arithmatic on the delta calculation so the absolute tick values are
214 * truncated to an integer.
215 */
216static void
217userret(struct lwp *lp, struct trapframe *frame, int sticks)
218{
219 struct proc *p = lp->lwp_proc;
220 int sig;
221
222 /*
223 * Charge system time if profiling. Note: times are in microseconds.
224 * This may do a copyout and block, so do it first even though it
225 * means some system time will be charged as user time.
226 */
4643740a 227 if (p->p_flags & P_PROFIL) {
bab69519 228 addupc_task(p, frame->tf_rip,
c8fe38ae
MD
229 (u_int)((int)lp->lwp_thread->td_sticks - sticks));
230 }
231
232recheck:
233 /*
62ae46c9
MD
234 * Specific on-return-to-usermode checks (LWP_MP_WEXIT,
235 * LWP_MP_VNLRU, etc).
c8fe38ae 236 */
62ae46c9
MD
237 if (lp->lwp_mpflags & LWP_MP_URETMASK)
238 lwpuserret(lp);
c8fe38ae
MD
239
240 /*
241 * Block here if we are in a stopped state.
242 */
5ea440eb 243 if (p->p_stat == SSTOP || dump_stop_usertds) {
4643740a 244 lwkt_gettoken(&p->p_token);
c8fe38ae 245 tstop();
4643740a 246 lwkt_reltoken(&p->p_token);
c8fe38ae
MD
247 goto recheck;
248 }
249
250 /*
251 * Post any pending upcalls. If running a virtual kernel be sure
252 * to restore the virtual kernel's vmspace before posting the upcall.
253 */
7adb15b6 254 if (p->p_flags & (P_SIGVTALRM | P_SIGPROF)) {
fc509460 255 lwkt_gettoken(&p->p_token);
4643740a
MD
256 if (p->p_flags & P_SIGVTALRM) {
257 p->p_flags &= ~P_SIGVTALRM;
898e34b3
MD
258 ksignal(p, SIGVTALRM);
259 }
4643740a
MD
260 if (p->p_flags & P_SIGPROF) {
261 p->p_flags &= ~P_SIGPROF;
898e34b3
MD
262 ksignal(p, SIGPROF);
263 }
fc509460 264 lwkt_reltoken(&p->p_token);
c8fe38ae
MD
265 goto recheck;
266 }
267
268 /*
269 * Post any pending signals. If running a virtual kernel be sure
270 * to restore the virtual kernel's vmspace before posting the signal.
2883d2d8
MD
271 *
272 * WARNING! postsig() can exit and not return.
c8fe38ae 273 */
e473f776 274 if ((sig = CURSIG_TRACE(lp)) != 0) {
fc509460 275 lwkt_gettoken(&p->p_token);
c8fe38ae 276 postsig(sig);
fc509460 277 lwkt_reltoken(&p->p_token);
c8fe38ae
MD
278 goto recheck;
279 }
280
281 /*
282 * block here if we are swapped out, but still process signals
283 * (such as SIGKILL). proc0 (the swapin scheduler) is already
284 * aware of our situation, we do not have to wake it up.
285 */
4643740a 286 if (p->p_flags & P_SWAPPEDOUT) {
616516c8 287 lwkt_gettoken(&p->p_token);
c8fe38ae 288 get_mplock();
4643740a 289 p->p_flags |= P_SWAPWAIT;
c8fe38ae 290 swapin_request();
4643740a 291 if (p->p_flags & P_SWAPWAIT)
c8fe38ae 292 tsleep(p, PCATCH, "SWOUT", 0);
4643740a 293 p->p_flags &= ~P_SWAPWAIT;
c8fe38ae 294 rel_mplock();
616516c8 295 lwkt_reltoken(&p->p_token);
c8fe38ae
MD
296 goto recheck;
297 }
298
299 /*
6562e2d8
MD
300 * In a multi-threaded program it is possible for a thread to change
301 * signal state during a system call which temporarily changes the
302 * signal mask. In this case postsig() might not be run and we
303 * have to restore the mask ourselves.
c8fe38ae 304 */
6562e2d8
MD
305 if (lp->lwp_flags & LWP_OLDMASK) {
306 lp->lwp_flags &= ~LWP_OLDMASK;
307 lp->lwp_sigmask = lp->lwp_oldsigmask;
308 goto recheck;
309 }
c8fe38ae
MD
310}
311
312/*
313 * Cleanup from userenter and any passive release that might have occured.
314 * We must reclaim the current-process designation before we can return
315 * to usermode. We also handle both LWKT and USER reschedule requests.
316 */
317static __inline void
318userexit(struct lwp *lp)
319{
320 struct thread *td = lp->lwp_thread;
bab69519 321 /* globaldata_t gd = td->td_gd; */
c8fe38ae 322
c8fe38ae 323 /*
89ffa1cf
SS
324 * Handle stop requests at kernel priority. Any requests queued
325 * after this loop will generate another AST.
c8fe38ae 326 */
89ffa1cf 327 while (lp->lwp_proc->p_stat == SSTOP) {
4643740a 328 lwkt_gettoken(&lp->lwp_proc->p_token);
89ffa1cf 329 tstop();
4643740a 330 lwkt_reltoken(&lp->lwp_proc->p_token);
c8fe38ae
MD
331 }
332
333 /*
c8fe38ae
MD
334 * Reduce our priority in preparation for a return to userland. If
335 * our passive release function was still in place, our priority was
336 * never raised and does not need to be reduced.
337 */
3824f392 338 lwkt_passive_recover(td);
89ffa1cf 339
e3e6be1f
MD
340 /* WARNING: we may have migrated cpu's */
341 /* gd = td->td_gd; */
342
89ffa1cf
SS
343 /*
344 * Become the current user scheduled process if we aren't already,
345 * and deal with reschedule requests and other factors.
