svn commit: r334926 - head/sys/arm64/arm64

[Andrew Turner]

Author: andrew
Date: Sun Jun 10 16:21:21 2018
New Revision: 334926
URL: https://svnweb.freebsd.org/changeset/base/334926

Log:
  Clean up handling of unexpected exceptions. Previously we would issue a
  breakpoint instruction, however this would lose information that may be
  useful for debugging.
  
  These are now handled in a similar way to other exceptions, however it
  won't exit out of the exception handler until it is known if we can
  handle these exceptions in a useful way.
  
  Sponsored by:	DARPA, AFRL

Modified:
  head/sys/arm64/arm64/exception.S
  head/sys/arm64/arm64/trap.c

Modified: head/sys/arm64/arm64/exception.S
==============================================================================
--- head/sys/arm64/arm64/exception.S	Sun Jun 10 14:49:13 2018	(r334925)
+++ head/sys/arm64/arm64/exception.S	Sun Jun 10 16:21:21 2018	(r334926)
@@ -161,10 +161,6 @@ ENTRY(handle_el1h_irq)
 	eret
 END(handle_el1h_irq)
 
-ENTRY(handle_el1h_error)
-	brk	0xf13
-END(handle_el1h_error)
-
 ENTRY(handle_el0_sync)
 	save_registers 0
 	ldr	x0, [x18, #PC_CURTHREAD]
@@ -185,18 +181,23 @@ ENTRY(handle_el0_irq)
 	eret
 END(handle_el0_irq)
 
-ENTRY(handle_el0_error)
+ENTRY(handle_serror)
 	save_registers 0
 	mov	x0, sp
-	bl	do_el0_error
-	brk	0xf23
-	1: b 1b
-END(handle_el0_error)
+1:	bl	do_serror
+	b	1b
+END(handle_serror)
 
+ENTRY(handle_empty_exception)
+	save_registers 0
+	mov	x0, sp
+1:	bl	unhandled_exception
+	b	1b
+END(handle_unhandled_exception)
+
 .macro	vempty
 	.align 7
-	brk	0xfff
-	1: b	1b
+	b	handle_empty_exception
 .endm
 
 .macro	vector	name
@@ -215,15 +216,15 @@ exception_vectors:
 	vector el1h_sync	/* Synchronous EL1h */
 	vector el1h_irq		/* IRQ EL1h */
 	vempty			/* FIQ EL1h */
-	vector el1h_error	/* Error EL1h */
+	vector serror		/* Error EL1h */
 
 	vector el0_sync		/* Synchronous 64-bit EL0 */
 	vector el0_irq		/* IRQ 64-bit EL0 */
 	vempty			/* FIQ 64-bit EL0 */
-	vector el0_error	/* Error 64-bit EL0 */
+	vector serror		/* Error 64-bit EL0 */
 
 	vector el0_sync		/* Synchronous 32-bit EL0 */
 	vector el0_irq		/* IRQ 32-bit EL0 */
 	vempty			/* FIQ 32-bit EL0 */
-	vector el0_error	/* Error 32-bit EL0 */
+	vector serror		/* Error 32-bit EL0 */
 

Modified: head/sys/arm64/arm64/trap.c
==============================================================================
--- head/sys/arm64/arm64/trap.c	Sun Jun 10 14:49:13 2018	(r334925)
+++ head/sys/arm64/arm64/trap.c	Sun Jun 10 16:21:21 2018	(r334926)
@@ -76,6 +76,9 @@ extern register_t fsu_intr_fault;
 void do_el1h_sync(struct thread *, struct trapframe *);
 void do_el0_sync(struct thread *, struct trapframe *);
 void do_el0_error(struct trapframe *);
+void do_serror(struct trapframe *);
+void unhandled_exception(struct trapframe *);
+
 static void print_registers(struct trapframe *frame);
 
 int (*dtrace_invop_jump_addr)(struct trapframe *);
@@ -477,10 +480,33 @@ do_el0_sync(struct thread *td, struct trapframe *frame
 	    ("Kernel VFP state in use when entering userspace"));
 }
 
+/*
+ * TODO: We will need to handle these later when we support ARMv8.2 RAS.
+ */
 void
-do_el0_error(struct trapframe *frame)
+do_serror(struct trapframe *frame)
 {
+	uint64_t esr, far;
 
-	panic("ARM64TODO: do_el0_error");
+	far = READ_SPECIALREG(far_el1);
+	esr = frame->tf_esr;
+
+	print_registers(frame);
+	printf(" far: %16lx\n", far);
+	printf(" esr:         %.8lx\n", esr);
+	panic("Unhandled System Error");
 }
 
+void
+unhandled_exception(struct trapframe *frame)
+{
+	uint64_t esr, far;
+
+	far = READ_SPECIALREG(far_el1);
+	esr = frame->tf_esr;
+
+	print_registers(frame);
+	printf(" far: %16lx\n", far);
+	printf(" esr:         %.8lx\n", esr);
+	panic("Unhandled exception");
+}