/* $OpenBSD: trap.c,v 1.13 2007/05/11 10:06:55 pedro Exp $ */
/* $NetBSD: trap.c,v 1.2 2003/05/04 23:51:56 fvdl Exp $ */
/*-
* Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)trap.c 7.4 (Berkeley) 5/13/91
*/
/*
* amd64 Trap and System call handling
*/
#undef TRAP_SIGDEBUG
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/acct.h>
#include <sys/kernel.h>
#include <sys/signal.h>
#include <sys/syscall.h>
#include <sys/reboot.h>
#include <sys/pool.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/fpu.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/trap.h>
#include <machine/userret.h>
#ifdef DDB
#include <machine/db_machdep.h>
#endif
#include "isa.h"
#ifdef KGDB
#include <sys/kgdb.h>
#endif
void trap(struct trapframe);
const char *trap_type[] = {
"privileged instruction fault", /* 0 T_PRIVINFLT */
"breakpoint trap", /* 1 T_BPTFLT */
"arithmetic trap", /* 2 T_ARITHTRAP */
"asynchronous system trap", /* 3 T_ASTFLT */
"protection fault", /* 4 T_PROTFLT */
"trace trap", /* 5 T_TRCTRAP */
"page fault", /* 6 T_PAGEFLT */
"alignment fault", /* 7 T_ALIGNFLT */
"integer divide fault", /* 8 T_DIVIDE */
"non-maskable interrupt", /* 9 T_NMI */
"overflow trap", /* 10 T_OFLOW */
"bounds check fault", /* 11 T_BOUND */
"FPU not available fault", /* 12 T_DNA */
"double fault", /* 13 T_DOUBLEFLT */
"FPU operand fetch fault", /* 14 T_FPOPFLT */
"invalid TSS fault", /* 15 T_TSSFLT */
"segment not present fault", /* 16 T_SEGNPFLT */
"stack fault", /* 17 T_STKFLT */
"machine check", /* 18 T_MCA */
"SSE FP exception", /* 19 T_XMM */
"reserved trap", /* 20 T_RESERVED */
};
int trap_types = sizeof trap_type / sizeof trap_type[0];
#ifdef DEBUG
int trapdebug = 0;
#endif
#define IDTVEC(name) __CONCAT(X, name)
#ifdef TRAP_SIGDEBUG
static void frame_dump(struct trapframe *);
#endif
/*
* trap(frame):
* Exception, fault, and trap interface to BSD kernel. This
* common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed. Note that the
* effect is as if the arguments were passed call by reference.
*/
/*ARGSUSED*/
void
trap(struct trapframe frame)
{
struct proc *p = curproc;
int type = (int)frame.tf_trapno;
struct pcb *pcb;
extern char resume_iret[], IDTVEC(oosyscall)[];
#if 0
extern char resume_pop_ds[], resume_pop_es[];
#endif
struct trapframe *vframe;
void *resume;
caddr_t onfault;
int error;
uint64_t cr2;
union sigval sv;
uvmexp.traps++;
pcb = (p != NULL && p->p_addr != NULL) ? &p->p_addr->u_pcb : NULL;
#ifdef DEBUG
if (trapdebug) {
printf("trap %d code %lx eip %lx cs %lx rflags %lx cr2 %lx "
"cpl %x\n",
type, frame.tf_err, frame.tf_rip, frame.tf_cs,
frame.tf_rflags, rcr2(), curcpu()->ci_ilevel);
printf("curproc %p\n", curproc);
if (curproc)
printf("pid %d\n", p->p_pid);
}
#endif
if (!KERNELMODE(frame.tf_cs, frame.tf_rflags)) {
type |= T_USER;
p->p_md.md_regs = &frame;
}
switch (type) {
default:
we_re_toast:
#ifdef KGDB
if (kgdb_trap(type, &frame))
return;
else {
/*
* If this is a breakpoint, don't panic
* if we're not connected.
*/
if (type == T_BPTFLT) {
printf("kgdb: ignored %s\n", trap_type[type]);
return;
}
}
#endif
#ifdef DDB
if (kdb_trap(type, 0, &frame))
return;
#endif
if (frame.tf_trapno < trap_types)
printf("fatal %s", trap_type[frame.tf_trapno]);
else
printf("unknown trap %ld", (u_long)frame.tf_trapno);
printf(" in %s mode\n", (type & T_USER) ? "user" : "supervisor");
printf("trap type %d code %lx rip %lx cs %lx rflags %lx cr2 "
" %lx cpl %x rsp %lx\n",
type, frame.tf_err, (u_long)frame.tf_rip, frame.tf_cs,
frame.tf_rflags, rcr2(), curcpu()->ci_ilevel, frame.tf_rsp);
/* panic("trap"); */
boot(RB_HALT);
/*NOTREACHED*/
case T_PROTFLT:
case T_SEGNPFLT:
case T_ALIGNFLT:
case T_TSSFLT:
if (p == NULL)
goto we_re_toast;
/* Check for copyin/copyout fault. */
if (pcb->pcb_onfault != 0) {
error = EFAULT;
copyfault:
frame.tf_rip = (u_int64_t)pcb->pcb_onfault;
frame.tf_rax = error;
return;
}
/*
* Check for failure during return to user mode.
