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, 79 insertions, 0 deletions

diff --git a/tools/perf/util/build-id.h b/tools/perf/util/build-id.h
new file mode 100644
index 000000000..73bad90b0
--- /dev/null
+++ b/tools/perf/util/build-id.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef PERF_BUILD_ID_H_
+#define PERF_BUILD_ID_H_ 1
+
+#define BUILD_ID_SIZE	20 /* SHA-1 length in bytes */
+#define BUILD_ID_MIN_SIZE	16 /* MD5/UUID/GUID length in bytes */
+#define SBUILD_ID_SIZE	(BUILD_ID_SIZE * 2 + 1)
+#define SBUILD_ID_MIN_SIZE	(BUILD_ID_MIN_SIZE * 2 + 1)
+
+#include "machine.h"
+#include "tool.h"
+#include <linux/types.h>
+
+struct build_id {
+	u8	data[BUILD_ID_SIZE];
+	u8	size;
+};
+
+struct dso;
+struct feat_fd;
+struct nsinfo;
+
+void build_id__init(struct build_id *bid, const u8 *data, size_t size);
+int build_id__snprintf(const struct build_id *build_id, char *bf, size_t bf_size);
+bool build_id__is_defined(const struct build_id *bid);
+int sysfs__snprintf_build_id(const char *root_dir, char *sbuild_id, size_t sbuild_id_size);
+int filename__snprintf_build_id(const char *pathname, char *sbuild_id, size_t sbuild_id_size);
+char *build_id_cache__kallsyms_path(const char *sbuild_id, char *bf,
+				    size_t size);
+
+char *dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
+			     bool is_debug);
+char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
+			       bool is_debug, bool is_kallsyms);
+
+int build_id__mark_dso_hit(const struct perf_tool *tool, union perf_event *event,
+			   struct perf_sample *sample, struct machine *machine);
+
+bool perf_session__read_build_ids(struct perf_session *session, bool with_hits);
+int perf_session__write_buildid_table(struct perf_session *session,
+				      struct feat_fd *fd);
+int perf_session__cache_build_ids(struct perf_session *session);
+int __perf_session__cache_build_ids(struct perf_session *session,
+				    machine__dso_t fn, void *priv);
+
+char *build_id_cache__origname(const char *sbuild_id);
+char *build_id_cache__linkname(const char *sbuild_id, char *bf, size_t size);
+char *build_id_cache__cachedir(const char *sbuild_id, const char *name,
+			       struct nsinfo *nsi, bool is_kallsyms,
+			       bool is_vdso);
+
+struct strlist;
+
+struct strlist *build_id_cache__list_all(bool validonly);
+char *build_id_cache__complement(const char *incomplete_sbuild_id);
+int build_id_cache__list_build_ids(const char *pathname, struct nsinfo *nsi,
+				   struct strlist **result);
+bool build_id_cache__cached(const char *sbuild_id);
+int build_id_cache__add(const char *sbuild_id, const char *name, const char *realname,
+			struct nsinfo *nsi, bool is_kallsyms, bool is_vdso,
+			const char *proper_name, const char *root_dir);
+int __build_id_cache__add_s(const char *sbuild_id,
+			    const char *name, struct nsinfo *nsi,
+			    bool is_kallsyms, bool is_vdso,
+			    const char *proper_name, const char *root_dir);
+static inline int build_id_cache__add_s(const char *sbuild_id,
+					const char *name, struct nsinfo *nsi,
+					bool is_kallsyms, bool is_vdso)
+{
+	return __build_id_cache__add_s(sbuild_id, name, nsi, is_kallsyms, is_vdso, NULL, NULL);
+}
+int build_id_cache__remove_s(const char *sbuild_id);
+
+extern char buildid_dir[];
+
+void set_buildid_dir(const char *dir);
+void disable_buildid_cache(void);
+
+#endif