freebsd-skq/sys/powerpc/aim/trap.c
nwhitehorn 5db25627cf Fix a typo in the SRR1 comparison for program exceptions. While here,
replace magic numbers with constants to keep this from happening again.

Without this fix, some programs would occasionally get SIGTRAP instead
of SIGILL on an illegal instruction. This affected Altivec detection
in pixman, and possibly other software.

Reported by:	Andreas Tobler
MFC after:	1 week
2009-04-19 06:30:00 +00:00

670 lines
15 KiB
C

/*-
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* All rights reserved.
*
* 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 TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
*
* $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ktrace.h"
#include <sys/param.h>
#include <sys/kdb.h>
#include <sys/proc.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/pioctl.h>
#include <sys/ptrace.h>
#include <sys/reboot.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/signalvar.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <sys/vmmeter.h>
#include <security/audit/audit.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <machine/altivec.h>
#include <machine/cpu.h>
#include <machine/db_machdep.h>
#include <machine/fpu.h>
#include <machine/frame.h>
#include <machine/pcb.h>
#include <machine/pmap.h>
#include <machine/psl.h>
#include <machine/trap.h>
#include <machine/spr.h>
#include <machine/sr.h>
static void trap_fatal(struct trapframe *frame);
static void printtrap(u_int vector, struct trapframe *frame, int isfatal,
int user);
static int trap_pfault(struct trapframe *frame, int user);
static int fix_unaligned(struct thread *td, struct trapframe *frame);
static int handle_onfault(struct trapframe *frame);
static void syscall(struct trapframe *frame);
static __inline void setusr(u_int);
int setfault(faultbuf); /* defined in locore.S */
/* Why are these not defined in a header? */
int badaddr(void *, size_t);
int badaddr_read(void *, size_t, int *);
extern char *syscallnames[];
struct powerpc_exception {
u_int vector;
char *name;
};
static struct powerpc_exception powerpc_exceptions[] = {
{ 0x0100, "system reset" },
{ 0x0200, "machine check" },
{ 0x0300, "data storage interrupt" },
{ 0x0400, "instruction storage interrupt" },
{ 0x0500, "external interrupt" },
{ 0x0600, "alignment" },
{ 0x0700, "program" },
{ 0x0800, "floating-point unavailable" },
{ 0x0900, "decrementer" },
{ 0x0c00, "system call" },
{ 0x0d00, "trace" },
{ 0x0e00, "floating-point assist" },
{ 0x0f00, "performance monitoring" },
{ 0x0f20, "altivec unavailable" },
{ 0x1000, "instruction tlb miss" },
{ 0x1100, "data load tlb miss" },
{ 0x1200, "data store tlb miss" },
{ 0x1300, "instruction breakpoint" },
{ 0x1400, "system management" },
{ 0x1600, "altivec assist" },
{ 0x1700, "thermal management" },
{ 0x2000, "run mode/trace" },
{ 0x3000, NULL }
};
static const char *
trapname(u_int vector)
{
struct powerpc_exception *pe;
for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) {
if (pe->vector == vector)
return (pe->name);
}
return ("unknown");
}
void
trap(struct trapframe *frame)
{
struct thread *td;
struct proc *p;
int sig, type, user;
u_int ucode;
ksiginfo_t ksi;
PCPU_INC(cnt.v_trap);
td = PCPU_GET(curthread);
p = td->td_proc;
type = ucode = frame->exc;
sig = 0;
user = frame->srr1 & PSL_PR;
CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name,
trapname(type), user ? "user" : "kernel");
if (user) {
td->td_pticks = 0;
td->td_frame = frame;
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
/* User Mode Traps */
switch (type) {
case EXC_RUNMODETRC:
case EXC_TRC:
frame->srr1 &= ~PSL_SE;
sig = SIGTRAP;
break;
case EXC_DSI:
case EXC_ISI:
sig = trap_pfault(frame, 1);
break;
case EXC_SC:
syscall(frame);
break;
case EXC_FPU:
KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
("FPU already enabled for thread"));
enable_fpu(td);
break;
case EXC_VEC:
KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC,
("Altivec already enabled for thread"));
enable_vec(td);
break;
case EXC_VECAST:
printf("Vector assist exception!\n");
sig = SIGILL;
break;
case EXC_ALI:
if (fix_unaligned(td, frame) != 0)
sig = SIGBUS;
else
frame->srr0 += 4;
break;
case EXC_PGM:
/* Identify the trap reason */
if (frame->srr1 & EXC_PGM_TRAP)
sig = SIGTRAP;
else
sig = SIGILL;
break;
default:
trap_fatal(frame);
}
} else {
/* Kernel Mode Traps */
KASSERT(cold || td->td_ucred != NULL,
