@@ -8,25 +8,57 @@
 
 #include <linux/linkage.h>
 #include <asm/assembler.h>
+#include <asm/unwind.h>
 
 /*
  * void call_with_stack(void (*fn)(void *), void *arg, void *sp)
  *
  * Change the stack to that pointed at by sp, then invoke fn(arg) with
  * the new stack.
+ *
+ * The sequence below follows the APCS frame convention for frame pointer
+ * unwinding, and implements the unwinder annotations needed by the EABI
+ * unwinder.
+ */
+
+#if defined(CONFIG_THUMB2_KERNEL) || \
+    (defined(CONFIG_UNWINDER_FRAME_POINTER) && defined(CONFIG_CC_IS_CLANG))
+/*
+ * Thumb-2 builds must use R7 as the frame pointer due to the way our unwind
+ * info based unwinder is constructed.
+ *
+ * The code below uses the GCC idiom for managing the frame pointer in the
+ * function prologue and epilogue, which Clang does not support. So the best we
+ * can do here is not touch the frame pointer at all: this will simply omit
+ * this frame when unwinding the call stack. So use R7 in this case as well,
+ * and leave R11 unmodified.
  */
+	fpreg	.req	r7
+#else
+	fpreg	.req	fp
+#endif
+
 ENTRY(call_with_stack)
-	str	sp, [r2, #-4]!
-	str	lr, [r2, #-4]!
+UNWIND(	.fnstart		)
+UNWIND(	.movsp	ip		)
+	mov	ip, sp
+
+UNWIND(	.pad	#4		)
+UNWIND(	.save	{fpreg, ip, lr}	)
+THUMB(	sub	sp, #4		)
+	push	{fpreg, ip, lr ARM(, pc)}
+
+UNWIND(	.setfp	fpreg, ip, #-4	)
+	sub	fpreg, ip, #4
 
 	mov	sp, r2
 	mov	r2, r0
 	mov	r0, r1
 
-	badr	lr, 1f
-	ret	r2
+	bl_r	r2
 
-1:	ldr	lr, [sp]
-	ldr	sp, [sp, #4]
+	ldmdb	fpreg, {fpreg, ip, lr}
+	mov	sp, ip
 	ret	lr
+UNWIND(	.fnend			)
 ENDPROC(call_with_stack)