[PATCH v5 perf,bpf 00/15] perf annotation of BPF programs

[PATCH v5 perf,bpf 00/15] perf annotation of BPF programs

[Song Liu]

Changes v4 to v5:
1. Rebase to latest bpf-next;
2. Add dependency of 94816add0005 from Arnaldo's tree;
3. More details in change logs;
4. Add perf_env__init() to init bpf related lock and rbtrees;
5. Small clean ups.

Changes v3 to v4:
1. Incorporate feedbacks from Jiri and Namhyung;
2. Fixed compilation error with different feature-disassembler-four-args;
3. Split some patches to smaller patches;
4. Improved error handleing in symbol__disassemble_bpf();
5. Made side band thread more generic;
6. Added comments as suggested.

Changes v2 to v3:
1. Remove unnecessary include in header files;
2. Improved error handling;
3. Better naming of functions, variables, etc.;
4. Enable bpf events by default for perf-top.

Changes v1 to v2:
1. Fix compilation error with different feature-disassembler-four-args;
2. Fix a segfault in perf-record;
3. Split patches 5/9 and 6/9 so that perf_env changes and perf.data changes
   are in separate patches.

This series enables annotation of BPF programs in perf.

perf tool gathers information via sys_bpf and (optionally) stores them in
perf.data as headers.

Patch 1/15 fixes a minor issue in kernel;
Patch 2/15 to 4/15 introduce new helper functions and use them in perf and
     bpftool;
Patch 5/15 to 9/15 saves information of bpf program in perf_env;
Patch 10/15 adds --bpf-event options to perf-top;
Patch 11/15 to 13/15 enables annotation of bpf progs based on information
     gathered in 5/15 to 9/15;
Patch 14/15 introduces side band polling thread that gathers information
     for special kernel events during perf-record or perf-top.
Patch 15/15 handles information of short living BPF program using the new
     side band polling thread.

Commands tested during developments are perf-top, perf-record, perf-report,
and perf-annotate.

===================== Note on patch dependency  ========================
This set has dependency in both bpf-next tree and tip/perf/core. Current
version is developed on bpf-next tree with the following commits
cherry-picked from tip/perf/core (or acme/perf/core):

(from 1/11 to 11/11)
commit 76193a94522f ("perf, bpf: Introduce PERF_RECORD_KSYMBOL")
commit d764ac646491 ("tools headers uapi: Sync tools/include/uapi/linux/perf_event.h")
commit 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
commit df063c83aa2c ("tools headers uapi: Sync tools/include/uapi/linux/perf_event.h")
commit 9aa0bfa370b2 ("perf tools: Handle PERF_RECORD_KSYMBOL")
commit 45178a928a4b ("perf tools: Handle PERF_RECORD_BPF_EVENT")
commit 7b612e291a5a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs")
commit a40b95bcd30c ("perf top: Synthesize BPF events for pre-existing loaded BPF programs")
commit 6934058d9fb6 ("bpf: Add module name [bpf] to ksymbols for bpf programs")
commit 811184fb6977 ("perf bpf: Fix synthesized PERF_RECORD_KSYMBOL/BPF_EVENT")
comimt 94816add0005 ("perf tools: Add perf_exe() helper to find perf binary")
========================================================================

This set is also available at:

https://github.com/liu-song-6/linux/tree/bpf-annotation

Thanks!!

Song Liu (15):
  perf, bpf: consider events with attr.bpf_event as side-band events
  bpf: libbpf: introduce bpf_program__get_prog_info_linear()
  bpf: bpftool: use bpf_program__get_prog_info_linear() in
    prog.c:do_dump()
  perf, bpf: synthesize bpf events with
    bpf_program__get_prog_info_linear()
  perf: change prototype of perf_event__synthesize_bpf_events()
  perf, bpf: save bpf_prog_info in a rbtree in perf_env
  perf, bpf: save bpf_prog_info information as headers to perf.data
  perf, bpf: save btf in a rbtree in perf_env
  perf, bpf: save btf information as headers to perf.data
  perf-top: add option --no-bpf-event
  perf: add -lopcodes to feature-libbfd
  perf, bpf: enable annotation of bpf program
  perf, bpf: process PERF_BPF_EVENT_PROG_LOAD for annotation
  perf: introduce side band thread
  perf, bpf: save bpf_prog_info and btf of short living bpf programs

 kernel/events/core.c         |   3 +-
 tools/bpf/bpftool/prog.c     | 266 +++++++------------------------
 tools/build/Makefile.feature |   6 +-
 tools/lib/bpf/libbpf.c       | 251 +++++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h       |  63 ++++++++
 tools/lib/bpf/libbpf.map     |   3 +
 tools/perf/Makefile.config   |   6 +-
 tools/perf/builtin-record.c  |  12 +-
 tools/perf/builtin-top.c     |  15 +-
 tools/perf/perf.c            |   1 +
 tools/perf/util/annotate.c   | 150 ++++++++++++++++-
 tools/perf/util/bpf-event.c  | 301 +++++++++++++++++++++++++----------
 tools/perf/util/bpf-event.h  |  36 ++++-
 tools/perf/util/dso.c        |   1 +
 tools/perf/util/dso.h        |  33 ++--
 tools/perf/util/env.c        | 149 +++++++++++++++++
 tools/perf/util/env.h        |  22 +++
 tools/perf/util/evlist.c     | 105 ++++++++++++
 tools/perf/util/evlist.h     |  13 ++
 tools/perf/util/header.c     | 249 ++++++++++++++++++++++++++++-
 tools/perf/util/header.h     |   2 +
 tools/perf/util/session.c    |   1 +
 tools/perf/util/symbol.c     |   1 +
 tools/perf/util/top.h        |   1 +
 24 files changed, 1379 insertions(+), 311 deletions(-)

--
2.17.1

[PATCH v5 perf,bpf 01/15] perf, bpf: consider events with attr.bpf_event as side-band events

[Song Liu]

Events with bpf_event should be considered as side-band event, as they
carry information about BPF programs.

Fixes: 6ee52e2a3fe4 ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 kernel/events/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 795bfab6f8a3..6a17584810ca 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4238,7 +4238,8 @@ static bool is_sb_event(struct perf_event *event)
 	if (attr->mmap || attr->mmap_data || attr->mmap2 ||
 	    attr->comm || attr->comm_exec ||
 	    attr->task || attr->ksymbol ||
-	    attr->context_switch)
+	    attr->context_switch ||
+	    attr->bpf_event)
 		return true;
 	return false;
 }
-- 
2.17.1

[PATCH v5 perf,bpf 02/15] bpf: libbpf: introduce bpf_program__get_prog_info_linear()

[Song Liu]

Currently, bpf_prog_info includes 9 arrays. The user has the option to
fetch any combination of these arrays. However, this requires a lot of
handling of these arrays. This work becomes more tricky when we need to
store bpf_prog_info to a file, because these arrays are allocated
independently.

This patch introduces struct bpf_prog_info_linear, which stores arrays
of bpf_prog_info in continues memory. Helper functions are introduced
to unify the work to get different information of bpf_prog_info.
Specifically, bpf_program__get_prog_info_linear() allows the user to
select which arrays to fetch, and handles details for the user.

