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("$FreeBSD$");
44 * 386 Trap and System call handling
47 #include "opt_clock.h"
49 #include "opt_hwpmc_hooks.h"
52 #include "opt_kdtrace.h"
56 #include <sys/param.h>
58 #include <sys/systm.h>
60 #include <sys/pioctl.h>
61 #include <sys/ptrace.h>
63 #include <sys/kernel.h>
66 #include <sys/mutex.h>
67 #include <sys/resourcevar.h>
68 #include <sys/signalvar.h>
69 #include <sys/syscall.h>
70 #include <sys/sysctl.h>
71 #include <sys/sysent.h>
73 #include <sys/vmmeter.h>
75 #include <sys/pmckern.h>
76 PMC_SOFT_DEFINE( , , page_fault, all);
77 PMC_SOFT_DEFINE( , , page_fault, read);
78 PMC_SOFT_DEFINE( , , page_fault, write);
80 #include <security/audit/audit.h>
83 #include <vm/vm_param.h>
85 #include <vm/vm_kern.h>
86 #include <vm/vm_map.h>
87 #include <vm/vm_page.h>
88 #include <vm/vm_extern.h>
90 #include <machine/cpu.h>
91 #include <machine/intr_machdep.h>
93 #include <machine/md_var.h>
94 #include <machine/pcb.h>
96 #include <machine/smp.h>
98 #include <machine/tss.h>
99 #include <machine/vm86.h>
102 #include <sys/syslog.h>
103 #include <machine/clock.h>
107 #include <sys/dtrace_bsd.h>
110 extern void trap(struct trapframe *frame);
111 extern void syscall(struct trapframe *frame);
113 static int trap_pfault(struct trapframe *, int, vm_offset_t);
114 static void trap_fatal(struct trapframe *, vm_offset_t);
115 void dblfault_handler(void);
117 extern inthand_t IDTVEC(lcall_syscall);
119 #define MAX_TRAP_MSG 32
120 static char *trap_msg[] = {
122 "privileged instruction fault", /* 1 T_PRIVINFLT */
124 "breakpoint instruction fault", /* 3 T_BPTFLT */
127 "arithmetic trap", /* 6 T_ARITHTRAP */
130 "general protection fault", /* 9 T_PROTFLT */
131 "trace trap", /* 10 T_TRCTRAP */
133 "page fault", /* 12 T_PAGEFLT */
135 "alignment fault", /* 14 T_ALIGNFLT */
139 "integer divide fault", /* 18 T_DIVIDE */
140 "non-maskable interrupt trap", /* 19 T_NMI */
141 "overflow trap", /* 20 T_OFLOW */
142 "FPU bounds check fault", /* 21 T_BOUND */
143 "FPU device not available", /* 22 T_DNA */
144 "double fault", /* 23 T_DOUBLEFLT */
145 "FPU operand fetch fault", /* 24 T_FPOPFLT */
146 "invalid TSS fault", /* 25 T_TSSFLT */
147 "segment not present fault", /* 26 T_SEGNPFLT */
148 "stack fault", /* 27 T_STKFLT */
149 "machine check trap", /* 28 T_MCHK */
150 "SIMD floating-point exception", /* 29 T_XMMFLT */
151 "reserved (unknown) fault", /* 30 T_RESERVED */
152 "", /* 31 unused (reserved) */
153 "DTrace pid return trap", /* 32 T_DTRACE_RET */
156 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
157 int has_f00f_bug = 0; /* Initialized so that it can be patched. */
161 static int kdb_on_nmi = 1;
162 SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RW,
163 &kdb_on_nmi, 0, "Go to KDB on NMI");
164 TUNABLE_INT("machdep.kdb_on_nmi", &kdb_on_nmi);
166 static int panic_on_nmi = 1;
167 SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW,
168 &panic_on_nmi, 0, "Panic on NMI");
169 TUNABLE_INT("machdep.panic_on_nmi", &panic_on_nmi);
170 static int prot_fault_translation = 0;
171 SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW,
172 &prot_fault_translation, 0, "Select signal to deliver on protection fault");
173 static int uprintf_signal;
174 SYSCTL_INT(_machdep, OID_AUTO, uprintf_signal, CTLFLAG_RW,
176 "Print debugging information on trap signal to ctty");
179 * Exception, fault, and trap interface to the FreeBSD kernel.
