void signal_frame(uint8_t *trapframe, uint32_t d0, uint32_t d1, uint32_t a0,
uint32_t a1)
{
extern void *udata_shadow;
uint8_t *usp = get_usp();
udata_ptr = udata_shadow;
uint16_t ccr = *(uint16_t *)trapframe;
uint32_t addr = *(uint32_t *)(trapframe + 2);
int err = 0;
/* Build the user stack frame */
/* FIXME: eventually we should put the trap frame details and trap
info into the frame */
usp -= 4;
err |= uputl(addr, usp);
usp -= 4;
err |= uputw(ccr, usp);
usp -= 2;
err |=uputl(a1, usp);
usp -= 4;
err |= uputl(a0, usp);
usp -= 4;
err |= uputl(d1, usp);
usp -= 4;
err |= uputl(d0, usp);
usp -= 4;
err |= uputl(udata.u_codebase + 4, usp);
set_usp(usp);
if (err) {
kprintf("%d: stack fault\n", udata.u_ptab->p_pid);
doexit(dump_core(SIGKILL));
}
/* Now patch up the kernel frame */
*(uint16_t *)trapframe = 0;
*(uint32_t *)(trapframe + 2) = (uint32_t)udata.u_sigvec[udata.u_cursig];
udata.u_sigvec[udata.u_cursig] = SIG_DFL;
udata.u_cursig = 0;
}
int exception(struct trapdata *framedata)
{
ptptr proc;
unsigned int frame, fsize;
uint8_t trap = framedata->trap;
unsigned int sig = 0;
uint16_t m;
uint16_t *sp = (uint16_t *)framedata;
uint16_t *usp = get_usp();
uint16_t *unwind, *context;
uint8_t err = 0;
int i;
/* We translate debug to SIGIOT and A and F line to SIGILL
We will need to fix up 68000 v 68010 move to/from SR */
static const uint8_t trap_to_sig[] = {
0, 0, SIGSEGV, SIGBUS, SIGILL, SIGFPE,
SIGABRT/*CHK*/, SIGTRAP/*TRAPV */,
SIGILL, SIGIOT, SIGILL, SIGFPE };
proc = udata.u_ptab;
if (sysinfo.cpu[0] == 10) {
/* Long or short frame: the CPU tells us the frame format */
if (framedata->exception[3] & 0x8000) {
fsize = 29;
frame = FRAME_C;
} else {
fsize = 4;
frame = FRAME_D;
}
} else {
frame = FRAME_B;
fsize = 3;
}
if (trap == 0) {
sig = udata.u_cursig;
udata.u_cursig = 0;
} else if (trap < 12) {
if (trap < 4) {
/* On a 68010 this frame is 29 words and the event is
restartable (although not always usefully). We need to
decide whether to set the restart flag case by case */
if (sysinfo.cpu[0] == 0) {
frame = FRAME_A;
fsize = 7;
}
}
sig = trap_to_sig[trap];
} else if (trap >= 32 && trap < 48)
sig = SIGTRAP;
/* This processing only applies to synchronous hardware exceptions */
if (trap) {
/* Went boom in kernel space or without a user recovery */
if (kernel_flag || sig == 0) {
explode(framedata, frame);
panic("trap");
}
/* Cheating here .. all our exceptions are low 16 signal */
m = 1 << sig;
/*
* The caller is ignoring our signal. In some cases this is fine
* but in others it's less clear (eg division by zero) and we
* may need to take different action.
*/
if (proc->p_sig[0].s_ignored & m)
return 0;
/* Weird case - we took a sync signal and the caller wants us to
report it later. */
if (proc->p_sig[0].s_held & m) {
/* TODO: if it's not meaningfully restartable we should
probably treat this as a kill */
ssig(proc, sig);
return 0;
}
recalc_cursig(); /* Put any async signal back */
}
if (udata.u_sigvec[sig] == SIG_DFL) {
/* Default action for our signal ? */
doexit(dump_core(sig));
/* This will never return. We will go schedule new work */
panic("exret");
}
/* build signal frame
Our unwinder code does
move.l 8(sp),sp
movem.l a0-a1/d0-d1,(sp)+
move.w (sp)+,ccr
rts */
/* Now update the user stack */
/* - Push the recovery PC */
/* - Patch the kernel exception frame */
if (sysinfo.cpu[0]) {
/* FIXME */
err |= pushw(&usp, sp[34]);
err |= pushw(&usp, sp[33]);
*(uint32_t *)(&sp[33]) = (uint32_t)udata.u_sigvec[sig];
} else {
err |= pushw(&usp, sp[31 + fsize]);
err |= pushw(&usp, sp[30 + fsize]);
*(uint32_t *)(&sp[30 + fsize]) = (uint32_t)udata.u_sigvec[sig];
}
/* FIXME: when we do ptrace we will need to support adding the T
flag back here as the exception cleared it */
err |= pushw(&usp, framedata->sr);
/* Push A1 A0 D1 D0 to match MOVEM.L */
err |= pushl(&usp, framedata->a[1]);
err |= pushl(&usp, framedata->a[0]);
err |= pushl(&usp, framedata->d[1]);
err |= pushl(&usp, framedata->d[0]);
/* Remember the target for undoing the frame */
unwind = usp;
/* Copy in the signal context itself. 30 words of registers, 2 of
trap code and then the hardware exception */
for (i = 0; i < 30 + 2 + fsize; i++)
err |= pushw(&usp, *sp++);
context = usp;
err |= pushl(&usp, (uint32_t)unwind);
/* Signal context is a secret extra non portable argument */
err |= pushl(&usp, (uint32_t)context);
/* We end it with the call frame as seen from the signal handler, a
single argument and a return address */
err |= pushl(&usp, sig);
err |= pushl(&usp, udata.u_codebase + 0x04);
set_usp(usp);
if (err) {
doexit(dump_core(SIGSTKFLT));
panic("exret2");
}
/* Once built clear the restart state */
udata.u_sigvec[sig] = SIG_DFL;
/* Return, RTE and end up on the signal frame */
return 1;
}
