NetBSD-5.0.2/sys/arch/amd64/amd64/trap.c
/* $NetBSD: trap.c,v 1.52.6.2 2009/08/14 21:32:18 snj 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.
*
* 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
*/
/*
* 386 Trap and System call handling
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.52.6.2 2009/08/14 21:32:18 snj Exp $");
#include "opt_ddb.h"
#include "opt_kgdb.h"
#include "opt_lockdebug.h"
#include "opt_multiprocessor.h"
#include "opt_compat_netbsd.h"
#include "opt_compat_ibcs2.h"
#include "opt_xen.h"
#if !defined(XEN)
#include "tprof.h"
#else /* !defined(XEN) */
#define NTPROF 0
#endif /* !defined(XEN) */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/acct.h>
#include <sys/kauth.h>
#include <sys/kernel.h>
#include <sys/signal.h>
#include <sys/syscall.h>
#include <sys/ras.h>
#include <sys/reboot.h>
#include <sys/pool.h>
#include <sys/cpu.h>
#include <sys/sa.h>
#include <sys/savar.h>
#include <uvm/uvm_extern.h>
#if NTPROF > 0
#include <x86/tprof.h>
#endif /* NTPROF > 0 */
#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
#ifndef XEN
#include "isa.h"
#endif
#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)
#undef TRAP_SIGDEBUG
#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 lwp *l = curlwp;
struct proc *p;
int type = (int)frame->tf_trapno;
struct pcb *pcb;
extern char fusuintrfailure[], kcopy_fault[],
resume_iret[];
#if defined(COMPAT_10) || defined(COMPAT_IBCS2)
extern char IDTVEC(oosyscall)[];
#endif
#if 0
extern char resume_pop_ds[], resume_pop_es[];
#endif
struct trapframe *vframe;
void *resume;
void *onfault;
int error;
uint64_t cr2;
ksiginfo_t ksi;
bool pfail;
if (__predict_true(l != NULL)) {
pcb = &l->l_addr->u_pcb;
p = l->l_proc;
} else {
/*
* this can happen eg. on break points in early on boot.
*/
pcb = NULL;
p = 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("curlwp %p\n", curlwp);
if (curlwp)
printf("pid %d lid %d\n", l->l_proc->p_pid, l->l_lid);
}
#endif
if (type != T_NMI && !KERNELMODE(frame->tf_cs, frame->tf_rflags)) {
type |= T_USER;
l->l_md.md_regs = frame;
LWP_CACHE_CREDS(l, p);
}
switch (type) {
default:
we_re_toast:
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);
#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
panic("trap");
/*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) {
copyefault:
error = EFAULT;
copyfault:
frame->tf_rip = (uint64_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 *)((uint64_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 *)((uint64_t)&frame->tf_rsp - 4);
resume = resume_pop_ds;
break;
case 0x07: /* popl %es */
vframe = (void *)((uint64_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 = (uint64_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_ALIGNFLT|T_USER:
#ifdef TRAP_SIGDEBUG
printf("pid %d (%s): BUS/SEGV (%x) at rip %lx addr %lx\n",
p->p_pid, p->p_comm, type, frame->tf_rip, rcr2());
frame_dump(frame);
#endif
KSI_INIT_TRAP(&ksi);
ksi.ksi_trap = type & ~T_USER;
ksi.ksi_addr = (void *)rcr2();
switch (type) {
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_ADRERR;
break;
case T_TSSFLT|T_USER:
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_OBJERR;
break;
case T_ALIGNFLT|T_USER:
ksi.ksi_signo = SIGBUS;
ksi.ksi_code = BUS_ADRALN;
break;
case T_PROTFLT|T_USER:
ksi.ksi_signo = SIGSEGV;
ksi.ksi_code = SEGV_ACCERR;
break;
default:
#ifdef DIAGNOSTIC
panic("unhandled type %x\n", type);
#endif
break;
}
goto trapsignal;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
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
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGILL;
ksi.ksi_trap = type & ~T_USER;
ksi.ksi_addr = (void *)rcr2();
switch (type) {
case T_PRIVINFLT|T_USER:
ksi.ksi_code = ILL_PRVOPC;
break;
case T_FPOPFLT|T_USER:
ksi.ksi_code = ILL_COPROC;
break;
default:
#ifdef DIAGNOSTIC
panic("unhandled type %x\n", type);
#endif
break;
}
goto trapsignal;
case T_ARITHTRAP|T_USER:
case T_XMM|T_USER:
/* Already handled by fputrap(), fall through. */
case T_ASTFLT|T_USER:
/* Allow process switch. */
uvmexp.softs++;
if (l->l_pflag & LP_OWEUPC) {
l->l_pflag &= ~LP_OWEUPC;
ADDUPROF(l);
}
/* Allow a forced task switch. */
if (curcpu()->ci_want_resched)
preempt();
goto out;
#if 0 /* handled by fpudna() */
case T_DNA|T_USER: {
printf("pid %d killed due to lack of floating point\n",
p->p_pid);
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGKILL;
ksi.ksi_trap = type & ~T_USER;
ksi.ksi_addr = (void *)frame->tf_rip;
goto trapsignal;
}
#endif
case T_BOUND|T_USER:
case T_OFLOW|T_USER:
case T_DIVIDE|T_USER:
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGFPE;
ksi.ksi_trap = type & ~T_USER;
ksi.ksi_addr = (void *)frame->tf_rip;
switch (type ) {
case T_BOUND|T_USER:
case T_OFLOW|T_USER:
ksi.ksi_code = FPE_FLTOVF;
break;
case T_DIVIDE|T_USER:
ksi.ksi_code = FPE_FLTDIV;
break;
default:
#ifdef DIAGNOSTIC
panic("unhandled type %x\n", type);
#endif
break;
}
goto trapsignal;
case T_PAGEFLT: /* allow page faults in kernel mode */
if (l == NULL)
goto we_re_toast;
/*
* fusuintrfailure is used by [fs]uswintr() to prevent
* page faulting from inside the profiling interrupt.
*/
if (pcb->pcb_onfault == fusuintrfailure) {
goto copyefault;
}
if (cpu_intr_p() || (l->l_pflag & LP_INTR) != 0) {
goto we_re_toast;
}
cr2 = rcr2();
goto faultcommon;
case T_PAGEFLT|T_USER: { /* page fault */
register vaddr_t va;
register struct vmspace *vm;
register struct vm_map *map;
vm_prot_t ftype;
extern struct vm_map *kernel_map;
cr2 = rcr2();
if (p->p_emul->e_usertrap != NULL &&
(*p->p_emul->e_usertrap)(l, cr2, frame) != 0)
return;
if (l->l_flag & LW_SA) {
l->l_savp->savp_faultaddr = (vaddr_t)cr2;
l->l_pflag |= LP_SA_PAGEFAULT;
}
faultcommon:
vm = p->p_vmspace;
if (vm == NULL)
goto we_re_toast;
pcb->pcb_cr2 = 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_X)
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, ftype);
pcb->pcb_onfault = onfault;
if (error == 0) {
if (map != kernel_map && (void *)va >= vm->vm_maxsaddr)
uvm_grow(p, va);
pfail = false;
while (type == T_PAGEFLT) {
/*
* we need to switch pmap now if we're in
* the middle of copyin/out.
*
* but we don't need to do so for kcopy as
* it never touch userspace.
*/
kpreempt_disable();
if (curcpu()->ci_want_pmapload) {
if (onfault != kcopy_fault) {
pmap_load();
}
}
/*
* We need to keep the pmap loaded and
* so avoid being preempted until back
* into the copy functions. Disable
* interrupts at the hardware level before
* re-enabling preemption. Interrupts
* will be re-enabled by 'iret' when
* returning back out of the trap stub.