346 */
347 lp->lwp_proc->p_usched->acquire_curproc(lp);
c8fe38ae
MD
348}
349
0855a2af
JG
350#if !defined(KTR_KERNENTRY)
351#define KTR_KERNENTRY KTR_ALL
352#endif
353KTR_INFO_MASTER(kernentry);
5bf48697 354KTR_INFO(KTR_KERNENTRY, kernentry, trap, 0,
0cccd3b7 355 "TRAP(pid %d, tid %d, trapno %ld, eva %lu)",
5bf48697 356 pid_t pid, lwpid_t tid, register_t trapno, vm_offset_t eva);
0cccd3b7 357KTR_INFO(KTR_KERNENTRY, kernentry, trap_ret, 0, "TRAP_RET(pid %d, tid %d)",
5bf48697 358 pid_t pid, lwpid_t tid);
0cccd3b7 359KTR_INFO(KTR_KERNENTRY, kernentry, syscall, 0, "SYSC(pid %d, tid %d, nr %ld)",
5bf48697 360 pid_t pid, lwpid_t tid, register_t trapno);
0cccd3b7 361KTR_INFO(KTR_KERNENTRY, kernentry, syscall_ret, 0, "SYSRET(pid %d, tid %d, err %d)",
5bf48697 362 pid_t pid, lwpid_t tid, int err);
0cccd3b7 363KTR_INFO(KTR_KERNENTRY, kernentry, fork_ret, 0, "FORKRET(pid %d, tid %d)",
5bf48697 364 pid_t pid, lwpid_t tid);
0855a2af 365
c8fe38ae
MD
366/*
367 * Exception, fault, and trap interface to the kernel.
368 * This common code is called from assembly language IDT gate entry
369 * routines that prepare a suitable stack frame, and restore this
370 * frame after the exception has been processed.
371 *
372 * This function is also called from doreti in an interlock to handle ASTs.
373 * For example: hardwareint->INTROUTINE->(set ast)->doreti->trap
374 *
375 * NOTE! We have to retrieve the fault address prior to obtaining the
376 * MP lock because get_mplock() may switch out. YYY cr2 really ought
377 * to be retrieved by the assembly code, not here.
378 *
379 * XXX gd_trap_nesting_level currently prevents lwkt_switch() from panicing
380 * if an attempt is made to switch from a fast interrupt or IPI. This is
bab69519 381 * necessary to properly take fatal kernel traps on SMP machines if
c8fe38ae
MD
382 * get_mplock() has to block.
383 */
384
385void
386trap(struct trapframe *frame)
387{
388 struct globaldata *gd = mycpu;
389 struct thread *td = gd->gd_curthread;
390 struct lwp *lp = td->td_lwp;
391 struct proc *p;
392 int sticks = 0;
393 int i = 0, ucode = 0, type, code;
c8fe38ae 394 int have_mplock = 0;
c8fe38ae 395#ifdef INVARIANTS
f9235b6d 396 int crit_count = td->td_critcount;
3933a3ab 397 lwkt_tokref_t curstop = td->td_toks_stop;
c8fe38ae
MD
398#endif
399 vm_offset_t eva;
400
401 p = td->td_proc;
f2081646 402 clear_quickret();
c8fe38ae 403
c8fe38ae 404#ifdef DDB
bfb6d329
AH
405 /*
406 * We need to allow T_DNA faults when the debugger is active since
2921c824 407 * some dumping paths do large bcopy() which use the floating
bfb6d329
AH
408 * point registers for faster copying.
409 */
5ea440eb 410 if (db_active && frame->tf_trapno != T_DNA) {
c8fe38ae
MD
411 eva = (frame->tf_trapno == T_PAGEFLT ? frame->tf_addr : 0);
412 ++gd->gd_trap_nesting_level;
413 MAKEMPSAFE(have_mplock);
414 trap_fatal(frame, eva);
415 --gd->gd_trap_nesting_level;
416 goto out2;
417 }
418#endif
419
420 eva = 0;
421
c8fe38ae
MD
422 if ((frame->tf_rflags & PSL_I) == 0) {
423 /*
424 * Buggy application or kernel code has disabled interrupts
425 * and then trapped. Enabling interrupts now is wrong, but
426 * it is better than running with interrupts disabled until
427 * they are accidentally enabled later.
428 */
429 type = frame->tf_trapno;
430 if (ISPL(frame->tf_cs) == SEL_UPL) {
431 MAKEMPSAFE(have_mplock);
432 /* JG curproc can be NULL */
433 kprintf(
434 "pid %ld (%s): trap %d with interrupts disabled\n",
435 (long)curproc->p_pid, curproc->p_comm, type);
436 } else if (type != T_NMI && type != T_BPTFLT &&
437 type != T_TRCTRAP) {
438 /*
439 * XXX not quite right, since this may be for a
440 * multiple fault in user mode.
