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freebsd/sys/kern/subr_trap.c

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/*-
* Copyright (C) 1994, David Greenman
* Copyright (c) 1990, 1993
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.39 1994/10/11 22:37:14 sos Exp $
*/
/*
* 386 Trap and System call handling
*/
#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/syscall.h>
#include <sys/sysent.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <machine/cpu.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/trap.h>
#include <machine/../isa/isa_device.h>
#include "isa.h"
#include "npx.h"
int trap_pfault __P((struct trapframe *, int));
void trap_fatal __P((struct trapframe *));
#define MAX_TRAP_MSG 27
char *trap_msg[] = {
"reserved addressing fault", /* 0 T_RESADFLT */
"privileged instruction fault", /* 1 T_PRIVINFLT */
"reserved operand fault", /* 2 T_RESOPFLT */
"breakpoint instruction fault", /* 3 T_BPTFLT */
"", /* 4 unused */
"system call trap", /* 5 T_SYSCALL */
"arithmetic trap", /* 6 T_ARITHTRAP */
"system forced exception", /* 7 T_ASTFLT */
"segmentation (limit) fault", /* 8 T_SEGFLT */
"general protection fault", /* 9 T_PROTFLT */
"trace trap", /* 10 T_TRCTRAP */
"", /* 11 unused */
"page fault", /* 12 T_PAGEFLT */
"page table fault", /* 13 T_TABLEFLT */
"alignment fault", /* 14 T_ALIGNFLT */
"kernel stack pointer not valid", /* 15 T_KSPNOTVAL */
"bus error", /* 16 T_BUSERR */
"kernel debugger fault", /* 17 T_KDBTRAP */
"integer divide fault", /* 18 T_DIVIDE */
"non-maskable interrupt trap", /* 19 T_NMI */
"overflow trap", /* 20 T_OFLOW */
"FPU bounds check fault", /* 21 T_BOUND */
"FPU device not available", /* 22 T_DNA */
"double fault", /* 23 T_DOUBLEFLT */
"FPU operand fetch fault", /* 24 T_FPOPFLT */
"invalid TSS fault", /* 25 T_TSSFLT */
"segment not present fault", /* 26 T_SEGNPFLT */
"stack fault", /* 27 T_STKFLT */
};
static inline void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
{
int sig, s;
while ((sig = CURSIG(p)) != 0)
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_resched) {
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrunqueue ourselves but before we
* mi_switch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splclock();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while ((sig = CURSIG(p)) != 0)
postsig(sig);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - oticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame->tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame->tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpriority = p->p_priority;
}
/*
* trap(frame):
* Exception, fault, and trap interface to the FreeBSD 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.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
{
struct proc *p = curproc;
u_quad_t sticks = 0;
int i = 0, ucode = 0, type, code;
#ifdef DIAGNOSTIC
u_long eva;
#endif
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
code = frame.tf_err;
if (ISPL(frame.tf_cs) == SEL_UPL) {
/* user trap */
sticks = p->p_sticks;
p->p_md.md_regs = (int *)&frame;
switch (type) {
case T_RESADFLT: /* reserved addressing fault */
case T_PRIVINFLT: /* privileged instruction fault */
case T_RESOPFLT: /* reserved operand fault */
ucode = type;
i = SIGILL;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
case T_STKFLT: /* stack fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(&frame, TRUE);
if (i == 0)
goto out;
ucode = T_PAGEFLT;
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
#if NISA > 0
case T_NMI:
#ifdef DDB
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
panic("NMI indicates hardware failure");
#endif
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_DNA:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna())
return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = T_FPOPFLT;
i = SIGILL;
break;
default:
trap_fatal(&frame);
}
} else {
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(&frame, FALSE);
return;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
if (curpcb && curpcb->pcb_onfault) {
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
break;
#ifdef DDB
case T_BPTFLT:
case T_TRCTRAP:
if (kdb_trap (type, 0, &frame))
return;
break;
#else
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
/* Q: how do we turn it on again? */
frame.tf_eflags &= ~PSL_T;
return;
#endif
#if NISA > 0
case T_NMI:
#ifdef DDB
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
}
trap_fatal(&frame);
}
trapsignal(p, i, ucode);
#ifdef DIAGNOSTIC
eva = rcr2();
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
userret(p, &frame, sticks);
}
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm = NULL;
vm_map_t map = 0;
int rv = 0;
vm_prot_t ftype;
extern vm_map_t kernel_map;
int eva;
struct proc *p = curproc;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
if (va >= KERNBASE) {
/*
* Don't allow user-mode faults in kernel address space.