*
* XXXfvdl check for rex prefix?
*
* We do this by looking at the instruction we faulted on. The
* specific instructions we recognize only happen when
* returning from a trap, syscall, or interrupt.
*
* XXX
* The heuristic used here will currently fail for the case of
* one of the 2 pop instructions faulting when returning from a
* a fast interrupt. This should not be possible. It can be
* fixed by rearranging the trap frame so that the stack format
* at this point is the same as on exit from a `slow'
* interrupt.
*/
switch (*(u_char *)frame.tf_rip) {
case 0xcf: /* iret */
vframe = (void *)((u_int64_t)&frame.tf_rsp - 44);
resume = resume_iret;
break;
/*
* XXXfvdl these are illegal in long mode (not in compat mode, though)
* and we do not take back the descriptors from the signal context anyway,
* but may do so later for USER_LDT, in which case we need to intercept
* other instructions (movl %eax, %Xs).
*/
#if 0
case 0x1f: /* popl %ds */
vframe = (void *)((u_int64_t)&frame.tf_rsp - 4);
resume = resume_pop_ds;
break;
case 0x07: /* popl %es */
vframe = (void *)((u_int64_t)&frame.tf_rsp - 0);
resume = resume_pop_es;
break;
#endif
default:
goto we_re_toast;
}
if (KERNELMODE(vframe->tf_cs, vframe->tf_rflags))
goto we_re_toast;
frame.tf_rip = (u_int64_t)resume;
return;
case T_PROTFLT|T_USER: /* protection fault */
case T_TSSFLT|T_USER:
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_NMI|T_USER:
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): BUS at rip %lx addr %lx\n",
p->p_pid, p->p_comm, frame.tf_rip, rcr2());
frame_dump(&frame);
#endif
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGBUS, type & ~T_USER, BUS_OBJERR, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_ALIGNFLT|T_USER:
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGBUS, type & ~T_USER, BUS_ADRALN, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGILL, type & ~T_USER, ILL_PRVOPC, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): ILL at rip %lx addr %lx\n",
p->p_pid, p->p_comm, frame.tf_rip, rcr2());
frame_dump(&frame);
#endif
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGILL, type & ~T_USER, ILL_COPROC, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_ASTFLT|T_USER: /* Allow process switch */
uvmexp.softs++;
if (p->p_flag & P_OWEUPC) {
KERNEL_PROC_LOCK(p);
ADDUPROF(p);
KERNEL_PROC_UNLOCK(p);
}
/* Allow a forced task switch. */
if (curcpu()->ci_want_resched)
preempt(NULL);
goto out;
case T_BOUND|T_USER:
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGFPE, type &~ T_USER, FPE_FLTSUB, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_OFLOW|T_USER:
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGFPE, type &~ T_USER, FPE_INTOVF, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_DIVIDE|T_USER:
sv.sival_ptr = (void *)frame.tf_rip;
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGFPE, type &~ T_USER, FPE_INTDIV, sv);
KERNEL_PROC_UNLOCK(p);
goto out;
case T_ARITHTRAP|T_USER:
case T_XMM|T_USER:
fputrap(&frame);
goto out;
case T_PAGEFLT: /* allow page faults in kernel mode */
if (p == NULL)
goto we_re_toast;
#ifdef MULTIPROCESSOR
if ((p->p_flag & P_BIGLOCK) == 0)
goto we_re_toast;
#endif
cr2 = rcr2();
KERNEL_LOCK();
goto faultcommon;
case T_PAGEFLT|T_USER: { /* page fault */
vaddr_t va, fa;
struct vmspace *vm;
struct vm_map *map;
vm_prot_t ftype;
extern struct vm_map *kernel_map;
cr2 = rcr2();
KERNEL_PROC_LOCK(p);
faultcommon:
vm = p->p_vmspace;
if (vm == NULL)
goto we_re_toast;
fa = cr2;
va = trunc_page((vaddr_t)cr2);
/*
* It is only a kernel address space fault iff:
* 1. (type & T_USER) == 0 and
* 2. pcb_onfault not set or
* 3. pcb_onfault set but supervisor space fault
* The last can occur during an exec() copyin where the
* argument space is lazy-allocated.
