| Message ID | 20211217093040.9530-1-lizhijian@cn.fujitsu.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] ksefltest: pidfd: Fix wait_states: Test terminated by timeout | expand |
ping On 17/12/2021 17:30, Li Zhijian wrote: > 0Day/LKP observed that the kselftest blocks foever 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); > > 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@cn.fujitsu.com> > --- > V2: rewrite with pipe to avoid usleep > --- > tools/testing/selftests/pidfd/pidfd_wait.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c > index be2943f072f6..d5c0ffa26c32 100644 > --- a/tools/testing/selftests/pidfd/pidfd_wait.c > +++ b/tools/testing/selftests/pidfd/pidfd_wait.c > @@ -96,21 +96,26 @@ TEST(wait_states) > .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, > .exit_signal = SIGCHLD, > }; > - int ret; > + int ret, pfd[2]; > pid_t pid; > siginfo_t info = { > .si_signo = 0, > }; > - > + ASSERT_EQ(pipe(pfd), 0); > pid = sys_clone3(&args); > ASSERT_GE(pid, 0); > > if (pid == 0) { > + char buf[2]; > + close(pfd[1]); > kill(getpid(), SIGSTOP); > + ASSERT_EQ(read(pfd[0], buf, 1), 1); > + close(pfd[0]); > kill(getpid(), SIGSTOP); > exit(EXIT_SUCCESS); > } > > + close(pfd[0]); > ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0); > ASSERT_EQ(info.si_signo, SIGCHLD); > ASSERT_EQ(info.si_code, CLD_STOPPED); > @@ -119,6 +124,8 @@ TEST(wait_states) > ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0); > > ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); > + ASSERT_EQ(write(pfd[1], "C", 1), 1); > + close(pfd[1]); > ASSERT_EQ(info.si_signo, SIGCHLD); > ASSERT_EQ(info.si_code, CLD_CONTINUED); > ASSERT_EQ(info.si_pid, parent_tid);
diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c index be2943f072f6..d5c0ffa26c32 100644 --- a/tools/testing/selftests/pidfd/pidfd_wait.c +++ b/tools/testing/selftests/pidfd/pidfd_wait.c @@ -96,21 +96,26 @@ TEST(wait_states) .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, .exit_signal = SIGCHLD, }; - int ret; + int ret, pfd[2]; pid_t pid; siginfo_t info = { .si_signo = 0, }; - + ASSERT_EQ(pipe(pfd), 0); pid = sys_clone3(&args); ASSERT_GE(pid, 0); if (pid == 0) { + char buf[2]; + close(pfd[1]); kill(getpid(), SIGSTOP); + ASSERT_EQ(read(pfd[0], buf, 1), 1); + close(pfd[0]); kill(getpid(), SIGSTOP); exit(EXIT_SUCCESS); } + close(pfd[0]); ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL), 0); ASSERT_EQ(info.si_signo, SIGCHLD); ASSERT_EQ(info.si_code, CLD_STOPPED); @@ -119,6 +124,8 @@ TEST(wait_states) ASSERT_EQ(sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0), 0); ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); + ASSERT_EQ(write(pfd[1], "C", 1), 1); + close(pfd[1]); ASSERT_EQ(info.si_signo, SIGCHLD); ASSERT_EQ(info.si_code, CLD_CONTINUED); ASSERT_EQ(info.si_pid, parent_tid);
0Day/LKP observed that the kselftest blocks foever 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); 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@cn.fujitsu.com> --- V2: rewrite with pipe to avoid usleep --- tools/testing/selftests/pidfd/pidfd_wait.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)