[PATCH v4] riscv: selftests: Fix warnings pointer masking test
Andrew Jones
ajones at ventanamicro.com
Fri Dec 6 01:15:17 PST 2024
On Thu, Dec 05, 2024 at 01:49:31PM -0800, Charlie Jenkins wrote:
> 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 at rivosinc.com>
> ---
> Changes in v4:
> - Skip sysctl_enabled test if first pwrite failed
> - Link to v3: https://lore.kernel.org/r/20241205-fix_warnings_pointer_masking_tests-v3-1-5c28b0f9640d@rivosinc.com
>
> Changes in v3:
> - Fix sysctl enabled test case (Drew/Alex)
> - Move pwrite err condition into goto (Drew)
> - Link to v2: https://lore.kernel.org/r/20241204-fix_warnings_pointer_masking_tests-v2-1-1bf0c5095f58@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 | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/riscv/abi/pointer_masking.c b/tools/testing/selftests/riscv/abi/pointer_masking.c
> index dee41b7ee3e3..759445d5f265 100644
> --- a/tools/testing/selftests/riscv/abi/pointer_masking.c
> +++ b/tools/testing/selftests/riscv/abi/pointer_masking.c
> @@ -189,6 +189,8 @@ static void test_tagged_addr_abi_sysctl(void)
> {
> char value;
> int fd;
> + int ret;
> + char *err_pwrite_msg = "failed to write to /proc/sys/abi/tagged_addr_disabled\n";
>
> ksft_print_msg("Testing tagged address ABI sysctl\n");
>
> @@ -200,18 +202,32 @@ 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_skip(err_pwrite_msg);
It seems like we should have a better way to keep the count balanced than
to require a ksft_test_result_skip() call for each test on each error
path. Every time we add a test we'll have to go add skips everywhere else.
> + goto err_pwrite;
> + }
> +
> ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == -EINVAL,
> "sysctl disabled\n");
>
> value = '0';
> - pwrite(fd, &value, 1, 0);
> + ret = pwrite(fd, &value, 1, 0);
> + if (ret != 1)
> + goto err_pwrite;
> +
> ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == 0,
> "sysctl enabled\n");
>
> set_tagged_addr_ctrl(0, false);
>
> close(fd);
> +
> + return;
> +
> +err_pwrite:
> + close(fd);
> + ksft_test_result_fail(err_pwrite_msg);
> }
I don't think the goto reduces much code or improves readability much. A
wrapper function should do better. I was thinking something like
static bool pwrite_wrapper(int fd, void *buf, size_t count, const char *msg)
{
int ret = pwrite(fd, buf, count, 0);
if (ret != count) {
ksft_perror(msg);
return false;
}
return true;
}
value = '1';
if (!pwrite_wrapper(fd, &value, 1, "write '1'"))
ksft_test_result_fail(...);
value = '0';
if (!pwrite_wrapper(fd, &value, 1, "write '0'"))
ksft_test_result_fail(...);
>
> static void test_tagged_addr_abi_pmlen(int pmlen)
>
> ---
> base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
> change-id: 20241204-fix_warnings_pointer_masking_tests-3860e4f35429
> --
> - Charlie
>
Thanks,
drew
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