traps.c

来自「优龙2410linux2.6.8内核源代码」· C语言 代码 · 共 2,048 行 · 第 1/4 页

				/* BAD, privileged state is corrupted. */
				recoverable = 0;
			}

			if (recoverable) {
				if (pfn_valid(afar >> PAGE_SHIFT))
					get_page(pfn_to_page(afar >> PAGE_SHIFT));
				else
					recoverable = 0;

				/* Only perform fixup if we still have a
				 * recoverable condition.
				 */
				if (recoverable) {
					regs->tpc = fixup;
					regs->tnpc = regs->tpc + 4;
					regs->u_regs[UREG_G2] = g2;
				}
			}
		}
	} else {
		recoverable = 0;
	}

	if (!recoverable)
		panic("Irrecoverable deferred error trap.\n");
}

/* Handle a D/I cache parity error trap.  TYPE is encoded as:
 *
 * Bit0:	0=dcache,1=icache
 * Bit1:	0=recoverable,1=unrecoverable
 *
 * The hardware has disabled both the I-cache and D-cache in
 * the %dcr register.  
 */
void cheetah_plus_parity_error(int type, struct pt_regs *regs)
{
	if (type & 0x1)
		__cheetah_flush_icache();
	else
		cheetah_plus_zap_dcache_parity();
	cheetah_flush_dcache();

	/* Re-enable I-cache/D-cache */
	__asm__ __volatile__("ldxa [%%g0] %0, %%g1\n\t"
			     "or %%g1, %1, %%g1\n\t"
			     "stxa %%g1, [%%g0] %0\n\t"
			     "membar #Sync"
			     : /* no outputs */
			     : "i" (ASI_DCU_CONTROL_REG),
			       "i" (DCU_DC | DCU_IC)
			     : "g1");

	if (type & 0x2) {
		printk(KERN_EMERG "CPU[%d]: Cheetah+ %c-cache parity error at TPC[%016lx]\n",
		       smp_processor_id(),
		       (type & 0x1) ? 'I' : 'D',
		       regs->tpc);
		panic("Irrecoverable Cheetah+ parity error.");
	}

	printk(KERN_WARNING "CPU[%d]: Cheetah+ %c-cache parity error at TPC[%016lx]\n",
	       smp_processor_id(),
	       (type & 0x1) ? 'I' : 'D',
	       regs->tpc);
}

void do_fpe_common(struct pt_regs *regs)
{
	if (regs->tstate & TSTATE_PRIV) {
		regs->tpc = regs->tnpc;
		regs->tnpc += 4;
	} else {
		unsigned long fsr = current_thread_info()->xfsr[0];
		siginfo_t info;

		if (test_thread_flag(TIF_32BIT)) {
			regs->tpc &= 0xffffffff;
			regs->tnpc &= 0xffffffff;
		}
		info.si_signo = SIGFPE;
		info.si_errno = 0;
		info.si_addr = (void __user *)regs->tpc;
		info.si_trapno = 0;
		info.si_code = __SI_FAULT;
		if ((fsr & 0x1c000) == (1 << 14)) {
			if (fsr & 0x10)
				info.si_code = FPE_FLTINV;
			else if (fsr & 0x08)
				info.si_code = FPE_FLTOVF;
			else if (fsr & 0x04)
				info.si_code = FPE_FLTUND;
			else if (fsr & 0x02)
				info.si_code = FPE_FLTDIV;
			else if (fsr & 0x01)
				info.si_code = FPE_FLTRES;
		}
		force_sig_info(SIGFPE, &info, current);
	}
}

void do_fpieee(struct pt_regs *regs)
{
	do_fpe_common(regs);
}

extern int do_mathemu(struct pt_regs *, struct fpustate *);

void do_fpother(struct pt_regs *regs)
{
	struct fpustate *f = FPUSTATE;
	int ret = 0;

	switch ((current_thread_info()->xfsr[0] & 0x1c000)) {
	case (2 << 14): /* unfinished_FPop */
	case (3 << 14): /* unimplemented_FPop */
		ret = do_mathemu(regs, f);
		break;
	}
	if (ret)
		return;
	do_fpe_common(regs);
}

void do_tof(struct pt_regs *regs)
{
	siginfo_t info;

	if (regs->tstate & TSTATE_PRIV)
		die_if_kernel("Penguin overflow trap from kernel mode", regs);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	info.si_signo = SIGEMT;
	info.si_errno = 0;
	info.si_code = EMT_TAGOVF;
	info.si_addr = (void __user *)regs->tpc;
	info.si_trapno = 0;
	force_sig_info(SIGEMT, &info, current);
}

void do_div0(struct pt_regs *regs)
{
	siginfo_t info;

	if (regs->tstate & TSTATE_PRIV)
		die_if_kernel("TL0: Kernel divide by zero.", regs);
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	info.si_signo = SIGFPE;
	info.si_errno = 0;
	info.si_code = FPE_INTDIV;
	info.si_addr = (void __user *)regs->tpc;
	info.si_trapno = 0;
	force_sig_info(SIGFPE, &info, current);
}

