NetBSD/sys/arch/sparc/sparc/trap.c

1158 lines
31 KiB
C

/* $NetBSD: trap.c,v 1.53 1997/03/15 20:31:33 pk Exp $ */
/*
* Copyright (c) 1996
* The President and Fellows of Harvard College. All rights reserved.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* 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, Lawrence Berkeley Laboratory.
* This product includes software developed by Harvard University.
*
* 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.
* This product includes software developed by Harvard University.
* 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.
*
* @(#)trap.c 8.4 (Berkeley) 9/23/93
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/resource.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <sys/syscall.h>
#include <sys/syslog.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <sparc/sparc/asm.h>
#include <machine/cpu.h>
#include <machine/ctlreg.h>
#include <machine/trap.h>
#include <machine/instr.h>
#include <machine/pmap.h>
#ifdef DDB
#include <machine/db_machdep.h>
#else
#include <machine/frame.h>
#endif
#ifdef COMPAT_SVR4
#include <machine/svr4_machdep.h>
#endif
#include <sparc/fpu/fpu_extern.h>
#include <sparc/sparc/memreg.h>
#include <sparc/sparc/cpuvar.h>
#define offsetof(s, f) ((int)&((s *)0)->f)
extern int cold;
#ifdef DEBUG
int rwindow_debug = 0;
#endif
/*
* Initial FPU state is all registers == all 1s, everything else == all 0s.
* This makes every floating point register a signalling NaN, with sign bit
* set, no matter how it is interpreted. Appendix N of the Sparc V8 document
* seems to imply that we should do this, and it does make sense.
*/
struct fpstate initfpstate = {
{ ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0,
~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0 }
};
/*
* There are more than 100 trap types, but most are unused.
*
* Trap type 0 is taken over as an `Asynchronous System Trap'.
* This is left-over Vax emulation crap that should be fixed.
*/
static const char T[] = "trap";
const char *trap_type[] = {
/* non-user vectors */
"ast", /* 0 */
"text fault", /* 1 */
"illegal instruction", /* 2 */
"privileged instruction",/*3 */
"fp disabled", /* 4 */
"window overflow", /* 5 */
"window underflow", /* 6 */
"alignment fault", /* 7 */
"fp exception", /* 8 */
"data fault", /* 9 */
"tag overflow", /* 0a */
T, T, T, T, T, T, /* 0b..10 */
"level 1 int", /* 11 */
"level 2 int", /* 12 */
"level 3 int", /* 13 */
"level 4 int", /* 14 */
"level 5 int", /* 15 */
"level 6 int", /* 16 */
"level 7 int", /* 17 */
"level 8 int", /* 18 */
"level 9 int", /* 19 */
"level 10 int", /* 1a */
"level 11 int", /* 1b */
"level 12 int", /* 1c */
"level 13 int", /* 1d */
"level 14 int", /* 1e */
"level 15 int", /* 1f */
T, T, T, T, T, T, T, T, /* 20..27 */
T, T, T, T, T, T, T, T, /* 28..2f */
T, T, T, T, T, T, /* 30..35 */
"cp disabled", /* 36 */
T, /* 37 */
T, T, T, T, T, T, T, T, /* 38..3f */
"cp exception", /* 40 */
T, T, T, T, T, T, T, /* 41..47 */
T, T, T, T, T, T, T, T, /* 48..4f */
T, T, T, T, T, T, T, T, /* 50..57 */
T, T, T, T, T, T, T, T, /* 58..5f */
T, T, T, T, T, T, T, T, /* 60..67 */
T, T, T, T, T, T, T, T, /* 68..6f */
T, T, T, T, T, T, T, T, /* 70..77 */
T, T, T, T, T, T, T, T, /* 78..7f */
/* user (software trap) vectors */
"syscall", /* 80 */
"breakpoint", /* 81 */
"zero divide", /* 82 */
"flush windows", /* 83 */
"clean windows", /* 84 */
"range check", /* 85 */
"fix align", /* 86 */
"integer overflow", /* 87 */
"svr4 syscall", /* 88 */
"4.4 syscall", /* 89 */
"kgdb exec", /* 8a */
T, T, T, T, T, /* 8b..8f */
T, T, T, T, T, T, T, T, /* 9a..97 */
T, T, T, T, T, T, T, T, /* 98..9f */
"svr4 getcc", /* a0 */
"svr4 setcc", /* a1 */
"svr4 getpsr", /* a2 */
"svr4 setpsr", /* a3 */
"svr4 gethrtime", /* a4 */
"svr4 gethrvtime", /* a5 */
T, /* a6 */
"svr4 gethrestime", /* a7 */
};
#define N_TRAP_TYPES (sizeof trap_type / sizeof *trap_type)
static __inline void userret __P((struct proc *, int, u_quad_t));
void trap __P((unsigned, int, int, struct trapframe *));
static __inline void share_fpu __P((struct proc *, struct trapframe *));
void mem_access_fault __P((unsigned, int, u_int, int, int, struct trapframe *));
void mem_access_fault4m __P((unsigned, u_int, u_int, u_int, u_int, struct trapframe *));
void syscall __P((register_t, struct trapframe *, register_t));
/*
* Define the code needed before returning to user mode, for
* trap, mem_access_fault, and syscall.