Plesae see the comments before enum bpf_prog_info_array for more details
and examples.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/lib/bpf/libbpf.c   | 251 +++++++++++++++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h   |  63 ++++++++++
 tools/lib/bpf/libbpf.map |   3 +
 3 files changed, 317 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b38dcbe7460a..fa12729de283 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -112,6 +112,11 @@ void libbpf_print(enum libbpf_print_level level, const char *format, ...)
 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
 #endif
 
+static inline __u64 ptr_to_u64(const void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
 struct bpf_capabilities {
 	/* v4.14: kernel support for program & map names. */
 	__u32 name:1;
@@ -2997,3 +3002,249 @@ bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
 	ring_buffer_write_tail(header, data_tail);
 	return ret;
 }
+
+struct bpf_prog_info_array_desc {
+	int	array_offset;	/* e.g. offset of jited_prog_insns */
+	int	count_offset;	/* e.g. offset of jited_prog_len */
+	int	size_offset;	/* > 0: offset of rec size,
+				 * < 0: fix size of -size_offset
+				 */
+};
+
+static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
+	[BPF_PROG_INFO_JITED_INSNS] = {
+		offsetof(struct bpf_prog_info, jited_prog_insns),
+		offsetof(struct bpf_prog_info, jited_prog_len),
+		-1,
+	},
+	[BPF_PROG_INFO_XLATED_INSNS] = {
+		offsetof(struct bpf_prog_info, xlated_prog_insns),
+		offsetof(struct bpf_prog_info, xlated_prog_len),
+		-1,
+	},
+	[BPF_PROG_INFO_MAP_IDS] = {
+		offsetof(struct bpf_prog_info, map_ids),
+		offsetof(struct bpf_prog_info, nr_map_ids),
+		-(int)sizeof(__u32),
+	},
+	[BPF_PROG_INFO_JITED_KSYMS] = {
+		offsetof(struct bpf_prog_info, jited_ksyms),
+		offsetof(struct bpf_prog_info, nr_jited_ksyms),
+		-(int)sizeof(__u64),
+	},
+	[BPF_PROG_INFO_JITED_FUNC_LENS] = {
+		offsetof(struct bpf_prog_info, jited_func_lens),
+		offsetof(struct bpf_prog_info, nr_jited_func_lens),
+		-(int)sizeof(__u32),
+	},
+	[BPF_PROG_INFO_FUNC_INFO] = {
+		offsetof(struct bpf_prog_info, func_info),
+		offsetof(struct bpf_prog_info, nr_func_info),
+		offsetof(struct bpf_prog_info, func_info_rec_size),
+	},
+	[BPF_PROG_INFO_LINE_INFO] = {
+		offsetof(struct bpf_prog_info, line_info),
+		offsetof(struct bpf_prog_info, nr_line_info),
+		offsetof(struct bpf_prog_info, line_info_rec_size),
+	},
+	[BPF_PROG_INFO_JITED_LINE_INFO] = {
+		offsetof(struct bpf_prog_info, jited_line_info),
+		offsetof(struct bpf_prog_info, nr_jited_line_info),
+		offsetof(struct bpf_prog_info, jited_line_info_rec_size),
+	},
+	[BPF_PROG_INFO_PROG_TAGS] = {
+		offsetof(struct bpf_prog_info, prog_tags),
+		offsetof(struct bpf_prog_info, nr_prog_tags),
+		-(int)sizeof(__u8) * BPF_TAG_SIZE,
+	},
+
+};
+
+static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info, int offset)
+{
+	__u32 *array = (__u32 *)info;
+
+	if (offset >= 0)
+		return array[offset / sizeof(__u32)];
+	return -(int)offset;
+}
+
+static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info, int offset)
+{
+	__u64 *array = (__u64 *)info;
+
+	if (offset >= 0)
+		return array[offset / sizeof(__u64)];
+	return -(int)offset;
+}
+
+static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
+					 __u32 val)
+{
+	__u32 *array = (__u32 *)info;
+
+	if (offset >= 0)
+		array[offset / sizeof(__u32)] = val;
+}
+
+static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
+					 __u64 val)
+{
+	__u64 *array = (__u64 *)info;
+
+	if (offset >= 0)
+		array[offset / sizeof(__u64)] = val;
+}
+
+struct bpf_prog_info_linear *
+bpf_program__get_prog_info_linear(int fd, __u64 arrays)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	__u32 data_len = 0;
+	int i, err;
+	void *ptr;
+
+	if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
+		return ERR_PTR(-EINVAL);
+
+	/* step 1: get array dimensions */
+	err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+	if (err) {
+		pr_debug("can't get prog info: %s", strerror(errno));
+		return ERR_PTR(-EFAULT);
+	}
+
+	/* step 2: calculate total size of all arrays */
+	for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+		bool include_array = (arrays & (1UL << i)) > 0;
+		struct bpf_prog_info_array_desc *desc;
+		__u32 count, size;
+
+		desc = bpf_prog_info_array_desc + i;
+
+		/* kernel is too old to support this field */
+		if (info_len < desc->array_offset + sizeof(__u32) ||
+		    info_len < desc->count_offset + sizeof(__u32) ||
+		    (desc->size_offset > 0 && info_len < desc->size_offset))
+			include_array = false;
+
+		if (!include_array) {
+			arrays &= ~(1UL << i);	/* clear the bit */
+			continue;
+		}
+
+		count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+		size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+
+		data_len += count * size;
+	}
+
+	/* step 3: allocate continuous memory */
+	data_len = roundup(data_len, sizeof(__u64));
+	info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
+	if (!info_linear)
+		return ERR_PTR(-ENOMEM);
+
+	/* step 4: fill data to info_linear->info */
+	info_linear->arrays = arrays;
+	memset(&info_linear->info, 0, sizeof(info));
+	ptr = info_linear->data;
+
+	for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+		struct bpf_prog_info_array_desc *desc;
+		__u32 count, size;
+
+		if ((arrays & (1UL << i)) == 0)
+			continue;
+
+		desc = bpf_prog_info_array_desc + i;
+		count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+		size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+		bpf_prog_info_set_offset_u32(&info_linear->info,
+					     desc->count_offset, count);
+		bpf_prog_info_set_offset_u32(&info_linear->info,
+					     desc->size_offset, size);
+		bpf_prog_info_set_offset_u64(&info_linear->info,
+					     desc->array_offset,
+					     ptr_to_u64(ptr));
+		ptr += count * size;
+	}
+
+	/* step 5: call syscall again to get required arrays */
+	err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
+	if (err) {
+		pr_debug("can't get prog info: %s", strerror(errno));
+		free(info_linear);
+		return ERR_PTR(-EFAULT);
+	}
+
+	/* step 6: verify the data */
+	for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+		struct bpf_prog_info_array_desc *desc;
+		__u32 v1, v2;
+
+		if ((arrays & (1UL << i)) == 0)
+			continue;
+
+		desc = bpf_prog_info_array_desc + i;
+		v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
+		v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
+						   desc->count_offset);
+		if (v1 != v2)
+			pr_warning("%s: mismatch in element count\n", __func__);
+
+		v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
+		v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
+						   desc->size_offset);
+		if (v1 != v2)
+			pr_warning("%s: mismatch in rec size\n", __func__);
+	}
+
+	/* step 7: update info_len and data_len */
+	info_linear->info_len = sizeof(struct bpf_prog_info);
+	info_linear->data_len = data_len;
+
+	return info_linear;
+}
+
+void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
+{
+	int i;
+
+	for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+		struct bpf_prog_info_array_desc *desc;
+		__u64 addr, offs;
+
+		if ((info_linear->arrays & (1UL << i)) == 0)
+			continue;
+
+		desc = bpf_prog_info_array_desc + i;
+		addr = bpf_prog_info_read_offset_u64(&info_linear->info,
+						     desc->array_offset);
+		offs = addr - ptr_to_u64(info_linear->data);
+		bpf_prog_info_set_offset_u64(&info_linear->info,
+					     desc->array_offset, offs);
+	}
+}
+
+void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
+{
+	int i;
+
+	for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
+		struct bpf_prog_info_array_desc *desc;
+		__u64 addr, offs;
+
+		if ((info_linear->arrays & (1UL << i)) == 0)
+			continue;
+
+		desc = bpf_prog_info_array_desc + i;
+		offs = bpf_prog_info_read_offset_u64(&info_linear->info,
+						     desc->array_offset);
+		addr = offs + ptr_to_u64(info_linear->data);
+		bpf_prog_info_set_offset_u64(&info_linear->info,
+					     desc->array_offset, addr);
+	}
+}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 6c0168f8bba5..809275c47bb5 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -376,6 +376,69 @@ LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
 LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
 				 enum bpf_prog_type prog_type, __u32 ifindex);
 
