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

[Bird, Tim]

> -----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
>