* They'll only be re-enabled when the
* program counter is once again in
* the copy functions, and so visible
* to cpu_kpreempt_exit().
*/
#ifndef XEN
x86_disable_intr();
#endif
l->l_nopreempt--;
if (l->l_nopreempt > 0 || !l->l_dopreempt ||
pfail) {
return;
}
#ifndef XEN
x86_enable_intr();
#endif
/*
* If preemption fails for some reason,
* don't retry it. The conditions won't
* change under our nose.
*/
pfail = kpreempt(0);
}
l->l_pflag &= ~LP_SA_PAGEFAULT;
goto out;
}
KSI_INIT_TRAP(&ksi);
ksi.ksi_trap = type & ~T_USER;
ksi.ksi_addr = (void *)rcr2();
if (error == EACCES) {
ksi.ksi_code = SEGV_ACCERR;
error = EFAULT;
} else
ksi.ksi_code = SEGV_MAPERR;
if (type == T_PAGEFLT) {
if (pcb->pcb_onfault != 0)
goto copyfault;
printf("uvm_fault(%p, 0x%lx, %d) -> %x\n",
map, va, ftype, error);
goto we_re_toast;
}
if (error == ENOMEM) {
ksi.ksi_signo = SIGKILL;
printf("UVM: pid %d (%s), uid %d killed: out of swap\n",
p->p_pid, p->p_comm,
l->l_cred ?
kauth_cred_geteuid(l->l_cred) : -1);
} 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
ksi.ksi_signo = SIGSEGV;
}
(*p->p_emul->e_trapsignal)(l, &ksi);
l->l_pflag &= ~LP_SA_PAGEFAULT;
break;
}
case T_TRCTRAP:
#if defined(COMPAT_10) || defined(COMPAT_IBCS2)
/* 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;
}
#endif
goto we_re_toast;
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
if (p->p_raslist == NULL ||
(ras_lookup(p, (void *)frame->tf_rip) == (void *)-1)) {
KSI_INIT_TRAP(&ksi);
ksi.ksi_signo = SIGTRAP;
ksi.ksi_trap = type & ~T_USER;
if (type == (T_BPTFLT|T_USER))
ksi.ksi_code = TRAP_BRKPT;
else
ksi.ksi_code = TRAP_TRACE;
(*p->p_emul->e_trapsignal)(l, &ksi);
}
break;
case T_NMI:
#if NTPROF > 0
if (tprof_pmi_nmi(frame))
return;
#endif /* NTPROF > 0 */
#if NISA > 0
#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 */
; /* avoid a label at end of compound statement */
}
if ((type & T_USER) == 0)
return;
out:
userret(l);
return;
trapsignal:
(*p->p_emul->e_trapsignal)(l, &ksi);
userret(l);
}
void
startlwp(void *arg)
{
int err;
ucontext_t *uc = arg;
struct lwp *l = curlwp;
err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
pool_put(&lwp_uc_pool, uc);
userret(l);
}
void
upcallret(struct lwp *l)
{
KERNEL_UNLOCK_LAST(l);
userret(l);
}
#ifdef TRAP_SIGDEBUG
static void
frame_dump(struct trapframe *tf)
{
int i;
unsigned long *p;
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);
printf("cs %p ds %p es %p fs %p gs %p ss %p\n",
tf->tf_cs & 0xffff, tf->tf_ds & 0xffff, tf->tf_es & 0xffff,
tf->tf_fs & 0xffff, tf->tf_gs & 0xffff, tf->tf_ss & 0xffff);
printf("\n");
printf("Stack dump:\n");
for (i = 0, p = (unsigned long *) tf; i < 20; i ++, p += 4)
printf(" 0x%.16lx 0x%.16lx 0x%.16lx 0x%.16lx\n", *p, p[1], p[2], p[3]);
printf("\n");
}
#endif