Commit 07a368b3 authored by Maxim Levitsky's avatar Maxim Levitsky Committed by Paolo Bonzini
Browse files

bug: introduce ASSERT_STRUCT_OFFSET 



ASSERT_STRUCT_OFFSET allows to assert during the build of
the kernel that a field in a struct have an expected offset.

KVM used to have such macro, but there is almost nothing KVM specific
in it so move it to build_bug.h, so that it can be used in other
places in KVM.

Signed-off-by: default avatarMaxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-10-mlevitsk@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 00009406

arch/x86/kvm/vmx/vmcs12.h

+2 −3
Original line number Diff line number Diff line
@@ -209,8 +209,7 @@ struct __packed vmcs12 { 
 * For save/restore compatibility, the vmcs12 field offsets must not change.

 */

#define CHECK_OFFSET(field, loc) \

	BUILD_BUG_ON_MSG(offsetof(struct vmcs12, field) != (loc),	\

		"Offset of " #field " in struct vmcs12 has changed.")

	ASSERT_STRUCT_OFFSET(struct vmcs12, field, loc)



static inline void vmx_check_vmcs12_offsets(void)

{

include/linux/build_bug.h

+9 −0
Original line number Diff line number Diff line
@@ -77,4 +77,13 @@ 
#define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)

#define __static_assert(expr, msg, ...) _Static_assert(expr, msg)





/*

 * Compile time check that field has an expected offset

 */

#define ASSERT_STRUCT_OFFSET(type, field, expected_offset)	\

	BUILD_BUG_ON_MSG(offsetof(type, field) != (expected_offset),	\

		"Offset of " #field " in " #type " has changed.")





#endif	/* _LINUX_BUILD_BUG_H */