*/
static __inline void
userret(p, pc, oticks)
struct proc *p;
int pc;
u_quad_t oticks;
{
int sig;
/* take pending signals */
while ((sig = CURSIG(p)) != 0)
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_ast) {
want_ast = 0;
if (p->p_flag & P_OWEUPC) {
p->p_flag &= ~P_OWEUPC;
ADDUPROF(p);
}
}
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 put ourselves on the run queue
* but before we switched, we might not be on the queue
* indicated by our priority.
*/
(void) splstatclock();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
(void) spl0();
while ((sig = CURSIG(p)) != 0)
postsig(sig);
}
/*
* If profiling, charge recent system time to the trapped pc.
*/
if (p->p_flag & P_PROFIL)
addupc_task(p, pc, (int)(p->p_sticks - oticks));
curpriority = p->p_priority;
}
/*
* If someone stole the FPU while we were away, do not enable it
* on return. This is not done in userret() above as it must follow
* the ktrsysret() in syscall(). Actually, it is likely that the
* ktrsysret should occur before the call to userret.
*/
static __inline void share_fpu(p, tf)
struct proc *p;
struct trapframe *tf;
{
if ((tf->tf_psr & PSR_EF) != 0 && fpproc != p)
tf->tf_psr &= ~PSR_EF;
}
/*
* Called from locore.s trap handling, for non-MMU-related traps.
* (MMU-related traps go through mem_access_fault, below.)
*/
void
trap(type, psr, pc, tf)
register unsigned type;
register int psr, pc;
register struct trapframe *tf;
{
register struct proc *p;
register struct pcb *pcb;
register int n;
char bits[64];
u_quad_t sticks;
/* This steps the PC over the trap. */
#define ADVANCE (n = tf->tf_npc, tf->tf_pc = n, tf->tf_npc = n + 4)
cnt.v_trap++;
/*
* Generally, kernel traps cause a panic. Any exceptions are
* handled early here.
*/
if (psr & PSR_PS) {
#ifdef DDB
if (type == T_BREAKPOINT) {
write_all_windows();
if (kdb_trap(type, tf)) {
ADVANCE;
return;
}
}
#endif
#ifdef DIAGNOSTIC
/*
* Currently, we allow DIAGNOSTIC kernel code to
* flush the windows to record stack traces.
*/
if (type == T_FLUSHWIN) {
write_all_windows();
ADVANCE;
return;
}
#endif
/*
* Storing %fsr in cpu_attach will cause this trap
* even though the fpu has been enabled, if and only
* if there is no FPU.