180 * This common code is called from assembly language IDT gate entry
181 * routines that prepare a suitable stack frame, and restore this
182 * frame after the exception has been processed.
186 trap(struct trapframe *frame)
191 struct thread *td = curthread;
192 struct proc *p = td->td_proc;
193 int i = 0, ucode = 0, code;
199 static int lastalert = 0;
202 PCPU_INC(cnt.v_trap);
203 type = frame->tf_trapno;
206 /* Handler for NMI IPIs used for stopping CPUs. */
208 if (ipi_nmi_handler() == 0)
220 if (type == T_RESERVED) {
221 trap_fatal(frame, 0);
227 * CPU PMCs interrupt using an NMI so we check for that first.
228 * If the HWPMC module is active, 'pmc_hook' will point to
229 * the function to be called. A return value of '1' from the
230 * hook means that the NMI was handled by it and that we can
231 * return immediately.
233 if (type == T_NMI && pmc_intr &&
234 (*pmc_intr)(PCPU_GET(cpuid), frame))
238 if (type == T_MCHK) {
245 * A trap can occur while DTrace executes a probe. Before
246 * executing the probe, DTrace blocks re-scheduling and sets
247 * a flag in its per-cpu flags to indicate that it doesn't
248 * want to fault. On returning from the probe, the no-fault
249 * flag is cleared and finally re-scheduling is enabled.
251 if ((type == T_PROTFLT || type == T_PAGEFLT) &&
252 dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
256 if ((frame->tf_eflags & PSL_I) == 0) {
258 * Buggy application or kernel code has disabled
259 * interrupts and then trapped. Enabling interrupts
260 * now is wrong, but it is better than running with
261 * interrupts disabled until they are accidentally
264 if (ISPL(frame->tf_cs) == SEL_UPL || (frame->tf_eflags & PSL_VM))
266 "pid %ld (%s): trap %d with interrupts disabled\n",
267 (long)curproc->p_pid, curthread->td_name, type);
268 else if (type != T_NMI && type != T_BPTFLT &&
270 frame->tf_eip != (int)cpu_switch_load_gs) {
272 * XXX not quite right, since this may be for a
273 * multiple fault in user mode.
275 printf("kernel trap %d with interrupts disabled\n",
278 * Page faults need interrupts disabled until later,
279 * and we shouldn't enable interrupts while holding
282 if (type != T_PAGEFLT &&
283 td->td_md.md_spinlock_count == 0)
288 code = frame->tf_err;
289 if (type == T_PAGEFLT) {
291 * For some Cyrix CPUs, %cr2 is clobbered by
292 * interrupts. This problem is worked around by using
293 * an interrupt gate for the pagefault handler. We
294 * are finally ready to read %cr2 and conditionally
295 * reenable interrupts. If we hold a spin lock, then
296 * we must not reenable interrupts. This might be a
297 * spurious page fault.
300 if (td->td_md.md_spinlock_count == 0)
304 if ((ISPL(frame->tf_cs) == SEL_UPL) ||
305 ((frame->tf_eflags & PSL_VM) &&
306 !(curpcb->pcb_flags & PCB_VM86CALL))) {
310 td->td_frame = frame;
311 addr = frame->tf_eip;
312 if (td->td_ucred != p->p_ucred)
313 cred_update_thread(td);
316 case T_PRIVINFLT: /* privileged instruction fault */
321 case T_BPTFLT: /* bpt instruction fault */
322 case T_TRCTRAP: /* trace trap */
325 if (type == T_BPTFLT) {
326 fill_frame_regs(frame, ®s);
327 if (dtrace_pid_probe_ptr != NULL &&
328 dtrace_pid_probe_ptr(®s) == 0)
332 frame->tf_eflags &= ~PSL_T;
334 ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
337 case T_ARITHTRAP: /* arithmetic trap */
339 ucode = npxtrap_x87();
349 * The following two traps can happen in
350 * vm86 mode, and, if so, we want to handle
353 case T_PROTFLT: /* general protection fault */
354 case T_STKFLT: /* stack fault */
355 if (frame->tf_eflags & PSL_VM) {
356 i = vm86_emulate((struct vm86frame *)frame);
362 ucode = (type == T_PROTFLT) ? BUS_OBJERR : BUS_ADRERR;
364 case T_SEGNPFLT: /* segment not present fault */
368 case T_TSSFLT: /* invalid TSS fault */
376 case T_DOUBLEFLT: /* double fault */
382 case T_PAGEFLT: /* page fault */
384 i = trap_pfault(frame, TRUE, eva);
385 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
388 * The f00f hack workaround has triggered, so
389 * treat the fault as an illegal instruction
390 * (T_PRIVINFLT) instead of a page fault.
