123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077 |
- #include "u.h"
- #include "tos.h"
- #include "../port/lib.h"
- #include "mem.h"
- #include "dat.h"
- #include "fns.h"
- #include "io.h"
- #include "ureg.h"
- #include "../port/error.h"
- #include <trace.h>
- static int trapinited;
- void noted(Ureg*, ulong);
- static void debugbpt(Ureg*, void*);
- static void fault386(Ureg*, void*);
- static void doublefault(Ureg*, void*);
- static void unexpected(Ureg*, void*);
- static void _dumpstack(Ureg*);
- static Lock vctllock;
- static Vctl *vctl[256];
- enum
- {
- Ntimevec = 20 /* number of time buckets for each intr */
- };
- ulong intrtimes[256][Ntimevec];
- void
- intrenable(int irq, void (*f)(Ureg*, void*), void* a, int tbdf, char *name)
- {
- int vno;
- Vctl *v;
- if(f == nil){
- print("intrenable: nil handler for %d, tbdf 0x%uX for %s\n",
- irq, tbdf, name);
- return;
- }
- v = xalloc(sizeof(Vctl));
- v->isintr = 1;
- v->irq = irq;
- v->tbdf = tbdf;
- v->f = f;
- v->a = a;
- strncpy(v->name, name, KNAMELEN-1);
- v->name[KNAMELEN-1] = 0;
- ilock(&vctllock);
- vno = arch->intrenable(v);
- if(vno == -1){
- iunlock(&vctllock);
- print("intrenable: couldn't enable irq %d, tbdf 0x%uX for %s\n",
- irq, tbdf, v->name);
- xfree(v);
- return;
- }
- if(vctl[vno]){
- if(vctl[vno]->isr != v->isr || vctl[vno]->eoi != v->eoi)
- panic("intrenable: handler: %s %s %#p %#p %#p %#p",
- vctl[vno]->name, v->name,
- vctl[vno]->isr, v->isr, vctl[vno]->eoi, v->eoi);
- v->next = vctl[vno];
- }
- vctl[vno] = v;
- iunlock(&vctllock);
- }
- int
- intrdisable(int irq, void (*f)(Ureg *, void *), void *a, int tbdf, char *name)
- {
- Vctl **pv, *v;
- int vno;
- /*
- * For now, none of this will work with the APIC code,
- * there is no mapping between irq and vector as the IRQ
- * is pretty meaningless.
- */
- if(arch->intrvecno == nil)
- return -1;
- vno = arch->intrvecno(irq);
- ilock(&vctllock);
- pv = &vctl[vno];
- while (*pv &&
- ((*pv)->irq != irq || (*pv)->tbdf != tbdf || (*pv)->f != f || (*pv)->a != a ||
- strcmp((*pv)->name, name)))
- pv = &((*pv)->next);
- assert(*pv);
- v = *pv;
- *pv = (*pv)->next; /* Link out the entry */
- if(vctl[vno] == nil && arch->intrdisable != nil)
- arch->intrdisable(irq);
- iunlock(&vctllock);
- xfree(v);
- return 0;
- }
- static long
- irqallocread(Chan*, void *vbuf, long n, vlong offset)
- {
- char *buf, *p, str[2*(11+1)+KNAMELEN+1+1];
- int m, vno;
- long oldn;
- Vctl *v;
- if(n < 0 || offset < 0)
- error(Ebadarg);
- oldn = n;
- buf = vbuf;
- for(vno=0; vno<nelem(vctl); vno++){
- for(v=vctl[vno]; v; v=v->next){
- m = snprint(str, sizeof str, "%11d %11d %.*s\n", vno, v->irq, KNAMELEN, v->name);
- if(m <= offset) /* if do not want this, skip entry */
- offset -= m;
- else{
- /* skip offset bytes */
- m -= offset;
- p = str+offset;
- offset = 0;
- /* write at most max(n,m) bytes */
- if(m > n)
- m = n;
- memmove(buf, p, m);
- n -= m;
- buf += m;
- if(n == 0)
- return oldn;
- }
- }
- }
- return oldn - n;
- }
- void
- trapenable(int vno, void (*f)(Ureg*, void*), void* a, char *name)
- {
- Vctl *v;
- if(vno < 0 || vno >= VectorPIC)
- panic("trapenable: vno %d", vno);
- v = xalloc(sizeof(Vctl));
- v->tbdf = BUSUNKNOWN;
- v->f = f;
- v->a = a;
- strncpy(v->name, name, KNAMELEN);
- v->name[KNAMELEN-1] = 0;
- ilock(&vctllock);
- if(vctl[vno])
- v->next = vctl[vno]->next;
- vctl[vno] = v;
- iunlock(&vctllock);
- }
- static void
- nmienable(void)
- {
- int x;
- /*
- * Hack: should be locked with NVRAM access.