441 */
442 MAKEMPSAFE(have_mplock);
443 kprintf("kernel trap %d with interrupts disabled\n",
444 type);
445 }
446 cpu_enable_intr();
447 }
448
449 type = frame->tf_trapno;
450 code = frame->tf_err;
451
452 if (ISPL(frame->tf_cs) == SEL_UPL) {
453 /* user trap */
454
455 KTR_LOG(kernentry_trap, p->p_pid, lp->lwp_tid,
456 frame->tf_trapno, eva);
457
d86a23e0 458 userenter(td, p);
c8fe38ae
MD
459
460 sticks = (int)td->td_sticks;
d1368d1a
MD
461 KASSERT(lp->lwp_md.md_regs == frame,
462 ("Frame mismatch %p %p", lp->lwp_md.md_regs, frame));
c8fe38ae
MD
463
464 switch (type) {
465 case T_PRIVINFLT: /* privileged instruction fault */
c8fe38ae 466 i = SIGILL;
bab69519 467 ucode = ILL_PRVOPC;
c8fe38ae
MD
468 break;
469
470 case T_BPTFLT: /* bpt instruction fault */
471 case T_TRCTRAP: /* trace trap */
472 frame->tf_rflags &= ~PSL_T;
473 i = SIGTRAP;
bab69519 474 ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
c8fe38ae
MD
475 break;
476
477 case T_ARITHTRAP: /* arithmetic trap */
478 ucode = code;
479 i = SIGFPE;
c8fe38ae
MD
480 break;
481
482 case T_ASTFLT: /* Allow process switch */
483 mycpu->gd_cnt.v_soft++;
484 if (mycpu->gd_reqflags & RQF_AST_OWEUPC) {
2a418930
MD
485 atomic_clear_int(&mycpu->gd_reqflags,
486 RQF_AST_OWEUPC);
c8fe38ae
MD
487 addupc_task(p, p->p_prof.pr_addr,
488 p->p_prof.pr_ticks);
489 }
490 goto out;
491
492 case T_PROTFLT: /* general protection fault */
f2642d5a
AH
493 i = SIGBUS;
494 ucode = BUS_OBJERR;
495 break;
bab69519 496 case T_STKFLT: /* stack fault */
c8fe38ae 497 case T_SEGNPFLT: /* segment not present fault */
f2642d5a
AH
498 i = SIGBUS;
499 ucode = BUS_ADRERR;
500 break;
c8fe38ae
MD
501 case T_TSSFLT: /* invalid TSS fault */
502 case T_DOUBLEFLT: /* double fault */
503 default:
c8fe38ae 504 i = SIGBUS;
bab69519 505 ucode = BUS_OBJERR;
c8fe38ae
MD
506 break;
507
508 case T_PAGEFLT: /* page fault */
c8fe38ae 509 i = trap_pfault(frame, TRUE);
d2d8515b 510 if (frame->tf_rip == 0) {
973c11b9 511 kprintf("T_PAGEFLT: Warning %%rip == 0!\n");
1fdd109e
SW
512#ifdef DDB
513 while (freeze_on_seg_fault)
d2d8515b 514 tsleep(p, 0, "freeze", hz * 20);
1fdd109e 515#endif
d2d8515b 516 }
bab69519 517 if (i == -1 || i == 0)
c8fe38ae
MD
518 goto out;
519
bab69519 520
f2642d5a
AH
521 if (i == SIGSEGV)
522 ucode = SEGV_MAPERR;
bab69519
JM
523 else {
524 i = SIGSEGV;
525 ucode = SEGV_ACCERR;
526 }
c8fe38ae
MD
527 break;
528
529 case T_DIVIDE: /* integer divide fault */
530 ucode = FPE_INTDIV;
531 i = SIGFPE;
532 break;
533
775ce2da 534#if NISA > 0
c8fe38ae
MD
535 case T_NMI:
536 MAKEMPSAFE(have_mplock);
537 /* machine/parity/power fail/"kitchen sink" faults */
538 if (isa_nmi(code) == 0) {
539#ifdef DDB
540 /*
541 * NMI can be hooked up to a pushbutton
542 * for debugging.
543 */
544 if (ddb_on_nmi) {
545 kprintf ("NMI ... going to debugger\n");
546 kdb_trap(type, 0, frame);
547 }
548#endif /* DDB */
549 goto out2;
550 } else if (panic_on_nmi)
551 panic("NMI indicates hardware failure");
552 break;
775ce2da 553#endif /* NISA > 0 */
c8fe38ae
MD
554
555 case T_OFLOW: /* integer overflow fault */
556 ucode = FPE_INTOVF;
557 i = SIGFPE;
558 break;
559
560 case T_BOUND: /* bounds check fault */
561 ucode = FPE_FLTSUB;
562 i = SIGFPE;
563 break;
564
565 case T_DNA:
566 /*
567 * Virtual kernel intercept - pass the DNA exception
568 * to the virtual kernel if it asked to handle it.
569 * This occurs when the virtual kernel is holding
570 * onto the FP context for a different emulated
571 * process then the one currently running.
572 *
573 * We must still call npxdna() since we may have
574 * saved FP state that the virtual kernel needs
575 * to hand over to a different emulated process.
576 */
577 if (lp->lwp_vkernel && lp->lwp_vkernel->ve &&
578 (td->td_pcb->pcb_flags & FP_VIRTFP)
579 ) {
580 npxdna();
581 break;
582 }
583
584 /*
585 * The kernel may have switched out the FP unit's
586 * state, causing the user process to take a fault
587 * when it tries to use the FP unit. Restore the
588 * state here
589 */
590 if (npxdna())
591 goto out;
592 i = SIGFPE;
593 ucode = FPE_FPU_NP_TRAP;
594 break;
595
596 case T_FPOPFLT: /* FPU operand fetch fault */
f2642d5a 597 ucode = ILL_COPROC;
c8fe38ae
MD
598 i = SIGILL;
599 break;
600
601 case T_XMMFLT: /* SIMD floating-point exception */
602 ucode = 0; /* XXX */
603 i = SIGFPE;
604 break;
605 }
606 } else {
607 /* kernel trap */
608
609 switch (type) {
610 case T_PAGEFLT: /* page fault */
c8fe38ae
MD
611 trap_pfault(frame, FALSE);
612 goto out2;
613
614 case T_DNA:
615 /*
616 * The kernel is apparently using fpu for copying.
617 * XXX this should be fatal unless the kernel has
618 * registered such use.
619 */
620 if (npxdna())
621 goto out2;
622 break;
623
624 case T_STKFLT: /* stack fault */
625 break;
626
627 case T_PROTFLT: /* general protection fault */
628 case T_SEGNPFLT: /* segment not present fault */
629 /*
630 * Invalid segment selectors and out of bounds
631 * %rip's and %rsp's can be set up in user mode.
632 * This causes a fault in kernel mode when the
633 * kernel tries to return to user mode. We want
634 * to get this fault so that we can fix the
635 * problem here and not have to check all the
636 * selectors and pointers when the user changes
637 * them.
638 */
c8fe38ae 639 if (mycpu->gd_intr_nesting_level == 0) {
93ad6da2
MD
640 /*
641 * NOTE: in 64-bit mode traps push rsp/ss
642 * even if no ring change occurs.
643 */
644 if (td->td_pcb->pcb_onfault &&
645 td->td_pcb->pcb_onfault_sp ==
646 frame->tf_rsp) {
c8fe38ae
MD
647 frame->tf_rip = (register_t)
648 td->td_pcb->pcb_onfault;
649 goto out2;
650 }
89ffa1cf
SS
651 if (frame->tf_rip == (long)doreti_iret) {
652 frame->tf_rip = (long)doreti_iret_fault;
653 goto out2;
654 }
c8fe38ae
MD
655 }
656 break;
657
658 case T_TSSFLT:
659 /*
660 * PSL_NT can be set in user mode and isn't cleared
661 * automatically when the kernel is entered. This
662 * causes a TSS fault when the kernel attempts to
663 * `iret' because the TSS link is uninitialized. We
664 * want to get this fault so that we can fix the
665 * problem here and not every time the kernel is
666 * entered.