392 type = frame->tf_trapno = T_PRIVINFLT;
394 /* Proceed as in that case. */
408 if (prot_fault_translation == 0) {
411 * This check also covers the images
412 * without the ABI-tag ELF note.
414 if (SV_CURPROC_ABI() == SV_ABI_FREEBSD
415 && p->p_osrel >= P_OSREL_SIGSEGV) {
420 ucode = BUS_PAGE_FAULT;
422 } else if (prot_fault_translation == 1) {
424 * Always compat mode.
427 ucode = BUS_PAGE_FAULT;
430 * Always SIGSEGV mode.
439 case T_DIVIDE: /* integer divide fault */
448 # define TIMER_FREQ 1193182
450 if (time_second - lastalert > 10) {
451 log(LOG_WARNING, "NMI: power fail\n");
453 lastalert = time_second;
456 #else /* !POWERFAIL_NMI */
457 /* machine/parity/power fail/"kitchen sink" faults */
458 if (isa_nmi(code) == 0) {
461 * NMI can be hooked up to a pushbutton
465 printf ("NMI ... going to debugger\n");
466 kdb_trap(type, 0, frame);
470 } else if (panic_on_nmi)
471 panic("NMI indicates hardware failure");
473 #endif /* POWERFAIL_NMI */
476 case T_OFLOW: /* integer overflow fault */
481 case T_BOUND: /* bounds check fault */
488 KASSERT(PCB_USER_FPU(td->td_pcb),
489 ("kernel FPU ctx has leaked"));
490 /* transparent fault (due to context switch "late") */
494 uprintf("pid %d killed due to lack of floating point\n",
500 case T_FPOPFLT: /* FPU operand fetch fault */
505 case T_XMMFLT: /* SIMD floating-point exception */
506 #if defined(DEV_NPX) && !defined(CPU_DISABLE_SSE) && defined(I686_CPU)
507 ucode = npxtrap_sse();
518 fill_frame_regs(frame, ®s);
519 if (dtrace_return_probe_ptr != NULL &&
520 dtrace_return_probe_ptr(®s) == 0)
528 KASSERT(cold || td->td_ucred != NULL,
529 ("kernel trap doesn't have ucred"));
531 case T_PAGEFLT: /* page fault */
532 (void) trap_pfault(frame, FALSE, eva);
537 KASSERT(!PCB_USER_FPU(td->td_pcb),
538 ("Unregistered use of FPU in kernel"));
544 case T_ARITHTRAP: /* arithmetic trap */
545 case T_XMMFLT: /* SIMD floating-point exception */
546 case T_FPOPFLT: /* FPU operand fetch fault */
548 * XXXKIB for now disable any FPU traps in kernel
549 * handler registration seems to be overkill
551 trap_fatal(frame, 0);
555 * The following two traps can happen in
556 * vm86 mode, and, if so, we want to handle
559 case T_PROTFLT: /* general protection fault */
560 case T_STKFLT: /* stack fault */
561 if (frame->tf_eflags & PSL_VM) {
562 i = vm86_emulate((struct vm86frame *)frame);
565 * returns to original process
567 vm86_trap((struct vm86frame *)frame);
570 if (type == T_STKFLT)
575 case T_SEGNPFLT: /* segment not present fault */
576 if (curpcb->pcb_flags & PCB_VM86CALL)
580 * Invalid %fs's and %gs's can be created using
581 * procfs or PT_SETREGS or by invalidating the
582 * underlying LDT entry. This causes a fault
583 * in kernel mode when the kernel attempts to
584 * switch contexts. Lose the bad context
585 * (XXX) so that we can continue, and generate
588 if (frame->tf_eip == (int)cpu_switch_load_gs) {
592 kern_psignal(p, SIGBUS);
598 if (td->td_intr_nesting_level != 0)
602 * Invalid segment selectors and out of bounds
603 * %eip's and %esp's can be set up in user mode.
