1 files changed, 40 insertions, 5 deletions

diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c
index 2bb6602a1ee7..5b19a23c8908 100644
--- a/arch/tile/kernel/traps.c
+++ b/arch/tile/kernel/traps.c
@@ -195,12 +195,31 @@ static int special_ill(bundle_bits bundle, int *sigp, int *codep)
 	return 1;
 }
 
+static const char *const int_name[] = {
+	[INT_MEM_ERROR] = "Memory error",
+	[INT_ILL] = "Illegal instruction",
+	[INT_GPV] = "General protection violation",
+	[INT_UDN_ACCESS] = "UDN access",
+	[INT_IDN_ACCESS] = "IDN access",
+#if CHIP_HAS_SN()
+	[INT_SN_ACCESS] = "SN access",
+#endif
+	[INT_SWINT_3] = "Software interrupt 3",
+	[INT_SWINT_2] = "Software interrupt 2",
+	[INT_SWINT_0] = "Software interrupt 0",
+	[INT_UNALIGN_DATA] = "Unaligned data",
+	[INT_DOUBLE_FAULT] = "Double fault",
+#ifdef __tilegx__
+	[INT_ILL_TRANS] = "Illegal virtual address",
+#endif
+};
+
 void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 		       unsigned long reason)
 {
 	siginfo_t info = { 0 };
 	int signo, code;
-	unsigned long address;
+	unsigned long address = 0;
 	bundle_bits instr;
 
 	/* Re-enable interrupts. */
@@ -211,10 +230,17 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 	 * current process and hope for the best.
 	 */
 	if (!user_mode(regs)) {
+		const char *name;
 		if (fixup_exception(regs))  /* only UNALIGN_DATA in practice */
 			return;
-		pr_alert("Kernel took bad trap %d at PC %#lx\n",
-		       fault_num, regs->pc);
+		if (fault_num >= 0 &&
+		    fault_num < sizeof(int_name)/sizeof(int_name[0]) &&
+		    int_name[fault_num] != NULL)
+			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);
 		show_regs(regs);
@@ -223,6 +249,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 	}
 
 	switch (fault_num) {
+	case INT_MEM_ERROR:
+		signo = SIGBUS;
+		code = BUS_OBJERR;
+		break;
 	case INT_ILL:
 		if (copy_from_user(&instr, (void __user *)regs->pc,
 				   sizeof(instr))) {
@@ -289,7 +319,10 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 		address = regs->pc;
 		break;
 #ifdef __tilegx__
-	case INT_ILL_TRANS:
+	case INT_ILL_TRANS: {
+		/* Avoid a hardware erratum with the return address stack. */
+		fill_ra_stack();
+
 		signo = SIGSEGV;
 		code = SEGV_MAPERR;
 		if (reason & SPR_ILL_TRANS_REASON__I_STREAM_VA_RMASK)
@@ -297,6 +330,7 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 		else
 			address = 0;  /* FIXME: GX: single-step for address */
 		break;
+	}
 #endif
 	default:
 		panic("Unexpected do_trap interrupt number %d", fault_num);
@@ -308,7 +342,8 @@ void __kprobes do_trap(struct pt_regs *regs, int fault_num,
 	info.si_addr = (void __user *)address;
 	if (signo == SIGILL)
 		info.si_trapno = fault_num;
-	trace_unhandled_signal("trap", regs, address, signo);
+	if (signo != SIGTRAP)
+		trace_unhandled_signal("trap", regs, address, signo);
 	force_sig_info(signo, &info, current);
 }