x86/paravirt: add debugging for missing operations
Rather than just jumping to 0 when there's a missing operation, raise a BUG.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
index 5467e2c..198293b 100644
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -459,10 +459,17 @@
#define VEXTRA_CLOBBERS , "rax", "r8", "r9", "r10", "r11"
#endif
+#ifdef CONFIG_PARAVIRT_DEBUG
+#define PVOP_TEST_NULL(op) BUG_ON(op == NULL)
+#else
+#define PVOP_TEST_NULL(op) ((void)op)
+#endif
+
#define __PVOP_CALL(rettype, op, pre, post, ...) \
({ \
rettype __ret; \
PVOP_CALL_ARGS; \
+ PVOP_TEST_NULL(op); \
/* This is 32-bit specific, but is okay in 64-bit */ \
/* since this condition will never hold */ \
if (sizeof(rettype) > sizeof(unsigned long)) { \
@@ -491,6 +498,7 @@
#define __PVOP_VCALL(op, pre, post, ...) \
({ \
PVOP_VCALL_ARGS; \
+ PVOP_TEST_NULL(op); \
asm volatile(pre \
paravirt_alt(PARAVIRT_CALL) \
post \