2021-07-09 06:40:32

by chenlifu

[permalink] [raw]
Subject: [PATCH -next 2/2] selftests: Fix fscanf warning

Compile selftests occurs the following warnings:
make -C tools/testing/selftests
...

lib/test_util.c: In function ‘get_trans_hugepagesz’:
lib/test_util.c:138:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
138 | fscanf(f, "%ld", &size);
| ^~~~~~~~~~~~~~~~~~~~~~~
x86_64/mmio_warning_test.c: In function ‘get_warnings_count’:
x86_64/mmio_warning_test.c:85:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
85 | fscanf(f, "%d", &warnings);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
x86_64/xen_shinfo_test.c: In function ‘get_run_delay’:
x86_64/xen_shinfo_test.c:109:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
109 | fscanf(fp, "%ld %ld ", &val[0], &val[1]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
steal_time.c: In function ‘get_run_delay’:
steal_time.c:228:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
228 | fscanf(fp, "%ld %ld ", &val[0], &val[1]);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Check the return value of ‘fscanf’ to fix it.

Signed-off-by: Chen Lifu <[email protected]>
---
tools/testing/selftests/kvm/lib/test_util.c | 3 ++-
tools/testing/selftests/kvm/steal_time.c | 3 ++-
tools/testing/selftests/kvm/x86_64/mmio_warning_test.c | 3 ++-
tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c | 3 ++-
4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c
index af1031fed97f..02ed0d5c3aa5 100644
--- a/tools/testing/selftests/kvm/lib/test_util.c
+++ b/tools/testing/selftests/kvm/lib/test_util.c
@@ -135,7 +135,8 @@ size_t get_trans_hugepagesz(void)
f = fopen("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size", "r");
TEST_ASSERT(f != NULL, "Error in opening transparent_hugepage/hpage_pmd_size");

- fscanf(f, "%ld", &size);
+ if (fscanf(f, "%ld", &size) != 1)
+ size = 0;
fclose(f);

return size;
diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
index b0031f2d38fd..18f231c45a12 100644
--- a/tools/testing/selftests/kvm/steal_time.c
+++ b/tools/testing/selftests/kvm/steal_time.c
@@ -225,7 +225,8 @@ static 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]);
+ if (fscanf(fp, "%ld %ld ", &val[0], &val[1]) != 2)
+ val[1] = 0;
fclose(fp);

return val[1];
diff --git a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
index e6480fd5c4bd..e770037e5cc9 100644
--- a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
+++ b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
@@ -82,7 +82,8 @@ int get_warnings_count(void)
FILE *f;

f = popen("dmesg | grep \"WARNING:\" | wc -l", "r");
- fscanf(f, "%d", &warnings);
+ if (fscanf(f, "%d", &warnings) != 1)
+ warnings = 0;
fclose(f);

return warnings;
diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
index 117bf49a3d79..6efda86083f1 100644
--- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
+++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
@@ -106,7 +106,8 @@ static 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]);
+ if (fscanf(fp, "%ld %ld ", &val[0], &val[1]) != 2)
+ val[1] = 0;
fclose(fp);

return val[1];
--
2.32.0


2021-08-13 08:48:43

by chenlifu

[permalink] [raw]
Subject: ping//Re: [PATCH -next 2/2] selftests: Fix fscanf warning



在 2021/7/9 14:37, Chen Lifu 写道:
> Compile selftests occurs the following warnings:
> make -C tools/testing/selftests
> ...
>
> lib/test_util.c: In function ‘get_trans_hugepagesz’:
> lib/test_util.c:138:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
> 138 | fscanf(f, "%ld", &size);
> | ^~~~~~~~~~~~~~~~~~~~~~~
> x86_64/mmio_warning_test.c: In function ‘get_warnings_count’:
> x86_64/mmio_warning_test.c:85:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
> 85 | fscanf(f, "%d", &warnings);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~
> x86_64/xen_shinfo_test.c: In function ‘get_run_delay’:
> x86_64/xen_shinfo_test.c:109:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
> 109 | fscanf(fp, "%ld %ld ", &val[0], &val[1]);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> steal_time.c: In function ‘get_run_delay’:
> steal_time.c:228:2: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result]
> 228 | fscanf(fp, "%ld %ld ", &val[0], &val[1]);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Check the return value of ‘fscanf’ to fix it.
>
> Signed-off-by: Chen Lifu <[email protected]>
> ---
> tools/testing/selftests/kvm/lib/test_util.c | 3 ++-
> tools/testing/selftests/kvm/steal_time.c | 3 ++-
> tools/testing/selftests/kvm/x86_64/mmio_warning_test.c | 3 ++-
> tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c | 3 ++-
> 4 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c
> index af1031fed97f..02ed0d5c3aa5 100644
> --- a/tools/testing/selftests/kvm/lib/test_util.c
> +++ b/tools/testing/selftests/kvm/lib/test_util.c
> @@ -135,7 +135,8 @@ size_t get_trans_hugepagesz(void)
> f = fopen("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size", "r");
> TEST_ASSERT(f != NULL, "Error in opening transparent_hugepage/hpage_pmd_size");
>
> - fscanf(f, "%ld", &size);
> + if (fscanf(f, "%ld", &size) != 1)
> + size = 0;
> fclose(f);
>
> return size;
> diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
> index b0031f2d38fd..18f231c45a12 100644
> --- a/tools/testing/selftests/kvm/steal_time.c
> +++ b/tools/testing/selftests/kvm/steal_time.c
> @@ -225,7 +225,8 @@ static 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]);
> + if (fscanf(fp, "%ld %ld ", &val[0], &val[1]) != 2)
> + val[1] = 0;
> fclose(fp);
>
> return val[1];
> diff --git a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
> index e6480fd5c4bd..e770037e5cc9 100644
> --- a/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/mmio_warning_test.c
> @@ -82,7 +82,8 @@ int get_warnings_count(void)
> FILE *f;
>
> f = popen("dmesg | grep \"WARNING:\" | wc -l", "r");
> - fscanf(f, "%d", &warnings);
> + if (fscanf(f, "%d", &warnings) != 1)
> + warnings = 0;
> fclose(f);
>
> return warnings;
> diff --git a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
> index 117bf49a3d79..6efda86083f1 100644
> --- a/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c
> @@ -106,7 +106,8 @@ static 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]);
> + if (fscanf(fp, "%ld %ld ", &val[0], &val[1]) != 2)
> + val[1] = 0;
> fclose(fp);
>
> return val[1];
>