*/
if (type == T_PAGEFLT && va >= VM_MIN_KERNEL_ADDRESS)
map = kernel_map;
else
map = &vm->vm_map;
if (frame.tf_err & PGEX_W)
ftype = VM_PROT_WRITE;
else if (frame.tf_err & PGEX_I)
ftype = VM_PROT_EXECUTE;
else
ftype = VM_PROT_READ;
#ifdef DIAGNOSTIC
if (map == kernel_map && va == 0) {
printf("trap: bad kernel access at %lx\n", va);
goto we_re_toast;
}
#endif
/* Fault the original page in. */
onfault = pcb->pcb_onfault;
pcb->pcb_onfault = NULL;
error = uvm_fault(map, va, frame.tf_err & PGEX_P?
VM_FAULT_PROTECT : VM_FAULT_INVALID, ftype);
pcb->pcb_onfault = onfault;
if (error == 0) {
if (map != kernel_map)
uvm_grow(p, va);
if (type == T_PAGEFLT) {
KERNEL_UNLOCK();
return;
}
KERNEL_PROC_UNLOCK(p);
goto out;
}
if (error == EACCES) {
error = EFAULT;
}
if (type == T_PAGEFLT) {
if (pcb->pcb_onfault != 0) {
KERNEL_UNLOCK();
goto copyfault;
}
printf("uvm_fault(%p, 0x%lx, 0, %d) -> %x\n",
map, va, ftype, error);
goto we_re_toast;
}
if (error == ENOMEM) {
printf("UVM: pid %d (%s), uid %d killed: out of swap\n",
p->p_pid, p->p_comm,
p->p_cred && p->p_ucred ?
(int)p->p_ucred->cr_uid : -1);
sv.sival_ptr = (void *)fa;
trapsignal(p, SIGKILL, T_PAGEFLT, SEGV_MAPERR, sv);
} else {
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): SEGV at rip %lx addr %lx\n",
p->p_pid, p->p_comm, frame.tf_rip, va);
frame_dump(&frame);
#endif
sv.sival_ptr = (void *)fa;
trapsignal(p, SIGSEGV, T_PAGEFLT, SEGV_MAPERR, sv);
}
if (type == T_PAGEFLT)
KERNEL_UNLOCK();
else
KERNEL_PROC_UNLOCK(p);
break;
}
case T_TRCTRAP:
/* Check whether they single-stepped into a lcall. */
if (frame.tf_rip == (int)IDTVEC(oosyscall))
return;
if (frame.tf_rip == (int)IDTVEC(oosyscall) + 1) {
frame.tf_rflags &= ~PSL_T;
return;
}
goto we_re_toast;
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
#ifdef MATH_EMULATE
trace:
#endif
KERNEL_PROC_LOCK(p);
trapsignal(p, SIGTRAP, type &~ T_USER, TRAP_BRKPT, sv);
KERNEL_PROC_UNLOCK(p);
break;
#if NISA > 0
case T_NMI:
#if defined(KGDB) || defined(DDB)
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
#ifdef KGDB
if (kgdb_trap(type, &frame))
return;
#endif
#ifdef DDB
if (kdb_trap(type, 0, &frame))
return;
#endif
#endif /* KGDB || DDB */
/* machine/parity/power fail/"kitchen sink" faults */
if (x86_nmi() != 0)
goto we_re_toast;
else
return;
#endif /* NISA > 0 */
}
if ((type & T_USER) == 0)
return;
out:
userret(p);
}
#ifdef TRAP_SIGDEBUG
static void
frame_dump(struct trapframe *tf)
{
printf("rip %p rsp %p rfl %p\n",
(void *)tf->tf_rip, (void *)tf->tf_rsp, (void *)tf->tf_rflags);
printf("rdi %p rsi %p rdx %p\n",
(void *)tf->tf_rdi, (void *)tf->tf_rsi, (void *)tf->tf_rdx);
printf("rcx %p r8 %p r9 %p\n",
(void *)tf->tf_rcx, (void *)tf->tf_r8, (void *)tf->tf_r9);
printf("r10 %p r11 %p r12 %p\n",
(void *)tf->tf_r10, (void *)tf->tf_r11, (void *)tf->tf_r12);
printf("r13 %p r14 %p r15 %p\n",
(void *)tf->tf_r13, (void *)tf->tf_r14, (void *)tf->tf_r15);
printf("rbp %p rbx %p rax %p\n",
(void *)tf->tf_rbp, (void *)tf->tf_rbx, (void *)tf->tf_rax);
}
#endif
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