604 * This causes a fault in kernel mode when the
605 * kernel tries to return to user mode. We want
606 * to get this fault so that we can fix the
607 * problem here and not have to check all the
608 * selectors and pointers when the user changes
611 if (frame->tf_eip == (int)doreti_iret) {
612 frame->tf_eip = (int)doreti_iret_fault;
615 if (frame->tf_eip == (int)doreti_popl_ds) {
616 frame->tf_eip = (int)doreti_popl_ds_fault;
619 if (frame->tf_eip == (int)doreti_popl_es) {
620 frame->tf_eip = (int)doreti_popl_es_fault;
623 if (frame->tf_eip == (int)doreti_popl_fs) {
624 frame->tf_eip = (int)doreti_popl_fs_fault;
627 if (curpcb->pcb_onfault != NULL) {
629 (int)curpcb->pcb_onfault;
636 * PSL_NT can be set in user mode and isn't cleared
637 * automatically when the kernel is entered. This
638 * causes a TSS fault when the kernel attempts to
639 * `iret' because the TSS link is uninitialized. We
640 * want to get this fault so that we can fix the
641 * problem here and not every time the kernel is
644 if (frame->tf_eflags & PSL_NT) {
645 frame->tf_eflags &= ~PSL_NT;
650 case T_TRCTRAP: /* trace trap */
651 if (frame->tf_eip == (int)IDTVEC(lcall_syscall)) {
653 * We've just entered system mode via the
654 * syscall lcall. Continue single stepping
655 * silently until the syscall handler has
660 if (frame->tf_eip == (int)IDTVEC(lcall_syscall) + 1) {
662 * The syscall handler has now saved the
663 * flags. Stop single stepping it.
665 frame->tf_eflags &= ~PSL_T;
669 * Ignore debug register trace traps due to
670 * accesses in the user's address space, which
671 * can happen under several conditions such as
672 * if a user sets a watchpoint on a buffer and
673 * then passes that buffer to a system call.
674 * We still want to get TRCTRAPS for addresses
675 * in kernel space because that is useful when
676 * debugging the kernel.
678 if (user_dbreg_trap() &&
679 !(curpcb->pcb_flags & PCB_VM86CALL)) {
681 * Reset breakpoint bits because the
684 load_dr6(rdr6() & 0xfffffff0);
688 * FALLTHROUGH (TRCTRAP kernel mode, kernel address)
692 * If KDB is enabled, let it handle the debugger trap.
693 * Otherwise, debugger traps "can't happen".
