Merge branch 'skip-callback-tests-if-jit-is-disabled-in-test_verifier'

Tiezhu Yang says:

====================
Skip callback tests if jit is disabled in test_verifier

Thanks very much for the feedbacks from Eduard, John, Jiri, Daniel,
Hou Tao, Song Liu and Andrii.

v7:
  -- Add an explicit flag F_NEEDS_JIT_ENABLED for checking,
     thanks Andrii.

v6:
  -- Copy insn_is_pseudo_func() into testing_helpers,
     thanks Andrii.

v5:
  -- Reuse is_ldimm64_insn() and insn_is_pseudo_func(),
     thanks Song Liu.

v4:
  -- Move the not-allowed-checking into "if (expected_ret ...)"
     block, thanks Hou Tao.
  -- Do some small changes to avoid checkpatch warning
     about "line length exceeds 100 columns".

v3:
  -- Rebase on the latest bpf-next tree.
  -- Address the review comments by Hou Tao,
     remove the second argument "0" of open(),
     check only once whether jit is disabled,
     check fd_prog, saved_errno and jit_disabled to skip.
====================

Link: https://lore.kernel.org/r/20240123090351.2207-1-yangtiezhu@loongson.cnSigned-off-by: Andrii Nakryiko <andrii@kernel.org>

tools/testing/selftests/bpf/test_progs.c

@@ -547,24 +547,6 @@ int bpf_find_map(const char *test, struct bpf_object *obj, const char *name)
 	return bpf_map__fd(map);
 }
 
-static bool is_jit_enabled(void)
-{
-	const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
-	bool enabled = false;
-	int sysctl_fd;
-
-	sysctl_fd = open(jit_sysctl, 0, O_RDONLY);
-	if (sysctl_fd != -1) {
-		char tmpc;
-
-		if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
-			enabled = (tmpc != '0');
-		close(sysctl_fd);
-	}
-
-	return enabled;
-}
-
 int compare_map_keys(int map1_fd, int map2_fd)
 {
 	__u32 key, next_key;

tools/testing/selftests/bpf/test_verifier.c

@@ -67,6 +67,7 @@
 
 #define F_NEEDS_EFFICIENT_UNALIGNED_ACCESS	(1 << 0)
 #define F_LOAD_WITH_STRICT_ALIGNMENT		(1 << 1)
+#define F_NEEDS_JIT_ENABLED			(1 << 2)
 
 /* need CAP_BPF, CAP_NET_ADMIN, CAP_PERFMON to load progs */
 #define ADMIN_CAPS (1ULL << CAP_NET_ADMIN |	\
@@ -74,6 +75,7 @@
 		    1ULL << CAP_BPF)
 #define UNPRIV_SYSCTL "kernel/unprivileged_bpf_disabled"
 static bool unpriv_disabled = false;
+static bool jit_disabled;
 static int skips;
 static bool verbose = false;
 static int verif_log_level = 0;
@@ -1524,6 +1526,13 @@ static void do_test_single(struct bpf_test *test, bool unpriv,
 	__u32 pflags;
 	int i, err;
 
+	if ((test->flags & F_NEEDS_JIT_ENABLED) && jit_disabled) {
+		printf("SKIP (requires BPF JIT)");
+		skips++;
+		sched_yield();
+		return;
+	}
+
 	fd_prog = -1;
 	for (i = 0; i < MAX_NR_MAPS; i++)
 		map_fds[i] = -1;
@@ -1844,6 +1853,8 @@ int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	}
 
+	jit_disabled = !is_jit_enabled();
+
 	/* Use libbpf 1.0 API mode */
 	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
 

tools/testing/selftests/bpf/testing_helpers.c

@@ -457,3 +457,21 @@ int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt)
 	*buf = NULL;
 	return -1;
 }
+
+bool is_jit_enabled(void)
+{
+	const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
+	bool enabled = false;
+	int sysctl_fd;
+
+	sysctl_fd = open(jit_sysctl, O_RDONLY);
+	if (sysctl_fd != -1) {
+		char tmpc;
+
+		if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
+			enabled = (tmpc != '0');
+		close(sysctl_fd);
+	}
+
+	return enabled;
+}

tools/testing/selftests/bpf/testing_helpers.h

@@ -52,5 +52,6 @@ struct bpf_insn;
  */
 int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt);
 int testing_prog_flags(void);
+bool is_jit_enabled(void);
 
 #endif /* __TESTING_HELPERS_H */

tools/testing/selftests/bpf/verifier/bpf_loop_inline.c

@@ -57,6 +57,7 @@
 	.expected_insns = { PSEUDO_CALL_INSN() },
 	.unexpected_insns = { HELPER_CALL_INSN() },
 	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.flags = F_NEEDS_JIT_ENABLED,
 	.result = ACCEPT,
 	.runs = 0,
 	.func_info = { { 0, MAIN_TYPE }, { 12, CALLBACK_TYPE } },
@@ -90,6 +91,7 @@
 	.expected_insns = { HELPER_CALL_INSN() },
 	.unexpected_insns = { PSEUDO_CALL_INSN() },
 	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.flags = F_NEEDS_JIT_ENABLED,
 	.result = ACCEPT,
 	.runs = 0,
 	.func_info = { { 0, MAIN_TYPE }, { 16, CALLBACK_TYPE } },
@@ -127,6 +129,7 @@
 	.expected_insns = { HELPER_CALL_INSN() },
 	.unexpected_insns = { PSEUDO_CALL_INSN() },
 	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.flags = F_NEEDS_JIT_ENABLED,
 	.result = ACCEPT,
 	.runs = 0,
 	.func_info = {
@@ -165,6 +168,7 @@
 	.expected_insns = { PSEUDO_CALL_INSN() },
 	.unexpected_insns = { HELPER_CALL_INSN() },
 	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.flags = F_NEEDS_JIT_ENABLED,
 	.result = ACCEPT,
 	.runs = 0,
 	.func_info = {
@@ -235,6 +239,7 @@
 	},
 	.unexpected_insns = { HELPER_CALL_INSN() },
 	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.flags = F_NEEDS_JIT_ENABLED,
 	.result = ACCEPT,
 	.func_info = {
 		{ 0, MAIN_TYPE },
@@ -252,6 +257,7 @@
 	.unexpected_insns = { HELPER_CALL_INSN() },
 	.result = ACCEPT,
 	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.flags = F_NEEDS_JIT_ENABLED,
 	.func_info = { { 0, MAIN_TYPE }, { 16, CALLBACK_TYPE } },
 	.func_info_cnt = 2,
 	BTF_TYPES