- */
- outb(0x70, 0x80); /* NMI latch clear */
- outb(0x70, 0);
- x = inb(0x61) & 0x07; /* Enable NMI */
- outb(0x61, 0x08|x);
- outb(0x61, x);
- }
- /*
- * Minimal trap setup. Just enough so that we can panic
- * on traps (bugs) during kernel initialization.
- * Called very early - malloc is not yet available.
- */
- void
- trapinit0(void)
- {
- int d1, v;
- ulong vaddr;
- Segdesc *idt;
- idt = (Segdesc*)IDTADDR;
- vaddr = (ulong)vectortable;
- for(v = 0; v < 256; v++){
- d1 = (vaddr & 0xFFFF0000)|SEGP;
- switch(v){
- case VectorBPT:
- d1 |= SEGPL(3)|SEGIG;
- break;
- case VectorSYSCALL:
- d1 |= SEGPL(3)|SEGIG;
- break;
- default:
- d1 |= SEGPL(0)|SEGIG;
- break;
- }
- idt[v].d0 = (vaddr & 0xFFFF)|(KESEL<<16);
- idt[v].d1 = d1;
- vaddr += 6;
- }
- }
- void
- trapinit(void)
- {
- /*
- * Special traps.
- * Syscall() is called directly without going through trap().
- */
- trapenable(VectorBPT, debugbpt, 0, "debugpt");
- trapenable(VectorPF, fault386, 0, "fault386");
- trapenable(Vector2F, doublefault, 0, "doublefault");
- trapenable(Vector15, unexpected, 0, "unexpected");
- nmienable();
- addarchfile("irqalloc", 0444, irqallocread, nil);
- trapinited = 1;
- }
- static char* excname[32] = {
- "divide error",
- "debug exception",
- "nonmaskable interrupt",
- "breakpoint",
- "overflow",
- "bounds check",
- "invalid opcode",
- "coprocessor not available",
- "double fault",
- "coprocessor segment overrun",
- "invalid TSS",
- "segment not present",
- "stack exception",
- "general protection violation",
- "page fault",
- "15 (reserved)",
- "coprocessor error",
- "alignment check",
- "machine check",
- "19 (reserved)",
- "20 (reserved)",
- "21 (reserved)",
- "22 (reserved)",
- "23 (reserved)",
- "24 (reserved)",
- "25 (reserved)",
- "26 (reserved)",
- "27 (reserved)",
- "28 (reserved)",
- "29 (reserved)",
- "30 (reserved)",
- "31 (reserved)",
- };
- /*
- * keep histogram of interrupt service times
- */
- void
- intrtime(Mach*, int vno)
- {
- ulong diff;
- ulong x;
- x = perfticks();
- diff = x - m->perf.intrts;
- m->perf.intrts = x;
- m->perf.inintr += diff;
- if(up == nil && m->perf.inidle > diff)
- m->perf.inidle -= diff;
- diff /= m->cpumhz*100; /* quantum = 100µsec */
- if(diff >= Ntimevec)
- diff = Ntimevec-1;
- intrtimes[vno][diff]++;
- }
- /* go to user space */
- void
- kexit(Ureg*)
- {
- uvlong t;
- Tos *tos;
- /* precise time accounting, kernel exit */
- tos = (Tos*)(USTKTOP-sizeof(Tos));
- cycles(&t);
- tos->kcycles += t - up->kentry;
- tos->pcycles = up->pcycles;
- tos->pid = up->pid;
- }
- /*
- * All traps come here. It is slower to have all traps call trap()
- * rather than directly vectoring the handler. However, this avoids a
- * lot of code duplication and possible bugs. The only exception is
- * VectorSYSCALL.