696 if (kdb_trap(type, 0, frame))
704 if (time_second - lastalert > 10) {
705 log(LOG_WARNING, "NMI: power fail\n");
707 lastalert = time_second;
710 #else /* !POWERFAIL_NMI */
711 /* machine/parity/power fail/"kitchen sink" faults */
712 if (isa_nmi(code) == 0) {
715 * NMI can be hooked up to a pushbutton
719 printf ("NMI ... going to debugger\n");
720 kdb_trap(type, 0, frame);
724 } else if (panic_on_nmi == 0)
727 #endif /* POWERFAIL_NMI */
731 trap_fatal(frame, eva);
735 /* Translate fault for emulators (e.g. Linux) */
736 if (*p->p_sysent->sv_transtrap)
737 i = (*p->p_sysent->sv_transtrap)(i, type);
739 ksiginfo_init_trap(&ksi);
741 ksi.ksi_code = ucode;
742 ksi.ksi_addr = (void *)addr;
743 ksi.ksi_trapno = type;
744 if (uprintf_signal) {
745 uprintf("pid %d comm %s: signal %d err %x code %d type %d "
746 "addr 0x%x esp 0x%08x eip 0x%08x "
747 "<%02x %02x %02x %02x %02x %02x %02x %02x>\n",
748 p->p_pid, p->p_comm, i, frame->tf_err, ucode, type, addr,
749 frame->tf_esp, frame->tf_eip,
750 fubyte((void *)(frame->tf_eip + 0)),
751 fubyte((void *)(frame->tf_eip + 1)),
752 fubyte((void *)(frame->tf_eip + 2)),
753 fubyte((void *)(frame->tf_eip + 3)),
754 fubyte((void *)(frame->tf_eip + 4)),
755 fubyte((void *)(frame->tf_eip + 5)),
756 fubyte((void *)(frame->tf_eip + 6)),
757 fubyte((void *)(frame->tf_eip + 7)));
759 KASSERT((read_eflags() & PSL_I) != 0, ("interrupts disabled"));
760 trapsignal(td, &ksi);
763 if (type <= MAX_TRAP_MSG) {
764 uprintf("fatal process exception: %s",
766 if ((type == T_PAGEFLT) || (type == T_PROTFLT))
767 uprintf(", fault VA = 0x%lx", (u_long)eva);
774 KASSERT(PCB_USER_FPU(td->td_pcb),
775 ("Return from trap with kernel FPU ctx leaked"));
782 trap_pfault(frame, usermode, eva)
783 struct trapframe *frame;
792 struct thread *td = curthread;
793 struct proc *p = td->td_proc;
795 if (__predict_false((td->td_pflags & TDP_NOFAULTING) != 0)) {
797 * Due to both processor errata and lazy TLB invalidation when
798 * access restrictions are removed from virtual pages, memory
799 * accesses that are allowed by the physical mapping layer may
800 * nonetheless cause one spurious page fault per virtual page.
801 * When the thread is executing a "no faulting" section that
802 * is bracketed by vm_fault_{disable,enable}_pagefaults(),
803 * every page fault is treated as a spurious page fault,
804 * unless it accesses the same virtual address as the most
805 * recent page fault within the same "no faulting" section.
807 if (td->td_md.md_spurflt_addr != eva ||
808 (td->td_pflags & TDP_RESETSPUR) != 0) {
810 * Do nothing to the TLB. A stale TLB entry is
811 * flushed automatically by a page fault.
813 td->td_md.md_spurflt_addr = eva;
814 td->td_pflags &= ~TDP_RESETSPUR;
819 * If we get a page fault while in a critical section, then
820 * it is most likely a fatal kernel page fault. The kernel
821 * is already going to panic trying to get a sleep lock to
822 * do the VM lookup, so just consider it a fatal trap so the
823 * kernel can print out a useful trap message and even get
826 * If we get a page fault while holding a non-sleepable
827 * lock, then it is most likely a fatal kernel page fault.
828 * If WITNESS is enabled, then it's going to whine about
829 * bogus LORs with various VM locks, so just skip to the
830 * fatal trap handling directly.
832 if (td->td_critnest != 0 ||
833 WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL,
834 "Kernel page fault") != 0) {
835 trap_fatal(frame, eva);
839 va = trunc_page(eva);
840 if (va >= KERNBASE) {
842 * Don't allow user-mode faults in kernel address space.
843 * An exception: if the faulting address is the invalid
844 * instruction entry in the IDT, then the Intel Pentium
845 * F00F bug workaround was triggered, and we need to
846 * treat it is as an illegal instruction, and not a page
849 #if defined(I586_CPU) && !defined(NO_F00F_HACK)
850 if ((eva == (unsigned int)&idt[6]) && has_f00f_bug)
859 * This is a fault on non-kernel virtual memory. If either
860 * p or p->p_vmspace is NULL, then the fault is fatal.
862 if (p == NULL || (vm = p->p_vmspace) == NULL)
868 * When accessing a user-space address, kernel must be
869 * ready to accept the page fault, and provide a
870 * handling routine. Since accessing the address
871 * without the handler is a bug, do not try to handle
872 * it normally, and panic immediately.