667 */
668 if (frame->tf_rflags & PSL_NT) {
669 frame->tf_rflags &= ~PSL_NT;
670 goto out2;
671 }
672 break;
673
674 case T_TRCTRAP: /* trace trap */
675#if 0
676 if (frame->tf_rip == (int)IDTVEC(syscall)) {
677 /*
678 * We've just entered system mode via the
679 * syscall lcall. Continue single stepping
680 * silently until the syscall handler has
681 * saved the flags.
682 */
683 goto out2;
684 }
685 if (frame->tf_rip == (int)IDTVEC(syscall) + 1) {
686 /*
687 * The syscall handler has now saved the
688 * flags. Stop single stepping it.
689 */
690 frame->tf_rflags &= ~PSL_T;
691 goto out2;
692 }
693#endif
694
695 /*
696 * Ignore debug register trace traps due to
697 * accesses in the user's address space, which
698 * can happen under several conditions such as
699 * if a user sets a watchpoint on a buffer and
700 * then passes that buffer to a system call.
701 * We still want to get TRCTRAPS for addresses
702 * in kernel space because that is useful when
703 * debugging the kernel.
704 */
705#if JG
706 if (user_dbreg_trap()) {
707 /*
708 * Reset breakpoint bits because the
709 * processor doesn't
710 */
711 /* XXX check upper bits here */
712 load_dr6(rdr6() & 0xfffffff0);
713 goto out2;
714 }
715#endif
716 /*
717 * FALLTHROUGH (TRCTRAP kernel mode, kernel address)
718 */
719 case T_BPTFLT:
720 /*
721 * If DDB is enabled, let it handle the debugger trap.
722 * Otherwise, debugger traps "can't happen".
723 */
f2642d5a 724 ucode = TRAP_BRKPT;
c8fe38ae
MD
725#ifdef DDB
726 MAKEMPSAFE(have_mplock);
727 if (kdb_trap(type, 0, frame))
728 goto out2;
729#endif
730 break;
731
775ce2da 732#if NISA > 0
c8fe38ae
MD
733 case T_NMI:
734 MAKEMPSAFE(have_mplock);
735 /* machine/parity/power fail/"kitchen sink" faults */
c8fe38ae
MD
736 if (isa_nmi(code) == 0) {
737#ifdef DDB
738 /*
739 * NMI can be hooked up to a pushbutton
740 * for debugging.
741 */
742 if (ddb_on_nmi) {
743 kprintf ("NMI ... going to debugger\n");
744 kdb_trap(type, 0, frame);
745 }
746#endif /* DDB */
747 goto out2;
748 } else if (panic_on_nmi == 0)
749 goto out2;
750 /* FALL THROUGH */
751#endif /* NISA > 0 */
752 }
753 MAKEMPSAFE(have_mplock);
754 trap_fatal(frame, 0);
73e24181
MD
755 goto out2;
756 }
757
758 /*
759 * Virtual kernel intercept - if the fault is directly related to a
760 * VM context managed by a virtual kernel then let the virtual kernel
761 * handle it.
762 */
763 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
764 vkernel_trap(lp, frame);
c8fe38ae
MD
765 goto out;
766 }
767
bab69519 768 /* Translate fault for emulators (e.g. Linux) */
c8fe38ae
MD
769 if (*p->p_sysent->sv_transtrap)
770 i = (*p->p_sysent->sv_transtrap)(i, type);
771
772 MAKEMPSAFE(have_mplock);
773 trapsignal(lp, i, ucode);
774
775#ifdef DEBUG
776 if (type <= MAX_TRAP_MSG) {
777 uprintf("fatal process exception: %s",
778 trap_msg[type]);
779 if ((type == T_PAGEFLT) || (type == T_PROTFLT))
780 uprintf(", fault VA = 0x%lx", frame->tf_addr);
781 uprintf("\n");
782 }
783#endif
784
785out:
c8fe38ae
MD
786 userret(lp, frame, sticks);
787 userexit(lp);
788out2: ;
c8fe38ae
MD
789 if (have_mplock)
790 rel_mplock();
c8fe38ae
MD
791 if (p != NULL && lp != NULL)
792 KTR_LOG(kernentry_trap_ret, p->p_pid, lp->lwp_tid);
793#ifdef INVARIANTS
f9235b6d 794 KASSERT(crit_count == td->td_critcount,
3933a3ab 795 ("trap: critical section count mismatch! %d/%d",
f9235b6d 796 crit_count, td->td_pri));
3933a3ab
MD
797 KASSERT(curstop == td->td_toks_stop,
798 ("trap: extra tokens held after trap! %ld/%ld",
799 curstop - &td->td_toks_base,
800 td->td_toks_stop - &td->td_toks_base));
c8fe38ae
MD
801#endif
802}
803
804static int
805trap_pfault(struct trapframe *frame, int usermode)
806{
807 vm_offset_t va;
808 struct vmspace *vm = NULL;
809 vm_map_t map;
810 int rv = 0;
1b9d3514 811 int fault_flags;
c8fe38ae
MD
812 vm_prot_t ftype;
813 thread_t td = curthread;
814 struct lwp *lp = td->td_lwp;
2883d2d8 815 struct proc *p;
c8fe38ae
MD
816
817 va = trunc_page(frame->tf_addr);
818 if (va >= VM_MIN_KERNEL_ADDRESS) {
819 /*
820 * Don't allow user-mode faults in kernel address space.
821 */
2883d2d8
MD
822 if (usermode) {
823 fault_flags = -1;
824 ftype = -1;
c8fe38ae 825 goto nogo;
2883d2d8 826 }
c8fe38ae
MD
827
828 map = &kernel_map;
829 } else {
830 /*
831 * This is a fault on non-kernel virtual memory.
832 * vm is initialized above to NULL. If curproc is NULL
833 * or curproc->p_vmspace is NULL the fault is fatal.