+/*
+ * 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 uniform way to
+ * fetch these data. All arrays in bpf_prog_info are stored in singile
+ * continuous memory region. This makes it easy to store the info in a
+ * file.
+ *
+ * Before writing bpf_prog_info_linear to files, it is necessary to
+ * translate pointers bpf_prog_info to offsets. Helper functions
+ * bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
+ * are introduced to switch between pointers and offsets.
+ *
+ * Examples:
+ *   # To fetch map_ids and prog_tags:
+ *   __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
+ *           (1UL << BPF_PROG_INFO_PROG_TAGS);
+ *   struct bpf_prog_info_linear *info_linear =
+ *           bpf_program__get_prog_info_linear(fd, arrays);
+ *
+ *   # To save data in file
+ *   bpf_program__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>);
+ *   bpf_program__bpil_offs_to_addr(info_linear);
+ */
+enum bpf_prog_info_array {
+	BPF_PROG_INFO_FIRST_ARRAY = 0,
+	BPF_PROG_INFO_JITED_INSNS = 0,
+	BPF_PROG_INFO_XLATED_INSNS,
+	BPF_PROG_INFO_MAP_IDS,
+	BPF_PROG_INFO_JITED_KSYMS,
+	BPF_PROG_INFO_JITED_FUNC_LENS,
+	BPF_PROG_INFO_FUNC_INFO,
+	BPF_PROG_INFO_LINE_INFO,
+	BPF_PROG_INFO_JITED_LINE_INFO,
+	BPF_PROG_INFO_PROG_TAGS,
+	BPF_PROG_INFO_LAST_ARRAY,
+};
+
+struct bpf_prog_info_linear {
+	/* 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[];
+};
+
+LIBBPF_API struct bpf_prog_info_linear *
+bpf_program__get_prog_info_linear(int fd, __u64 arrays);
+
+LIBBPF_API void
+bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
+
+LIBBPF_API void
+bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 778a26702a70..f3ce50500cf2 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -153,4 +153,7 @@ LIBBPF_0.0.2 {
 		xsk_socket__delete;
 		xsk_umem__fd;
 		xsk_socket__fd;
+		bpf_program__get_prog_info_linear;
+		bpf_program__bpil_addr_to_offs;
+		bpf_program__bpil_offs_to_addr;
 } LIBBPF_0.0.1;
-- 
2.17.1

[PATCH v5 perf,bpf 03/15] bpf: bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump()

[Song Liu]

This patches uses bpf_program__get_prog_info_linear() to simplify the
logic in prog.c do_dump().

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/bpf/bpftool/prog.c | 266 +++++++++------------------------------
 1 file changed, 59 insertions(+), 207 deletions(-)

diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 0c35dd543d49..c09b960c0b67 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -401,41 +401,31 @@ static int do_show(int argc, char **argv)
 
 static int do_dump(int argc, char **argv)
 {
-	unsigned int finfo_rec_size, linfo_rec_size, jited_linfo_rec_size;
-	void *func_info = NULL, *linfo = NULL, *jited_linfo = NULL;
-	unsigned int nr_finfo, nr_linfo = 0, nr_jited_linfo = 0;
+	struct bpf_prog_info_linear *info_linear;
 	struct bpf_prog_linfo *prog_linfo = NULL;
-	unsigned long *func_ksyms = NULL;
-	struct bpf_prog_info info = {};
-	unsigned int *func_lens = NULL;
+	enum {DUMP_JITED, DUMP_XLATED} mode;
 	const char *disasm_opt = NULL;
-	unsigned int nr_func_ksyms;
-	unsigned int nr_func_lens;
+	struct bpf_prog_info *info;
 	struct dump_data dd = {};
-	__u32 len = sizeof(info);
+	void *func_info = NULL;
 	struct btf *btf = NULL;
-	unsigned int buf_size;
 	char *filepath = NULL;
 	bool opcodes = false;
 	bool visual = false;
 	char func_sig[1024];
 	unsigned char *buf;
 	bool linum = false;
-	__u32 *member_len;
-	__u64 *member_ptr;
+	__u32 member_len;
+	__u64 arrays;
 	ssize_t n;
-	int err;
 	int fd;
 
 	if (is_prefix(*argv, "jited")) {
 		if (disasm_init())
 			return -1;
-
-		member_len = &info.jited_prog_len;
-		member_ptr = &info.jited_prog_insns;
+		mode = DUMP_JITED;
 	} else if (is_prefix(*argv, "xlated")) {
-		member_len = &info.xlated_prog_len;
-		member_ptr = &info.xlated_prog_insns;
+		mode = DUMP_XLATED;
 	} else {
 		p_err("expected 'xlated' or 'jited', got: %s", *argv);
 		return -1;
@@ -474,175 +464,50 @@ static int do_dump(int argc, char **argv)
 		return -1;
 	}
 
-	err = bpf_obj_get_info_by_fd(fd, &info, &len);
-	if (err) {
-		p_err("can't get prog info: %s", strerror(errno));
-		return -1;
-	}
-
-	if (!*member_len) {
-		p_info("no instructions returned");
-		close(fd);
-		return 0;
-	}
+	if (mode == DUMP_JITED)
+		arrays = 1UL << BPF_PROG_INFO_JITED_INSNS;
+	else
+		arrays = 1UL << BPF_PROG_INFO_XLATED_INSNS;
 
-	buf_size = *member_len;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_KSYMS;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
+	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
 
-	buf = malloc(buf_size);
-	if (!buf) {
-		p_err("mem alloc failed");
-		close(fd);
+	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
+	close(fd);
+	if (IS_ERR_OR_NULL(info_linear)) {
+		p_err("can't get prog info: %s", strerror(errno));
 		return -1;
 	}
 
-	nr_func_ksyms = info.nr_jited_ksyms;
-	if (nr_func_ksyms) {
-		func_ksyms = malloc(nr_func_ksyms * sizeof(__u64));
-		if (!func_ksyms) {
-			p_err("mem alloc failed");
-			close(fd);
-			goto err_free;
-		}
-	}
-
-	nr_func_lens = info.nr_jited_func_lens;
-	if (nr_func_lens) {
-		func_lens = malloc(nr_func_lens * sizeof(__u32));
-		if (!func_lens) {
-			p_err("mem alloc failed");
-			close(fd);
+	info = &info_linear->info;
+	if (mode == DUMP_JITED) {
+		if (info->jited_prog_len == 0) {
+			p_info("no instructions returned");
 			goto err_free;
 		}
-	}
-
-	nr_finfo = info.nr_func_info;
-	finfo_rec_size = info.func_info_rec_size;
-	if (nr_finfo && finfo_rec_size) {
-		func_info = malloc(nr_finfo * finfo_rec_size);
-		if (!func_info) {
-			p_err("mem alloc failed");
-			close(fd);
+		buf = (unsigned char *)(info->jited_prog_insns);
+		member_len = info->jited_prog_len;
+	} else {	/* DUMP_XLATED */
+		if (info->xlated_prog_len == 0) {
+			p_err("error retrieving insn dump: kernel.kptr_restrict set?");
 			goto err_free;
 		}
+		buf = (unsigned char *)info->xlated_prog_insns;
+		member_len = info->xlated_prog_len;
 	}
 
