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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accounting
arch	x86/cpu: Restore AMD's DE_CFG MSR after resume	2022-11-16 10:04:14 +01:00
bootconfig
bpf	bpftool: Fix NULL pointer dereference when pin {PROG, MAP, LINK} without FILE	2022-11-16 10:03:51 +01:00
build	tools build: Switch to new openssl API for test-libcrypto	2022-08-10 10:44:02 -03:00
certs
cgroup
counter
debugging	tools: Add new "test" taint to kernel-chktaint	2022-09-07 14:51:12 -06:00
edid
firewire
firmware
gpio
hv	tools: hv: kvp: remove unnecessary (void*) conversions	2022-09-05 16:55:20 +00:00
iio	tools: iio: iio_utils: fix digit calculation	2022-11-04 00:00:20 +09:00
include	tools/nolibc/string: Fix memcmp() implementation	2022-11-10 18:17:33 +01:00
io_uring
kvm/kvm_stat
laptop
leds
lib	libbpf: Fix overrun in netlink attribute iteration	2022-10-21 12:39:11 +02:00
memory-model
objtool	objtool: Preserve special st_shndx indexes in elf_update_symbol	2022-10-21 12:38:00 +02:00
pci
pcmcia
perf	perf tools: Add the include/perf/ directory to .gitignore	2022-11-16 10:03:59 +01:00
power	tools/power turbostat: Use standard Energy Unit for SPR Dram RAPL domain	2022-10-21 12:39:02 +02:00
rcu
scripts
spi
testing	ksefltests: pidfd: Fix wait_states: Test terminated by timeout	2022-11-26 09:27:19 +01:00
thermal
time
tracing	rtla: Consolidate and show all necessary libraries that failed for building	2022-08-10 12:03:02 -04:00
usb
verification	rv/dot2c: Make automaton definition static	2022-10-29 10:08:35 +02:00
virtio	virtio_test: fixup for vq reset	2022-09-27 18:30:49 -04:00
vm	- The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe	2022-08-05 16:32:45 -07:00
wmi
Makefile