834 */
835 if (lp != NULL)
836 vm = lp->lwp_vmspace;
837
2883d2d8
MD
838 if (vm == NULL) {
839 fault_flags = -1;
840 ftype = -1;
c8fe38ae 841 goto nogo;
2883d2d8 842 }
c8fe38ae 843
4643740a
MD
844 /*
845 * Debugging, try to catch kernel faults on the user address space when not inside
846 * on onfault (e.g. copyin/copyout) routine.
847 */
93ad6da2
MD
848 if (usermode == 0 && (td->td_pcb == NULL ||
849 td->td_pcb->pcb_onfault == NULL)) {
1fdd109e 850#ifdef DDB
4643740a
MD
851 if (freeze_on_seg_fault) {
852 kprintf("trap_pfault: user address fault from kernel mode "
853 "%016lx\n", (long)frame->tf_addr);
1fdd109e 854 while (freeze_on_seg_fault)
4643740a 855 tsleep(&freeze_on_seg_fault, 0, "frzseg", hz * 20);
4643740a 856 }
1fdd109e 857#endif
4643740a 858 }
c8fe38ae
MD
859 map = &vm->vm_map;
860 }
861
862 /*
863 * PGEX_I is defined only if the execute disable bit capability is
864 * supported and enabled.
865 */
866 if (frame->tf_err & PGEX_W)
867 ftype = VM_PROT_WRITE;
868#if JG
869 else if ((frame->tf_err & PGEX_I) && pg_nx != 0)
870 ftype = VM_PROT_EXECUTE;
871#endif
872 else
873 ftype = VM_PROT_READ;
874
875 if (map != &kernel_map) {
876 /*
877 * Keep swapout from messing with us during this
878 * critical time.
879 */
880 PHOLD(lp->lwp_proc);
881
882 /*
1b9d3514
MD
883 * Issue fault
884 */
885 fault_flags = 0;
886 if (usermode)
887 fault_flags |= VM_FAULT_BURST;
888 if (ftype & VM_PROT_WRITE)
889 fault_flags |= VM_FAULT_DIRTY;
890 else
891 fault_flags |= VM_FAULT_NORMAL;
892 rv = vm_fault(map, va, ftype, fault_flags);
c8fe38ae
MD
893
894 PRELE(lp->lwp_proc);
895 } else {
896 /*
bab69519
JM
897 * Don't have to worry about process locking or stacks in the
898 * kernel.
c8fe38ae 899 */
2883d2d8 900 fault_flags = VM_FAULT_NORMAL;
c8fe38ae
MD
901 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
902 }
c8fe38ae
MD
903 if (rv == KERN_SUCCESS)
904 return (0);
905nogo:
906 if (!usermode) {
93ad6da2
MD
907 /*
908 * NOTE: in 64-bit mode traps push rsp/ss
909 * even if no ring change occurs.
910 */
911 if (td->td_pcb->pcb_onfault &&
912 td->td_pcb->pcb_onfault_sp == frame->tf_rsp &&
913 td->td_gd->gd_intr_nesting_level == 0) {
c8fe38ae
MD
914 frame->tf_rip = (register_t)td->td_pcb->pcb_onfault;
915 return (0);
916 }
917 trap_fatal(frame, frame->tf_addr);
918 return (-1);
919 }
920
921 /*
b2b3ffcd 922 * NOTE: on x86_64 we have a tf_addr field in the trapframe, no
c8fe38ae
MD
923 * kludge is needed to pass the fault address to signal handlers.
924 */
2883d2d8 925 p = td->td_proc;
2deef24c 926 if (td->td_lwp->lwp_vkernel == NULL) {
1fdd109e 927#ifdef DDB
d2d8515b 928 if (bootverbose || freeze_on_seg_fault || ddb_on_seg_fault) {
1fdd109e
SW
929#else
930 if (bootverbose) {
931#endif
c98f2169 932 kprintf("seg-fault ft=%04x ff=%04x addr=%p rip=%p "
3338cc67 933 "pid=%d cpu=%d p_comm=%s\n",
c98f2169
SW
934 ftype, fault_flags,
935 (void *)frame->tf_addr,
936 (void *)frame->tf_rip,
3338cc67 937 p->p_pid, mycpu->gd_cpuid, p->p_comm);
d2d8515b 938 }
3f6724a9 939#ifdef DDB
d2d8515b
MD
940 while (freeze_on_seg_fault) {
941 tsleep(p, 0, "freeze", hz * 20);
942 }
2883d2d8
MD
943 if (ddb_on_seg_fault)
944 Debugger("ddb_on_seg_fault");
3f6724a9 945#endif
2deef24c 946 }
c8fe38ae
MD
947
948 return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
949}
950
951static void
952trap_fatal(struct trapframe *frame, vm_offset_t eva)
953{
954 int code, ss;
955 u_int type;
956 long rsp;
957 struct soft_segment_descriptor softseg;
958 char *msg;
959
960 code = frame->tf_err;
961 type = frame->tf_trapno;
962 sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)], &softseg);
963
964 if (type <= MAX_TRAP_MSG)
965 msg = trap_msg[type];
966 else
967 msg = "UNKNOWN";
968 kprintf("\n\nFatal trap %d: %s while in %s mode\n", type, msg,
969 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
46d4e165 970 /* three separate prints in case of a trap on an unmapped page */
46d4e165
JG
971 kprintf("cpuid = %d; ", mycpu->gd_cpuid);
972 kprintf("lapic->id = %08x\n", lapic->id);
c8fe38ae
MD
973 if (type == T_PAGEFLT) {
974 kprintf("fault virtual address = 0x%lx\n", eva);
975 kprintf("fault code = %s %s %s, %s\n",
976 code & PGEX_U ? "user" : "supervisor",
977 code & PGEX_W ? "write" : "read",
978 code & PGEX_I ? "instruction" : "data",
979 code & PGEX_P ? "protection violation" : "page not present");
980 }
981 kprintf("instruction pointer = 0x%lx:0x%lx\n",
982 frame->tf_cs & 0xffff, frame->tf_rip);
983 if (ISPL(frame->tf_cs) == SEL_UPL) {
984 ss = frame->tf_ss & 0xffff;
985 rsp = frame->tf_rsp;
986 } else {
93ad6da2
MD
987 /*
988 * NOTE: in 64-bit mode traps push rsp/ss even if no ring
989 * change occurs.