*/
if (type == T_FPDISABLED && cold) {
ADVANCE;
return;
}
dopanic:
printf("trap type 0x%x: pc=%x npc=%x psr=%s\n",
type, pc, tf->tf_npc, bitmask_snprintf(psr,
PSR_BITS, bits, sizeof(bits)));
panic(type < N_TRAP_TYPES ? trap_type[type] : T);
/* NOTREACHED */
}
if ((p = curproc) == NULL)
p = &proc0;
sticks = p->p_sticks;
pcb = &p->p_addr->u_pcb;
p->p_md.md_tf = tf; /* for ptrace/signals */
switch (type) {
default:
if (type < 0x80) {
#ifdef SUSTAIN_BOGUS_TRAPS
if (0)
#endif
goto dopanic;
printf("trap type 0x%x: pc=%x npc=%x psr=%s\n",
type, pc, tf->tf_npc, bitmask_snprintf(psr,
PSR_BITS, bits, sizeof(bits)));
trapsignal(p, SIGILL, type);
break;
}
#if defined(COMPAT_SVR4)
badtrap:
#endif
/* the following message is gratuitous */
/* ... but leave it in until we find anything */
printf("%s[%d]: unimplemented software trap 0x%x\n",
p->p_comm, p->p_pid, type);
trapsignal(p, SIGILL, type);
break;
#ifdef COMPAT_SVR4
case T_SVR4_GETCC:
case T_SVR4_SETCC:
case T_SVR4_GETPSR:
case T_SVR4_SETPSR:
case T_SVR4_GETHRTIME:
case T_SVR4_GETHRVTIME:
case T_SVR4_GETHRESTIME:
if (!svr4_trap(type, p))
goto badtrap;
break;
#endif
case T_AST:
break; /* the work is all in userret() */
case T_ILLINST:
if ((n = emulinstr(pc, tf)) == 0) {
ADVANCE;
break;
}
trapsignal(p, n, 0); /* XXX code?? */
break;
case T_PRIVINST:
trapsignal(p, SIGILL, 0); /* XXX code?? */
break;
case T_FPDISABLED: {
register struct fpstate *fs = p->p_md.md_fpstate;
if (fs == NULL) {
fs = malloc(sizeof *fs, M_SUBPROC, M_WAITOK);
*fs = initfpstate;
p->p_md.md_fpstate = fs;
}
/*
* If we have not found an FPU, we have to emulate it.
*/
if (!foundfpu) {
#ifdef notyet
fpu_emulate(p, tf, fs);
break;
#else
trapsignal(p, SIGFPE, 0); /* XXX code?? */
break;
#endif
}
/*
* We may have more FPEs stored up and/or ops queued.
* If they exist, handle them and get out. Otherwise,
* resolve the FPU state, turn it on, and try again.
*/
if (fs->fs_qsize) {
fpu_cleanup(p, fs);
break;
}
if (fpproc != p) { /* we do not have it */
if (fpproc != NULL) /* someone else had it */
savefpstate(fpproc->p_md.md_fpstate);
loadfpstate(fs);
fpproc = p; /* now we do have it */
}
tf->tf_psr |= PSR_EF;
break;
}
case T_WINOF:
if (rwindow_save(p))
sigexit(p, SIGILL);
break;
#define read_rw(src, dst) \
copyin((caddr_t)(src), (caddr_t)(dst), sizeof(struct rwindow))
case T_RWRET:
/*
* T_RWRET is a window load needed in order to rett.
* It simply needs the window to which tf->tf_out[6]
* (%sp) points. There are no user or saved windows now.
* Copy the one from %sp into pcb->pcb_rw[0] and set
* nsaved to -1. If we decide to deliver a signal on
* our way out, we will clear nsaved.
*/
if (pcb->pcb_uw || pcb->pcb_nsaved)
panic("trap T_RWRET 1");
#ifdef DEBUG
if (rwindow_debug)
printf("%s[%d]: rwindow: pcb<-stack: %x\n",
p->p_comm, p->p_pid, tf->tf_out[6]);
#endif
if (read_rw(tf->tf_out[6], &pcb->pcb_rw[0]))
sigexit(p, SIGILL);
if (pcb->pcb_nsaved)
panic("trap T_RWRET 2");
pcb->pcb_nsaved = -1; /* mark success */
break;
case T_WINUF:
/*
* T_WINUF is a real window underflow, from a restore
* instruction. It needs to have the contents of two
* windows---the one belonging to the restore instruction
* itself, which is at its %sp, and the one belonging to
* the window above, which is at its %fp or %i6---both
* in the pcb. The restore's window may still be in
* the cpu; we need to force it out to the stack.
