in kernel/fpu.c [204:249]
inline void handle_fpu_exception(struct pt_regs *regs)
{
unsigned int fpcsr;
int si_code = 0, si_signo = SIGFPE;
#if IS_ENABLED(CONFIG_SUPPORT_DENORMAL_ARITHMETIC)
unsigned long redo_except = FPCSR_mskDNIT|FPCSR_mskUDFT|FPCSR_mskIEXT;
#else
unsigned long redo_except = FPCSR_mskDNIT;
#endif
lose_fpu();
fpcsr = current->thread.fpu.fpcsr;
if (fpcsr & redo_except) {
si_signo = do_fpuemu(regs, ¤t->thread.fpu);
fpcsr = current->thread.fpu.fpcsr;
if (!si_signo) {
current->thread.fpu.fpcsr &= ~(redo_except);
goto done;
}
} else if (fpcsr & FPCSR_mskRIT) {
if (!user_mode(regs))
make_task_dead(SIGILL);
si_signo = SIGILL;
}
switch (si_signo) {
case SIGFPE:
fill_sigfpe_signo(fpcsr, &si_code);
break;
case SIGILL:
show_regs(regs);
si_code = ILL_COPROC;
break;
case SIGBUS:
si_code = BUS_ADRERR;
break;
default:
break;
}
force_sig_fault(si_signo, si_code,
(void __user *)instruction_pointer(regs));
done:
own_fpu();
}