-	linfo_rec_size = info.line_info_rec_size;
-	if (info.nr_line_info && linfo_rec_size && info.btf_id) {
-		nr_linfo = info.nr_line_info;
-		linfo = malloc(nr_linfo * linfo_rec_size);
-		if (!linfo) {
-			p_err("mem alloc failed");
-			close(fd);
-			goto err_free;
-		}
-	}
-
-	jited_linfo_rec_size = info.jited_line_info_rec_size;
-	if (info.nr_jited_line_info &&
-	    jited_linfo_rec_size &&
-	    info.nr_jited_ksyms &&
-	    info.nr_jited_func_lens &&
-	    info.btf_id) {
-		nr_jited_linfo = info.nr_jited_line_info;
-		jited_linfo = malloc(nr_jited_linfo * jited_linfo_rec_size);
-		if (!jited_linfo) {
-			p_err("mem alloc failed");
-			close(fd);
-			goto err_free;
-		}
-	}
-
-	memset(&info, 0, sizeof(info));
-
-	*member_ptr = ptr_to_u64(buf);
-	*member_len = buf_size;
-	info.jited_ksyms = ptr_to_u64(func_ksyms);
-	info.nr_jited_ksyms = nr_func_ksyms;
-	info.jited_func_lens = ptr_to_u64(func_lens);
-	info.nr_jited_func_lens = nr_func_lens;
-	info.nr_func_info = nr_finfo;
-	info.func_info_rec_size = finfo_rec_size;
-	info.func_info = ptr_to_u64(func_info);
-	info.nr_line_info = nr_linfo;
-	info.line_info_rec_size = linfo_rec_size;
-	info.line_info = ptr_to_u64(linfo);
-	info.nr_jited_line_info = nr_jited_linfo;
-	info.jited_line_info_rec_size = jited_linfo_rec_size;
-	info.jited_line_info = ptr_to_u64(jited_linfo);
-
-	err = bpf_obj_get_info_by_fd(fd, &info, &len);
-	close(fd);
-	if (err) {
-		p_err("can't get prog info: %s", strerror(errno));
-		goto err_free;
-	}
-
-	if (*member_len > buf_size) {
-		p_err("too many instructions returned");
-		goto err_free;
-	}
-
-	if (info.nr_jited_ksyms > nr_func_ksyms) {
-		p_err("too many addresses returned");
-		goto err_free;
-	}
-
-	if (info.nr_jited_func_lens > nr_func_lens) {
-		p_err("too many values returned");
-		goto err_free;
-	}
-
-	if (info.nr_func_info != nr_finfo) {
-		p_err("incorrect nr_func_info %d vs. expected %d",
-		      info.nr_func_info, nr_finfo);
-		goto err_free;
-	}
-
-	if (info.func_info_rec_size != finfo_rec_size) {
-		p_err("incorrect func_info_rec_size %d vs. expected %d",
-		      info.func_info_rec_size, finfo_rec_size);
-		goto err_free;
-	}
-
-	if (linfo && info.nr_line_info != nr_linfo) {
-		p_err("incorrect nr_line_info %u vs. expected %u",
-		      info.nr_line_info, nr_linfo);
-		goto err_free;
-	}
-
-	if (info.line_info_rec_size != linfo_rec_size) {
-		p_err("incorrect line_info_rec_size %u vs. expected %u",
-		      info.line_info_rec_size, linfo_rec_size);
-		goto err_free;
-	}
-
-	if (jited_linfo && info.nr_jited_line_info != nr_jited_linfo) {
-		p_err("incorrect nr_jited_line_info %u vs. expected %u",
-		      info.nr_jited_line_info, nr_jited_linfo);
-		goto err_free;
-	}
-
-	if (info.jited_line_info_rec_size != jited_linfo_rec_size) {
-		p_err("incorrect jited_line_info_rec_size %u vs. expected %u",
-		      info.jited_line_info_rec_size, jited_linfo_rec_size);
-		goto err_free;
-	}
-
-	if ((member_len == &info.jited_prog_len &&
-	     info.jited_prog_insns == 0) ||
-	    (member_len == &info.xlated_prog_len &&
-	     info.xlated_prog_insns == 0)) {
-		p_err("error retrieving insn dump: kernel.kptr_restrict set?");
-		goto err_free;
-	}
-
-	if (info.btf_id && btf__get_from_id(info.btf_id, &btf)) {
+	if (info->btf_id && btf__get_from_id(info->btf_id, &btf)) {
 		p_err("failed to get btf");
 		goto err_free;
 	}
 
-	if (nr_linfo) {
-		prog_linfo = bpf_prog_linfo__new(&info);
+	func_info = (void *)info->func_info;
+
+	if (info->nr_line_info) {
+		prog_linfo = bpf_prog_linfo__new(info);
 		if (!prog_linfo)
 			p_info("error in processing bpf_line_info.  continue without it.");
 	}
@@ -655,9 +520,9 @@ static int do_dump(int argc, char **argv)
 			goto err_free;
 		}
 
-		n = write(fd, buf, *member_len);
+		n = write(fd, buf, member_len);
 		close(fd);
-		if (n != *member_len) {
+		if (n != member_len) {
 			p_err("error writing output file: %s",
 			      n < 0 ? strerror(errno) : "short write");
 			goto err_free;
@@ -665,19 +530,19 @@ static int do_dump(int argc, char **argv)
 
 		if (json_output)
 			jsonw_null(json_wtr);
-	} else if (member_len == &info.jited_prog_len) {
+	} else if (mode == DUMP_JITED) {
 		const char *name = NULL;
 
-		if (info.ifindex) {
-			name = ifindex_to_bfd_params(info.ifindex,
-						     info.netns_dev,
-						     info.netns_ino,
+		if (info->ifindex) {
+			name = ifindex_to_bfd_params(info->ifindex,
+						     info->netns_dev,
+						     info->netns_ino,
 						     &disasm_opt);
 			if (!name)
 				goto err_free;
 		}
 
-		if (info.nr_jited_func_lens && info.jited_func_lens) {
+		if (info->nr_jited_func_lens && info->jited_func_lens) {
 			struct kernel_sym *sym = NULL;
 			struct bpf_func_info *record;
 			char sym_name[SYM_MAX_NAME];
@@ -685,17 +550,16 @@ static int do_dump(int argc, char **argv)
 			__u64 *ksyms = NULL;
 			__u32 *lens;
 			__u32 i;
-
-			if (info.nr_jited_ksyms) {
+			if (info->nr_jited_ksyms) {
 				kernel_syms_load(&dd);
-				ksyms = (__u64 *) info.jited_ksyms;
+				ksyms = (__u64 *) info->jited_ksyms;
 			}
 
 			if (json_output)
 				jsonw_start_array(json_wtr);
 
-			lens = (__u32 *) info.jited_func_lens;
-			for (i = 0; i < info.nr_jited_func_lens; i++) {
+			lens = (__u32 *) info->jited_func_lens;
+			for (i = 0; i < info->nr_jited_func_lens; i++) {
 				if (ksyms) {
 					sym = kernel_syms_search(&dd, ksyms[i]);
 					if (sym)
@@ -707,7 +571,7 @@ static int do_dump(int argc, char **argv)
 				}
 
 				if (func_info) {
-					record = func_info + i * finfo_rec_size;
+					record = func_info + i * info->func_info_rec_size;
 					btf_dumper_type_only(btf, record->type_id,
 							     func_sig,
 							     sizeof(func_sig));
@@ -744,49 +608,37 @@ static int do_dump(int argc, char **argv)
 			if (json_output)
 				jsonw_end_array(json_wtr);
 		} else {
-			disasm_print_insn(buf, *member_len, opcodes, name,
+			disasm_print_insn(buf, member_len, opcodes, name,
 					  disasm_opt, btf, NULL, 0, 0, false);
 		}
 	} else if (visual) {
 		if (json_output)
 			jsonw_null(json_wtr);
 		else
-			dump_xlated_cfg(buf, *member_len);
+			dump_xlated_cfg(buf, member_len);
 	} else {
 		kernel_syms_load(&dd);
-		dd.nr_jited_ksyms = info.nr_jited_ksyms;
-		dd.jited_ksyms = (__u64 *) info.jited_ksyms;
+		dd.nr_jited_ksyms = info->nr_jited_ksyms;
+		dd.jited_ksyms = (__u64 *) info->jited_ksyms;
 		dd.btf = btf;
 		dd.func_info = func_info;
-		dd.finfo_rec_size = finfo_rec_size;
+		dd.finfo_rec_size = info->func_info_rec_size;
 		dd.prog_linfo = prog_linfo;
 
 		if (json_output)
-			dump_xlated_json(&dd, buf, *member_len, opcodes,
+			dump_xlated_json(&dd, buf, member_len, opcodes,
 					 linum);
 		else
-			dump_xlated_plain(&dd, buf, *member_len, opcodes,
+			dump_xlated_plain(&dd, buf, member_len, opcodes,
 					  linum);
 		kernel_syms_destroy(&dd);
 	}
 
