[LTP] [PATCH] accept02: Add SAFE_FORK to clean CLOSE_WAIT fds

[LTP] [PATCH] accept02: Add SAFE_FORK to clean CLOSE_WAIT fds

[Zhao Gongyi via ltp]

If we run the test with option -i 1000, and the ulimit
of open files little than 1000, the test would fail and
report the error of EMFILE. We can see that the socket
fds are in the status of CLOSE_WAIT.

Signed-off-by: Zhao Gongyi <zhaogongyi@huawei.com>
---
 testcases/kernel/syscalls/accept/accept02.c | 25 ++++++++++++++-------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/testcases/kernel/syscalls/accept/accept02.c b/testcases/kernel/syscalls/accept/accept02.c
index 12a1e3ca3..d46293386 100644
--- a/testcases/kernel/syscalls/accept/accept02.c
+++ b/testcases/kernel/syscalls/accept/accept02.c
@@ -23,6 +23,8 @@

 #include <errno.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
+#include <stdlib.h>
 #include "tst_test.h"
 #include "tst_safe_net.h"
 #include "tst_safe_pthread.h"
@@ -92,17 +94,23 @@ static void *client_thread(void *arg)

 static void run(void)
 {
-	pthread_t server_thr, client_thr;
+	pid_t child = SAFE_FORK();
+	if (!child) {
+		pthread_t server_thr, client_thr;

-	server_addr->sin_port = server_port;
-	client_addr->sin_port = htons(0);
+		server_addr->sin_port = server_port;
+		client_addr->sin_port = htons(0);

-	SAFE_PTHREAD_CREATE(&server_thr, NULL, server_thread, NULL);
-	TST_CHECKPOINT_WAIT(0);
-	SAFE_PTHREAD_CREATE(&client_thr, NULL, client_thread, NULL);
+		SAFE_PTHREAD_CREATE(&server_thr, NULL, server_thread, NULL);
+		TST_CHECKPOINT_WAIT(0);
+		SAFE_PTHREAD_CREATE(&client_thr, NULL, client_thread, NULL);

-	SAFE_PTHREAD_JOIN(server_thr, NULL);
-	SAFE_PTHREAD_JOIN(client_thr, NULL);
+		SAFE_PTHREAD_JOIN(server_thr, NULL);
+		SAFE_PTHREAD_JOIN(client_thr, NULL);
+		exit(0);
+	}
+
+	SAFE_WAIT(NULL);
 }

 static void setup(void)
@@ -145,6 +153,7 @@ static struct tst_test test = {
 	.setup = setup,
 	.cleanup = cleanup,
 	.needs_checkpoints = 1,
+	.forks_child = 1,
 	.tags = (const struct tst_tag[]) {
 		{"CVE", "2017-8890"},
 		{"linux-git", "657831ff"},
--
2.17.1


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Re: [LTP] [PATCH] accept02: Add SAFE_FORK to clean CLOSE_WAIT fds

[Cyril Hrubis]

Hi!
As far as I can tell we should rather close the fd returned from the
accept() call like this:

diff --git a/testcases/kernel/syscalls/accept/accept02.c b/testcases/kernel/syscalls/accept/accept02.c
index 12a1e3ca3..b2d27a260 100644
--- a/testcases/kernel/syscalls/accept/accept02.c
+++ b/testcases/kernel/syscalls/accept/accept02.c
@@ -68,6 +68,8 @@ static void *server_thread(void *arg)
        TEST(setsockopt(clone_server_sockfd, SOL_IP, MCAST_LEAVE_GROUP,
                        mc_group, mc_group_len));

+       SAFE_CLOSE(clone_server_sockfd);
+
        if (TST_RET != -1)
                tst_res(TFAIL, "Multicast group was copied!");
        else if (TST_ERR == EADDRNOTAVAIL)


-- 
Cyril Hrubis
chrubis@suse.cz

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Re: [LTP] [PATCH] accept02: Add SAFE_FORK to clean CLOSE_WAIT fds

[zhaogongyi via ltp]

Hi Cyril,

Thanks for your review! Yes, I cann't the clone_server_sockfd is not closed before, 
and I will resubmit a patch, please see: https://patchwork.ozlabs.org/project/ltp/patch/20220324022455.245300-1-zhaogongyi@huawei.com/

Best regards,

Gongyi

> 
> Hi!
> As far as I can tell we should rather close the fd returned from the
> accept() call like this:
> 
> diff --git a/testcases/kernel/syscalls/accept/accept02.c
> b/testcases/kernel/syscalls/accept/accept02.c
> index 12a1e3ca3..b2d27a260 100644
> --- a/testcases/kernel/syscalls/accept/accept02.c
> +++ b/testcases/kernel/syscalls/accept/accept02.c
> @@ -68,6 +68,8 @@ static void *server_thread(void *arg)
>         TEST(setsockopt(clone_server_sockfd, SOL_IP,
> MCAST_LEAVE_GROUP,
>                         mc_group, mc_group_len));
> 
> +       SAFE_CLOSE(clone_server_sockfd);
> +
>         if (TST_RET != -1)
>                 tst_res(TFAIL, "Multicast group was copied!");
>         else if (TST_ERR == EADDRNOTAVAIL)
> 
> 
> --
> Cyril Hrubis
> chrubis@suse.cz

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