Re: [PATCH v2] KVM: selftests: Compile code with warnings enabled

On 17/05/19 12:07, Thomas Huth wrote:

lib/ucall.c: In function ‘get_ucall’: lib/ucall.c:145:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] gva = *(vm_vaddr_t *)run->mmio.data;

x86_64/vmx_set_nested_state_test.c: In function ‘set_revision_id_for_vmcs12’: x86_64/vmx_set_nested_state_test.c:78:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] *(u32 *)(state->data) = vmcs12_revision;

... how do we want to handle such spots in the kvm selftest code? Compile with -fno-strict-aliasing? Or fix it with type-punning through unions?

I would use memcpy. I'll send a patch shortly.

Paolo