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, 31 insertions, 0 deletions

diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
new file mode 100644
index 000000000..0b61840d4
--- /dev/null
+++ b/tools/perf/util/cache.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_CACHE_H
+#define __PERF_CACHE_H
+
+#include "strbuf.h"
+#include <subcmd/pager.h>
+#include "../ui/ui.h"
+
+#include <linux/compiler.h>
+#include <linux/string.h>
+
+#define CMD_EXEC_PATH "--exec-path"
+#define CMD_DEBUGFS_DIR "--debugfs-dir="
+
+#define EXEC_PATH_ENVIRONMENT "PERF_EXEC_PATH"
+#define PERF_DEBUGFS_ENVIRONMENT "PERF_DEBUGFS_DIR"
+#define PERF_TRACEFS_ENVIRONMENT "PERF_TRACEFS_DIR"
+#define PERF_PAGER_ENVIRONMENT "PERF_PAGER"
+
+int split_cmdline(char *cmdline, const char ***argv);
+
+#define alloc_nr(x) (((x)+16)*3/2)
+
+static inline int is_absolute_path(const char *path)
+{
+	return path[0] == '/';
+}
+
+char *mkpath(char *path_buf, size_t sz, const char *fmt, ...) __printf(3, 4);
+
+#endif /* __PERF_CACHE_H */