*/
#ifdef DEBUG
if (rwindow_debug)
printf("%s[%d]: rwindow: T_WINUF 0: pcb<-stack: %x\n",
p->p_comm, p->p_pid, tf->tf_out[6]);
#endif
write_user_windows();
if (rwindow_save(p) || read_rw(tf->tf_out[6], &pcb->pcb_rw[0]))
sigexit(p, SIGILL);
#ifdef DEBUG
if (rwindow_debug)
printf("%s[%d]: rwindow: T_WINUF 1: pcb<-stack: %x\n",
p->p_comm, p->p_pid, pcb->pcb_rw[0].rw_in[6]);
#endif
if (read_rw(pcb->pcb_rw[0].rw_in[6], &pcb->pcb_rw[1]))
sigexit(p, SIGILL);
if (pcb->pcb_nsaved)
panic("trap T_WINUF");
pcb->pcb_nsaved = -1; /* mark success */
break;
case T_ALIGN:
if ((p->p_md.md_flags & MDP_FIXALIGN) != 0 &&
fixalign(p, tf) == 0) {
ADVANCE;
break;
}
trapsignal(p, SIGBUS, 0); /* XXX code?? */
break;
case T_FPE:
/*
* Clean up after a floating point exception.
* fpu_cleanup can (and usually does) modify the
* state we save here, so we must `give up' the FPU
* chip context. (The software and hardware states
* will not match once fpu_cleanup does its job, so
* we must not save again later.)
*/
if (p != fpproc)
panic("fpe without being the FP user");
savefpstate(p->p_md.md_fpstate);
fpproc = NULL;
/* tf->tf_psr &= ~PSR_EF; */ /* share_fpu will do this */
fpu_cleanup(p, p->p_md.md_fpstate);
/* fpu_cleanup posts signals if needed */
#if 0 /* ??? really never??? */
ADVANCE;
#endif
break;
case T_TAGOF:
trapsignal(p, SIGEMT, 0); /* XXX code?? */
break;
case T_CPDISABLED:
uprintf("coprocessor instruction\n"); /* XXX */
trapsignal(p, SIGILL, 0); /* XXX code?? */
break;
case T_BREAKPOINT:
trapsignal(p, SIGTRAP, 0);
break;
case T_DIV0:
case T_IDIV0:
ADVANCE;
trapsignal(p, SIGFPE, FPE_INTDIV_TRAP);
break;
case T_FLUSHWIN:
write_user_windows();
#ifdef probably_slower_since_this_is_usually_false
if (pcb->pcb_nsaved && rwindow_save(p))
sigexit(p, SIGILL);
#endif
ADVANCE;
break;
case T_CLEANWIN:
uprintf("T_CLEANWIN\n"); /* XXX */
ADVANCE;
break;
case T_RANGECHECK:
uprintf("T_RANGECHECK\n"); /* XXX */
ADVANCE;
trapsignal(p, SIGILL, 0); /* XXX code?? */
break;
case T_FIXALIGN:
#ifdef DEBUG_ALIGN
uprintf("T_FIXALIGN\n");
#endif
/* User wants us to fix alignment faults */
p->p_md.md_flags |= MDP_FIXALIGN;
ADVANCE;
break;
case T_INTOF:
uprintf("T_INTOF\n"); /* XXX */
ADVANCE;
trapsignal(p, SIGFPE, FPE_INTOVF_TRAP);
break;
}
userret(p, pc, sticks);
share_fpu(p, tf);
#undef ADVANCE
}
/*
* Save windows from PCB into user stack, and return 0. This is used on
* window overflow pseudo-traps (from locore.s, just before returning to
* user mode) and when ptrace or sendsig needs a consistent state.
* As a side effect, rwindow_save() always sets pcb_nsaved to 0,
* clobbering the `underflow restore' indicator if it was -1.
*
* If the windows cannot be saved, pcb_nsaved is restored and we return -1.
*/
int
rwindow_save(p)
register struct proc *p;
{
register struct pcb *pcb = &p->p_addr->u_pcb;
register struct rwindow *rw = &pcb->pcb_rw[0];
register int i;
i = pcb->pcb_nsaved;
if (i < 0) {
pcb->pcb_nsaved = 0;
return (0);
}
if (i == 0)
return (0);
#ifdef DEBUG
if (rwindow_debug)
printf("%s[%d]: rwindow: pcb->stack:", p->p_comm, p->p_pid);
#endif
do {
#ifdef DEBUG
if (rwindow_debug)
printf(" %x", rw[1].rw_in[6]);
#endif
if (copyout((caddr_t)rw, (caddr_t)rw[1].rw_in[6],
sizeof *rw))
return (-1);
rw++;
} while (--i > 0);
#ifdef DEBUG
if (rwindow_debug)
printf("\n");
#endif
pcb->pcb_nsaved = 0;
return (0);
}
/*
* Kill user windows (before exec) by writing back to stack or pcb
* and then erasing any pcb tracks. Otherwise we might try to write
* the registers into the new process after the exec.