-	free(buf);
-	free(func_ksyms);
-	free(func_lens);
-	free(func_info);
-	free(linfo);
-	free(jited_linfo);
-	bpf_prog_linfo__free(prog_linfo);
+	free(info_linear);
 	return 0;
 
 err_free:
-	free(buf);
-	free(func_ksyms);
-	free(func_lens);
-	free(func_info);
-	free(linfo);
-	free(jited_linfo);
-	bpf_prog_linfo__free(prog_linfo);
+	free(info_linear);
 	return -1;
 }
 
-- 
2.17.1

[PATCH v5 perf,bpf 04/15] perf, bpf: synthesize bpf events with bpf_program__get_prog_info_linear()

[Song Liu]

With bpf_program__get_prog_info_linear, we can simplify the logic that
synthesizes bpf events.

This patch doesn't change the behavior of the code.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/bpf-event.c | 118 ++++++++++++------------------------
 1 file changed, 40 insertions(+), 78 deletions(-)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 796ef793f4ce..e6dfb95029e5 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -3,7 +3,9 @@
 #include <stdlib.h>
 #include <bpf/bpf.h>
 #include <bpf/btf.h>
+#include <bpf/libbpf.h>
 #include <linux/btf.h>
+#include <linux/err.h>
 #include "bpf-event.h"
 #include "debug.h"
 #include "symbol.h"
@@ -49,99 +51,62 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
 {
 	struct ksymbol_event *ksymbol_event = &event->ksymbol_event;
 	struct bpf_event *bpf_event = &event->bpf_event;
-	u32 sub_prog_cnt, i, func_info_rec_size = 0;
-	u8 (*prog_tags)[BPF_TAG_SIZE] = NULL;
-	struct bpf_prog_info info = { .type = 0, };
-	u32 info_len = sizeof(info);
-	void *func_infos = NULL;
-	u64 *prog_addrs = NULL;
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info *info;
 	struct btf *btf = NULL;
-	u32 *prog_lens = NULL;
 	bool has_btf = false;
-	char errbuf[512];
+	u32 sub_prog_cnt, i;
 	int err = 0;
+	u64 arrays;
 
-	/* Call bpf_obj_get_info_by_fd() to get sizes of arrays */
-	err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
+	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
+	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
 
-	if (err) {
-		pr_debug("%s: failed to get BPF program info: %s, aborting\n",
-			 __func__, str_error_r(errno, errbuf, sizeof(errbuf)));
+	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
+	if (IS_ERR_OR_NULL(info_linear)) {
+		info_linear = NULL;
+		pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
 		return -1;
 	}
-	if (info_len < offsetof(struct bpf_prog_info, prog_tags)) {
+
+	if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
 		pr_debug("%s: the kernel is too old, aborting\n", __func__);
 		return -2;
 	}
 
+	info = &info_linear->info;
+
 	/* number of ksyms, func_lengths, and tags should match */
-	sub_prog_cnt = info.nr_jited_ksyms;
-	if (sub_prog_cnt != info.nr_prog_tags ||
-	    sub_prog_cnt != info.nr_jited_func_lens)
+	sub_prog_cnt = info->nr_jited_ksyms;
+	if (sub_prog_cnt != info->nr_prog_tags ||
+	    sub_prog_cnt != info->nr_jited_func_lens)
 		return -1;
 
 	/* check BTF func info support */
-	if (info.btf_id && info.nr_func_info && info.func_info_rec_size) {
+	if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
 		/* btf func info number should be same as sub_prog_cnt */
-		if (sub_prog_cnt != info.nr_func_info) {
+		if (sub_prog_cnt != info->nr_func_info) {
 			pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
-			return -1;
-		}
-		if (btf__get_from_id(info.btf_id, &btf)) {
-			pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info.btf_id);
-			return -1;
+			err = -1;
+			goto out;
 		}
-		func_info_rec_size = info.func_info_rec_size;
-		func_infos = calloc(sub_prog_cnt, func_info_rec_size);
-		if (!func_infos) {
-			pr_debug("%s: failed to allocate memory for func_infos, aborting\n", __func__);
-			return -1;
+		if (btf__get_from_id(info->btf_id, &btf)) {
+			pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
+			err = -1;
+			btf = NULL;
+			goto out;
 		}
 		has_btf = true;
 	}
 
-	/*
-	 * We need address, length, and tag for each sub program.
-	 * Allocate memory and call bpf_obj_get_info_by_fd() again
-	 */
-	prog_addrs = calloc(sub_prog_cnt, sizeof(u64));
-	if (!prog_addrs) {
-		pr_debug("%s: failed to allocate memory for prog_addrs, aborting\n", __func__);
-		goto out;
-	}
-	prog_lens = calloc(sub_prog_cnt, sizeof(u32));
-	if (!prog_lens) {
-		pr_debug("%s: failed to allocate memory for prog_lens, aborting\n", __func__);
-		goto out;
-	}
-	prog_tags = calloc(sub_prog_cnt, BPF_TAG_SIZE);
-	if (!prog_tags) {
-		pr_debug("%s: failed to allocate memory for prog_tags, aborting\n", __func__);
-		goto out;
-	}
-
-	memset(&info, 0, sizeof(info));
-	info.nr_jited_ksyms = sub_prog_cnt;
-	info.nr_jited_func_lens = sub_prog_cnt;
-	info.nr_prog_tags = sub_prog_cnt;
-	info.jited_ksyms = ptr_to_u64(prog_addrs);
-	info.jited_func_lens = ptr_to_u64(prog_lens);
-	info.prog_tags = ptr_to_u64(prog_tags);
-	info_len = sizeof(info);
-	if (has_btf) {
-		info.nr_func_info = sub_prog_cnt;
-		info.func_info_rec_size = func_info_rec_size;
-		info.func_info = ptr_to_u64(func_infos);
-	}
-
-	err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
-	if (err) {
-		pr_debug("%s: failed to get BPF program info, aborting\n", __func__);
-		goto out;
-	}
-
 	/* Synthesize PERF_RECORD_KSYMBOL */
 	for (i = 0; i < sub_prog_cnt; i++) {
+		u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(info->prog_tags);
+		__u32 *prog_lens = (__u32 *)(info->jited_func_lens);
+		__u64 *prog_addrs = (__u64 *)(info->jited_ksyms);
+		void *func_infos = (void *)(info->func_info);
 		const struct bpf_func_info *finfo;
 		const char *short_name = NULL;
 		const struct btf_type *t;
@@ -163,13 +128,13 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
 					 KSYM_NAME_LEN - name_len,
 					 prog_tags[i], BPF_TAG_SIZE);
 		if (has_btf) {
-			finfo = func_infos + i * info.func_info_rec_size;
+			finfo = func_infos + i * info->func_info_rec_size;
 			t = btf__type_by_id(btf, finfo->type_id);
 			short_name = btf__name_by_offset(btf, t->name_off);
 		} else if (i == 0 && sub_prog_cnt == 1) {
 			/* no subprog */
-			if (info.name[0])
-				short_name = info.name;
+			if (info->name[0])
+				short_name = info->name;
 		} else
 			short_name = "F";
 		if (short_name)
@@ -195,9 +160,9 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
 			},
 			.type = PERF_BPF_EVENT_PROG_LOAD,
 			.flags = 0,
-			.id = info.id,
+			.id = info->id,
 		};
-		memcpy(bpf_event->tag, prog_tags[i], BPF_TAG_SIZE);
+		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
 		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
 		event->header.size += machine->id_hdr_size;
 		err = perf_tool__process_synth_event(tool, event,
@@ -205,10 +170,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
 	}
 
 out:
-	free(prog_tags);
-	free(prog_lens);
-	free(prog_addrs);
-	free(func_infos);
+	free(info_linear);
 	free(btf);
 	return err ? -1 : 0;
 }
-- 
2.17.1