990 */
c8fe38ae 991 ss = GSEL(GDATA_SEL, SEL_KPL);
93ad6da2 992 rsp = frame->tf_rsp;
c8fe38ae
MD
993 }
994 kprintf("stack pointer = 0x%x:0x%lx\n", ss, rsp);
995 kprintf("frame pointer = 0x%x:0x%lx\n", ss, frame->tf_rbp);
996 kprintf("code segment = base 0x%lx, limit 0x%lx, type 0x%x\n",
997 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
998 kprintf(" = DPL %d, pres %d, long %d, def32 %d, gran %d\n",
999 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_long, softseg.ssd_def32,
1000 softseg.ssd_gran);
1001 kprintf("processor eflags = ");
1002 if (frame->tf_rflags & PSL_T)
1003 kprintf("trace trap, ");
1004 if (frame->tf_rflags & PSL_I)
1005 kprintf("interrupt enabled, ");
1006 if (frame->tf_rflags & PSL_NT)
1007 kprintf("nested task, ");
1008 if (frame->tf_rflags & PSL_RF)
1009 kprintf("resume, ");
1010 kprintf("IOPL = %ld\n", (frame->tf_rflags & PSL_IOPL) >> 12);
1011 kprintf("current process = ");
1012 if (curproc) {
1013 kprintf("%lu\n",
1014 (u_long)curproc->p_pid);
1015 } else {
1016 kprintf("Idle\n");
1017 }
1018 kprintf("current thread = pri %d ", curthread->td_pri);
f9235b6d 1019 if (curthread->td_critcount)
c8fe38ae
MD
1020 kprintf("(CRIT)");
1021 kprintf("\n");
1022
1023#ifdef DDB
1024 if ((debugger_on_panic || db_active) && kdb_trap(type, code, frame))
1025 return;
1026#endif
1027 kprintf("trap number = %d\n", type);
1028 if (type <= MAX_TRAP_MSG)
1029 panic("%s", trap_msg[type]);
1030 else
1031 panic("unknown/reserved trap");
1032}
1033
1034/*
1035 * Double fault handler. Called when a fault occurs while writing
1036 * a frame for a trap/exception onto the stack. This usually occurs
1037 * when the stack overflows (such is the case with infinite recursion,
1038 * for example).
1039 */
093565f2
MD
1040static __inline
1041int
1042in_kstack_guard(register_t rptr)
1043{
1044 thread_t td = curthread;
1045
1046 if ((char *)rptr >= td->td_kstack &&
1047 (char *)rptr < td->td_kstack + PAGE_SIZE) {
1048 return 1;
1049 }
1050 return 0;
1051}
1052
c8fe38ae
MD
1053void
1054dblfault_handler(struct trapframe *frame)
1055{
093565f2
MD
1056 thread_t td = curthread;
1057
1058 if (in_kstack_guard(frame->tf_rsp) || in_kstack_guard(frame->tf_rbp)) {
0174149e 1059 kprintf("DOUBLE FAULT - KERNEL STACK GUARD HIT!\n");
093565f2
MD
1060 if (in_kstack_guard(frame->tf_rsp))
1061 frame->tf_rsp = (register_t)(td->td_kstack + PAGE_SIZE);
1062 if (in_kstack_guard(frame->tf_rbp))
1063 frame->tf_rbp = (register_t)(td->td_kstack + PAGE_SIZE);
1064 } else {
0174149e 1065 kprintf("DOUBLE FAULT\n");
093565f2 1066 }
c8fe38ae
MD
1067 kprintf("\nFatal double fault\n");
1068 kprintf("rip = 0x%lx\n", frame->tf_rip);
1069 kprintf("rsp = 0x%lx\n", frame->tf_rsp);
1070 kprintf("rbp = 0x%lx\n", frame->tf_rbp);
46d4e165 1071 /* three separate prints in case of a trap on an unmapped page */
46d4e165
JG
1072 kprintf("cpuid = %d; ", mycpu->gd_cpuid);
1073 kprintf("lapic->id = %08x\n", lapic->id);
c8fe38ae
MD
1074 panic("double fault");
1075}
1076
1077/*
7bd858e5 1078 * syscall2 - MP aware system call request C handler
c8fe38ae 1079 *
7bd858e5
MD
1080 * A system call is essentially treated as a trap except that the
1081 * MP lock is not held on entry or return. We are responsible for
1082 * obtaining the MP lock if necessary and for handling ASTs
1083 * (e.g. a task switch) prior to return.
c8fe38ae 1084 *
7bd858e5 1085 * MPSAFE
c8fe38ae
MD
1086 */
1087void
1088syscall2(struct trapframe *frame)
1089{
1090 struct thread *td = curthread;
1091 struct proc *p = td->td_proc;
1092 struct lwp *lp = td->td_lwp;
1093 caddr_t params;
1094 struct sysent *callp;
1095 register_t orig_tf_rflags;
1096 int sticks;
1097 int error;
1098 int narg;
1099#ifdef INVARIANTS
f9235b6d 1100 int crit_count = td->td_critcount;
c8fe38ae 1101#endif
c8fe38ae 1102 int have_mplock = 0;
c8fe38ae
MD
1103 register_t *argp;
1104 u_int code;
1105 int reg, regcnt;
1106 union sysunion args;
1107 register_t *argsdst;
c8fe38ae 1108
46d4e165 1109 mycpu->gd_cnt.v_syscall++;
c8fe38ae 1110
c8fe38ae
MD
1111#ifdef DIAGNOSTIC
1112 if (ISPL(frame->tf_cs) != SEL_UPL) {
1113 get_mplock();
1114 panic("syscall");
1115 /* NOT REACHED */
1116 }
1117#endif
1118
1119 KTR_LOG(kernentry_syscall, p->p_pid, lp->lwp_tid,
4afe74da 1120 frame->tf_rax);
c8fe38ae 1121
d86a23e0 1122 userenter(td, p); /* lazy raise our priority */
c8fe38ae
MD
1123
1124 reg = 0;
1125 regcnt = 6;
1126 /*
1127 * Misc
1128 */
1129 sticks = (int)td->td_sticks;
1130 orig_tf_rflags = frame->tf_rflags;
1131
1132 /*
1133 * Virtual kernel intercept - if a VM context managed by a virtual
1134 * kernel issues a system call the virtual kernel handles it, not us.
