Li Zhijian bfa4a8690c ksefltests: pidfd: Fix wait_states: Test terminated by timeout ... [ Upstream commit 88e1f16ba5 ] 0Day/LKP observed that the kselftest blocks forever since one of the pidfd_wait doesn't terminate in 1 of 30 runs. After digging into the source, we found that it blocks at: ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); wait_states has below testing flow: CHILD PARENT ---------------+-------------- 1 STOP itself 2 WAIT for CHILD STOPPED 3 SIGNAL CHILD to CONT 4 CONT 5 STOP itself 5' WAIT for CHILD CONT 6 WAIT for CHILD STOPPED The problem is that the kernel cannot ensure the order of 5 and 5', once 5 goes first, the test will fail. we can reproduce it by: $ while true; do make run_tests -C pidfd; done Introduce a blocking read in child process to make sure the parent can check its WCONTINUED. CC: Philip Li <philip.li@intel.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-11-26 09:27:19 +01:00
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crypto/chacha20-s390	tools/testing/crypto: Use vzalloc instead of vmalloc+memset	2022-07-05 14:46:36 +02:00
cxl	cxl/hdm: Commit decoder state to hardware	2022-07-25 12:18:07 -07:00
fault-injection
ktest
kunit	kunit: tool: Enable virtio/PCI by default on UML	2022-07-08 11:22:29 -06:00
memblock	memblock updates for v5.20	2022-08-09 09:48:30 -07:00
nvdimm	ndtest: Cleanup all of blk namespace specific code	2022-07-12 17:57:55 -07:00
radix-tree
scatterlist
selftests	ksefltests: pidfd: Fix wait_states: Test terminated by timeout	2022-11-26 09:27:19 +01:00
vsock