[PATCH v5 perf,bpf 05/15] perf: change prototype of perf_event__synthesize_bpf_events()

[Song Liu]

This patch changes the arguments of perf_event__synthesize_bpf_events()
to include perf_session* instead of perf_tool*. perf_session will be used
in the next patch.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/builtin-record.c | 2 +-
 tools/perf/builtin-top.c    | 2 +-
 tools/perf/util/bpf-event.c | 8 +++++---
 tools/perf/util/bpf-event.h | 4 ++--
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 88ea11d57c6f..2355e0a9eda0 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1083,7 +1083,7 @@ static int record__synthesize(struct record *rec, bool tail)
 		return err;
 	}
 
-	err = perf_event__synthesize_bpf_events(tool, process_synthesized_event,
+	err = perf_event__synthesize_bpf_events(session, process_synthesized_event,
 						machine, opts);
 	if (err < 0)
 		pr_warning("Couldn't synthesize bpf events.\n");
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 5a486d4de56e..27d8d42e0a4d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1216,7 +1216,7 @@ static int __cmd_top(struct perf_top *top)
 
 	init_process_thread(top);
 
-	ret = perf_event__synthesize_bpf_events(&top->tool, perf_event__process,
+	ret = perf_event__synthesize_bpf_events(top->session, perf_event__process,
 						&top->session->machines.host,
 						&top->record_opts);
 	if (ret < 0)
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index e6dfb95029e5..ff7ee149ec46 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -10,6 +10,7 @@
 #include "debug.h"
 #include "symbol.h"
 #include "machine.h"
+#include "session.h"
 
 #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
 
@@ -42,7 +43,7 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
  *   -1 for failures;
  *   -2 for lack of kernel support.
  */
-static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
+static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 					       perf_event__handler_t process,
 					       struct machine *machine,
 					       int fd,
@@ -52,6 +53,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
 	struct ksymbol_event *ksymbol_event = &event->ksymbol_event;
 	struct bpf_event *bpf_event = &event->bpf_event;
 	struct bpf_prog_info_linear *info_linear;
+	struct perf_tool *tool = session->tool;
 	struct bpf_prog_info *info;
 	struct btf *btf = NULL;
 	bool has_btf = false;
@@ -175,7 +177,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
 	return err ? -1 : 0;
 }
 
-int perf_event__synthesize_bpf_events(struct perf_tool *tool,
+int perf_event__synthesize_bpf_events(struct perf_session *session,
 				      perf_event__handler_t process,
 				      struct machine *machine,
 				      struct record_opts *opts)
@@ -209,7 +211,7 @@ int perf_event__synthesize_bpf_events(struct perf_tool *tool,
 			continue;
 		}
 
-		err = perf_event__synthesize_one_bpf_prog(tool, process,
+		err = perf_event__synthesize_one_bpf_prog(session, process,
 							  machine, fd,
 							  event, opts);
 		close(fd);
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index 7890067e1a37..6698683612a7 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -15,7 +15,7 @@ struct record_opts;
 int machine__process_bpf_event(struct machine *machine, union perf_event *event,
 			       struct perf_sample *sample);
 
-int perf_event__synthesize_bpf_events(struct perf_tool *tool,
+int perf_event__synthesize_bpf_events(struct perf_session *session,
 				      perf_event__handler_t process,
 				      struct machine *machine,
 				      struct record_opts *opts);
@@ -27,7 +27,7 @@ static inline int machine__process_bpf_event(struct machine *machine __maybe_unu
 	return 0;
 }
 
-static inline int perf_event__synthesize_bpf_events(struct perf_tool *tool __maybe_unused,
+static inline int perf_event__synthesize_bpf_events(struct perf_session *session __maybe_unused,
 						    perf_event__handler_t process __maybe_unused,
 						    struct machine *machine __maybe_unused,
 						    struct record_opts *opts __maybe_unused)
-- 
2.17.1

[PATCH v5 perf,bpf 06/15] perf, bpf: save bpf_prog_info in a rbtree in perf_env

[Song Liu]

bpf_prog_info contains information necessary to annotate bpf programs.
This patch saves bpf_prog_info for bpf programs loaded in the system.

Some big picture of the next few patches:

To fully annotate BPF programs with source code mapping, 4 different
information are needed:
    1) PERF_RECORD_KSYMBOL
    2) PERF_RECORD_BPF_EVENT
    3) bpf_prog_info
    4) btf

Before this set, 1) and 2) in the list are already saved to perf.data
file. For BPF programs that are already loaded before perf run, 1) and 2)
are synthesized by perf_event__synthesize_bpf_events(). For short living
BPF programs, 1) and 2) are generated by kernel.

This set handles 3) and 4) from the list. Again, it is necessary to handle
existing BPF program and short living program separately.

This patch handles 3) for exising BPF programs while synthesizing 1) and
2) in perf_event__synthesize_bpf_events(). These data are stored in
perf_env. The next patch saves these data from perf_env to perf.data as
headers.

Similarly, the two patches after the next saves 4) of existing BPF
programs to perf_env and perf.data.

Another patch later will handle 3) and 4) for short living BPF programs
by monitoring 1) and 2) in a dedicate thread.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/perf.c           |  1 +
 tools/perf/util/bpf-event.c | 32 +++++++++++++-
 tools/perf/util/bpf-event.h |  7 +++-
 tools/perf/util/env.c       | 84 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/env.h       | 18 ++++++++
 tools/perf/util/session.c   |  1 +
 6 files changed, 141 insertions(+), 2 deletions(-)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index a11cb006f968..72df4b6fa36f 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -298,6 +298,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 		use_pager = 1;
 	commit_pager_choice();
 
+	perf_env__init(&perf_env);
 	perf_env__set_cmdline(&perf_env, argc, argv);
 	status = p->fn(argc, argv);
 	perf_config__exit();
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index ff7ee149ec46..ce81b2c43a51 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -10,6 +10,7 @@
 #include "debug.h"
 #include "symbol.h"
 #include "machine.h"
+#include "env.h"
 #include "session.h"
 
 #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
@@ -54,17 +55,28 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 	struct bpf_event *bpf_event = &event->bpf_event;
 	struct bpf_prog_info_linear *info_linear;
 	struct perf_tool *tool = session->tool;
+	struct bpf_prog_info_node *info_node;
 	struct bpf_prog_info *info;
 	struct btf *btf = NULL;
 	bool has_btf = false;
+	struct perf_env *env;
 	u32 sub_prog_cnt, i;
 	int err = 0;
 	u64 arrays;
 
+	/*
+	 * for perf-record and perf-report use header.env;
+	 * otherwise, use global perf_env.
+	 */
+	env = session->data ? &session->header.env : &perf_env;
+
 	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
 	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
 	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
 	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
+	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
 
 	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
 	if (IS_ERR_OR_NULL(info_linear)) {
@@ -153,8 +165,8 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 						     machine, process);
 	}
 
