On Fri, Dec 06, 2024 at 09:52:11AM -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@xxxxxxxxxxxx>
> ---
> Changes in v5:
> - No longer skip second pwrite if first one fails
> - Use wrapper function instead of goto (Drew)
> - Link to v4: https://lore.kernel.org/r/20241205-fix_warnings_pointer_masking_tests-v4-1-0c77eb725486@xxxxxxxxxxxx
>
> 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@xxxxxxxxxxxx
>
> 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@xxxxxxxxxxxx
>
> 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@xxxxxxxxxxxx
> ---
> .../testing/selftests/riscv/abi/pointer_masking.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/riscv/abi/pointer_masking.c b/tools/testing/selftests/riscv/abi/pointer_masking.c
> index dee41b7ee3e3..50c4d1bc7570 100644
> --- a/tools/testing/selftests/riscv/abi/pointer_masking.c
> +++ b/tools/testing/selftests/riscv/abi/pointer_masking.c
> @@ -185,8 +185,20 @@ static void test_fork_exec(void)
> }
> }
>
> +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;
> +}
> +
> static void test_tagged_addr_abi_sysctl(void)
> {
> + char *err_pwrite_msg = "failed to write to /proc/sys/abi/tagged_addr_disabled\n";
> char value;
> int fd;
>
> @@ -200,14 +212,12 @@ static void test_tagged_addr_abi_sysctl(void)
> }
>
> value = '1';
> - pwrite(fd, &value, 1, 0);
> - ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == -EINVAL,
> - "sysctl disabled\n");
> + if (!pwrite_wrapper(fd, &value, 1, "write '1'"))
> + ksft_test_result_fail(err_pwrite_msg);
>
> value = '0';
> - pwrite(fd, &value, 1, 0);
> - ksft_test_result(set_tagged_addr_ctrl(min_pmlen, true) == 0,
> - "sysctl enabled\n");
> + if (!pwrite_wrapper(fd, &value, 1, "write '0'"))
> + ksft_test_result_fail(err_pwrite_msg);
>
> set_tagged_addr_ctrl(0, false);
>
>
> ---
> base-commit: 40384c840ea1944d7c5a392e8975ed088ecf0b37
> change-id: 20241204-fix_warnings_pointer_masking_tests-3860e4f35429
> --
> - Charlie
>
Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
Thanks,
drew