1135 * Restore the virtual kernel context and return from its system
1136 * call. The current frame is copied out to the virtual kernel.
1137 */
1138 if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
bb47c072 1139 vkernel_trap(lp, frame);
c8fe38ae
MD
1140 error = EJUSTRETURN;
1141 goto out;
1142 }
1143
1144 /*
1145 * Get the system call parameters and account for time
1146 */
d1368d1a
MD
1147 KASSERT(lp->lwp_md.md_regs == frame,
1148 ("Frame mismatch %p %p", lp->lwp_md.md_regs, frame));
c8fe38ae
MD
1149 params = (caddr_t)frame->tf_rsp + sizeof(register_t);
1150 code = frame->tf_rax;
1151
1152 if (p->p_sysent->sv_prepsyscall) {
1153 (*p->p_sysent->sv_prepsyscall)(
1154 frame, (int *)(&args.nosys.sysmsg + 1),
1155 &code, &params);
1156 } else {
1157 if (code == SYS_syscall || code == SYS___syscall) {
1158 code = frame->tf_rdi;
1159 reg++;
1160 regcnt--;
1161 }
1162 }
1163
bab69519
JM
1164 if (p->p_sysent->sv_mask)
1165 code &= p->p_sysent->sv_mask;
c8fe38ae
MD
1166
1167 if (code >= p->p_sysent->sv_size)
1168 callp = &p->p_sysent->sv_table[0];
1169 else
1170 callp = &p->p_sysent->sv_table[code];
1171
1172 narg = callp->sy_narg & SYF_ARGMASK;
1173
1174 /*
b2b3ffcd 1175 * On x86_64 we get up to six arguments in registers. The rest are
a6a09809 1176 * on the stack. The first six members of 'struct trapframe' happen
c8fe38ae
MD
1177 * to be the registers used to pass arguments, in exactly the right
1178 * order.
1179 */
1180 argp = &frame->tf_rdi;
1181 argp += reg;
1182 argsdst = (register_t *)(&args.nosys.sysmsg + 1);
1183 /*
1184 * JG can we overflow the space pointed to by 'argsdst'
1185 * either with 'bcopy' or with 'copyin'?
1186 */
1187 bcopy(argp, argsdst, sizeof(register_t) * regcnt);
1188 /*
1189 * copyin is MP aware, but the tracing code is not
1190 */
1191 if (narg > regcnt) {
1192 KASSERT(params != NULL, ("copyin args with no params!"));
1193 error = copyin(params, &argsdst[regcnt],
bab69519 1194 (narg - regcnt) * sizeof(register_t));
c8fe38ae
MD
1195 if (error) {
1196#ifdef KTRACE
1197 if (KTRPOINT(td, KTR_SYSCALL)) {
1198 MAKEMPSAFE(have_mplock);
bab69519 1199
c8fe38ae
MD
1200 ktrsyscall(lp, code, narg,
1201 (void *)(&args.nosys.sysmsg + 1));
1202 }
1203#endif
1204 goto bad;
1205 }
1206 }
1207
1208#ifdef KTRACE
1209 if (KTRPOINT(td, KTR_SYSCALL)) {
1210 MAKEMPSAFE(have_mplock);
1211 ktrsyscall(lp, code, narg, (void *)(&args.nosys.sysmsg + 1));
1212 }
1213#endif
1214
1215 /*
1216 * Default return value is 0 (will be copied to %rax). Double-value
1217 * returns use %rax and %rdx. %rdx is left unchanged for system
1218 * calls which return only one result.
1219 */
1220 args.sysmsg_fds[0] = 0;
1221 args.sysmsg_fds[1] = frame->tf_rdx;
1222
1223 /*
1224 * The syscall might manipulate the trap frame. If it does it
1225 * will probably return EJUSTRETURN.
1226 */
1227 args.sysmsg_frame = frame;
1228
1229 STOPEVENT(p, S_SCE, narg); /* MP aware */
1230
c8fe38ae 1231 /*
3919ced0
MD
1232 * NOTE: All system calls run MPSAFE now. The system call itself
1233 * is responsible for getting the MP lock.
c8fe38ae 1234 */
d2d8515b
MD
1235#ifdef SYSCALL_DEBUG
1236 uint64_t tscval = rdtsc();
1237#endif
c8fe38ae 1238 error = (*callp->sy_call)(&args);
d2d8515b
MD
1239#ifdef SYSCALL_DEBUG
1240 tscval = rdtsc() - tscval;
1241 tscval = tscval * 1000000 / tsc_frequency;
1242 if (SysCallsWorstCase[code] < tscval)
1243 SysCallsWorstCase[code] = tscval;
1244#endif
c8fe38ae
MD
1245
1246out:
1247 /*
1248 * MP SAFE (we may or may not have the MP lock at this point)
1249 */
0855a2af 1250 //kprintf("SYSMSG %d ", error);
c8fe38ae
MD
1251 switch (error) {
1252 case 0:
1253 /*
1254 * Reinitialize proc pointer `p' as it may be different
1255 * if this is a child returning from fork syscall.
1256 */
1257 p = curproc;
1258 lp = curthread->td_lwp;
1259 frame->tf_rax = args.sysmsg_fds[0];
1260 frame->tf_rdx = args.sysmsg_fds[1];
c8fe38ae
MD
1261 frame->tf_rflags &= ~PSL_C;
1262 break;
1263 case ERESTART:
1264 /*
1265 * Reconstruct pc, we know that 'syscall' is 2 bytes.
1266 * We have to do a full context restore so that %r10
1267 * (which was holding the value of %rcx) is restored for
1268 * the next iteration.