874 if (!usermode && (td->td_intr_nesting_level != 0 ||
875 curpcb->pcb_onfault == NULL)) {
876 trap_fatal(frame, eva);
882 * PGEX_I is defined only if the execute disable bit capability is
883 * supported and enabled.
885 if (frame->tf_err & PGEX_W)
886 ftype = VM_PROT_WRITE;
887 #if defined(PAE) || defined(PAE_TABLES)
888 else if ((frame->tf_err & PGEX_I) && pg_nx != 0)
889 ftype = VM_PROT_EXECUTE;
892 ftype = VM_PROT_READ;
894 if (map != kernel_map) {
896 * Keep swapout from messing with us during this
903 /* Fault in the user page: */
904 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
911 * Don't have to worry about process locking or stacks in the
914 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
916 if (rv == KERN_SUCCESS) {
918 if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) {
919 PMC_SOFT_CALL_TF( , , page_fault, all, frame);
920 if (ftype == VM_PROT_READ)
921 PMC_SOFT_CALL_TF( , , page_fault, read,
924 PMC_SOFT_CALL_TF( , , page_fault, write,
932 if (td->td_intr_nesting_level == 0 &&
933 curpcb->pcb_onfault != NULL) {
934 frame->tf_eip = (int)curpcb->pcb_onfault;
937 trap_fatal(frame, eva);
940 return ((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
944 trap_fatal(frame, eva)
945 struct trapframe *frame;
950 struct soft_segment_descriptor softseg;
953 code = frame->tf_err;
954 type = frame->tf_trapno;
955 sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg);
957 if (type <= MAX_TRAP_MSG)
958 msg = trap_msg[type];
961 printf("\n\nFatal trap %d: %s while in %s mode\n", type, msg,
962 frame->tf_eflags & PSL_VM ? "vm86" :
963 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
965 /* two separate prints in case of a trap on an unmapped page */
966 printf("cpuid = %d; ", PCPU_GET(cpuid));
967 printf("apic id = %02x\n", PCPU_GET(apic_id));
969 if (type == T_PAGEFLT) {
970 printf("fault virtual address = 0x%x\n", eva);
971 printf("fault code = %s %s, %s\n",
972 code & PGEX_U ? "user" : "supervisor",
973 code & PGEX_W ? "write" : "read",
974 code & PGEX_P ? "protection violation" : "page not present");
976 printf("instruction pointer = 0x%x:0x%x\n",
977 frame->tf_cs & 0xffff, frame->tf_eip);
978 if ((ISPL(frame->tf_cs) == SEL_UPL) || (frame->tf_eflags & PSL_VM)) {
979 ss = frame->tf_ss & 0xffff;
982 ss = GSEL(GDATA_SEL, SEL_KPL);
983 esp = (int)&frame->tf_esp;
985 printf("stack pointer = 0x%x:0x%x\n", ss, esp);
986 printf("frame pointer = 0x%x:0x%x\n", ss, frame->tf_ebp);
987 printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n",
988 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
989 printf(" = DPL %d, pres %d, def32 %d, gran %d\n",
990 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32,
992 printf("processor eflags = ");
993 if (frame->tf_eflags & PSL_T)
994 printf("trace trap, ");
995 if (frame->tf_eflags & PSL_I)
996 printf("interrupt enabled, ");
997 if (frame->tf_eflags & PSL_NT)
998 printf("nested task, ");
999 if (frame->tf_eflags & PSL_RF)
1001 if (frame->tf_eflags & PSL_VM)
1003 printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12);
1004 printf("current process = %d (%s)\n",
1005 curproc->p_pid, curthread->td_name);
1008 if (debugger_on_panic || kdb_active) {
1009 frame->tf_err = eva; /* smuggle fault address to ddb */
1010 if (kdb_trap(type, 0, frame)) {
1011 frame->tf_err = code; /* restore error code */
1014 frame->tf_err = code; /* restore error code */
1017 printf("trap number = %d\n", type);
1018 if (type <= MAX_TRAP_MSG)
1019 panic("%s", trap_msg[type]);
1021 panic("unknown/reserved trap");
1025 * Double fault handler. Called when a fault occurs while writing
1026 * a frame for a trap/exception onto the stack. This usually occurs
1027 * when the stack overflows (such is the case with infinite recursion,
1030 * XXX Note that the current PTD gets replaced by IdlePTD when the
1031 * task switch occurs. This means that the stack that was active at
1032 * the time of the double fault is not available at <kstack> unless
1033 * the machine was idle when the double fault occurred. The downside
1034 * of this is that "trace <ebp>" in ddb won't work.