void instruction_dump (unsigned int *pc)
{
	int i;

	if ((((unsigned long) pc) & 3))
		return;

	printk("Instruction DUMP:");
	for (i = -3; i < 6; i++)
		printk("%c%08x%c",i?' ':'<',pc[i],i?' ':'>');
	printk("\n");
}

static void user_instruction_dump (unsigned int __user *pc)
{
	int i;
	unsigned int buf[9];
	
	if ((((unsigned long) pc) & 3))
		return;
		
	if (copy_from_user(buf, pc - 3, sizeof(buf)))
		return;

	printk("Instruction DUMP:");
	for (i = 0; i < 9; i++)
		printk("%c%08x%c",i==3?' ':'<',buf[i],i==3?' ':'>');
	printk("\n");
}

void show_stack(struct task_struct *tsk, unsigned long *_ksp)
{
	unsigned long pc, fp, thread_base, ksp;
	struct thread_info *tp = tsk->thread_info;
	struct reg_window *rw;
	int count = 0;

	ksp = (unsigned long) _ksp;

	if (tp == current_thread_info())
		flushw_all();

	fp = ksp + STACK_BIAS;
	thread_base = (unsigned long) tp;

	printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
	printk("\n");
#endif
	do {
		/* Bogus frame pointer? */
		if (fp < (thread_base + sizeof(struct thread_info)) ||
		    fp >= (thread_base + THREAD_SIZE))
			break;
		rw = (struct reg_window *)fp;
		pc = rw->ins[7];
		printk(" [%016lx] ", pc);
		print_symbol("%s\n", pc);
		fp = rw->ins[6] + STACK_BIAS;
	} while (++count < 16);
#ifndef CONFIG_KALLSYMS
	printk("\n");
#endif
}

void dump_stack(void)
{
	unsigned long *ksp;

	__asm__ __volatile__("mov	%%fp, %0"
			     : "=r" (ksp));
	show_stack(current, ksp);
}

EXPORT_SYMBOL(dump_stack);

void die_if_kernel(char *str, struct pt_regs *regs)
{
	static int die_counter;
	extern void __show_regs(struct pt_regs * regs);
	extern void smp_report_regs(void);
	int count = 0;
	
	/* Amuse the user. */
	printk(
"              \\|/ ____ \\|/\n"
"              \"@'/ .. \\`@\"\n"
"              /_| \\__/ |_\\\n"
"                 \\__U_/\n");

	printk("%s(%d): %s [#%d]\n", current->comm, current->pid, str, ++die_counter);
	__asm__ __volatile__("flushw");
	__show_regs(regs);
	if (regs->tstate & TSTATE_PRIV) {
		struct reg_window *rw = (struct reg_window *)
			(regs->u_regs[UREG_FP] + STACK_BIAS);

		/* Stop the back trace when we hit userland or we
		 * find some badly aligned kernel stack.
		 */
		while (rw					&&
		       count++ < 30				&&
		       (((unsigned long) rw) >= PAGE_OFFSET)	&&
		       (char *) rw < ((char *) current)
		       + sizeof (union thread_union) 		&&
		       !(((unsigned long) rw) & 0x7)) {
			printk("Caller[%016lx]", rw->ins[7]);
			print_symbol(": %s", rw->ins[7]);
			printk("\n");
			rw = (struct reg_window *)
				(rw->ins[6] + STACK_BIAS);
		}
		instruction_dump ((unsigned int *) regs->tpc);
	} else {
		if (test_thread_flag(TIF_32BIT)) {
			regs->tpc &= 0xffffffff;
			regs->tnpc &= 0xffffffff;
		}
		user_instruction_dump ((unsigned int __user *) regs->tpc);
	}
#ifdef CONFIG_SMP
	smp_report_regs();
#endif
                                                	
	if (regs->tstate & TSTATE_PRIV)
		do_exit(SIGKILL);
	do_exit(SIGSEGV);
}

extern int handle_popc(u32 insn, struct pt_regs *regs);
extern int handle_ldf_stq(u32 insn, struct pt_regs *regs);

void do_illegal_instruction(struct pt_regs *regs)
{
	unsigned long pc = regs->tpc;
	unsigned long tstate = regs->tstate;
	u32 insn;
	siginfo_t info;

	if (tstate & TSTATE_PRIV)
		die_if_kernel("Kernel illegal instruction", regs);
	if (test_thread_flag(TIF_32BIT))
		pc = (u32)pc;
	if (get_user(insn, (u32 __user *) pc) != -EFAULT) {
		if ((insn & 0xc1ffc000) == 0x81700000) /* POPC */ {
			if (handle_popc(insn, regs))
				return;
		} else if ((insn & 0xc1580000) == 0xc1100000) /* LDQ/STQ */ {
			if (handle_ldf_stq(insn, regs))
				return;
		}
	}
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_ILLOPC;
	info.si_addr = (void __user *)pc;
	info.si_trapno = 0;
	force_sig_info(SIGILL, &info, current);
}

void mem_address_unaligned(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
{
	siginfo_t info;

	if (regs->tstate & TSTATE_PRIV) {
		extern void kernel_unaligned_trap(struct pt_regs *regs,
						  unsigned int insn, 
						  unsigned long sfar,
						  unsigned long sfsr);

		kernel_unaligned_trap(regs, *((unsigned int *)regs->tpc),
				      sfar, sfsr);
		return;
	}
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRALN;
	info.si_addr = (void __user *)sfar;
	info.si_trapno = 0;
	force_sig_info(SIGBUS, &info, current);
}

void do_privop(struct pt_regs *regs)
{
	siginfo_t info;