- * Trap is called with interrupts disabled via interrupt-gates.
- */
- void
- trap(Ureg* ureg)
- {
- int clockintr, i, vno, user;
- char buf[ERRMAX];
- Vctl *ctl, *v;
- Mach *mach;
- if(!trapinited){
- /* fault386 can give a better error message */
- if(ureg->trap == VectorPF)
- fault386(ureg, nil);
- panic("trap %lud: not ready", ureg->trap);
- }
- m->perf.intrts = perfticks();
- user = (ureg->cs & 0xFFFF) == UESEL;
- if(user){
- up->dbgreg = ureg;
- cycles(&up->kentry);
- }
- clockintr = 0;
- vno = ureg->trap;
- if(ctl = vctl[vno]){
- if(ctl->isintr){
- m->intr++;
- if(vno >= VectorPIC && vno != VectorSYSCALL)
- m->lastintr = ctl->irq;
- }
- if(ctl->isr)
- ctl->isr(vno);
- for(v = ctl; v != nil; v = v->next){
- if(v->f)
- v->f(ureg, v->a);
- }
- if(ctl->eoi)
- ctl->eoi(vno);
- if(ctl->isintr){
- intrtime(m, vno);
- if(ctl->irq == IrqCLOCK || ctl->irq == IrqTIMER)
- clockintr = 1;
- if(up && !clockintr)
- preempted();
- }
- }
- else if(vno < nelem(excname) && user){
- spllo();
- sprint(buf, "sys: trap: %s", excname[vno]);
- postnote(up, 1, buf, NDebug);
- }
- else if(vno >= VectorPIC && vno != VectorSYSCALL){
- /*
- * An unknown interrupt.
- * Check for a default IRQ7. This can happen when
- * the IRQ input goes away before the acknowledge.
- * In this case, a 'default IRQ7' is generated, but
- * the corresponding bit in the ISR isn't set.
- * In fact, just ignore all such interrupts.
- */
- /* call all interrupt routines, just in case */
- for(i = VectorPIC; i <= MaxIrqLAPIC; i++){
- ctl = vctl[i];
- if(ctl == nil)
- continue;
- if(!ctl->isintr)
- continue;
- for(v = ctl; v != nil; v = v->next){
- if(v->f)
- v->f(ureg, v->a);
- }
- /* should we do this? */
- if(ctl->eoi)
- ctl->eoi(i);
- }
- /* clear the interrupt */
- i8259isr(vno);
- if(0)print("cpu%d: spurious interrupt %d, last %d\n",
- m->machno, vno, m->lastintr);
- if(0)if(conf.nmach > 1){
- for(i = 0; i < 32; i++){
- if(!(active.machs & (1<<i)))
- continue;
- mach = MACHP(i);
- if(m->machno == mach->machno)
- continue;
- print(" cpu%d: last %d",
- mach->machno, mach->lastintr);
- }
- print("\n");
- }
- m->spuriousintr++;
- if(user)
- kexit(ureg);
- return;
- }
- else{
- if(vno == VectorNMI){
- /*
- * Don't re-enable, it confuses the crash dumps.
