KVM: selftests: Fix a condition in test_hv_cpuid()
Subsystems (3)
PATCH 1/1 KVM: selftests: Fix a condition in test_hv_cpuid()
The code is trying to check that all the padding is zeroed out and it does this:
entry->padding[0] = entry->padding[1] = entry->padding[2] = 0
Assume everything is zeroed correctly, then the first comparison is true, the next comparison is false and false is equal to zero so the overall condition is true. This bug doesn't affect run time very badly, but the code should instead just check that all three paddings are zero individually.
Also the error message was copy and pasted from an earlier error and it wasn't correct.
--- tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +2 -3
@@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,TEST_ASSERT (entry->flags =0 ,".flags field should be zero" ); -TEST_ASSERT (entry->padding[0 ] = entry->padding[1 ] - = entry->padding[2 ] =0 , -".index field should be zero" ); +TEST_ASSERT (!entry->padding[0 ] && !entry->padding[1 ] && + !entry->padding[2 ],"padding should be zero" );/* * If needed for debug:
Signature · 1 line
2.20.1
Quoted 25 lines · Dan Carpenter
The code is trying to check that all the padding is zeroed out and it does this:
entry->padding[0] = entry->padding[1] = entry->padding[2] = 0Assume everything is zeroed correctly, then the first comparison is true, the next comparison is false and false is equal to zero so the overall condition is true. This bug doesn't affect run time very badly, but the code should instead just check that all three paddings are zero individually.
Also the error message was copy and pasted from an earlier error and it wasn't correct.
Fixes 7edcb7343327 ("KVM: selftests: Add hyperv_cpuid test")Signed-off-by Dan Carpenter <[email protected]>--- tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +0
-0
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c static void test_hv_cpuid(struct kvm_cpuid2 · line 58
Quoted 1 line
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +0
-0@@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries,
we also seem to check for 'entry->index = 0' twice here.
Quoted 11 lines
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +2
-3TEST_ASSERT (entry->flags =0 ,".flags field should be zero" ); -TEST_ASSERT (entry->padding[0 ] = entry->padding[1 ] - = entry->padding[2 ] =0 , -".index field should be zero" ); +TEST_ASSERT (!entry->padding[0 ] && !entry->padding[1 ] && + !entry->padding[2 ],"padding should be zero" );/* * If needed for debug:
Signature · 1 line
Vitaly
Quoted 27 lines · Dan Carpenter
The code is trying to check that all the padding is zeroed out and it does this:
entry->padding[0] = entry->padding[1] = entry->padding[2] = 0Assume everything is zeroed correctly, then the first comparison is true, the next comparison is false and false is equal to zero so the overall condition is true. This bug doesn't affect run time very badly, but the code should instead just check that all three paddings are zero individually.
Also the error message was copy and pasted from an earlier error and it wasn't correct.
Fixes 7edcb7343327 ("KVM: selftests: Add hyperv_cpuid test")Signed-off-by Dan Carpenter <[email protected]>--- tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +0
-0@@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, TEST_ASSERT(entry->flags = 0,
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, · line 65
Quoted 10 lines
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +2
-3".flags field should be zero"); -TEST_ASSERT (entry->padding[0 ] = entry->padding[1 ] - = entry->padding[2 ] =0 , -".index field should be zero" ); +TEST_ASSERT (!entry->padding[0 ] && !entry->padding[1 ] && + !entry->padding[2 ],"padding should be zero" );/* * If needed for debug:
That was yet another good example that compiling with "-Wall" is a good idea...
Quoted 27 lines · Dan Carpenter
The code is trying to check that all the padding is zeroed out and it does this:
entry->padding[0] = entry->padding[1] = entry->padding[2] = 0Assume everything is zeroed correctly, then the first comparison is true, the next comparison is false and false is equal to zero so the overall condition is true. This bug doesn't affect run time very badly, but the code should instead just check that all three paddings are zero individually.
Also the error message was copy and pasted from an earlier error and it wasn't correct.
Fixes 7edcb7343327 ("KVM: selftests: Add hyperv_cpuid test")Signed-off-by Dan Carpenter <[email protected]>--- tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +0
-0@@ -58,9 +58,8 @@ static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, TEST_ASSERT(entry->flags = 0,
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c static void test_hv_cpuid(struct kvm_cpuid2 *hv_cpuid_entries, · line 65
Quoted 10 lines
tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c +2
-3".flags field should be zero"); -TEST_ASSERT (entry->padding[0 ] = entry->padding[1 ] - = entry->padding[2 ] =0 , -".index field should be zero" ); +TEST_ASSERT (!entry->padding[0 ] && !entry->padding[1 ] && + !entry->padding[2 ],"padding should be zero" );/* * If needed for debug:
Queued, thanks.
Paolo