("kernel trap doesn't have ucred"));
switch (type) {
case EXC_DSI:
if (trap_pfault(frame, 0) == 0)
return;
break;
case EXC_MCHK:
if (handle_onfault(frame))
return;
break;
default:
break;
}
trap_fatal(frame);
}
#ifdef ALTIVEC
if (td != PCPU_GET(vecthread) ||
td->td_pcb->pcb_veccpu != PCPU_GET(cpuid))
frame->srr1 &= ~PSL_VEC;
#endif /* ALTIVEC */
if (sig != 0) {
if (p->p_sysent->sv_transtrap != NULL)
sig = (p->p_sysent->sv_transtrap)(sig, type);
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = sig;
ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
/* ksi.ksi_addr = ? */
ksi.ksi_trapno = type;
trapsignal(td, &ksi);
}
userret(td, frame);
mtx_assert(&Giant, MA_NOTOWNED);
}
static void
trap_fatal(struct trapframe *frame)
{
printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
#ifdef KDB
if ((debugger_on_panic || kdb_active) &&
kdb_trap(frame->exc, 0, frame))
return;
#endif
panic("%s trap", trapname(frame->exc));
}
static void
printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
{
printf("\n");
printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
user ? "user" : "kernel");
printf("\n");
printf(" exception = 0x%x (%s)\n", vector >> 8,
trapname(vector));
switch (vector) {
case EXC_DSI:
printf(" virtual address = 0x%x\n", frame->cpu.aim.dar);
break;
case EXC_ISI:
printf(" virtual address = 0x%x\n", frame->srr0);
break;
}
printf(" srr0 = 0x%x\n", frame->srr0);
printf(" srr1 = 0x%x\n", frame->srr1);
printf(" lr = 0x%x\n", frame->lr);
printf(" curthread = %p\n", curthread);
if (curthread != NULL)
printf(" pid = %d, comm = %s\n",
curthread->td_proc->p_pid, curthread->td_name);
printf("\n");
}
/*
* Handles a fatal fault when we have onfault state to recover. Returns
* non-zero if there was onfault recovery state available.
*/
static int
handle_onfault(struct trapframe *frame)
{
struct thread *td;
faultbuf *fb;
td = curthread;
fb = td->td_pcb->pcb_onfault;
if (fb != NULL) {
frame->srr0 = (*fb)[0];
frame->fixreg[1] = (*fb)[1];
frame->fixreg[2] = (*fb)[2];
frame->fixreg[3] = 1;
frame->cr = (*fb)[3];
bcopy(&(*fb)[4], &frame->fixreg[13],
19 * sizeof(register_t));
return (1);
}
return (0);
}
void
syscall(struct trapframe *frame)
{
caddr_t params;
struct sysent *callp;
struct thread *td;
struct proc *p;
int error, n;
size_t narg;
register_t args[10];
u_int code;
td = PCPU_GET(curthread);
p = td->td_proc;
PCPU_INC(cnt.v_syscall);
code = frame->fixreg[0];
params = (caddr_t)(frame->fixreg + FIRSTARG);
n = NARGREG;
if (p->p_sysent->sv_prepsyscall) {
/*
* The prep code is MP aware.
*/
(*p->p_sysent->sv_prepsyscall)(frame, args, &code, &params);
} else if (code == SYS_syscall) {
/*
* code is first argument,
* followed by actual args.
*/
code = *(u_int *) params;
params += sizeof(register_t);
n -= 1;
} else if (code == SYS___syscall) {
/*
* Like syscall, but code is a quad,
* so as to maintain quad alignment
* for the rest of the args.
*/
params += sizeof(register_t);
code = *(u_int *) params;
params += sizeof(register_t);
n -= 2;
}
if (p->p_sysent->sv_mask)
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];
narg = callp->sy_narg;
if (narg > n) {
bcopy(params, args, n * sizeof(register_t));
error = copyin(MOREARGS(frame->fixreg[1]), args + n,
(narg - n) * sizeof(register_t));
params = (caddr_t)args;
} else
error = 0;
CTR5(KTR_SYSC, "syscall: p=%s %s(%x %x %x)", td->td_name,
syscallnames[code],
frame->fixreg[FIRSTARG],
frame->fixreg[FIRSTARG+1],
frame->fixreg[FIRSTARG+2]);
#ifdef KTRACE
if (KTRPOINT(td, KTR_SYSCALL))
ktrsyscall(code, narg, (register_t *)params);
#endif
td->td_syscalls++;
if (error == 0) {
td->td_retval[0] = 0;
td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
STOPEVENT(p, S_SCE, narg);
PTRACESTOP_SC(p, td, S_PT_SCE);
AUDIT_SYSCALL_ENTER(code, td);
error = (*callp->sy_call)(td, params);
AUDIT_SYSCALL_EXIT(error, td);
CTR3(KTR_SYSC, "syscall: p=%s %s ret=%x", td->td_name,
syscallnames[code], td->td_retval[0]);
}
switch (error) {
case 0:
if (frame->fixreg[0] == SYS___syscall &&
code != SYS_freebsd6_lseek && code != SYS_lseek) {
/*
* 64-bit return, 32-bit syscall. Fixup byte order
*/
frame->fixreg[FIRSTARG] = 0;
frame->fixreg[FIRSTARG + 1] = td->td_retval[0];
} else {
frame->fixreg[FIRSTARG] = td->td_retval[0];
frame->fixreg[FIRSTARG + 1] = td->td_retval[1];
}
/* XXX: Magic number */
frame->cr &= ~0x10000000;
break;
case ERESTART:
/*
* Set user's pc back to redo the system call.
