Unverified Commit f0ece18e authored by Tycho Andersen's avatar Tycho Andersen Committed by Christian Brauner
Browse files

selftests: add ESRCH tests for pidfd_getfd() 



Ensure that pidfd_getfd() reports -ESRCH if the task is already exiting.

Signed-off-by: default avatarTycho Andersen <tandersen@netflix.com>
Link: https://lore.kernel.org/r/20240206192357.81942-1-tycho@tycho.pizza


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 0c9bd6bc

tools/testing/selftests/pidfd/pidfd_getfd_test.c

+30 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <fcntl.h>

#include <limits.h>

#include <linux/types.h>

#include <poll.h>

#include <sched.h>

#include <signal.h>

#include <stdio.h>
@@ -129,6 +130,7 @@ FIXTURE(child) 
	 * When it is closed, the child will exit.

	 */

	int sk;

	bool ignore_child_result;

};



FIXTURE_SETUP(child)
@@ -165,10 +167,14 @@ FIXTURE_SETUP(child) 


FIXTURE_TEARDOWN(child)

{

	int ret;



	EXPECT_EQ(0, close(self->pidfd));

	EXPECT_EQ(0, close(self->sk));



	EXPECT_EQ(0, wait_for_pid(self->pid));

	ret = wait_for_pid(self->pid);

	if (!self->ignore_child_result)

		EXPECT_EQ(0, ret);

}



TEST_F(child, disable_ptrace)
@@ -235,6 +241,29 @@ TEST(flags_set) 
	EXPECT_EQ(errno, EINVAL);

}



TEST_F(child, no_strange_EBADF)

{

	struct pollfd fds;



	self->ignore_child_result = true;



	fds.fd = self->pidfd;

	fds.events = POLLIN;



	ASSERT_EQ(kill(self->pid, SIGKILL), 0);

	ASSERT_EQ(poll(&fds, 1, 5000), 1);



	/*

	 * It used to be that pidfd_getfd() could race with the exiting thread

	 * between exit_files() and release_task(), and get a non-null task

	 * with a NULL files struct, and you'd get EBADF, which was slightly

	 * confusing.

	 */

	errno = 0;

	EXPECT_EQ(sys_pidfd_getfd(self->pidfd, self->remote_fd, 0), -1);

	EXPECT_EQ(errno, ESRCH);

}



#if __NR_pidfd_getfd == -1

int main(void)

{