*/
void
kill_user_windows(p)
struct proc *p;
{
write_user_windows();
p->p_addr->u_pcb.pcb_nsaved = 0;
}
/*
* Called from locore.s trap handling, for synchronous memory faults.
*
* This duplicates a lot of logic in trap() and perhaps should be
* moved there; but the bus-error-register parameters are unique to
* this routine.
*
* Since synchronous errors accumulate during prefetch, we can have
* more than one `cause'. But we do not care what the cause, here;
* we just want to page in the page and try again.
*/
void
mem_access_fault(type, ser, v, pc, psr, tf)
register unsigned type;
register int ser;
register u_int v;
register int pc, psr;
register struct trapframe *tf;
{
#if defined(SUN4) || defined(SUN4C)
register struct proc *p;
register struct vmspace *vm;
register vm_offset_t va;
register int rv;
vm_prot_t ftype;
int onfault;
u_quad_t sticks;
char bits[64];
cnt.v_trap++;
if ((p = curproc) == NULL) /* safety check */
p = &proc0;
sticks = p->p_sticks;
/*
* Figure out what to pass the VM code, and ignore the sva register
* value in v on text faults (text faults are always at pc).
* Kernel faults are somewhat different: text faults are always
* illegal, and data faults are extra complex. User faults must
* set p->p_md.md_tf, in case we decide to deliver a signal. Check
* for illegal virtual addresses early since those can induce more
* faults.
*/
if (type == T_TEXTFAULT)
v = pc;
if (VA_INHOLE(v))
goto fault;
ftype = ser & SER_WRITE ? VM_PROT_READ|VM_PROT_WRITE : VM_PROT_READ;
va = trunc_page(v);
if (psr & PSR_PS) {
extern char Lfsbail[];
if (type == T_TEXTFAULT) {
(void) splhigh();
printf("text fault: pc=%x ser=%s\n", pc,
bitmask_snprintf(ser, SER_BITS, bits, sizeof(bits)));
panic("kernel fault");
/* NOTREACHED */
}
/*
* If this was an access that we shouldn't try to page in,
* resume at the fault handler without any action.
*/
if (p->p_addr && p->p_addr->u_pcb.pcb_onfault == Lfsbail)
goto kfault;
/*
* During autoconfiguration, faults are never OK unless
* pcb_onfault is set. Once running normally we must allow
* exec() to cause copy-on-write faults to kernel addresses.
*/
if (cold)
goto kfault;
if (va >= KERNBASE) {
if (vm_fault(kernel_map, va, ftype, 0) == KERN_SUCCESS)
return;
goto kfault;
}
} else
p->p_md.md_tf = tf;
/*
* mmu_pagein returns -1 if the page is already valid, in which
* case we have a hard fault; it returns 1 if it loads a segment
* that got bumped out via LRU replacement.
*/
vm = p->p_vmspace;
rv = mmu_pagein(&vm->vm_pmap, va,
ser & SER_WRITE ? VM_PROT_WRITE : VM_PROT_READ);
if (rv < 0)
goto fault;
if (rv > 0)
goto out;
/* alas! must call the horrible vm code */
rv = vm_fault(&vm->vm_map, (vm_offset_t)va, ftype, FALSE);
/*
* If this was a stack access we keep track of the maximum
* accessed stack size. Also, if vm_fault gets a protection
* failure it is due to accessing the stack region outside
* the current limit and we need to reflect that as an access
* error.
*/
if ((caddr_t)va >= vm->vm_maxsaddr) {
if (rv == KERN_SUCCESS) {
unsigned nss = clrnd(btoc(USRSTACK - va));
if (nss > vm->vm_ssize)
vm->vm_ssize = nss;
} else if (rv == KERN_PROTECTION_FAILURE)
rv = KERN_INVALID_ADDRESS;
}
if (rv == KERN_SUCCESS) {
/*
* pmap_enter() does not enter all requests made from
* vm_fault into the MMU (as that causes unnecessary
* entries for `wired' pages). Instead, we call
* mmu_pagein here to make sure the new PTE gets installed.
