Patch "vsock/test: fix SEQPACKET message bounds test" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    vsock/test: fix SEQPACKET message bounds test

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vsock-test-fix-seqpacket-message-bounds-test.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 81f2bdf9535157e73dd6e83fe61d8650c4242e89
Author: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
Date:   Wed Nov 22 00:16:42 2023 +0300

    vsock/test: fix SEQPACKET message bounds test
    
    [ Upstream commit f0863888f6cfef33e3117dccfe94fa78edf76be4 ]
    
    Tune message length calculation to make this test work on machines
    where 'getpagesize()' returns >32KB. Now maximum message length is not
    hardcoded (on machines above it was smaller than 'getpagesize()' return
    value, thus we get negative value and test fails), but calculated at
    runtime and always bigger than 'getpagesize()' result. Reproduced on
    aarch64 with 64KB page size.
    
    Fixes: 5c338112e48a ("test/vsock: rework message bounds test")
    Signed-off-by: Arseniy Krasnov <avkrasnov@xxxxxxxxxxxxxxxxx>
    Reported-by: Bogdan Marcynkov <bmarcynk@xxxxxxxxxx>
    Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20231121211642.163474-1-avkrasnov@xxxxxxxxxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index 90718c2fd4ea9..5dc7767039f6f 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -392,11 +392,12 @@ static void test_stream_msg_peek_server(const struct test_opts *opts)
 }
 
 #define SOCK_BUF_SIZE (2 * 1024 * 1024)
-#define MAX_MSG_SIZE (32 * 1024)
+#define MAX_MSG_PAGES 4
 
 static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
 {
 	unsigned long curr_hash;
+	size_t max_msg_size;
 	int page_size;
 	int msg_count;
 	int fd;
@@ -412,7 +413,8 @@ static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
 
 	curr_hash = 0;
 	page_size = getpagesize();
-	msg_count = SOCK_BUF_SIZE / MAX_MSG_SIZE;
+	max_msg_size = MAX_MSG_PAGES * page_size;
+	msg_count = SOCK_BUF_SIZE / max_msg_size;
 
 	for (int i = 0; i < msg_count; i++) {
 		ssize_t send_size;
@@ -423,7 +425,7 @@ static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
 		/* Use "small" buffers and "big" buffers. */
 		if (i & 1)
 			buf_size = page_size +
-					(rand() % (MAX_MSG_SIZE - page_size));
+					(rand() % (max_msg_size - page_size));
 		else
 			buf_size = 1 + (rand() % page_size);
 
@@ -479,7 +481,6 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
 	unsigned long remote_hash;
 	unsigned long curr_hash;
 	int fd;
-	char buf[MAX_MSG_SIZE];
 	struct msghdr msg = {0};
 	struct iovec iov = {0};
 
@@ -507,8 +508,13 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
 	control_writeln("SRVREADY");
 	/* Wait, until peer sends whole data. */
 	control_expectln("SENDDONE");
-	iov.iov_base = buf;
-	iov.iov_len = sizeof(buf);
+	iov.iov_len = MAX_MSG_PAGES * getpagesize();
+	iov.iov_base = malloc(iov.iov_len);
+	if (!iov.iov_base) {
+		perror("malloc");
+		exit(EXIT_FAILURE);
+	}
+
 	msg.msg_iov = &iov;
 	msg.msg_iovlen = 1;
 
@@ -533,6 +539,7 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
 		curr_hash += hash_djb2(msg.msg_iov[0].iov_base, recv_size);
 	}
 
+	free(iov.iov_base);
 	close(fd);
 	remote_hash = control_readulong();