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-rw-r--r--tools/perf/util/bpf-utils.h76
1 files changed, 76 insertions, 0 deletions
diff --git a/tools/perf/util/bpf-utils.h b/tools/perf/util/bpf-utils.h
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+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+#ifndef __PERF_BPF_UTILS_H
+#define __PERF_BPF_UTILS_H
+
+#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr))
+
+#ifdef HAVE_LIBBPF_SUPPORT
+
+#include <bpf/libbpf.h>
+
+/*
+ * Get bpf_prog_info in continuous memory
+ *
+ * struct bpf_prog_info has multiple arrays. The user has option to choose
+ * arrays to fetch from kernel. The following APIs provide an uniform way to
+ * fetch these data. All arrays in bpf_prog_info are stored in a single
+ * continuous memory region. This makes it easy to store the info in a
+ * file.
+ *
+ * Before writing perf_bpil to files, it is necessary to
+ * translate pointers in bpf_prog_info to offsets. Helper functions
+ * bpil_addr_to_offs() and bpil_offs_to_addr()
+ * are introduced to switch between pointers and offsets.
+ *
+ * Examples:
+ * # To fetch map_ids and prog_tags:
+ * __u64 arrays = (1UL << PERF_BPIL_MAP_IDS) |
+ * (1UL << PERF_BPIL_PROG_TAGS);
+ * struct perf_bpil *info_linear =
+ * get_bpf_prog_info_linear(fd, arrays);
+ *
+ * # To save data in file
+ * bpil_addr_to_offs(info_linear);
+ * write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
+ *
+ * # To read data from file
+ * read(f, info_linear, <proper_size>);
+ * bpil_offs_to_addr(info_linear);
+ */
+enum perf_bpil_array_types {
+ PERF_BPIL_FIRST_ARRAY = 0,
+ PERF_BPIL_JITED_INSNS = 0,
+ PERF_BPIL_XLATED_INSNS,
+ PERF_BPIL_MAP_IDS,
+ PERF_BPIL_JITED_KSYMS,
+ PERF_BPIL_JITED_FUNC_LENS,
+ PERF_BPIL_FUNC_INFO,
+ PERF_BPIL_LINE_INFO,
+ PERF_BPIL_JITED_LINE_INFO,
+ PERF_BPIL_PROG_TAGS,
+ PERF_BPIL_LAST_ARRAY,
+};
+
+struct perf_bpil {
+ /* size of struct bpf_prog_info, when the tool is compiled */
+ __u32 info_len;
+ /* total bytes allocated for data, round up to 8 bytes */
+ __u32 data_len;
+ /* which arrays are included in data */
+ __u64 arrays;
+ struct bpf_prog_info info;
+ __u8 data[];
+};
+
+struct perf_bpil *
+get_bpf_prog_info_linear(int fd, __u64 arrays);
+
+void
+bpil_addr_to_offs(struct perf_bpil *info_linear);
+
+void
+bpil_offs_to_addr(struct perf_bpil *info_linear);
+
+#endif /* HAVE_LIBBPF_SUPPORT */
+#endif /* __PERF_BPF_UTILS_H */