From: Shuah Khan skhan@linuxfoundation.org

[ Upstream commit f5013d412a43662b63f3d5f3a804d63213acd471 ]

Fix get_run_delay() to check fscanf() return value to get rid of the following warning. When fscanf() fails return MIN_RUN_DELAY_NS from get_run_delay(). Move MIN_RUN_DELAY_NS from steal_time.c to test_util.h so get_run_delay() and steal_time.c can use it.

lib/test_util.c: In function ‘get_run_delay’: lib/test_util.c:316:2: warning: ignoring return value of ‘fscanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 316 | fscanf(fp, "%ld %ld ", &val[0], &val[1]); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Shuah Khan skhan@linuxfoundation.org Acked-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/kvm/include/test_util.h | 2 ++ tools/testing/selftests/kvm/lib/test_util.c | 4 +++- tools/testing/selftests/kvm/steal_time.c | 1 - 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index c7409b9b4e5b..451fed5ce8e7 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -95,6 +95,8 @@ struct vm_mem_backing_src_alias { uint32_t flag; };

+#define MIN_RUN_DELAY_NS 200000UL + bool thp_configured(void); size_t get_trans_hugepagesz(void); size_t get_def_hugetlb_pagesz(void); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index f80dd38a38b2..a9107bfae402 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -313,7 +313,9 @@ long get_run_delay(void)

sprintf(path, "/proc/%ld/schedstat", syscall(SYS_gettid)); fp = fopen(path, "r"); - fscanf(fp, "%ld %ld ", &val[0], &val[1]); + /* Return MIN_RUN_DELAY_NS upon failure just to be safe */ + if (fscanf(fp, "%ld %ld ", &val[0], &val[1]) < 2) + val[1] = MIN_RUN_DELAY_NS; fclose(fp);

return val[1]; diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c index 51fe95a5c36a..2172d65b85e4 100644 --- a/tools/testing/selftests/kvm/steal_time.c +++ b/tools/testing/selftests/kvm/steal_time.c @@ -19,7 +19,6 @@

#define NR_VCPUS 4 #define ST_GPA_BASE (1 << 30) -#define MIN_RUN_DELAY_NS 200000UL

static void *st_gva[NR_VCPUS]; static uint64_t guest_stolen_time[NR_VCPUS];