- nmienable();
- */
- iprint("cpu%d: PC %#8.8lux\n", m->machno, ureg->pc);
- while(m->machno != 0)
- ;
- }
- dumpregs(ureg);
- if(!user){
- ureg->sp = (ulong)&ureg->sp;
- _dumpstack(ureg);
- }
- if(vno < nelem(excname))
- panic("%s", excname[vno]);
- panic("unknown trap/intr: %d", vno);
- }
- splhi();
- /* delaysched set because we held a lock or because our quantum ended */
- if(up && up->delaysched && clockintr){
- sched();
- splhi();
- }
- if(user){
- if(up->procctl || up->nnote)
- notify(ureg);
- kexit(ureg);
- }
- }
- /*
- * dump registers
- */
- void
- dumpregs2(Ureg* ureg)
- {
- if(up)
- iprint("cpu%d: registers for %s %lud\n",
- m->machno, up->text, up->pid);
- else
- iprint("cpu%d: registers for kernel\n", m->machno);
- iprint("FLAGS=%luX TRAP=%luX ECODE=%luX PC=%luX",
- ureg->flags, ureg->trap, ureg->ecode, ureg->pc);
- iprint(" SS=%4.4luX USP=%luX\n", ureg->ss & 0xFFFF, ureg->usp);
- iprint(" AX %8.8luX BX %8.8luX CX %8.8luX DX %8.8luX\n",
- ureg->ax, ureg->bx, ureg->cx, ureg->dx);
- iprint(" SI %8.8luX DI %8.8luX BP %8.8luX\n",
- ureg->si, ureg->di, ureg->bp);
- iprint(" CS %4.4luX DS %4.4luX ES %4.4luX FS %4.4luX GS %4.4luX\n",
- ureg->cs & 0xFFFF, ureg->ds & 0xFFFF, ureg->es & 0xFFFF,
- ureg->fs & 0xFFFF, ureg->gs & 0xFFFF);
- }
- void
- dumpregs(Ureg* ureg)
- {
- vlong mca, mct;
- dumpregs2(ureg);
- /*
- * Processor control registers.
- * If machine check exception, time stamp counter, page size extensions
- * or enhanced virtual 8086 mode extensions are supported, there is a
- * CR4. If there is a CR4 and machine check extensions, read the machine
- * check address and machine check type registers if RDMSR supported.
- */
- iprint(" CR0 %8.8lux CR2 %8.8lux CR3 %8.8lux",
- getcr0(), getcr2(), getcr3());
- if(m->cpuiddx & 0x9A){
- iprint(" CR4 %8.8lux", getcr4());
- if((m->cpuiddx & 0xA0) == 0xA0){
- rdmsr(0x00, &mca);
- rdmsr(0x01, &mct);
- iprint("\n MCA %8.8llux MCT %8.8llux", mca, mct);
- }
- }
- iprint("\n ur %#p up %#p\n", ureg, up);
- }
- /*
- * Fill in enough of Ureg to get a stack trace, and call a function.
- * Used by debugging interface rdb.
- */
- void
- callwithureg(void (*fn)(Ureg*))
- {
- Ureg ureg;
- ureg.pc = getcallerpc(&fn);
- ureg.sp = (ulong)&fn;
- fn(&ureg);
- }
- static void
- _dumpstack(Ureg *ureg)
- {
- uintptr l, v, i, estack;
- extern ulong etext;
- int x;
- char *s;
- if((s = getconf("*nodumpstack")) != nil && strcmp(s, "0") != 0){
- iprint("dumpstack disabled\n");
- return;
- }
- iprint("dumpstack\n");
- x = 0;
- x += iprint("ktrace /kernel/path %.8lux %.8lux <<EOF\n", ureg->pc, ureg->sp);
- i = 0;
- if(up
- && (uintptr)&l >= (uintptr)up->kstack
- && (uintptr)&l <= (uintptr)up->kstack+KSTACK)
- estack = (uintptr)up->kstack+KSTACK;
- else if((uintptr)&l >= (uintptr)m->stack
- && (uintptr)&l <= (uintptr)m+MACHSIZE)
- estack = (uintptr)m+MACHSIZE;
- else
- return;
- x += iprint("estackx %p\n", estack);
- for(l = (uintptr)&l; l < estack; l += sizeof(uintptr)){
- v = *(uintptr*)l;
- if((KTZERO < v && v < (uintptr)&etext) || estack-l < 32){
- /*
- * Could Pick off general CALL (((uchar*)v)[-5] == 0xE8)
- * and CALL indirect through AX
- * (((uchar*)v)[-2] == 0xFF && ((uchar*)v)[-2] == 0xD0),
- * but this is too clever and misses faulting address.
