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Commit 70d2b595 authored by Chris Metcalf's avatar Chris Metcalf
Browse files

tile: improve illegal translation interrupt handling 



First, don't re-enable interrupts blindly in the Linux trap handler.
We already handle page faults this way; synchronous interrupts like
ILL_TRANS will fire even when interrupts are disabled, and we don't
want to re-enable interrupts in that case.

For ILL_TRANS, we now pass the ILL_VA_PC reason into the trap handler
so we can report it properly; this is the address that caused the
illegal translation trap.  We print the address as part of the
pr_alert() message now if it's coming from the kernel.

Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
parent dadf78bf

arch/tile/kernel/intvec_64.S

+1 −1
Original line number Diff line number Diff line
@@ -492,7 +492,7 @@ intvec_\vecname: 
	mfspr   r3, SPR_SYSTEM_SAVE_K_2   /* info about page fault */

	.else

	.ifc \vecnum, INT_ILL_TRANS

	mfspr   r2, ILL_TRANS_REASON

	mfspr   r2, ILL_VA_PC

	.else

	.ifc \vecnum, INT_DOUBLE_FAULT

	mfspr   r2, SPR_SYSTEM_SAVE_K_2   /* double fault info from HV */

arch/tile/kernel/traps.c

+15 −10
Original line number Diff line number Diff line
@@ -222,7 +222,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, 
	unsigned long address = 0;

	bundle_bits instr;



	/* Re-enable interrupts. */

	/* Re-enable interrupts, if they were previously enabled. */

	if (!(regs->flags & PT_FLAGS_DISABLE_IRQ))

		local_irq_enable();



	/*
@@ -231,7 +232,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, 
	 */

	if (!user_mode(regs)) {

		const char *name;

		if (fixup_exception(regs))  /* only UNALIGN_DATA in practice */

		char buf[100];

		if (fixup_exception(regs))  /* ILL_TRANS or UNALIGN_DATA */

			return;

		if (fault_num >= 0 &&

		    fault_num < sizeof(int_name)/sizeof(int_name[0]) &&
@@ -239,10 +241,16 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, 
			name = int_name[fault_num];

		else

			name = "Unknown interrupt";

		pr_alert("Kernel took bad trap %d (%s) at PC %#lx\n",

			 fault_num, name, regs->pc);

		if (fault_num == INT_GPV)

			pr_alert("GPV_REASON is %#lx\n", reason);

			snprintf(buf, sizeof(buf), "; GPV_REASON %#lx", reason);

#ifdef __tilegx__

		else if (fault_num == INT_ILL_TRANS)

			snprintf(buf, sizeof(buf), "; address %#lx", reason);

#endif

		else

			buf[0] = '\0';

		pr_alert("Kernel took bad trap %d (%s) at PC %#lx%s\n",

			 fault_num, name, regs->pc, buf);

		show_regs(regs);

		do_exit(SIGKILL);  /* FIXME: implement i386 die() */

		return;
@@ -324,11 +332,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num, 
		fill_ra_stack();



		signo = SIGSEGV;

		address = reason;

		code = SEGV_MAPERR;

		if (reason & SPR_ILL_TRANS_REASON__I_STREAM_VA_RMASK)

			address = regs->pc;

		else

			address = 0;  /* FIXME: GX: single-step for address */

		break;

	}

#endif