1269 */
3338cc67
MD
1270 if (frame->tf_err != 0 && frame->tf_err != 2)
1271 kprintf("lp %s:%d frame->tf_err is weird %ld\n",
1272 td->td_comm, lp->lwp_proc->p_pid, frame->tf_err);
c8fe38ae
MD
1273 frame->tf_rip -= frame->tf_err;
1274 frame->tf_r10 = frame->tf_rcx;
c8fe38ae
MD
1275 break;
1276 case EJUSTRETURN:
1277 break;
1278 case EASYNC:
1279 panic("Unexpected EASYNC return value (for now)");
1280 default:
1281bad:
1282 if (p->p_sysent->sv_errsize) {
1283 if (error >= p->p_sysent->sv_errsize)
1284 error = -1; /* XXX */
1285 else
1286 error = p->p_sysent->sv_errtbl[error];
1287 }
c8fe38ae
MD
1288 frame->tf_rax = error;
1289 frame->tf_rflags |= PSL_C;
1290 break;
1291 }
1292
1293 /*
1294 * Traced syscall. trapsignal() is not MP aware.
1295 */
1296 if (orig_tf_rflags & PSL_T) {
1297 MAKEMPSAFE(have_mplock);
1298 frame->tf_rflags &= ~PSL_T;
f2642d5a 1299 trapsignal(lp, SIGTRAP, TRAP_TRACE);
c8fe38ae
MD
1300 }
1301
1302 /*
1303 * Handle reschedule and other end-of-syscall issues
1304 */
1305 userret(lp, frame, sticks);
1306
1307#ifdef KTRACE
1308 if (KTRPOINT(td, KTR_SYSRET)) {
1309 MAKEMPSAFE(have_mplock);
1310 ktrsysret(lp, code, error, args.sysmsg_result);
1311 }
1312#endif
1313
1314 /*
1315 * This works because errno is findable through the
1316 * register set. If we ever support an emulation where this
1317 * is not the case, this code will need to be revisited.
1318 */
1319 STOPEVENT(p, S_SCX, code);
1320
1321 userexit(lp);
c8fe38ae
MD
1322 /*
1323 * Release the MP lock if we had to get it
1324 */
c8fe38ae
MD
1325 if (have_mplock)
1326 rel_mplock();
c8fe38ae
MD
1327 KTR_LOG(kernentry_syscall_ret, p->p_pid, lp->lwp_tid, error);
1328#ifdef INVARIANTS
f9235b6d 1329 KASSERT(crit_count == td->td_critcount,
c8fe38ae 1330 ("syscall: critical section count mismatch! %d/%d",
f9235b6d 1331 crit_count, td->td_pri));
3933a3ab
MD
1332 KASSERT(&td->td_toks_base == td->td_toks_stop,
1333 ("syscall: extra tokens held after trap! %ld",
1334 td->td_toks_stop - &td->td_toks_base));
c8fe38ae
MD
1335#endif
1336}
d7f50089 1337
2b0bd8aa
MD
1338/*
1339 * NOTE: mplock not held at any point
1340 */
d7f50089
YY
1341void
1342fork_return(struct lwp *lp, struct trapframe *frame)
1343{
c8fe38ae
MD
1344 frame->tf_rax = 0; /* Child returns zero */
1345 frame->tf_rflags &= ~PSL_C; /* success */
1346 frame->tf_rdx = 1;
1347
1348 generic_lwp_return(lp, frame);
1349 KTR_LOG(kernentry_fork_ret, lp->lwp_proc->p_pid, lp->lwp_tid);
d7f50089
YY
1350}
1351
1352/*
1353 * Simplified back end of syscall(), used when returning from fork()
2b0bd8aa
MD
1354 * directly into user mode.
1355 *
1356 * This code will return back into the fork trampoline code which then
1357 * runs doreti.
1358 *
1359 * NOTE: The mplock is not held at any point.
d7f50089
YY
1360 */
1361void
1362generic_lwp_return(struct lwp *lp, struct trapframe *frame)
1363{
c8fe38ae
MD
1364 struct proc *p = lp->lwp_proc;
1365
1366 /*
1367 * Newly forked processes are given a kernel priority. We have to
1368 * adjust the priority to a normal user priority and fake entry
1369 * into the kernel (call userenter()) to install a passive release
1370 * function just in case userret() decides to stop the process. This
1371 * can occur when ^Z races a fork. If we do not install the passive
1372 * release function the current process designation will not be
1373 * released when the thread goes to sleep.
1374 */
1375 lwkt_setpri_self(TDPRI_USER_NORM);
d86a23e0 1376 userenter(lp->lwp_thread, p);
c8fe38ae
MD
1377 userret(lp, frame, 0);
1378#ifdef KTRACE
1379 if (KTRPOINT(lp->lwp_thread, KTR_SYSRET))
1380 ktrsysret(lp, SYS_fork, 0, 0);
1381#endif
4643740a 1382 lp->lwp_flags |= LWP_PASSIVE_ACQ;
c8fe38ae 1383 userexit(lp);
4643740a 1384 lp->lwp_flags &= ~LWP_PASSIVE_ACQ;
d7f50089
YY
1385}
1386
1387/*
1388 * If PGEX_FPFAULT is set then set FP_VIRTFP in the PCB to force a T_DNA
1389 * fault (which is then passed back to the virtual kernel) if an attempt is
1390 * made to use the FP unit.
c8fe38ae 1391 *
d7f50089
YY
1392 * XXX this is a fairly big hack.
1393 */
1394void
1395set_vkernel_fp(struct trapframe *frame)
1396{
2deef24c
JG
1397 struct thread *td = curthread;
1398
1399 if (frame->tf_xflags & PGEX_FPFAULT) {
1400 td->td_pcb->pcb_flags |= FP_VIRTFP;
1401 if (mdcpu->gd_npxthread == td)
1402 npxexit();
1403 } else {
1404 td->td_pcb->pcb_flags &= ~FP_VIRTFP;
1405 }
d7f50089 1406}
bb47c072
MD
1407
1408/*
1409 * Called from vkernel_trap() to fixup the vkernel's syscall
1410 * frame for vmspace_ctl() return.
1411 */
1412void
1413cpu_vkernel_trap(struct trapframe *frame, int error)
1414{
1415 frame->tf_rax = error;
1416 if (error)
1417 frame->tf_rflags |= PSL_C;
1418 else
1419 frame->tf_rflags &= ~PSL_C;
1420}