- */
- x += iprint("%.8p=%.8p ", l, v);
- i++;
- }
- if(i == 4){
- i = 0;
- x += iprint("\n");
- }
- }
- if(i)
- iprint("\n");
- iprint("EOF\n");
- if(ureg->trap != VectorNMI)
- return;
- i = 0;
- for(l = (uintptr)&l; l < estack; l += sizeof(uintptr)){
- iprint("%.8p ", *(uintptr*)l);
- if(++i == 8){
- i = 0;
- iprint("\n");
- }
- }
- if(i)
- iprint("\n");
- }
- void
- dumpstack(void)
- {
- callwithureg(_dumpstack);
- }
- static void
- debugbpt(Ureg* ureg, void*)
- {
- char buf[ERRMAX];
- if(up == 0)
- panic("kernel bpt");
- /* restore pc to instruction that caused the trap */
- ureg->pc--;
- sprint(buf, "sys: breakpoint");
- postnote(up, 1, buf, NDebug);
- }
- static void
- doublefault(Ureg*, void*)
- {
- panic("double fault");
- }
- static void
- unexpected(Ureg* ureg, void*)
- {
- print("unexpected trap %lud; ignoring\n", ureg->trap);
- }
- extern void checkpages(void);
- extern void checkfault(ulong, ulong);
- static void
- fault386(Ureg* ureg, void*)
- {
- ulong addr;
- int read, user, n, insyscall;
- char buf[ERRMAX];
- addr = getcr2();
- read = !(ureg->ecode & 2);
- user = (ureg->cs & 0xFFFF) == UESEL;
- if(!user){
- if(vmapsync(addr))
- return;
- if(addr >= USTKTOP)
- panic("kernel fault: bad address pc=0x%.8lux addr=0x%.8lux", ureg->pc, addr);
- if(up == nil)
- panic("kernel fault: no user process pc=0x%.8lux addr=0x%.8lux", ureg->pc, addr);
- }
- if(up == nil)
- panic("user fault: up=0 pc=0x%.8lux addr=0x%.8lux", ureg->pc, addr);
- insyscall = up->insyscall;
- up->insyscall = 1;
- n = fault(addr, read);
- if(n < 0){
- if(!user){
- dumpregs(ureg);
- panic("fault: 0x%lux", addr);
- }
- checkpages();
- checkfault(addr, ureg->pc);
- sprint(buf, "sys: trap: fault %s addr=0x%lux",
- read ? "read" : "write", addr);
- postnote(up, 1, buf, NDebug);
- }
- up->insyscall = insyscall;
- }
- /*
- * system calls
- */
- #include "../port/systab.h"
- /*
- * Syscall is called directly from assembler without going through trap().
- */
- void
- syscall(Ureg* ureg)
- {
- char *e;
- ulong sp;
- long ret;
- int i, s;
- ulong scallnr;
- vlong startns, stopns;
- if((ureg->cs & 0xFFFF) != UESEL)
- panic("syscall: cs 0x%4.4luX", ureg->cs);
- cycles(&up->kentry);
- m->syscall++;
- up->insyscall = 1;
- up->pc = ureg->pc;
- up->dbgreg = ureg;
- sp = ureg->usp;
- scallnr = ureg->ax;
- up->scallnr = scallnr;
- if(up->procctl == Proc_tracesyscall){
- /*
- * Redundant validaddr. Do we care?
- * Tracing syscalls is not exactly a fast path...
- * Beware, validaddr currently does a pexit rather
- * than an error if there's a problem; that might
- * change in the future.
