bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/tools/perf/builtin-version.c b/tools/perf/builtin-version.c
new file mode 100644
index 000000000..10f25c670
--- /dev/null
+++ b/tools/perf/builtin-version.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "builtin.h"
+#include "color.h"
+#include "util/debug.h"
+#include "util/header.h"
+#include <tools/config.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <subcmd/parse-options.h>
+
+struct version {
+	bool	build_options;
+};
+
+static struct version version;
+
+static struct option version_options[] = {
+	OPT_BOOLEAN(0, "build-options", &version.build_options,
+		    "display the build options"),
+	OPT_END(),
+};
+
+static const char * const version_usage[] = {
+	"perf version [<options>]",
+	NULL
+};
+
+static void library_status(void)
+{
+	for (int i = 0; supported_features[i].name; ++i)
+		feature_status__printf(&supported_features[i]);
+}
+
+int cmd_version(int argc, const char **argv)
+{
+	argc = parse_options(argc, argv, version_options, version_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+
+	printf("perf version %s\n", perf_version_string);
+
+	if (version.build_options || verbose > 0)
+		library_status();
+
+	return 0;
+}