*/
(void) mmu_pagein(&vm->vm_pmap, va, VM_PROT_NONE);
} else {
/*
* Pagein failed. If doing copyin/out, return to onfault
* address. Any other page fault in kernel, die; if user
* fault, deliver SIGSEGV.
*/
fault:
if (psr & PSR_PS) {
kfault:
onfault = p->p_addr ?
(int)p->p_addr->u_pcb.pcb_onfault : 0;
if (!onfault) {
(void) splhigh();
printf("data fault: pc=%x addr=%x ser=%s\n",
pc, v, bitmask_snprintf(ser, SER_BITS,
bits, sizeof(bits)));
panic("kernel fault");
/* NOTREACHED */
}
tf->tf_pc = onfault;
tf->tf_npc = onfault + 4;
return;
}
trapsignal(p, SIGSEGV, (u_int)v);
}
out:
if ((psr & PSR_PS) == 0) {
userret(p, pc, sticks);
share_fpu(p, tf);
}
#endif /* Sun4/Sun4C */
}
#if defined(SUN4M) /* 4m version of mem_access_fault() follows */
static int tfaultaddr = (int) 0xdeadbeef;
#ifdef DEBUG
int dfdebug = 0;
#endif
void
mem_access_fault4m(type, sfsr, sfva, afsr, afva, tf)
register unsigned type;
register u_int sfsr;
register u_int sfva;
register u_int afsr;
register u_int afva;
register struct trapframe *tf;
{
register int pc, psr;
register struct proc *p;
register struct vmspace *vm;
register vm_offset_t va;
register int rv;
vm_prot_t ftype;
int onfault;
u_quad_t sticks;
char bits[64];
cnt.v_trap++;
if ((p = curproc) == NULL) /* safety check */
p = &proc0;
sticks = p->p_sticks;
pc = tf->tf_pc; /* These are needed below */
psr = tf->tf_psr;
/*
* Our first priority is handling serious faults, such as
* parity errors or async faults that might have come through here.
* If afsr & AFSR_AFO != 0, then we're on a HyperSPARC and we
* got an async fault. We pass it on to memerr4m. Similarly, if
* the trap was T_STOREBUFFAULT, we pass it on to memerr4m.
* If we have a data fault, but SFSR_FAV is not set in the sfsr,
* then things are really bizarre, and we treat it as a hard
* error and pass it on to memerr4m. See pg. 9-35 in the SuperSPARC
* user's guide for more info, and for a possible solution which we
* don't implement here.
*/
if ((afsr & AFSR_AFO) != 0 || type == T_STOREBUFFAULT ||
(type == T_DATAFAULT && !(sfsr & SFSR_FAV))) {
memerr4m(type, sfsr, sfva, afsr, afva, tf);
/*
* If we get here, exit the trap handler and wait for the
* trap to re-occur.
*/
goto out;
}
/*
* Figure out what to pass the VM code. We cannot ignore the sfva
* register on text faults, since this might be a trap on an
* alternate-ASI access to code space. However, if we're on a
* supersparc, we can't help using PC, since we don't get a VA in
* sfva.
* Kernel faults are somewhat different: text faults are always
* illegal, and data faults are extra complex. User faults must
* set p->p_md.md_tf, in case we decide to deliver a signal. Check
* for illegal virtual addresses early since those can induce more
* faults.
* All translation faults are illegal, and result in a SIGSEGV
* being delivered to the running process (or a kernel panic, for
* a kernel fault). We check the translation first to make sure
* it is not spurious.
* Also, note that in the case where we have an overwritten
* text fault (OW==1, AT==2,3), we attempt to service the
* second (overwriting) fault, then restart the instruction
* (which is from the first fault) and allow the first trap
* to reappear. XXX is this right? It will probably change...
*/
if ((sfsr & SFSR_FT) == SFSR_FT_NONE)
goto out; /* No fault. Why were we called? */
/*
* NOTE: the per-CPU fault status register readers (in locore)
* may already have decided to pass `pc' in `sfva', so we avoid
* testing CPU types here.
* Q: test SFSR_FAV in the locore stubs too?
*/
if ((sfsr & SFSR_FAV) == 0) {
if (type == T_TEXTFAULT)
sfva = pc;
else
goto fault;
}
if ((sfsr & SFSR_FT) == SFSR_FT_TRANSERR) {
/* Translation errors are always fatal, as they indicate
* a corrupt translation (page) table hierarchy.
