| Message ID | 20241021100644.3591-1-liujing@cmss.chinamobile.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftests: kvm: Adds a judgment on the return value | expand |
Am 21.10.24 um 12:06 schrieb Liu Jing: > The global variable errno is not recommended to be assigned, Just curious: from where is that information? Reading the man page: "errno is defined by the ISO C standard to be a modifiable lvalue of type int, and must not be explicitly declared; errno may be a macro. errno is thread-local; setting it in one thread does not affect its value in any other thread." Paired with "For some system calls and library functions (e.g., getpriority(2)), -1 is a valid return on success. In such cases, a successful return can be distinguished from an error return by setting errno to zero before the call" Not objecting that relying on the rc looks cleaner. > and rc in the function does not check its return value, so it is fixed > > Signed-off-by: Liu Jing <liujing@cmss.chinamobile.com> > --- > tools/testing/selftests/kvm/s390x/cmma_test.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c > index e32dd59703a0..c59c21f28bbd 100644 > --- a/tools/testing/selftests/kvm/s390x/cmma_test.c > +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c > @@ -210,7 +210,7 @@ static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) > struct kvm_s390_cmma_log args; > int rc; > > - errno = 0; > + *errno_out = 0; > > args = (struct kvm_s390_cmma_log){ > .start_gfn = 0, > @@ -219,8 +219,10 @@ static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) > .values = (__u64)&cmma_value_buf[0] > }; > rc = __vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); > + if (rc < 0) { > + *errno_out = errno; > + } > if (rc < 0) *errno_out = errno;
diff --git a/tools/testing/selftests/kvm/s390x/cmma_test.c b/tools/testing/selftests/kvm/s390x/cmma_test.c index e32dd59703a0..c59c21f28bbd 100644 --- a/tools/testing/selftests/kvm/s390x/cmma_test.c +++ b/tools/testing/selftests/kvm/s390x/cmma_test.c @@ -210,7 +210,7 @@ static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) struct kvm_s390_cmma_log args; int rc; - errno = 0; + *errno_out = 0; args = (struct kvm_s390_cmma_log){ .start_gfn = 0, @@ -219,8 +219,10 @@ static int vm_get_cmma_bits(struct kvm_vm *vm, u64 flags, int *errno_out) .values = (__u64)&cmma_value_buf[0] }; rc = __vm_ioctl(vm, KVM_S390_GET_CMMA_BITS, &args); + if (rc < 0) { + *errno_out = errno; + } - *errno_out = errno; return rc; }
The global variable errno is not recommended to be assigned, and rc in the function does not check its return value, so it is fixed Signed-off-by: Liu Jing <liujing@cmss.chinamobile.com> --- tools/testing/selftests/kvm/s390x/cmma_test.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)