	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code = ILL_PRVOPC;
	info.si_addr = (void __user *)regs->tpc;
	info.si_trapno = 0;
	force_sig_info(SIGILL, &info, current);
}

void do_privact(struct pt_regs *regs)
{
	do_privop(regs);
}

/* Trap level 1 stuff or other traps we should never see... */
void do_cee(struct pt_regs *regs)
{
	die_if_kernel("TL0: Cache Error Exception", regs);
}

void do_cee_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Cache Error Exception", regs);
}

void do_dae_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Data Access Exception", regs);
}

void do_iae_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Instruction Access Exception", regs);
}

void do_div0_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: DIV0 Exception", regs);
}

void do_fpdis_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: FPU Disabled", regs);
}

void do_fpieee_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: FPU IEEE Exception", regs);
}

void do_fpother_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: FPU Other Exception", regs);
}

void do_ill_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Illegal Instruction Exception", regs);
}

void do_irq_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: IRQ Exception", regs);
}

void do_lddfmna_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: LDDF Exception", regs);
}

void do_stdfmna_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: STDF Exception", regs);
}

void do_paw(struct pt_regs *regs)
{
	die_if_kernel("TL0: Phys Watchpoint Exception", regs);
}

void do_paw_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Phys Watchpoint Exception", regs);
}

void do_vaw(struct pt_regs *regs)
{
	die_if_kernel("TL0: Virt Watchpoint Exception", regs);
}

void do_vaw_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Virt Watchpoint Exception", regs);
}

void do_tof_tl1(struct pt_regs *regs)
{
	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
	die_if_kernel("TL1: Tag Overflow Exception", regs);
}

void do_getpsr(struct pt_regs *regs)
{
	regs->u_regs[UREG_I0] = tstate_to_psr(regs->tstate);
	regs->tpc   = regs->tnpc;
	regs->tnpc += 4;
	if (test_thread_flag(TIF_32BIT)) {
		regs->tpc &= 0xffffffff;
		regs->tnpc &= 0xffffffff;
	}
}

extern void thread_info_offsets_are_bolixed_dave(void);

/* Only invoked on boot processor. */
void __init trap_init(void)
{
	/* Compile time sanity check. */
	if (TI_TASK != offsetof(struct thread_info, task) ||
	    TI_FLAGS != offsetof(struct thread_info, flags) ||
	    TI_CPU != offsetof(struct thread_info, cpu) ||
	    TI_FPSAVED != offsetof(struct thread_info, fpsaved) ||
	    TI_KSP != offsetof(struct thread_info, ksp) ||
	    TI_FAULT_ADDR != offsetof(struct thread_info, fault_address) ||
	    TI_KREGS != offsetof(struct thread_info, kregs) ||
	    TI_UTRAPS != offsetof(struct thread_info, utraps) ||
	    TI_EXEC_DOMAIN != offsetof(struct thread_info, exec_domain) ||
	    TI_REG_WINDOW != offsetof(struct thread_info, reg_window) ||
	    TI_RWIN_SPTRS != offsetof(struct thread_info, rwbuf_stkptrs) ||
	    TI_GSR != offsetof(struct thread_info, gsr) ||
	    TI_XFSR != offsetof(struct thread_info, xfsr) ||
	    TI_USER_CNTD0 != offsetof(struct thread_info, user_cntd0) ||
	    TI_USER_CNTD1 != offsetof(struct thread_info, user_cntd1) ||
	    TI_KERN_CNTD0 != offsetof(struct thread_info, kernel_cntd0) ||
	    TI_KERN_CNTD1 != offsetof(struct thread_info, kernel_cntd1) ||
	    TI_PCR != offsetof(struct thread_info, pcr_reg) ||
	    TI_CEE_STUFF != offsetof(struct thread_info, cee_stuff) ||
	    TI_PRE_COUNT != offsetof(struct thread_info, preempt_count) ||
	    TI_FPREGS != offsetof(struct thread_info, fpregs) ||
	    (TI_FPREGS & (64 - 1)))
		thread_info_offsets_are_bolixed_dave();

	/* Attach to the address space of init_task.  On SMP we
	 * do this in smp.c:smp_callin for other cpus.
	 */
	atomic_inc(&init_mm.mm_count);
	current->active_mm = &init_mm;
}