On 17/05/2019 11.41, Vitaly Kuznetsov wrote: > Peter Xu <peterx@xxxxxxxxxx> writes: > >> On Fri, May 17, 2019 at 11:04:45AM +0200, Thomas Huth wrote: >>> So far the KVM selftests are compiled without any compiler warnings >>> enabled. That's quite bad, since we miss a lot of possible bugs this >>> way. Let's enable at least "-Wall" and some other useful warning flags >>> now, and fix at least the trivial problems in the code (like unused >>> variables). >>> >>> Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx> >>> --- >>> v2: >>> - Rebased to kvm/queue >>> - Fix warnings in state_test.c and evmcs_test.c, too >> >> I still see these warnings (probably because the hyperv_cpuid.c is a >> new test): >> >> In file included from x86_64/hyperv_cpuid.c:18: >> x86_64/hyperv_cpuid.c: In function ‘test_hv_cpuid’: >> x86_64/hyperv_cpuid.c:61:33: warning: suggest parentheses around comparison in operand of ‘==’ [-Wparentheses] >> TEST_ASSERT(entry->padding[0] == entry->padding[1] >> ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~ >> include/test_util.h:32:15: note: in definition of macro ‘TEST_ASSERT’ >> test_assert((e), #e, __FILE__, __LINE__, fmt, ##__VA_ARGS__) >> ^ >> x86_64/hyperv_cpuid.c:62:8: warning: suggest parentheses around comparison in operand of ‘==’ [-Wparentheses] >> TEST_ASSERT(entry->padding[0] == entry->padding[1] >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> == entry->padding[2] == 0, >> ^~~~~~~~~~~~~~~~~~~~ >> include/test_util.h:32:15: note: in definition of macro ‘TEST_ASSERT’ >> test_assert((e), #e, __FILE__, __LINE__, fmt, ##__VA_ARGS__) > > There's a fix from Dan Carpenter on the list: > https://marc.info/?l=kernel-janitors&m=155783012012532&w=2 Right, that fix should preferably be committed first. >> x86_64/hyperv_cpuid.c: In function ‘kvm_get_supported_hv_cpuid’: >> x86_64/hyperv_cpuid.c:93:6: warning: unused variable ‘ret’ [-Wunused-variable] >> int ret; >> ^~~ ... but I obviously missed this one here again :-/ There are also these compiler warnings left: 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? Thomas