- */
- if(sp < (USTKTOP-BY2PG) || sp > (USTKTOP-sizeof(Sargs)-BY2WD))
- validaddr(sp, sizeof(Sargs)+BY2WD, 0);
- syscallfmt(scallnr, ureg->pc, (va_list)(sp+BY2WD));
- up->procctl = Proc_stopme;
- procctl(up);
- if(up->syscalltrace)
- free(up->syscalltrace);
- up->syscalltrace = nil;
- startns = todget(nil);
- }
- if(scallnr == RFORK && up->fpstate == FPactive){
- fpsave(&up->fpsave);
- up->fpstate = FPinactive;
- }
- spllo();
- up->nerrlab = 0;
- ret = -1;
- if(!waserror()){
- if(scallnr >= nsyscall || systab[scallnr] == 0){
- pprint("bad sys call number %lud pc %lux\n",
- scallnr, ureg->pc);
- postnote(up, 1, "sys: bad sys call", NDebug);
- error(Ebadarg);
- }
- if(sp<(USTKTOP-BY2PG) || sp>(USTKTOP-sizeof(Sargs)-BY2WD))
- validaddr(sp, sizeof(Sargs)+BY2WD, 0);
- up->s = *((Sargs*)(sp+BY2WD));
- up->psstate = sysctab[scallnr];
- ret = systab[scallnr](up->s.args);
- poperror();
- }else{
- /* failure: save the error buffer for errstr */
- e = up->syserrstr;
- up->syserrstr = up->errstr;
- up->errstr = e;
- if(0 && up->pid == 1)
- print("syscall %lud error %s\n", scallnr, up->syserrstr);
- }
- if(up->nerrlab){
- print("bad errstack [%lud]: %d extra\n", scallnr, up->nerrlab);
- for(i = 0; i < NERR; i++)
- print("sp=%lux pc=%lux\n",
- up->errlab[i].sp, up->errlab[i].pc);
- panic("error stack");
- }
- /*
- * Put return value in frame. On the x86 the syscall is
- * just another trap and the return value from syscall is
- * ignored. On other machines the return value is put into
- * the results register by caller of syscall.
- */
- ureg->ax = ret;
- if(up->procctl == Proc_tracesyscall){
- stopns = todget(nil);
- up->procctl = Proc_stopme;
- sysretfmt(scallnr, (va_list)(sp+BY2WD), ret, startns, stopns);
- s = splhi();
- procctl(up);
- splx(s);
- if(up->syscalltrace)
- free(up->syscalltrace);
- up->syscalltrace = nil;
- }
- up->insyscall = 0;
- up->psstate = 0;
- if(scallnr == NOTED)
- noted(ureg, *(ulong*)(sp+BY2WD));
- if(scallnr!=RFORK && (up->procctl || up->nnote)){
- splhi();
- notify(ureg);
- }
- /* if we delayed sched because we held a lock, sched now */
- if(up->delaysched)
- sched();
- kexit(ureg);
- }
- /*
- * Call user, if necessary, with note.
- * Pass user the Ureg struct and the note on his stack.
- */
- int
- notify(Ureg* ureg)
- {
- int l;
- ulong s, sp;
- Note *n;
- if(up->procctl)
- procctl(up);
- if(up->nnote == 0)
- return 0;
- if(up->fpstate == FPactive){
- fpsave(&up->fpsave);
- up->fpstate = FPinactive;
- }
- up->fpstate |= FPillegal;
- s = spllo();
- qlock(&up->debug);
- up->notepending = 0;
- n = &up->note[0];
- if(strncmp(n->msg, "sys:", 4) == 0){
- l = strlen(n->msg);
- if(l > ERRMAX-15) /* " pc=0x12345678\0" */
- l = ERRMAX-15;
- sprint(n->msg+l, " pc=0x%.8lux", ureg->pc);
- }
- if(n->flag!=NUser && (up->notified || up->notify==0)){
- if(n->flag == NDebug)
- pprint("suicide: %s\n", n->msg);
- qunlock(&up->debug);
- pexit(n->msg, n->flag!=NDebug);
- }
