3 files changed, 114 insertions, 6 deletions

diff --git a/tools/testing/selftests/sigaltstack/current_stack_pointer.h b/tools/testing/selftests/sigaltstack/current_stack_pointer.h
new file mode 100644
index 000000000000..ea9bdf3a90b1
--- /dev/null
+++ b/tools/testing/selftests/sigaltstack/current_stack_pointer.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#if __alpha__
+register unsigned long sp asm("$30");
+#elif __arm__ || __aarch64__ || __csky__ || __m68k__ || __mips__ || __riscv
+register unsigned long sp asm("sp");
+#elif __i386__
+register unsigned long sp asm("esp");
+#elif __loongarch64
+register unsigned long sp asm("$sp");
+#elif __ppc__
+register unsigned long sp asm("r1");
+#elif __s390x__
+register unsigned long sp asm("%15");
+#elif __sh__
+register unsigned long sp asm("r15");
+#elif __x86_64__
+register unsigned long sp asm("rsp");
+#elif __XTENSA__
+register unsigned long sp asm("a1");
+#else
+#error "implement current_stack_pointer equivalent"
+#endif
diff --git a/tools/testing/selftests/sigaltstack/sas.c b/tools/testing/selftests/sigaltstack/sas.c
index c53b070755b6..98d37cb744fb 100644
--- a/tools/testing/selftests/sigaltstack/sas.c
+++ b/tools/testing/selftests/sigaltstack/sas.c
@@ -20,6 +20,7 @@
 #include <sys/auxv.h>
 
 #include "../kselftest.h"
+#include "current_stack_pointer.h"
 
 #ifndef SS_AUTODISARM
 #define SS_AUTODISARM  (1U << 31)
@@ -46,12 +47,6 @@ void my_usr1(int sig, siginfo_t *si, void *u)
 	stack_t stk;
 	struct stk_data *p;
 
-#if __s390x__
-	register unsigned long sp asm("%15");
-#else
-	register unsigned long sp asm("sp");
-#endif
-
 	if (sp < (unsigned long)sstack ||
 			sp >= (unsigned long)sstack + stack_size) {
 		ksft_exit_fail_msg("SP is not on sigaltstack\n");
diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
index 3de10dbb50f5..12b97c92fbb2 100644
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@ -968,6 +968,91 @@ static void test_seqpacket_inv_buf_server(const struct test_opts *opts)
 	test_inv_buf_server(opts, false);
 }
 
+#define HELLO_STR "HELLO"
+#define WORLD_STR "WORLD"
+
+static void test_stream_virtio_skb_merge_client(const struct test_opts *opts)
+{
+	ssize_t res;
+	int fd;
+
+	fd = vsock_stream_connect(opts->peer_cid, 1234);
+	if (fd < 0) {
+		perror("connect");
+		exit(EXIT_FAILURE);
+	}
+
+	/* Send first skbuff. */
+	res = send(fd, HELLO_STR, strlen(HELLO_STR), 0);
+	if (res != strlen(HELLO_STR)) {
+		fprintf(stderr, "unexpected send(2) result %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("SEND0");
+	/* Peer reads part of first skbuff. */
+	control_expectln("REPLY0");
+
+	/* Send second skbuff, it will be appended to the first. */
+	res = send(fd, WORLD_STR, strlen(WORLD_STR), 0);
+	if (res != strlen(WORLD_STR)) {
+		fprintf(stderr, "unexpected send(2) result %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("SEND1");
+	/* Peer reads merged skbuff packet. */
+	control_expectln("REPLY1");
+
+	close(fd);
+}
+
+static void test_stream_virtio_skb_merge_server(const struct test_opts *opts)
+{
+	unsigned char buf[64];
+	ssize_t res;
+	int fd;
+
+	fd = vsock_stream_accept(VMADDR_CID_ANY, 1234, NULL);
+	if (fd < 0) {
+		perror("accept");
+		exit(EXIT_FAILURE);
+	}
+
+	control_expectln("SEND0");
+
+	/* Read skbuff partially. */
+	res = recv(fd, buf, 2, 0);
+	if (res != 2) {
+		fprintf(stderr, "expected recv(2) returns 2 bytes, got %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("REPLY0");
+	control_expectln("SEND1");
+
+	res = recv(fd, buf + 2, sizeof(buf) - 2, 0);
+	if (res != 8) {
+		fprintf(stderr, "expected recv(2) returns 8 bytes, got %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	res = recv(fd, buf, sizeof(buf) - 8 - 2, MSG_DONTWAIT);
+	if (res != -1) {
+		fprintf(stderr, "expected recv(2) failure, got %zi\n", res);
+		exit(EXIT_FAILURE);
+	}
+
+	if (memcmp(buf, HELLO_STR WORLD_STR, strlen(HELLO_STR WORLD_STR))) {
+		fprintf(stderr, "pattern mismatch\n");
+		exit(EXIT_FAILURE);
+	}
+
+	control_writeln("REPLY1");
+
+	close(fd);
+}
+
 static struct test_case test_cases[] = {
 	{
 		.name = "SOCK_STREAM connection reset",
@@ -1038,6 +1123,11 @@ static struct test_case test_cases[] = {
 		.run_client = test_seqpacket_inv_buf_client,
 		.run_server = test_seqpacket_inv_buf_server,
 	},
+	{
+		.name = "SOCK_STREAM virtio skb merge",
+		.run_client = test_stream_virtio_skb_merge_client,
+		.run_server = test_stream_virtio_skb_merge_server,
+	},
 	{},
 };