1039 #ifdef KDTRACE_HOOKS
1040 if (dtrace_doubletrap_func != NULL)
1041 (*dtrace_doubletrap_func)();
1043 printf("\nFatal double fault:\n");
1044 printf("eip = 0x%x\n", PCPU_GET(common_tss.tss_eip));
1045 printf("esp = 0x%x\n", PCPU_GET(common_tss.tss_esp));
1046 printf("ebp = 0x%x\n", PCPU_GET(common_tss.tss_ebp));
1048 /* two separate prints in case of a trap on an unmapped page */
1049 printf("cpuid = %d; ", PCPU_GET(cpuid));
1050 printf("apic id = %02x\n", PCPU_GET(apic_id));
1052 panic("double fault");
1056 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
1059 struct trapframe *frame;
1065 frame = td->td_frame;
1067 params = (caddr_t)frame->tf_esp + sizeof(int);
1068 sa->code = frame->tf_eax;
1071 * Need to check if this is a 32 bit or 64 bit syscall.
1073 if (sa->code == SYS_syscall) {
1075 * Code is first argument, followed by actual args.
1077 error = fueword(params, &tmp);
1081 params += sizeof(int);
1082 } else if (sa->code == SYS___syscall) {
1084 * Like syscall, but code is a quad, so as to maintain
1085 * quad alignment for the rest of the arguments.
1087 error = fueword(params, &tmp);
1091 params += sizeof(quad_t);
1094 if (p->p_sysent->sv_mask)
1095 sa->code &= p->p_sysent->sv_mask;
1096 if (sa->code >= p->p_sysent->sv_size)
1097 sa->callp = &p->p_sysent->sv_table[0];
1099 sa->callp = &p->p_sysent->sv_table[sa->code];
1100 sa->narg = sa->callp->sy_narg;
1102 if (params != NULL && sa->narg != 0)
1103 error = copyin(params, (caddr_t)sa->args,
1104 (u_int)(sa->narg * sizeof(int)));
1109 td->td_retval[0] = 0;
1110 td->td_retval[1] = frame->tf_edx;
1116 #include "../../kern/subr_syscall.c"
1119 * syscall - system call request C handler. A system call is
1120 * essentially treated as a trap by reusing the frame layout.
1123 syscall(struct trapframe *frame)
1126 struct syscall_args sa;
1127 register_t orig_tf_eflags;
1132 if (ISPL(frame->tf_cs) != SEL_UPL) {
1137 orig_tf_eflags = frame->tf_eflags;
1140 td->td_frame = frame;
1142 error = syscallenter(td, &sa);
1147 if ((orig_tf_eflags & PSL_T) && !(orig_tf_eflags & PSL_VM)) {
1148 frame->tf_eflags &= ~PSL_T;
1149 ksiginfo_init_trap(&ksi);
1150 ksi.ksi_signo = SIGTRAP;
1151 ksi.ksi_code = TRAP_TRACE;
1152 ksi.ksi_addr = (void *)frame->tf_eip;
1153 trapsignal(td, &ksi);
1156 KASSERT(PCB_USER_FPU(td->td_pcb),
1157 ("System call %s returning with kernel FPU ctx leaked",
1158 syscallname(td->td_proc, sa.code)));
1159 KASSERT(td->td_pcb->pcb_save == get_pcb_user_save_td(td),
1160 ("System call %s returning with mangled pcb_save",
1161 syscallname(td->td_proc, sa.code)));
1163 syscallret(td, error, &sa);