- if(up->notified){
- qunlock(&up->debug);
- splhi();
- return 0;
- }
- if(!up->notify){
- qunlock(&up->debug);
- pexit(n->msg, n->flag!=NDebug);
- }
- sp = ureg->usp;
- sp -= 256; /* debugging: preserve context causing problem */
- sp -= sizeof(Ureg);
- if(0) print("%s %lud: notify %.8lux %.8lux %.8lux %s\n",
- up->text, up->pid, ureg->pc, ureg->usp, sp, n->msg);
- if(!okaddr((ulong)up->notify, 1, 0)
- || !okaddr(sp-ERRMAX-4*BY2WD, sizeof(Ureg)+ERRMAX+4*BY2WD, 1)){
- qunlock(&up->debug);
- pprint("suicide: bad address in notify\n");
- pexit("Suicide", 0);
- }
- memmove((Ureg*)sp, ureg, sizeof(Ureg));
- *(Ureg**)(sp-BY2WD) = up->ureg; /* word under Ureg is old up->ureg */
- up->ureg = (void*)sp;
- sp -= BY2WD+ERRMAX;
- memmove((char*)sp, up->note[0].msg, ERRMAX);
- sp -= 3*BY2WD;
- *(ulong*)(sp+2*BY2WD) = sp+3*BY2WD; /* arg 2 is string */
- *(ulong*)(sp+1*BY2WD) = (ulong)up->ureg; /* arg 1 is ureg* */
- *(ulong*)(sp+0*BY2WD) = 0; /* arg 0 is pc */
- ureg->usp = sp;
- ureg->pc = (ulong)up->notify;
- up->notified = 1;
- up->nnote--;
- memmove(&up->lastnote, &up->note[0], sizeof(Note));
- memmove(&up->note[0], &up->note[1], up->nnote*sizeof(Note));
- qunlock(&up->debug);
- splx(s);
- return 1;
- }
- /*
- * Return user to state before notify()
- */
- void
- noted(Ureg* ureg, ulong arg0)
- {
- Ureg *nureg;
- ulong oureg, sp;
- qlock(&up->debug);
- if(arg0!=NRSTR && !up->notified) {
- qunlock(&up->debug);
- pprint("call to noted() when not notified\n");
- pexit("Suicide", 0);
- }
- up->notified = 0;
- nureg = up->ureg; /* pointer to user returned Ureg struct */
- up->fpstate &= ~FPillegal;
- /* sanity clause */
- oureg = (ulong)nureg;
- if(!okaddr((ulong)oureg-BY2WD, BY2WD+sizeof(Ureg), 0)){
- qunlock(&up->debug);
- pprint("bad ureg in noted or call to noted when not notified\n");
- pexit("Suicide", 0);
- }
- /*
- * Check the segment selectors are all valid, otherwise
- * a fault will be taken on attempting to return to the
- * user process.
- * Take care with the comparisons as different processor
- * generations push segment descriptors in different ways.
- */
- if((nureg->cs & 0xFFFF) != UESEL || (nureg->ss & 0xFFFF) != UDSEL
- || (nureg->ds & 0xFFFF) != UDSEL || (nureg->es & 0xFFFF) != UDSEL
- || (nureg->fs & 0xFFFF) != UDSEL || (nureg->gs & 0xFFFF) != UDSEL){
- qunlock(&up->debug);
- pprint("bad segment selector in noted\n");
- pexit("Suicide", 0);
- }
- /* don't let user change system flags */
- nureg->flags = (ureg->flags & ~0xCD5) | (nureg->flags & 0xCD5);
- memmove(ureg, nureg, sizeof(Ureg));
- switch(arg0){
- case NCONT:
- case NRSTR:
- if(0) print("%s %lud: noted %.8lux %.8lux\n",
- up->text, up->pid, nureg->pc, nureg->usp);
- if(!okaddr(nureg->pc, 1, 0) || !okaddr(nureg->usp, BY2WD, 0)){
- qunlock(&up->debug);
- pprint("suicide: trap in noted\n");
- pexit("Suicide", 0);
- }
- up->ureg = (Ureg*)(*(ulong*)(oureg-BY2WD));
- qunlock(&up->debug);
- break;
- case NSAVE:
