Merge branch 'Support bpf trampoline for s390x'

Ilya Leoshkevich says:

====================

v2: https://lore.kernel.org/bpf/20230128000650.1516334-1-iii@linux.ibm.com/#t
v2 -> v3:
- Make __arch_prepare_bpf_trampoline static.
  (Reported-by: kernel test robot <lkp@intel.com>)
- Support both old- and new- style map definitions in sk_assign. (Alexei)
- Trim DENYLIST.s390x. (Alexei)
- Adjust s390x vmlinux path in vmtest.sh.
- Drop merged fixes.

v1: https://lore.kernel.org/bpf/20230125213817.1424447-1-iii@linux.ibm.com/#t
v1 -> v2:
- Fix core_read_macros, sk_assign, test_profiler, test_bpffs (24/31;
  I'm not quite happy with the fix, but don't have better ideas),
  and xdp_synproxy. (Andrii)
- Prettify liburandom_read and verify_pkcs7_sig fixes. (Andrii)
- Fix bpf_usdt_arg using barrier_var(); prettify barrier_var(). (Andrii)
- Change BPF_MAX_TRAMP_LINKS to enum and query it using BTF. (Andrii)
- Improve bpf_jit_supports_kfunc_call() description. (Alexei)
- Always check sign_extend() return value.
- Cc: Alexander Gordeev.

Hi,

This series implements poke, trampoline, kfunc, and mixing subprogs
and tailcalls on s390x.

The following failures still remain:

#82      get_stack_raw_tp:FAIL
get_stack_print_output:FAIL:user_stack corrupted user stack
Known issue:
We cannot reliably unwind userspace on s390x without DWARF.

#101     ksyms_module:FAIL
address of kernel function bpf_testmod_test_mod_kfunc is out of range
Known issue:
Kernel and modules are too far away from each other on s390x.

#190     stacktrace_build_id:FAIL
Known issue:
We cannot reliably unwind userspace on s390x without DWARF.

#281     xdp_metadata:FAIL
See patch 6.

None of these seem to be due to the new changes.

Best regards,
Ilya
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

include/linux/bpf.h

@@ -944,7 +944,11 @@ struct btf_func_model {
  * bytes on x86.
  */
 enum {
+#if defined(__s390x__)
+	BPF_MAX_TRAMP_LINKS = 27,
+#else
 	BPF_MAX_TRAMP_LINKS = 38,
+#endif
 };
 
 struct bpf_tramp_links {

tools/testing/selftests/bpf/prog_tests/sk_assign.c

@@ -29,7 +29,23 @@ static int stop, duration;
 static bool
 configure_stack(void)
 {
+	char tc_version[128];
 	char tc_cmd[BUFSIZ];
+	char *prog;
+	FILE *tc;
+
+	/* Check whether tc is built with libbpf. */
+	tc = popen("tc -V", "r");
+	if (CHECK_FAIL(!tc))
+		return false;
+	if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
+		return false;
+	if (strstr(tc_version, ", libbpf "))
+		prog = "test_sk_assign_libbpf.bpf.o";
+	else
+		prog = "test_sk_assign.bpf.o";
+	if (CHECK_FAIL(pclose(tc)))
+		return false;
 
 	/* Move to a new networking namespace */
 	if (CHECK_FAIL(unshare(CLONE_NEWNET)))
@@ -46,8 +62,8 @@ configure_stack(void)
 	/* Load qdisc, BPF program */
 	if (CHECK_FAIL(system("tc qdisc add dev lo clsact")))
 		return false;
-	sprintf(tc_cmd, "%s %s %s %s", "tc filter add dev lo ingress bpf",
-		       "direct-action object-file ./test_sk_assign.bpf.o",
+	sprintf(tc_cmd, "%s %s %s %s %s", "tc filter add dev lo ingress bpf",
+		       "direct-action object-file", prog,
 		       "section tc",
 		       (env.verbosity < VERBOSE_VERY) ? " 2>/dev/null" : "verbose");
 	if (CHECK(system(tc_cmd), "BPF load failed;",
@@ -129,15 +145,12 @@ get_port(int fd)
 static ssize_t
 rcv_msg(int srv_client, int type)
 {
-	struct sockaddr_storage ss;
 	char buf[BUFSIZ];
-	socklen_t slen;
 
 	if (type == SOCK_STREAM)
 		return read(srv_client, &buf, sizeof(buf));
 	else
-		return recvfrom(srv_client, &buf, sizeof(buf), 0,
-				(struct sockaddr *)&ss, &slen);
+		return recvfrom(srv_client, &buf, sizeof(buf), 0, NULL, NULL);
 }
 
 static int

tools/testing/selftests/bpf/progs/test_sk_assign.c

@@ -16,6 +16,16 @@
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
 
+#if defined(IPROUTE2_HAVE_LIBBPF)
+/* Use a new-style map definition. */
+struct {
+	__uint(type, BPF_MAP_TYPE_SOCKMAP);
+	__type(key, int);
+	__type(value, __u64);
+	__uint(pinning, LIBBPF_PIN_BY_NAME);
+	__uint(max_entries, 1);
+} server_map SEC(".maps");
+#else
 /* Pin map under /sys/fs/bpf/tc/globals/<map name> */
 #define PIN_GLOBAL_NS 2
 
@@ -35,6 +45,7 @@ struct {
 	.max_elem = 1,
 	.pinning = PIN_GLOBAL_NS,
 };
+#endif
 
 char _license[] SEC("license") = "GPL";
 

tools/testing/selftests/bpf/progs/test_sk_assign_libbpf.c

+// SPDX-License-Identifier: GPL-2.0
+#define IPROUTE2_HAVE_LIBBPF
+#include "test_sk_assign.c"

tools/testing/selftests/bpf/vmtest.sh

@@ -13,7 +13,7 @@ s390x)
 	QEMU_BINARY=qemu-system-s390x
 	QEMU_CONSOLE="ttyS1"
 	QEMU_FLAGS=(-smp 2)
-	BZIMAGE="arch/s390/boot/compressed/vmlinux"
+	BZIMAGE="arch/s390/boot/vmlinux"
 	;;
 x86_64)
 	QEMU_BINARY=qemu-system-x86_64