void
trap(struct trapframe *frame)
{
struct thread *td;
struct proc *p;
int sig, type, user;
ksiginfo_t ksi;
#ifdef KDB
if (kdb_active) {
kdb_reenter();
return;
}
#endif
PCPU_INC(cnt.v_trap);
td = curthread;
p = td->td_proc;
type = frame->exc;
sig = 0;
user = (frame->srr1 & PSL_PR) ? 1 : 0;
CTR3(KTR_TRAP, "trap: %s type=%s (%s)", p->p_comm,
trapname(type), user ? "user" : "kernel");
if (user) {
td->td_frame = frame;
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
/* User Mode Traps */
switch (type) {
case EXC_DSI:
case EXC_ISI:
sig = trap_pfault(frame, 1);
break;
case EXC_SC:
syscall(frame);
break;
case EXC_ALI:
if (fix_unaligned(td, frame) != 0)
sig = SIGBUS;
else
frame->srr0 += 4;
break;
case EXC_DEBUG: /* Single stepping */
mtspr(SPR_DBSR, mfspr(SPR_DBSR));
frame->srr1 &= ~PSL_DE;
frame->cpu.booke.dbcr0 &= ~(DBCR0_IDM || DBCR0_IC);
sig = SIGTRAP;
break;
case EXC_PGM: /* Program exception */
#ifdef FPU_EMU
sig = fpu_emulate(frame,
(struct fpreg *)&td->td_pcb->pcb_fpu);
#else
/* XXX SIGILL for non-trap instructions. */
sig = SIGTRAP;
#endif
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_DEBUG:
mtspr(SPR_DBSR, mfspr(SPR_DBSR));
kdb_trap(frame->exc, 0, frame);
return;
case EXC_DSI:
if (trap_pfault(frame, 0) == 0)
return;
break;
case EXC_MCHK:
if (handle_onfault(frame))
return;
break;
#ifdef KDB
case EXC_PGM:
if (frame->cpu.booke.esr & ESR_PTR)
kdb_trap(EXC_PGM, 0, frame);
return;
#endif
default:
break;
}
trap_fatal(frame);
}
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 = type; /* XXX, not POSIX */
/* ksi.ksi_addr = ? */
ksi.ksi_trapno = type;
trapsignal(td, &ksi);
}
userret(td, frame);
}
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;
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.booke.dear;
if (frame->cpu.booke.esr & ESR_ST)
ftype = VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
}
if (user) {
KASSERT(p->p_vmspace != NULL, ("trap_pfault: vmspace NULL"));
map = &p->p_vmspace->vm_map;
} else {
if (eva < VM_MAXUSER_ADDRESS) {
if (p->p_vmspace == NULL)
return (SIGSEGV);
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, 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 ((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
void
trap(struct trapframe *frame)
{
struct thread *td;
struct proc *p;
#ifdef KDTRACE_HOOKS
uint32_t inst;
#endif
int sig, type, user;
u_int ucode;
ksiginfo_t ksi;
PCPU_INC(cnt.v_trap);
td = 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");
#ifdef KDTRACE_HOOKS
/*
* A trap can occur while DTrace executes a probe. Before
* executing the probe, DTrace blocks re-scheduling and sets
* a flag in its per-cpu flags to indicate that it doesn't
* want to fault. On returning from the probe, the no-fault
* flag is cleared and finally re-scheduling is enabled.
*
* If the DTrace kernel module has registered a trap handler,
* call it and if it returns non-zero, assume that it has
* handled the trap and modified the trap frame so that this
* function can return normally.
