[PATCH v2] riscv: selftests: Fix warnings pointer masking test

Charlie Jenkins
2024-12-05T02:57:22Z

When compiling the pointer masking tests with -Wall this warning
is present:

pointer_masking.c: In function ‘test_tagged_addr_abi_sysctl’:
pointer_masking.c:203:9: warning: ignoring return value of ‘pwrite’
declared with attribute ‘warn_unused_result’ [-Wunused-result]
203 | pwrite(fd, &value, 1, 0); |
^~~~~~~~~~~~~~~~~~~~~~~~ pointer_masking.c:208:9: warning:
ignoring return value of ‘pwrite’ declared with attribute
‘warn_unused_result’ [-Wunused-result]
208 | pwrite(fd, &value, 1, 0);

I came across this on riscv64-linux-gnu-gcc (Ubuntu
11.4.0-1ubuntu1~22.04).

Fix this by checking that the number of bytes written equal the expected
number of bytes written.

Fixes: 7470b5afd150 ("riscv: selftests: Add a pointer masking test")
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
Changes in v2:
- I had ret != 2 for testing, I changed it to be ret != 1.
- Link to v1: https://lore.kernel.org/r/20241204-fix_warnings_pointer_masking_tests-v1-1-ea1e9665ce7a@rivosinc.com
---
tools/testing/selftests/riscv/abi/pointer_masking.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/riscv/abi/pointer_masking.c b/tools/testing/selftests/riscv/abi/pointer_masking.c
index dee41b7ee3e3..229d85ccff50 100644
--- a/tools/testing/selftests/riscv/abi/pointer_masking.c
+++ b/tools/testing/selftests/riscv/abi/pointer_masking.c
@@ -189,6 +189,7 @@ static void test_tagged_addr_abi_sysctl(void)
{
char value;
int fd;
+ int ret;

ksft_print_msg("Testing tagged address ABI sysctl\n");

@@ -200,14 +201,24 @@ static void test_tagged_addr_abi_sysctl(void)
}

value = '1';
- pwrite(fd, &value, 1, 0);
+ ret = pwrite(fd, &value, 1, 0);
+ if (ret != 1) {
+ ksft_test_result_fail("Write to /proc/sys/abi/tagged_addr_disabled failed.\n");
+ return;
+ }
+
ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == -EINVAL,
"sysctl disabled\n");

value = '0';
- pwrite(fd, &value, 1, 0);
- ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == 0,
- "sysctl enabled\n");
+ ret = pwrite(fd, &value, 1, 0);
+ if (ret != 1) {
+ ksft_test_result_fail("Write to /proc/sys/abi/tagged_addr_disabled failed.\n");
+ return;
+ }
+
+ ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == -EINVAL,
+ "sysctl disabled\n");

set_tagged_addr_ctrl(0, false);

---
base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
change-id: 20241204-fix_warnings_pointer_masking_tests-3860e4f35429
--