strace/bpf-add-support-for-jited_ksyms-and-jited_func_lens-.patch

From d1f90bcdc7cf95cf442321f18452d0367e80b7d5 Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Tue, 12 Mar 2019 11:17:20 +0000
Subject: [PATCH 271/293] bpf: add support for *jited_ksyms and
 *jited_func_lens fields in struct bpf_prog_info

* bpf_attr.h (struct bpf_prog_info_struct): Add nr_jited_ksyms,
nr_jited_func_lens, jited_ksyms, and jited_func_lens fields.
* bpf.c (struct obj_get_info_saved): Likewise.
(print_bpf_prog_info): Decode these fields introduced by Linux commits
v4.18-rc1~114^2~148^2~3^2~6 and v4.18-rc1~114^2~148^2~3^2~2.
* tests/bpf-obj_get_info_by_fd.c (main): Update expected output.
---
 bpf.c                          | 40 ++++++++++++++++++++++++++++++++++++++++
 bpf_attr.h                     |  6 +++++-
 tests/bpf-obj_get_info_by_fd.c | 21 +++++++++++++++++++++
 3 files changed, 66 insertions(+), 1 deletion(-)

diff --git a/bpf.c b/bpf.c
index 31bdd9b..c1a4e52 100644
--- a/bpf.c
+++ b/bpf.c
@@ -447,6 +447,11 @@ struct obj_get_info_saved {
 	uint32_t jited_prog_len;
 	uint32_t xlated_prog_len;
 	uint32_t nr_map_ids;
+	uint32_t nr_jited_ksyms;
+
+	uint32_t nr_jited_func_lens;
+	uint64_t jited_ksyms;
+	uint64_t jited_func_lens;
 };
 
 static void
@@ -507,6 +512,10 @@ print_bpf_prog_info(struct tcb * const tcp, uint32_t bpf_fd,
 		saved->jited_prog_len = info.jited_prog_len;
 		saved->xlated_prog_len = info.xlated_prog_len;
 		saved->nr_map_ids = info.nr_map_ids;
+		saved->nr_jited_ksyms = info.nr_jited_ksyms;
+		saved->nr_jited_func_lens = info.nr_jited_func_lens;
+		saved->jited_ksyms = info.jited_ksyms;
+		saved->jited_func_lens = info.jited_func_lens;
 
 		return;
 	}
@@ -569,6 +578,37 @@ print_bpf_prog_info(struct tcb * const tcp, uint32_t bpf_fd,
 	PRINT_FIELD_DEV(", ", info, netns_dev);
 	PRINT_FIELD_U(", ", info, netns_ino);
 
+	/*
+	 * The next four fields were introduced by Linux commits
+	 * v4.18-rc1~114^2~148^2~3^2~6 and v4.18-rc1~114^2~148^2~3^2~2.
+	 */
+	if (len <= offsetof(struct bpf_prog_info_struct, nr_jited_ksyms))
+		goto print_bpf_prog_info_end;
+
+	tprints(", nr_jited_ksyms=");
+	if (saved->nr_jited_ksyms != info.nr_jited_ksyms)
+		tprintf("%" PRIu32 " => ", saved->nr_jited_ksyms);
+	tprintf("%" PRIu32, info.nr_jited_ksyms);
+
+	tprints(", nr_jited_func_lens=");
+	if (saved->nr_jited_func_lens != info.nr_jited_func_lens)
+		tprintf("%" PRIu32 " => ", saved->nr_jited_func_lens);
+	tprintf("%" PRIu32, info.nr_jited_func_lens);
+
+	tprints(", jited_ksyms=");
+	if (saved->jited_ksyms != info.jited_ksyms) {
+		printaddr64(saved->jited_ksyms);
+		tprints(" => ");
+	}
+	printaddr64(info.jited_ksyms);
+
+	tprints(", jited_func_lens=");
+	if (saved->jited_func_lens != info.jited_func_lens) {
+		printaddr64(saved->jited_func_lens);
+		tprints(" => ");
+	}
+	printaddr64(info.jited_func_lens);
+
 	decode_attr_extra_data(tcp, info_buf, size, bpf_prog_info_struct_size);
 
 print_bpf_prog_info_end:
diff --git a/bpf_attr.h b/bpf_attr.h
index 7da8af6..d23d464 100644
--- a/bpf_attr.h
+++ b/bpf_attr.h
@@ -289,10 +289,14 @@ struct bpf_prog_info_struct {
 	 */
 	uint64_t ATTRIBUTE_ALIGNED(8) netns_dev; /* skip check */
 	uint64_t ATTRIBUTE_ALIGNED(8) netns_ino; /* skip check */
+	uint32_t nr_jited_ksyms;
+	uint32_t nr_jited_func_lens;
+	uint64_t ATTRIBUTE_ALIGNED(8) jited_ksyms;
+	uint64_t ATTRIBUTE_ALIGNED(8) jited_func_lens;
 };
 
 #define bpf_prog_info_struct_size \
 	sizeof(struct bpf_prog_info_struct)
-#define expected_bpf_prog_info_struct_size 104
+#define expected_bpf_prog_info_struct_size 128
 
 #endif /* !STRACE_BPF_ATTR_H */
diff --git a/tests/bpf-obj_get_info_by_fd.c b/tests/bpf-obj_get_info_by_fd.c
index 5096f16..96c8837 100644
--- a/tests/bpf-obj_get_info_by_fd.c
+++ b/tests/bpf-obj_get_info_by_fd.c
@@ -366,6 +366,8 @@ main(void)
 
 	for (unsigned int i = 0; i < 4; i++) {
 		prog_info->jited_prog_len = 0;
+		prog_info->nr_jited_ksyms = 0;
+		prog_info->nr_jited_func_lens = 0;
 		switch (i) {
 		case 1:
 			prog_info->xlated_prog_insns =
@@ -492,6 +494,25 @@ main(void)
 		    offsetof(struct bpf_prog_info_struct, netns_ino))
 			printf(", netns_ino=%" PRIu64, prog_info->netns_ino);
 
+		if (bpf_prog_get_info_attr.info_len >
+		    offsetof(struct bpf_prog_info_struct, nr_jited_ksyms)) {
+			printf(", nr_jited_ksyms=0");
+			if (prog_info->nr_jited_ksyms)
+				printf(" => %u", prog_info->nr_jited_ksyms);
+		}
+		if (bpf_prog_get_info_attr.info_len >
+		    offsetof(struct bpf_prog_info_struct, nr_jited_func_lens)) {
+			printf(", nr_jited_func_lens=0");
+			if (prog_info->nr_jited_func_lens)
+				printf(" => %u", prog_info->nr_jited_func_lens);
+		}
+		if (bpf_prog_get_info_attr.info_len >
+		    offsetof(struct bpf_prog_info_struct, jited_ksyms))
+			printf(", jited_ksyms=NULL");
+		if (bpf_prog_get_info_attr.info_len >
+		    offsetof(struct bpf_prog_info_struct, jited_func_lens))
+			printf(", jited_func_lens=NULL");
+
 		printf("}");
 # else /* !VERBOSE */
 		printf("%p", prog_info);
-- 
1.7.12.4