-	/* Synthesize PERF_RECORD_BPF_EVENT */
 	if (opts->bpf_event) {
+		/* Synthesize PERF_RECORD_BPF_EVENT */
 		*bpf_event = (struct bpf_event){
 			.header = {
 				.type = PERF_RECORD_BPF_EVENT,
@@ -167,6 +179,24 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 		memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
 		memset((void *)event + event->header.size, 0, machine->id_hdr_size);
 		event->header.size += machine->id_hdr_size;
+
+		/* save bpf_prog_info to env */
+		info_node = malloc(sizeof(struct bpf_prog_info_node));
+
+		/*
+		 * Do not bail out for !info_node, as we still want to
+		 * call  perf_tool__process_synth_event()
+		 */
+		if (info_node) {
+			info_node->info_linear = info_linear;
+			perf_env__insert_bpf_prog_info(env, info_node);
+			info_linear = NULL;
+		}
+
+		/*
+		 * process after saving bpf_prog_info to env, so that
+		 * required information is ready for look up
+		 */
 		err = perf_tool__process_synth_event(tool, event,
 						     machine, process);
 	}
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index 6698683612a7..fad932f7404f 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -3,14 +3,19 @@
 #define __PERF_BPF_EVENT_H
 
 #include <linux/compiler.h>
+#include <linux/rbtree.h>
 #include "event.h"
 
 struct machine;
 union perf_event;
 struct perf_sample;
-struct perf_tool;
 struct record_opts;
 
+struct bpf_prog_info_node {
+	struct bpf_prog_info_linear	*info_linear;
+	struct rb_node			rb_node;
+};
+
 #ifdef HAVE_LIBBPF_SUPPORT
 int machine__process_bpf_event(struct machine *machine, union perf_event *event,
 			       struct perf_sample *sample);
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 4c23779e271a..cdda46f2633f 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -3,15 +3,93 @@
 #include "env.h"
 #include "sane_ctype.h"
 #include "util.h"
+#include "bpf-event.h"
 #include <errno.h>
 #include <sys/utsname.h>
+#include <bpf/libbpf.h>
 
 struct perf_env perf_env;
 
+void perf_env__insert_bpf_prog_info(struct perf_env *env,
+				    struct bpf_prog_info_node *info_node)
+{
+	__u32 prog_id = info_node->info_linear->info.id;
+	struct bpf_prog_info_node *node;
+	struct rb_node *parent = NULL;
+	struct rb_node **p;
+
+	down_write(&env->bpf_progs.lock);
+	p = &env->bpf_progs.infos.rb_node;
+
+	while (*p != NULL) {
+		parent = *p;
+		node = rb_entry(parent, struct bpf_prog_info_node, rb_node);
+		if (prog_id < node->info_linear->info.id) {
+			p = &(*p)->rb_left;
+		} else if (prog_id > node->info_linear->info.id) {
+			p = &(*p)->rb_right;
+		} else {
+			pr_debug("duplicated bpf prog info %u\n", prog_id);
+			goto out;
+		}
+	}
+
+	rb_link_node(&info_node->rb_node, parent, p);
+	rb_insert_color(&info_node->rb_node, &env->bpf_progs.infos);
+out:
+	up_write(&env->bpf_progs.lock);
+}
+
+struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
+							__u32 prog_id)
+{
+	struct bpf_prog_info_node *node = NULL;
+	struct rb_node *n;
+
+	down_read(&env->bpf_progs.lock);
+	n = env->bpf_progs.infos.rb_node;
+
+	while (n) {
+		node = rb_entry(n, struct bpf_prog_info_node, rb_node);
+		if (prog_id < node->info_linear->info.id)
+			n = n->rb_left;
+		else if (prog_id > node->info_linear->info.id)
+			n = n->rb_right;
+		else
+			break;
+	}
+
+	up_read(&env->bpf_progs.lock);
+	return node;
+}
+
+/* purge data in bpf_progs.infos tree */
+static void perf_env__purge_bpf(struct perf_env *env)
+{
+	struct rb_root *root;
+	struct rb_node *next;
+
+	down_write(&env->bpf_progs.lock);
+
+	root = &env->bpf_progs.infos;
+	next = rb_first(root);
+
+	while (next) {
+		struct bpf_prog_info_node *node;
+
+		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+		next = rb_next(&node->rb_node);
+		rb_erase_init(&node->rb_node, root);
+		free(node);
+	}
+	up_write(&env->bpf_progs.lock);
+}
+
 void perf_env__exit(struct perf_env *env)
 {
 	int i;
 
+	perf_env__purge_bpf(env);
 	zfree(&env->hostname);
 	zfree(&env->os_release);
 	zfree(&env->version);
@@ -38,6 +116,12 @@ void perf_env__exit(struct perf_env *env)
 	zfree(&env->memory_nodes);
 }
 
+void perf_env__init(struct perf_env *env)
+{
+	env->bpf_progs.infos = RB_ROOT;
+	init_rwsem(&env->bpf_progs.lock);
+}
+
 int perf_env__set_cmdline(struct perf_env *env, int argc, const char *argv[])
 {
 	int i;
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index d01b8355f4ca..e034e5b438e3 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -3,7 +3,9 @@
 #define __PERF_ENV_H
 
 #include <linux/types.h>
+#include <linux/rbtree.h>
 #include "cpumap.h"
+#include "rwsem.h"
 
 struct cpu_topology_map {
 	int	socket_id;
@@ -64,8 +66,19 @@ struct perf_env {
 	struct memory_node	*memory_nodes;
 	unsigned long long	 memory_bsize;
 	u64                     clockid_res_ns;
+
+	/*
+	 * bpf_info_lock protects bpf rbtrees. This is needed because the
+	 * trees are accessed by different threads in perf-top
+	 */
+	struct {
+		struct rw_semaphore	lock;
+		struct rb_root		infos;
+	} bpf_progs;
 };
 
+struct bpf_prog_info_node;
+
 extern struct perf_env perf_env;
 
 void perf_env__exit(struct perf_env *env);
@@ -80,4 +93,9 @@ const char *perf_env__arch(struct perf_env *env);
 const char *perf_env__raw_arch(struct perf_env *env);
 int perf_env__nr_cpus_avail(struct perf_env *env);
 
+void perf_env__init(struct perf_env *env);
+void perf_env__insert_bpf_prog_info(struct perf_env *env,
+				    struct bpf_prog_info_node *info_node);
+struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
+							__u32 prog_id);
 #endif /* __PERF_ENV_H */
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 026bf04bba74..3c858f1b254e 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -129,6 +129,7 @@ struct perf_session *perf_session__new(struct perf_data *data,
 	ordered_events__init(&session->ordered_events,
 			     ordered_events__deliver_event, NULL);
 
+	perf_env__init(&session->header.env);
 	if (data) {
 		if (perf_data__open(data))
 			goto out_delete;
-- 
2.17.1

[PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Song Liu]

This patch enables perf-record to save bpf_prog_info information as
headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
introduced for this data.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/header.c | 143 ++++++++++++++++++++++++++++++++++++++-
 tools/perf/util/header.h |   1 +
 2 files changed, 143 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 4b88de5e9192..16f5bedb0b7d 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -18,6 +18,7 @@
 #include <sys/utsname.h>
 #include <linux/time64.h>
 #include <dirent.h>
+#include <bpf/libbpf.h>
 
 #include "evlist.h"
 #include "evsel.h"
@@ -39,6 +40,7 @@
 #include "tool.h"
 #include "time-utils.h"
 #include "units.h"
+#include "bpf-event.h"
 
 #include "sane_ctype.h"
 
@@ -1074,6 +1076,51 @@ static int write_clockid(struct feat_fd *ff,
 			sizeof(ff->ph->env.clockid_res_ns));
 }
 
