void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
if (kernel_mode(regs))
die("Exception in kernel mode", regs, signr);
force_sig_fault(signr, code, (void __user *)addr, current);
}
void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
siginfo_t info;
if (kernel_mode(regs)) {
die("Exception in kernel mode", regs, signr);
}
info.si_signo = signr;
info.si_errno = 0;
info.si_code = code;
info.si_addr = (void __user *) addr;
force_sig_info(signr, &info, current);
}
asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall)
{
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (kernel_mode(regs))
return;
if (test_thread_flag(TIF_SIGPENDING))
do_signal(regs, in_syscall);
if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
tracehook_notify_resume(regs);
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* Note that we go through the signals twice: once to check the signals that
* the kernel can handle, and then we build all the user-level signal handling
* stack-frames in one go after that.
*/
int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall)
{
siginfo_t info;
int signr;
struct k_sigaction ka;
#ifdef DEBUG_SIG
printk(KERN_INFO "do signal: %p %p %d\n", regs, oldset, in_syscall);
printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
regs->r12, current_thread_info()->flags);
#endif
/*
* We want the common case to go fast, which
* is why we may in certain cases get here from
* kernel mode. Just return without doing anything
* if so.
*/
if (kernel_mode(regs))
return 1;
if (!oldset)
oldset = ¤t->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Whee! Actually deliver the signal. */
if (in_syscall)
handle_restart(regs, &ka, 1);
handle_signal(signr, &ka, &info, oldset, regs);
return 1;
}
if (in_syscall)
handle_restart(regs, NULL, 0);
/* Did we come from a system call? */
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
struct pt_regs *childregs = task_pt_regs(p);
struct thread_info *ti = task_thread_info(p);
*childregs = *regs;
if (user_mode(regs))
childregs->r1 = usp;
else
childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
#ifndef CONFIG_MMU
memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
ti->cpu_context.r1 = (unsigned long)childregs;
ti->cpu_context.msr = (unsigned long)childregs->msr;
#else
/* if creating a kernel thread then update the current reg (we don't
* want to use the parent's value when restoring by POP_STATE) */
if (kernel_mode(regs))
/* save new current on stack to use POP_STATE */
childregs->CURRENT_TASK = (unsigned long)p;
/* if returning to user then use the parent's value of this register */
/* if we're creating a new kernel thread then just zeroing all
* the registers. That's OK for a brand new thread.*/
/* Pls. note that some of them will be restored in POP_STATE */
if (kernel_mode(regs))
memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
/* if this thread is created for fork/vfork/clone, then we want to
* restore all the parent's context */
/* in addition to the registers which will be restored by POP_STATE */
else {
ti->cpu_context = *(struct cpu_context *)regs;
childregs->msr |= MSR_UMS;
}
/* FIXME STATE_SAVE_PT_OFFSET; */
ti->cpu_context.r1 = (unsigned long)childregs;
/* we should consider the fact that childregs is a copy of the parent
* regs which were saved immediately after entering the kernel state
* before enabling VM. This MSR will be restored in switch_to and
* RETURN() and we want to have the right machine state there
* specifically this state must have INTs disabled before and enabled
* after performing rtbd
* compose the right MSR for RETURN(). It will work for switch_to also
* excepting for VM and UMS
* don't touch UMS , CARRY and cache bits
* right now MSR is a copy of parent one */
childregs->msr |= MSR_BIP;
childregs->msr &= ~MSR_EIP;
childregs->msr |= MSR_IE;
childregs->msr &= ~MSR_VM;
childregs->msr |= MSR_VMS;
childregs->msr |= MSR_EE; /* exceptions will be enabled*/
ti->cpu_context.msr = (childregs->msr|MSR_VM);
ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
ti->cpu_context.msr &= ~MSR_IE;
#endif
ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
/*
* r21 is the thread reg, r10 is 6th arg to clone
* which contains TLS area
*/
if (clone_flags & CLONE_SETTLS)
childregs->r21 = childregs->r10;
return 0;
}
asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
int fsr, int addr)
{
#ifdef CONFIG_MMU
addr = regs->pc;
#endif
#if 0
printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
"ESR=%08x\n",
type, user_mode(regs) ? "user" : "kernel", fsr,
(unsigned int) regs->pc, (unsigned int) regs->esr);
#endif
switch (type & 0x1F) {
case MICROBLAZE_ILL_OPCODE_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Illegal opcode exception in user mode\n");
_exception(SIGILL, regs, ILL_ILLOPC, addr);
return;
}
printk(KERN_WARNING "Illegal opcode exception " \
"in kernel mode.\n");
die("opcode exception", regs, SIGBUS);
break;
case MICROBLAZE_IBUS_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Instruction bus error exception in user mode\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
printk(KERN_WARNING "Instruction bus error exception " \
"in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DBUS_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Data bus error exception in user mode\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
printk(KERN_WARNING "Data bus error exception " \
"in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DIV_ZERO_EXCEPTION:
if (user_mode(regs)) {
pr_debug("Divide by zero exception in user mode\n");
_exception(SIGILL, regs, FPE_INTDIV, addr);
return;
}
printk(KERN_WARNING "Divide by zero exception " \
"in kernel mode.\n");
die("Divide by zero exception", regs, SIGBUS);
break;
case MICROBLAZE_FPU_EXCEPTION:
pr_debug("FPU exception\n");
/* IEEE FP exception */
/* I removed fsr variable and use code var for storing fsr */
if (fsr & FSR_IO)
fsr = FPE_FLTINV;
else if (fsr & FSR_OF)
fsr = FPE_FLTOVF;
else if (fsr & FSR_UF)
fsr = FPE_FLTUND;
else if (fsr & FSR_DZ)
fsr = FPE_FLTDIV;
else if (fsr & FSR_DO)
fsr = FPE_FLTRES;
_exception(SIGFPE, regs, fsr, addr);
break;
#ifdef CONFIG_MMU
case MICROBLAZE_PRIVILEGED_EXCEPTION:
pr_debug("Privileged exception\n");
_exception(SIGILL, regs, ILL_PRVOPC, addr);
break;
#endif
default:
/* FIXME what to do in unexpected exception */
printk(KERN_WARNING "Unexpected exception %02x "
"PC=%08x in %s mode\n", type, (unsigned int) addr,
kernel_mode(regs) ? "kernel" : "user");
}
return;
}
