diff options
Diffstat (limited to 'sys/kern/subr_trap.c')
| -rw-r--r-- | sys/kern/subr_trap.c | 689 |
1 files changed, 689 insertions, 0 deletions
diff --git a/sys/kern/subr_trap.c b/sys/kern/subr_trap.c new file mode 100644 index 0000000..dc62dc9 --- /dev/null +++ b/sys/kern/subr_trap.c @@ -0,0 +1,689 @@ +/*- + * 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 1.29 1994/08/18 22:34:43 wollman 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/eflags.h> +#include <machine/trap.h> + +#include "isa.h" +#include "npx.h" +#include "ddb.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)) + 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)) + 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, eva, fault_type; + + 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: +#if NDDB > 0 + /* 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; + +#if NDDB > 0 + 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: +#if NDDB > 0 + /* 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; + vm_map_t map = 0; + int rv = 0, oldflags; + 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); + + /* + * Don't allow user-mode faults in kernel address space + */ + if (usermode && (va >= KERNBASE)) { + goto nogo; + } + + if ((p == 0) || (va >= KERNBASE)) { + vm = 0; + map = kernel_map; + } else { + vm = p->p_vmspace; + 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 pa; + 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->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; + + code = frame->tf_err; + type = frame->tf_trapno; + eva = rcr2(); + + 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\n", frame->tf_eip); + printf("processor eflags = "); + if (frame->tf_eflags & EFL_TF) + printf("trace/trap, "); + if (frame->tf_eflags & EFL_IF) + printf("interrupt enabled, "); + if (frame->tf_eflags & EFL_NT) + printf("nested task, "); + if (frame->tf_eflags & EFL_RF) + printf("resume, "); + if (frame->tf_eflags & EFL_VM) + printf("vm86, "); + printf("IOPL = %d\n", (frame->tf_eflags & EFL_IOPL) >> 12); + printf("current process = "); + if (curproc) { + printf("%d (%s)\n", + 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 +#if NDDB > 0 + 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 oldflags; + 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 < 0 || 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: + 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 +} |