*/
if (tfaultaddr == sfva) /* Prevent infinite loops w/a static */
goto fault;
tfaultaddr = sfva;
if ((lda((sfva & 0xFFFFF000) | ASI_SRMMUFP_LN, ASI_SRMMUFP) &
SRMMU_TETYPE) != SRMMU_TEPTE)
goto fault; /* Translation bad */
else goto out; /* Translation OK, retry operation */
}
va = trunc_page(sfva);
if (((sfsr & SFSR_AT_TEXT) || type == T_TEXTFAULT) &&
!(sfsr & SFSR_AT_STORE) && (sfsr & SFSR_OW)) {
if (psr & PSR_PS) /* never allow in kernel */
goto kfault;
#if 0
/*
* Double text fault. The evil "case 5" from the HS manual...
* Attempt to handle early fault. Ignores ASI 8,9 issue...may
* do a useless VM read.
* XXX: Is this really necessary?
*/
if (mmumod == SUN4M_MMU_HS) { /* On HS, we have va for both */
if (vm_fault(kernel_map, trunc_page(pc),
VM_PROT_READ, 0) != KERN_SUCCESS)
#ifdef DEBUG
printf("mem_access_fault: "
"can't pagein 1st text fault.\n")
#endif
;
}
#endif
}
/* Now munch on protections... */
ftype = sfsr & SFSR_AT_STORE ? VM_PROT_READ|VM_PROT_WRITE:VM_PROT_READ;
if (psr & PSR_PS) {
extern char Lfsbail[];
if (sfsr & SFSR_AT_TEXT || type == T_TEXTFAULT) {
(void) splhigh();
printf("text fault: pc=%x sfsr=%s sfva=%x\n", pc,
bitmask_snprintf(sfsr, SFSR_BITS, bits,
sizeof(bits)), sfva);
panic("kernel fault");
/* NOTREACHED */
}
/*
* If this was an access that we shouldn't try to page in,
* resume at the fault handler without any action.
*/
if (p->p_addr && p->p_addr->u_pcb.pcb_onfault == Lfsbail)
goto kfault;
/*
* During autoconfiguration, faults are never OK unless
* pcb_onfault is set. Once running normally we must allow
* exec() to cause copy-on-write faults to kernel addresses.
*/
if (cold)
goto kfault;
if (va >= KERNBASE) {
if (vm_fault(kernel_map, va, ftype, 0) == KERN_SUCCESS)
return;
goto kfault;
}
} else
p->p_md.md_tf = tf;
vm = p->p_vmspace;
/* alas! must call the horrible vm code */
rv = vm_fault(&vm->vm_map, (vm_offset_t)va, ftype, FALSE);
/*
* If this was a stack access we keep track of the maximum
* accessed stack size. Also, if vm_fault gets a protection
* failure it is due to accessing the stack region outside
* the current limit and we need to reflect that as an access
* error.
*/
if ((caddr_t)va >= vm->vm_maxsaddr) {
if (rv == KERN_SUCCESS) {
unsigned nss = clrnd(btoc(USRSTACK - va));
if (nss > vm->vm_ssize)
vm->vm_ssize = nss;
} else if (rv == KERN_PROTECTION_FAILURE)
rv = KERN_INVALID_ADDRESS;
}
if (rv != KERN_SUCCESS) {
/*
* Pagein failed. If doing copyin/out, return to onfault
* address. Any other page fault in kernel, die; if user
* fault, deliver SIGSEGV.
*/
fault:
if (psr & PSR_PS) {
kfault:
onfault = p->p_addr ?
(int)p->p_addr->u_pcb.pcb_onfault : 0;
if (!onfault) {
(void) splhigh();
printf("data fault: pc=%x addr=%x sfsr=%s\n",
pc, sfva, bitmask_snprintf(sfsr, SFSR_BITS,
bits, sizeof(bits)));
panic("kernel fault");
/* NOTREACHED */
}
tf->tf_pc = onfault;
tf->tf_npc = onfault + 4;
return;
}
trapsignal(p, SIGSEGV, (u_int)sfva);
}
out:
if ((psr & PSR_PS) == 0) {
userret(p, pc, sticks);
share_fpu(p, tf);
}
}
#endif
/*
* System calls. `pc' is just a copy of tf->tf_pc.