*/
if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type) != 0)
return;
#endif
if (user) {
td->td_pticks = 0;
td->td_frame = frame;
if (td->td_cowgen != p->p_cowgen)
thread_cow_update(td);
/* User Mode Traps */
switch (type) {
case EXC_RUNMODETRC:
case EXC_TRC:
frame->srr1 &= ~PSL_SE;
sig = SIGTRAP;
ucode = TRAP_TRACE;
break;
#ifdef __powerpc64__
case EXC_ISE:
case EXC_DSE:
if (handle_user_slb_spill(&p->p_vmspace->vm_pmap,
(type == EXC_ISE) ? frame->srr0 : frame->dar) != 0){
sig = SIGSEGV;
ucode = SEGV_MAPERR;
}
break;
#endif
case EXC_DSI:
case EXC_ISI:
sig = trap_pfault(frame, 1);
if (sig == SIGSEGV)
ucode = SEGV_MAPERR;
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_VSX:
KASSERT((td->td_pcb->pcb_flags & PCB_VSX) != PCB_VSX,
("VSX already enabled for thread"));
if (!(td->td_pcb->pcb_flags & PCB_VEC))
enable_vec(td);
if (!(td->td_pcb->pcb_flags & PCB_FPU))
save_fpu(td);
td->td_pcb->pcb_flags |= PCB_VSX;
enable_fpu(td);
break;
case EXC_VECAST_G4:
case EXC_VECAST_G5:
/*
* We get a VPU assist exception for IEEE mode
* vector operations on denormalized floats.
* Emulating this is a giant pain, so for now,
* just switch off IEEE mode and treat them as
* zero.
*/
save_vec(td);
td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ;
enable_vec(td);
break;
case EXC_ALI:
if (fix_unaligned(td, frame) != 0) {
sig = SIGBUS;
ucode = BUS_ADRALN;
}
else
frame->srr0 += 4;
break;
case EXC_DEBUG: /* Single stepping */
mtspr(SPR_DBSR, mfspr(SPR_DBSR));
frame->srr1 &= ~PSL_DE;
frame->cpu.booke.dbcr0 &= ~(DBCR0_IDM || DBCR0_IC);
sig = SIGTRAP;
ucode = TRAP_TRACE;
break;
case EXC_PGM:
/* Identify the trap reason */
#ifdef AIM
if (frame->srr1 & EXC_PGM_TRAP) {
#else
if (frame->cpu.booke.esr & ESR_PTR) {
#endif
#ifdef KDTRACE_HOOKS
inst = fuword32((const void *)frame->srr0);
if (inst == 0x0FFFDDDD &&
dtrace_pid_probe_ptr != NULL) {
struct reg regs;
fill_regs(td, ®s);
(*dtrace_pid_probe_ptr)(®s);
break;
}
#endif
sig = SIGTRAP;
ucode = TRAP_BRKPT;
} else {
sig = ppc_instr_emulate(frame, td->td_pcb);
if (sig == SIGILL) {
if (frame->srr1 & EXC_PGM_PRIV)
ucode = ILL_PRVOPC;
else if (frame->srr1 & EXC_PGM_ILLEGAL)
ucode = ILL_ILLOPC;
} else if (sig == SIGFPE)
ucode = FPE_FLTINV; /* Punt for now, invalid operation. */
}
break;
case EXC_MCHK:
/*
* Note that this may not be recoverable for the user
* process, depending on the type of machine check,
* but it at least prevents the kernel from dying.
*/
sig = SIGBUS;
ucode = BUS_OBJERR;
break;
default:
trap_fatal(frame);
}
} else {
/* Kernel Mode Traps */
KASSERT(cold || td->td_ucred != NULL,
("kernel trap doesn't have ucred"));
switch (type) {
#ifdef KDTRACE_HOOKS
case EXC_PGM:
if (frame->srr1 & EXC_PGM_TRAP) {
if (*(uint32_t *)frame->srr0 == EXC_DTRACE) {
if (dtrace_invop_jump_addr != NULL) {
dtrace_invop_jump_addr(frame);
return;
}
}
}
break;
#endif
#ifdef __powerpc64__
case EXC_DSE:
if ((frame->dar & SEGMENT_MASK) == USER_ADDR) {
__asm __volatile ("slbmte %0, %1" ::
"r"(td->td_pcb->pcb_cpu.aim.usr_vsid),
"r"(USER_SLB_SLBE));
return;
}
break;
#endif
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);
}
