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.eventfd_check_flag_rdwr ... # OK global.eventfd_check_flag_rdwr ok 1 global.eventfd_check_flag_rdwr # RUN global.eventfd_check_flag_cloexec ... # OK global.eventfd_check_flag_cloexec ok 2 global.eventfd_check_flag_cloexec # RUN global.eventfd_check_flag_nonblock ... # OK global.eventfd_check_flag_nonblock ok 3 global.eventfd_check_flag_nonblock # RUN global.eventfd_chek_flag_cloexec_and_nonblock ... # OK global.eventfd_chek_flag_cloexec_and_nonblock ok 4 global.eventfd_chek_flag_cloexec_and_nonblock # RUN global.eventfd_check_flag_semaphore ... # OK global.eventfd_check_flag_semaphore ok 5 global.eventfd_check_flag_semaphore # RUN global.eventfd_check_write ... # OK global.eventfd_check_write ok 6 global.eventfd_check_write # RUN global.eventfd_check_read ... # OK global.eventfd_check_read ok 7 global.eventfd_check_read # RUN global.eventfd_check_read_with_nonsemaphore ... # OK global.eventfd_check_read_with_nonsemaphore ok 8 global.eventfd_check_read_with_nonsemaphore # RUN global.eventfd_check_read_with_semaphore ... # OK global.eventfd_check_read_with_semaphore ok 9 global.eventfd_check_read_with_semaphore # 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@linux.dev Cc: SShuah Khan shuah@kernel.org Cc: Christian Brauner brauner@kernel.org Cc: Andrei Vagin avagin@google.com Cc: Mathieu Desnoyers mathieu.desnoyers@efficios.com Cc: Steven Rostedt rostedt@goodmis.org Cc: Andrew Morton akpm@linux-foundation.org Cc: Dave Young dyoung@redhat.com Cc: Tim Bird tim.bird@sony.com Cc: linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- v2: use strings which indicate what is being tested, that are useful to a human

.../filesystems/eventfd/eventfd_test.c | 136 +++++++++++++++++- 1 file changed, 131 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/filesystems/eventfd/eventfd_test.c b/tools/testing/selftests/filesystems/eventfd/eventfd_test.c index f142a137526c..85acb4e3ef00 100644 --- a/tools/testing/selftests/filesystems/eventfd/eventfd_test.c +++ b/tools/testing/selftests/filesystems/eventfd/eventfd_test.c @@ -13,6 +13,8 @@ #include <sys/eventfd.h> #include "../../kselftest_harness.h"

+#define EVENTFD_TEST_ITERATIONS 100000UL + struct error { int code; char msg[512]; @@ -40,7 +42,7 @@ static inline int sys_eventfd2(unsigned int count, int flags) return syscall(__NR_eventfd2, count, flags); }

-TEST(eventfd01) +TEST(eventfd_check_flag_rdwr) { int fd, flags;

@@ -54,7 +56,7 @@ TEST(eventfd01) close(fd); }

-TEST(eventfd02) +TEST(eventfd_check_flag_cloexec) { int fd, flags;

@@ -68,7 +70,7 @@ TEST(eventfd02) close(fd); }

-TEST(eventfd03) +TEST(eventfd_check_flag_nonblock) { int fd, flags;

@@ -83,7 +85,7 @@ TEST(eventfd03) close(fd); }

-TEST(eventfd04) +TEST(eventfd_chek_flag_cloexec_and_nonblock) { int fd, flags;

@@ -161,7 +163,7 @@ static int verify_fdinfo(int fd, struct error *err, const char *prefix, return 0; }

-TEST(eventfd05) +TEST(eventfd_check_flag_semaphore) { struct error err = {0}; int fd, ret; @@ -183,4 +185,128 @@ 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(eventfd_check_write) +{ + 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); + + size = write(fd, &value, sizeof(value)); + EXPECT_EQ(size, sizeof(value)); + + 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(eventfd_check_read) +{ + uint64_t value; + ssize_t size; + int fd; + + fd = sys_eventfd2(1, 0); + ASSERT_GE(fd, 0); + + size = read(fd, &value, sizeof(int)); + EXPECT_EQ(size, -1); + EXPECT_EQ(errno, EINVAL); + + size = read(fd, &value, sizeof(value)); + EXPECT_EQ(size, sizeof(value)); + EXPECT_EQ(value, 1); + + 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(eventfd_check_read_with_nonsemaphore) +{ + 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 < EVENTFD_TEST_ITERATIONS; 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, EVENTFD_TEST_ITERATIONS); + + 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(eventfd_check_read_with_semaphore) +{ + 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 < EVENTFD_TEST_ITERATIONS; i++) { + size = write(fd, &value, sizeof(value)); + EXPECT_EQ(size, sizeof(value)); + } + + for (i = 0; i < EVENTFD_TEST_ITERATIONS; 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