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| author | Maxim Levitsky <mlevitsk@redhat.com> | 2022-10-25 15:47:27 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-11-09 12:31:16 -0500 |
| commit | 07a368b3f55a79d33cad113d506b279e04fd2a00 (patch) | |
| tree | a5cc4f6daeedce9bdb81f08525650557fcb30874 | |
| parent | 00009406f0dbc53b95b9062c0cc297d6893ff394 (diff) | |
| download | linux-next-07a368b3f55a79d33cad113d506b279e04fd2a00.tar.gz | |
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: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20221025124741.228045-10-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx/vmcs12.h | 5 | ||||
| -rw-r--r-- | include/linux/build_bug.h | 9 |
2 files changed, 11 insertions, 3 deletions
diff --git a/arch/x86/kvm/vmx/vmcs12.h b/arch/x86/kvm/vmx/vmcs12.h index 746129ddd5ae..01936013428b 100644 --- a/arch/x86/kvm/vmx/vmcs12.h +++ b/arch/x86/kvm/vmx/vmcs12.h @@ -208,9 +208,8 @@ 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.") +#define CHECK_OFFSET(field, loc) \ + ASSERT_STRUCT_OFFSET(struct vmcs12, field, loc) static inline void vmx_check_vmcs12_offsets(void) { diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h index e3a0be2c90ad..3aa3640f8c18 100644 --- a/include/linux/build_bug.h +++ b/include/linux/build_bug.h @@ -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 */ |