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, 64 insertions, 0 deletions

diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
new file mode 100644
index 000000000..4d72c5fa5
--- /dev/null
+++ b/tools/perf/util/mmap.h
@@ -0,0 +1,64 @@
+#ifndef __PERF_MMAP_H
+#define __PERF_MMAP_H 1
+
+#include <internal/mmap.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+#include <perf/cpumap.h>
+#ifdef HAVE_AIO_SUPPORT
+#include <aio.h>
+#endif
+#include "auxtrace.h"
+#include "util/compress.h"
+
+struct aiocb;
+
+struct mmap_cpu_mask {
+	unsigned long *bits;
+	size_t nbits;
+};
+
+#define MMAP_CPU_MASK_BYTES(m) \
+	(BITS_TO_LONGS(((struct mmap_cpu_mask *)m)->nbits) * sizeof(unsigned long))
+
+/**
+ * struct mmap - perf's ring buffer mmap details
+ *
+ * @refcnt - e.g. code using PERF_EVENT_IOC_SET_OUTPUT to share this
+ */
+struct mmap {
+	struct perf_mmap	core;
+	struct auxtrace_mmap auxtrace_mmap;
+#ifdef HAVE_AIO_SUPPORT
+	struct {
+		void		 **data;
+		struct aiocb	 *cblocks;
+		struct aiocb	 **aiocb;
+		int		 nr_cblocks;
+	} aio;
+#endif
+	struct mmap_cpu_mask	affinity_mask;
+	void		*data;
+	struct perf_data_file *file;
+	struct zstd_data      zstd_data;
+};
+
+struct mmap_params {
+	struct perf_mmap_param core;
+	int nr_cblocks, affinity, flush, comp_level;
+	struct auxtrace_mmap_params auxtrace_mp;
+};
+
+int mmap__mmap(struct mmap *map, struct mmap_params *mp, int fd, struct perf_cpu cpu);
+void mmap__munmap(struct mmap *map);
+
+union perf_event *perf_mmap__read_forward(struct mmap *map);
+
+int perf_mmap__push(struct mmap *md, void *to,
+		    int push(struct mmap *map, void *to, void *buf, size_t size));
+
+size_t mmap__mmap_len(struct mmap *map);
+
+void mmap_cpu_mask__scnprintf(struct mmap_cpu_mask *mask, const char *tag);
+
+#endif /*__PERF_MMAP_H */