*/
frame->srr0 -= 4;
break;
case EJUSTRETURN:
/* nothing to do */
break;
default:
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->fixreg[FIRSTARG] = error;
/* XXX: Magic number: Carry Flag Equivalent? */
frame->cr |= 0x10000000;
break;
}
/*
* Check for misbehavior.
*/
WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
(code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???");
KASSERT(td->td_critnest == 0,
("System call %s returning in a critical section",
(code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???"));
KASSERT(td->td_locks == 0,
("System call %s returning with %d locks held",
(code >= 0 && code < SYS_MAXSYSCALL) ? syscallnames[code] : "???",
td->td_locks));
#ifdef KTRACE
if (KTRPOINT(td, KTR_SYSRET))
ktrsysret(code, error, td->td_retval[0]);
#endif
/*
* Does the comment in the i386 code about errno apply here?
*/
STOPEVENT(p, S_SCX, code);
PTRACESTOP_SC(p, td, S_PT_SCX);
}
static int
trap_pfault(struct trapframe *frame, int user)
{
vm_offset_t eva, va;
struct thread *td;
struct proc *p;
vm_map_t map;
vm_prot_t ftype;
int rv;
u_int user_sr;
td = curthread;
p = td->td_proc;
if (frame->exc == EXC_ISI) {
eva = frame->srr0;
ftype = VM_PROT_READ | VM_PROT_EXECUTE;
} else {
eva = frame->cpu.aim.dar;
if (frame->cpu.aim.dsisr & DSISR_STORE)
ftype = VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
}
if (user) {
map = &p->p_vmspace->vm_map;
} else {
if ((eva >> ADDR_SR_SHFT) == USER_SR) {
if (p->p_vmspace == NULL)
return (SIGSEGV);
__asm ("mfsr %0, %1"
: "=r"(user_sr)
: "K"(USER_SR));
eva &= ADDR_PIDX | ADDR_POFF;
eva |= user_sr << ADDR_SR_SHFT;
map = &p->p_vmspace->vm_map;
} else {
map = kernel_map;
}
}
va = trunc_page(eva);
if (map != kernel_map) {
/*
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype,
(ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY
: VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
} else {
/*
* Don't have to worry about process locking or stacks in the
* kernel.
*/
rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
}
if (rv == KERN_SUCCESS)
return (0);
if (!user && handle_onfault(frame))
return (0);
return (SIGSEGV);
}
static __inline void
setusr(u_int content)
{
__asm __volatile ("isync; mtsr %0,%1; isync"
:: "n"(USER_SR), "r"(content));
}
int
badaddr(void *addr, size_t size)
{
return (badaddr_read(addr, size, NULL));
}
int
badaddr_read(void *addr, size_t size, int *rptr)
{
struct thread *td;
faultbuf env;
int x;
/* Get rid of any stale machine checks that have been waiting. */
__asm __volatile ("sync; isync");
td = PCPU_GET(curthread);
if (setfault(env)) {
td->td_pcb->pcb_onfault = 0;
__asm __volatile ("sync");
return 1;
}
__asm __volatile ("sync");
switch (size) {
case 1:
x = *(volatile int8_t *)addr;
break;
case 2:
x = *(volatile int16_t *)addr;
break;
case 4:
x = *(volatile int32_t *)addr;
break;
default:
panic("badaddr: invalid size (%d)", size);
}
/* Make sure we took the machine check, if we caused one. */
__asm __volatile ("sync; isync");
td->td_pcb->pcb_onfault = 0;
__asm __volatile ("sync"); /* To be sure. */
/* Use the value to avoid reorder. */
if (rptr)
*rptr = x;
return (0);
}
/*
* For now, this only deals with the particular unaligned access case
* that gcc tends to generate. Eventually it should handle all of the
* possibilities that can happen on a 32-bit PowerPC in big-endian mode.
*/
static int
fix_unaligned(struct thread *td, struct trapframe *frame)
{
struct thread *fputhread;
int indicator, reg;
double *fpr;
indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr);
switch (indicator) {
case EXC_ALI_LFD:
case EXC_ALI_STFD:
reg = EXC_ALI_RST(frame->cpu.aim.dsisr);
fpr = &td->td_pcb->pcb_fpu.fpr[reg];
fputhread = PCPU_GET(fputhread);
/* Juggle the FPU to ensure that we've initialized
* the FPRs, and that their current state is in
* the PCB.
*/
if (fputhread != td) {
if (fputhread)
save_fpu(fputhread);
enable_fpu(td);
}
save_fpu(td);
if (indicator == EXC_ALI_LFD) {
if (copyin((void *)frame->cpu.aim.dar, fpr,
sizeof(double)) != 0)
return -1;
enable_fpu(td);
} else {
if (copyout(fpr, (void *)frame->cpu.aim.dar,
sizeof(double)) != 0)
return -1;
}
return 0;
break;
}
return -1;
}