RE: [PATCH] selftests: introduce additional eventfd test coverage

From: Bird, Tim
Date: Mon May 06 2024 - 14:30:58 EST




> -----Original Message-----
> From: Wen Yang <wen.yang@xxxxxxxxx>
> Add several new test cases which assert corner cases on the eventfd
> mechanism, for example, the supplied buffer is less than 8 bytes,
> attempting to write a value that is too large, etc.
>
> ./eventfd_test
> # Starting 9 tests from 1 test cases.
> # RUN global.eventfd01 ...
> # OK global.eventfd01
> ok 1 global.eventfd01

These are horrible test case names. Can you please use strings which indicate
what is being tested, that are useful to a human?
-- Tim

> # RUN global.eventfd02 ...
> # OK global.eventfd02
> ok 2 global.eventfd02
> # RUN global.eventfd03 ...
> # OK global.eventfd03
> ok 3 global.eventfd03
> # RUN global.eventfd04 ...
> # OK global.eventfd04
> ok 4 global.eventfd04
> # RUN global.eventfd05 ...
> # OK global.eventfd05
> ok 5 global.eventfd05
> # RUN global.eventfd06 ...
> # OK global.eventfd06
> ok 6 global.eventfd06
> # RUN global.eventfd07 ...
> # OK global.eventfd07
> ok 7 global.eventfd07
> # RUN global.eventfd08 ...
> # OK global.eventfd08
> ok 8 global.eventfd08
> # RUN global.eventfd09 ...
> # OK global.eventfd09
> ok 9 global.eventfd09
> # PASSED: 9 / 9 tests passed.
> # Totals: pass:9 fail:0 xfail:0 xpass:0 skip:0 error:0
>
> Signed-off-by: Wen Yang <wen.yang@xxxxxxxxx>
> Cc: SShuah Khan <shuah@xxxxxxxxxx>
> Cc: Christian Brauner <brauner@xxxxxxxxxx>
> Cc: Andrei Vagin <avagin@xxxxxxxxxx>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Dave Young <dyoung@xxxxxxxxxx>
> Cc: linux-kselftest@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> .../filesystems/eventfd/eventfd_test.c | 116 ++++++++++++++++++
> 1 file changed, 116 insertions(+)
>
> diff --git a/tools/testing/selftests/filesystems/eventfd/eventfd_test.c b/tools/testing/selftests/filesystems/eventfd/eventfd_test.c
> index f142a137526c..eeab8df5b1b5 100644
> --- a/tools/testing/selftests/filesystems/eventfd/eventfd_test.c
> +++ b/tools/testing/selftests/filesystems/eventfd/eventfd_test.c
> @@ -183,4 +183,120 @@ TEST(eventfd05)
> close(fd);
> }
>
> +/*
> + * A write(2) fails with the error EINVAL if the size of the supplied buffer
> + * is less than 8 bytes, or if an attempt is made to write the value
> + * 0xffffffffffffffff.
> + */
> +TEST(eventfd06)
> +{
> + uint64_t value = 1;
> + ssize_t size;
> + int fd;
> +
> + fd = sys_eventfd2(0, 0);
> + ASSERT_GE(fd, 0);
> +
> + size = write(fd, &value, sizeof(int));
> + EXPECT_EQ(size, -1);
> + EXPECT_EQ(errno, EINVAL);
> +
> + value = (uint64_t)-1;
> + size = write(fd, &value, sizeof(value));
> + EXPECT_EQ(size, -1);
> + EXPECT_EQ(errno, EINVAL);
> +
> + close(fd);
> +}
> +
> +/*
> + * A read(2) fails with the error EINVAL if the size of the supplied buffer is
> + * less than 8 bytes.
> + */
> +TEST(eventfd07)
> +{
> + int value = 0;
> + ssize_t size;
> + int fd;
> +
> + fd = sys_eventfd2(0, 0);
> + ASSERT_GE(fd, 0);
> +
> + size = write(fd, &value, sizeof(value));
> + EXPECT_EQ(size, -1);
> + EXPECT_EQ(errno, EINVAL);
> +
> + close(fd);
> +}
> +
> +/*
> + * If EFD_SEMAPHORE was not specified and the eventfd counter has a nonzero
> + * value, then a read(2) returns 8 bytes containing that value, and the
> + * counter's value is reset to zero.
> + * If the eventfd counter is zero at the time of the call to read(2), then the
> + * call fails with the error EAGAIN if the file descriptor has been made nonblocking.
> + */
> +TEST(eventfd08)
> +{
> + uint64_t value;
> + ssize_t size;
> + int fd;
> + int i;
> +
> + fd = sys_eventfd2(0, EFD_NONBLOCK);
> + ASSERT_GE(fd, 0);
> +
> + value = 1;
> + for (i = 0; i < 10000000; i++) {
> + size = write(fd, &value, sizeof(value));
> + EXPECT_EQ(size, sizeof(value));
> + }
> +
> + size = read(fd, &value, sizeof(value));
> + EXPECT_EQ(size, sizeof(uint64_t));
> + EXPECT_EQ(value, 10000000);
> +
> + size = read(fd, &value, sizeof(value));
> + EXPECT_EQ(size, -1);
> + EXPECT_EQ(errno, EAGAIN);
> +
> + close(fd);
> +}
> +
> +/*
> + * If EFD_SEMAPHORE was specified and the eventfd counter has a nonzero value,
> + * then a read(2) returns 8 bytes containing the value 1, and the counter's
> + * value is decremented by 1.
> + * If the eventfd counter is zero at the time of the call to read(2), then the
> + * call fails with the error EAGAIN if the file descriptor has been made nonblocking.
> + */
> +TEST(eventfd09)
> +{
> + uint64_t value;
> + ssize_t size;
> + int fd;
> + int i;
> +
> + fd = sys_eventfd2(0, EFD_SEMAPHORE|EFD_NONBLOCK);
> + ASSERT_GE(fd, 0);
> +
> + value = 1;
> + for (i = 0; i < 10000000; i++) {
> + size = write(fd, &value, sizeof(value));
> + EXPECT_EQ(size, sizeof(value));
> + }
> +
> + for (i = 0; i < 10000000; i++) {
> + size = read(fd, &value, sizeof(value));
> + EXPECT_EQ(size, sizeof(value));
> + EXPECT_EQ(value, 1);
> + }
> +
> + size = read(fd, &value, sizeof(value));
> + EXPECT_EQ(size, -1);
> + EXPECT_EQ(errno, EAGAIN);
> +
> + close(fd);
> +}
> +
> TEST_HARNESS_MAIN
> --
> 2.25.1
>