*/
if (usermode)
goto nogo;
map = kernel_map;
} else {
/*
* This is a fault on non-kernel virtual memory.
* vm is initialized above to NULL. If curproc is NULL
* or curproc->p_vmspace is NULL the fault is fatal.
*/
if (p != NULL)
vm = p->p_vmspace;
if (vm == NULL)
goto nogo;
map = &vm->vm_map;
}
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
if( ptepg->hold_count == 0)
ptepg->act_count += 3;
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb && curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
void
trap_fatal(frame)
struct trapframe *frame;
{
int code, type, eva;
struct soft_segment_descriptor softseg;
code = frame->tf_err;
type = frame->tf_trapno;
eva = rcr2();
sdtossd(gdt + IDXSEL(frame->tf_cs & 0xffff), &softseg);
if (type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
type, trap_msg[type],
ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
if (type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x:0x%x\n", frame->tf_cs & 0xffff, frame->tf_eip);
printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n",
softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
printf(" = DPL %d, pres %d, def32 %d, gran %d\n",
softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32, softseg.ssd_gran);
printf("processor eflags = ");
if (frame->tf_eflags & PSL_T)
printf("trace/trap, ");
if (frame->tf_eflags & PSL_I)
printf("interrupt enabled, ");
if (frame->tf_eflags & PSL_NT)
printf("nested task, ");
if (frame->tf_eflags & PSL_RF)
printf("resume, ");
if (frame->tf_eflags & PSL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%lu (%s)\n",
(u_long)curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#ifdef DDB
if (kdb_trap (type, 0, frame))
return;
#endif
if (type <= MAX_TRAP_MSG)
panic(trap_msg[type]);
else
panic("unknown/reserved trap");
}
/*
* Compensate for 386 brain damage (missing URKR).
* This is a little simpler than the pagefault handler in trap() because
* it the page tables have already been faulted in and high addresses
* are thrown out early for other reasons.
*/
int trapwrite(addr)
unsigned addr;
{
struct proc *p;
vm_offset_t va, v;
struct vmspace *vm;
int rv;
va = trunc_page((vm_offset_t)addr);
/*
* XXX - MAX is END. Changed > to >= for temp. fix.
*/
if (va >= VM_MAXUSER_ADDRESS)
return (1);
p = curproc;
vm = p->p_vmspace;
++p->p_lock;
if ((caddr_t)va >= vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
--p->p_lock;
return (1);
}
}
v = trunc_page(vtopte(va));
/*
* wire the pte page
*/
if (va < USRSTACK) {
vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE);
}
/*
* fault the data page
*/
rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE);
/*
* unwire the pte page
*/
if (va < USRSTACK) {
vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE);
}
--p->p_lock;
if (rv != KERN_SUCCESS)
return 1;
return (0);
}
/*
* syscall(frame):
* System call request from POSIX system call gate interface to kernel.
* Like trap(), argument is call by reference.
*/
/*ARGSUSED*/
void
syscall(frame)
struct trapframe frame;
{
caddr_t params;
int i;
struct sysent *callp;
struct proc *p = curproc;
u_quad_t sticks;
int error, opc;
int args[8], rval[2];
u_int code;
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("syscall");
code = frame.tf_eax;
p->p_md.md_regs = (int *)&frame;
params = (caddr_t)frame.tf_esp + sizeof (int) ;
/*
* Reconstruct pc, assuming lcall $X,y is 7 bytes, as it is always.
*/
opc = frame.tf_eip - 7;
/*
* Need to check if this is a 32 bit or 64 bit syscall.
*/
if (code == SYS_syscall) {
/*
* Code is first argument, followed by actual args.
*/
code = fuword(params);
params += sizeof (int);
} else if (code == SYS___syscall) {
/*
* Like syscall, but code is a quad, so as to maintain
* quad alignment for the rest of the arguments.
*/
code = fuword(params + _QUAD_LOWWORD * sizeof(int));
params += sizeof(quad_t);
}
if (p->p_sysent->sv_mask)
code = code & p->p_sysent->sv_mask;
if (code >= p->p_sysent->sv_size)
callp = &p->p_sysent->sv_table[0];
else
callp = &p->p_sysent->sv_table[code];
if ((i = callp->sy_narg * sizeof (int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
goto bad;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
rval[0] = 0;
rval[1] = frame.tf_edx;
error = (*callp->sy_call)(p, args, rval);
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
frame.tf_eip = opc;
break;
case EJUSTRETURN:
break;
default:
bad:
if (p->p_sysent->sv_errsize)
if (error >= p->p_sysent->sv_errsize)
error = -1; /* XXX */
else
error = p->p_sysent->sv_errtbl[error];
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
break;
}
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}
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