- if(!okaddr(nureg->pc, BY2WD, 0)
- || !okaddr(nureg->usp, BY2WD, 0)){
- qunlock(&up->debug);
- pprint("suicide: trap in noted\n");
- pexit("Suicide", 0);
- }
- qunlock(&up->debug);
- sp = oureg-4*BY2WD-ERRMAX;
- splhi();
- ureg->sp = sp;
- ((ulong*)sp)[1] = oureg; /* arg 1 0(FP) is ureg* */
- ((ulong*)sp)[0] = 0; /* arg 0 is pc */
- break;
- default:
- pprint("unknown noted arg 0x%lux\n", arg0);
- up->lastnote.flag = NDebug;
- /* fall through */
- case NDFLT:
- if(up->lastnote.flag == NDebug){
- qunlock(&up->debug);
- pprint("suicide: %s\n", up->lastnote.msg);
- } else
- qunlock(&up->debug);
- pexit(up->lastnote.msg, up->lastnote.flag!=NDebug);
- }
- }
- long
- execregs(ulong entry, ulong ssize, ulong nargs)
- {
- ulong *sp;
- Ureg *ureg;
- up->fpstate = FPinit;
- fpoff();
- sp = (ulong*)(USTKTOP - ssize);
- *--sp = nargs;
- ureg = up->dbgreg;
- ureg->usp = (ulong)sp;
- ureg->pc = entry;
- return USTKTOP-sizeof(Tos); /* address of kernel/user shared data */
- }
- /*
- * return the userpc the last exception happened at
- */
- ulong
- userpc(void)
- {
- Ureg *ureg;
- ureg = (Ureg*)up->dbgreg;
- return ureg->pc;
- }
- /* This routine must save the values of registers the user is not permitted
- * to write from devproc and then restore the saved values before returning.
- */
- void
- setregisters(Ureg* ureg, char* pureg, char* uva, int n)
- {
- ulong cs, ds, es, flags, fs, gs, ss;
- ss = ureg->ss;
- flags = ureg->flags;
- cs = ureg->cs;
- ds = ureg->ds;
- es = ureg->es;
- fs = ureg->fs;
- gs = ureg->gs;
- memmove(pureg, uva, n);
- ureg->gs = gs;
- ureg->fs = fs;
- ureg->es = es;
- ureg->ds = ds;
- ureg->cs = cs;
- ureg->flags = (ureg->flags & 0x00FF) | (flags & 0xFF00);
- ureg->ss = ss;
- }
- static void
- linkproc(void)
- {
- spllo();
- up->kpfun(up->kparg);
- pexit("kproc dying", 0);
- }
- void
- kprocchild(Proc* p, void (*func)(void*), void* arg)
- {
- /*
- * gotolabel() needs a word on the stack in
- * which to place the return PC used to jump
- * to linkproc().
- */
- p->sched.pc = (ulong)linkproc;
- p->sched.sp = (ulong)p->kstack+KSTACK-BY2WD;
- p->kpfun = func;
- p->kparg = arg;
- }
- void
- forkchild(Proc *p, Ureg *ureg)
- {
- Ureg *cureg;
- /*
- * Add 2*BY2WD to the stack to account for
- * - the return PC
- * - trap's argument (ur)
- */
- p->sched.sp = (ulong)p->kstack+KSTACK-(sizeof(Ureg)+2*BY2WD);
- p->sched.pc = (ulong)forkret;
- cureg = (Ureg*)(p->sched.sp+2*BY2WD);
- memmove(cureg, ureg, sizeof(Ureg));
- /* return value of syscall in child */
- cureg->ax = 0;
- /* Things from bottom of syscall which were never executed */
- p->psstate = 0;
- p->insyscall = 0;
- }
- /* Give enough context in the ureg to produce a kernel stack for
- * a sleeping process
- */
- void
- setkernur(Ureg* ureg, Proc* p)
- {
- ureg->pc = p->sched.pc;
- ureg->sp = p->sched.sp+4;
- }
- ulong
- dbgpc(Proc *p)
- {
- Ureg *ureg;
- ureg = p->dbgreg;
- if(ureg == 0)
- return 0;
- return ureg->pc;
- }
|