*
* Note that the things labelled `out' registers in the trapframe were the
* `in' registers within the syscall trap code (because of the automatic
* `save' effect of each trap). They are, however, the %o registers of the
* thing that made the system call, and are named that way here.
*/
void
syscall(code, tf, pc)
register_t code;
register struct trapframe *tf;
register_t pc;
{
register int i, nsys, *ap, nap;
register struct sysent *callp;
register struct proc *p;
int error, new;
struct args {
register_t i[8];
} args;
register_t rval[2];
u_quad_t sticks;
#ifdef DIAGNOSTIC
extern struct pcb *cpcb;
#endif
cnt.v_syscall++;
p = curproc;
#ifdef DIAGNOSTIC
if (tf->tf_psr & PSR_PS)
panic("syscall");
if (cpcb != &p->p_addr->u_pcb)
panic("syscall cpcb/ppcb");
if (tf != (struct trapframe *)((caddr_t)cpcb + USPACE) - 1)
panic("syscall trapframe");
#endif
sticks = p->p_sticks;
p->p_md.md_tf = tf;
new = code & (SYSCALL_G7RFLAG | SYSCALL_G2RFLAG);
code &= ~(SYSCALL_G7RFLAG | SYSCALL_G2RFLAG);
callp = p->p_emul->e_sysent;
nsys = p->p_emul->e_nsysent;
/*
* The first six system call arguments are in the six %o registers.
* Any arguments beyond that are in the `argument extension' area
* of the user's stack frame (see <machine/frame.h>).
*
* Check for ``special'' codes that alter this, namely syscall and
* __syscall. The latter takes a quad syscall number, so that other
* arguments are at their natural alignments. Adjust the number
* of ``easy'' arguments as appropriate; we will copy the hard
* ones later as needed.
*/
ap = &tf->tf_out[0];
nap = 6;
switch (code) {
case SYS_syscall:
code = *ap++;
nap--;
break;
case SYS___syscall:
if (callp != sysent)
break;
code = ap[_QUAD_LOWWORD];
ap += 2;
nap -= 2;
break;
}
if (code < 0 || code >= nsys)
callp += p->p_emul->e_nosys;
else {
callp += code;
i = callp->sy_argsize / sizeof(register_t);
if (i > nap) { /* usually false */
if (i > 8)
panic("syscall nargs");
error = copyin((caddr_t)tf->tf_out[6] +
offsetof(struct frame, fr_argx),
(caddr_t)&args.i[nap], (i - nap) * sizeof(register_t));
if (error) {
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code,
callp->sy_argsize, args.i);
#endif
goto bad;
}
i = nap;
}
copywords(ap, args.i, i * sizeof(register_t));
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_argsize, args.i);
#endif
rval[0] = 0;
rval[1] = tf->tf_out[1];
error = (*callp->sy_call)(p, &args, rval);
if (error == 0) {
/* Note: fork() does not return here in the child */
tf->tf_out[0] = rval[0];
tf->tf_out[1] = rval[1];
if (new) {
/* jmp %g2 (or %g7, deprecated) on success */
i = tf->tf_global[new & SYSCALL_G2RFLAG ? 2 : 7];
if (i & 3) {
error = EINVAL;
goto bad;
}
} else {
/* old system call convention: clear C on success */
tf->tf_psr &= ~PSR_C; /* success */
i = tf->tf_npc;
}
tf->tf_pc = i;
tf->tf_npc = i + 4;
} else if (error > 0 /*error != ERESTART && error != EJUSTRETURN*/) {
bad:
if (p->p_emul->e_errno)
error = p->p_emul->e_errno[error];
tf->tf_out[0] = error;
tf->tf_psr |= PSR_C; /* fail */
i = tf->tf_npc;
tf->tf_pc = i;
tf->tf_npc = i + 4;
}
/* else if (error == ERESTART || error == EJUSTRETURN) */
/* nothing to do */
userret(p, pc, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
share_fpu(p, tf);
}
/*
* Process the tail end of a fork() for the child.
*/
void
child_return(p)
struct proc *p;
{
/*
* Return values in the frame set by cpu_fork().
*/
userret(p, p->p_md.md_tf->tf_pc, 0);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep,
(p->p_flag & P_PPWAIT) ? SYS_vfork : SYS_fork, 0, 0);
#endif
}