+static int write_bpf_prog_info(struct feat_fd *ff,
+			       struct perf_evlist *evlist __maybe_unused)
+{
+	struct perf_env *env = &ff->ph->env;
+	struct rb_root *root;
+	struct rb_node *next;
+	u32 count = 0;
+	int ret;
+
+	down_read(&env->bpf_progs.lock);
+
+	root = &env->bpf_progs.infos;
+	next = rb_first(root);
+	while (next) {
+		++count;
+		next = rb_next(next);
+	}
+
+	ret = do_write(ff, &count, sizeof(count));
+
+	if (ret < 0)
+		goto out;
+
+	next = rb_first(root);
+	while (next) {
+		struct bpf_prog_info_node *node;
+		size_t len;
+
+		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+		next = rb_next(&node->rb_node);
+		len = sizeof(struct bpf_prog_info_linear) +
+			node->info_linear->data_len;
+
+		/* before writing to file, translate address to offset */
+		bpf_program__bpil_addr_to_offs(node->info_linear);
+		ret = do_write(ff, node->info_linear, len);
+		bpf_program__bpil_offs_to_addr(node->info_linear);
+		if (ret < 0)
+			goto out;
+	}
+out:
+	up_read(&env->bpf_progs.lock);
+	return ret;
+}
+
 static int cpu_cache_level__sort(const void *a, const void *b)
 {
 	struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
@@ -1554,6 +1601,29 @@ static void print_clockid(struct feat_fd *ff, FILE *fp)
 		ff->ph->env.clockid_res_ns * 1000);
 }
 
+static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
+{
+	struct perf_env *env = &ff->ph->env;
+	struct rb_root *root;
+	struct rb_node *next;
+
+	down_read(&env->bpf_progs.lock);
+
+	root = &env->bpf_progs.infos;
+	next = rb_first(root);
+
+	while (next) {
+		struct bpf_prog_info_node *node;
+
+		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
+		next = rb_next(&node->rb_node);
+		fprintf(fp, "# bpf_prog_info of id %u\n",
+			node->info_linear->info.id);
+	}
+
+	up_read(&env->bpf_progs.lock);
+}
+
 static void free_event_desc(struct perf_evsel *events)
 {
 	struct perf_evsel *evsel;
@@ -2586,6 +2656,76 @@ static int process_clockid(struct feat_fd *ff,
 	return 0;
 }
 
+static int process_bpf_prog_info(struct feat_fd *ff,
+				 void *data __maybe_unused)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info_node *info_node;
+	struct perf_env *env = &ff->ph->env;
+	u32 count, i;
+	int err = -1;
+
+	if (do_read_u32(ff, &count))
+		return -1;
+
+	down_write(&env->bpf_progs.lock);
+
+	for (i = 0; i < count; ++i) {
+		u32 info_len, data_len;
+
+		info_linear = NULL;
+		info_node = NULL;
+		if (do_read_u32(ff, &info_len))
+			goto out;
+		if (do_read_u32(ff, &data_len))
+			goto out;
+
+		if (info_len > sizeof(struct bpf_prog_info)) {
+			pr_warning("detected invalid bpf_prog_info\n");
+			goto out;
+		}
+
+		info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
+				     data_len);
+		if (!info_linear)
+			goto out;
+		info_linear->info_len = sizeof(struct bpf_prog_info);
+		info_linear->data_len = data_len;
+		if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
+			goto out;
+		if (__do_read(ff, &info_linear->info, info_len))
+			goto out;
+		if (info_len < sizeof(struct bpf_prog_info))
+			memset(((void *)(&info_linear->info)) + info_len, 0,
+			       sizeof(struct bpf_prog_info) - info_len);
+
+		if (__do_read(ff, info_linear->data, data_len))
+			goto out;
+
+		/* endian mismatch, drop the info, continue */
+		if (ff->ph->needs_swap) {
+			free(info_linear);
+			continue;
+		}
+
+		info_node = malloc(sizeof(struct bpf_prog_info_node));
+		if (!info_node)
+			goto out;
+
+		/* after reading from file, translate offset to address */
+		bpf_program__bpil_offs_to_addr(info_linear);
+		info_node->info_linear = info_linear;
+		perf_env__insert_bpf_prog_info(env, info_node);
+	}
+
+	return 0;
+out:
+	free(info_linear);
+	free(info_node);
+	up_write(&env->bpf_progs.lock);
+	return err;
+}
+
 struct feature_ops {
 	int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
 	void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2645,7 +2785,8 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
 	FEAT_OPN(CACHE,		cache,		true),
 	FEAT_OPR(SAMPLE_TIME,	sample_time,	false),
 	FEAT_OPR(MEM_TOPOLOGY,	mem_topology,	true),
-	FEAT_OPR(CLOCKID,       clockid,        false)
+	FEAT_OPR(CLOCKID,       clockid,        false),
+	FEAT_OPR(BPF_PROG_INFO, bpf_prog_info,  false)
 };
 
 struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 0d553ddca0a3..0785c91b4c3a 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -39,6 +39,7 @@ enum {
 	HEADER_SAMPLE_TIME,
 	HEADER_MEM_TOPOLOGY,
 	HEADER_CLOCKID,
+	HEADER_BPF_PROG_INFO,
 	HEADER_LAST_FEATURE,
 	HEADER_FEAT_BITS	= 256,
 };
-- 
2.17.1

[PATCH v5 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

[Song Liu]

btf contains information necessary to annotate bpf programs. This patch
saves btf for bpf programs loaded in the system.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/bpf-event.c | 24 ++++++++++++++
 tools/perf/util/bpf-event.h |  7 ++++
 tools/perf/util/env.c       | 65 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/env.h       |  4 +++
 4 files changed, 100 insertions(+)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index ce81b2c43a51..370b830f2433 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -34,6 +34,29 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
 	return 0;
 }
 
+static int perf_env__fetch_btf(struct perf_env *env,
+			       u32 btf_id,
+			       struct btf *btf)
+{
+	struct btf_node *node;
+	u32 data_size;
+	const void *data;
+
+	data = btf__get_raw_data(btf, &data_size);
+
+	node = malloc(data_size + sizeof(struct btf_node));
+
+	if (!node)
+		return -1;
+
+	node->id = btf_id;
+	node->data_size = data_size;
+	memcpy(node->data, data, data_size);
+
+	perf_env__insert_btf(env, node);
+	return 0;
+}
+
 /*
  * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
  * program. One PERF_RECORD_BPF_EVENT is generated for the program. And
@@ -113,6 +136,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
 			goto out;
 		}
 		has_btf = true;
+		perf_env__fetch_btf(env, info->btf_id, btf);
 	}
 
 	/* Synthesize PERF_RECORD_KSYMBOL */
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index fad932f7404f..b9ec394dc7c7 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -16,6 +16,13 @@ struct bpf_prog_info_node {
 	struct rb_node			rb_node;
 };
 
+struct btf_node {
+	struct rb_node	rb_node;
+	u32		id;
+	u32		data_size;
+	char		data[];
+};
+
 #ifdef HAVE_LIBBPF_SUPPORT
 int machine__process_bpf_event(struct machine *machine, union perf_event *event,
 			       struct perf_sample *sample);
diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index cdda46f2633f..9e4ee7b0a3d1 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -63,6 +63,57 @@ struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
 	return node;
 }
 
+void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node)
+{
+	struct rb_node *parent = NULL;
+	__u32 btf_id = btf_node->id;
+	struct btf_node *node;
+	struct rb_node **p;
+
+	down_write(&env->bpf_progs.lock);
+	p = &env->bpf_progs.btfs.rb_node;
+
+	while (*p != NULL) {
+		parent = *p;
+		node = rb_entry(parent, struct btf_node, rb_node);
+		if (btf_id < node->id) {
+			p = &(*p)->rb_left;
+		} else if (btf_id > node->id) {
+			p = &(*p)->rb_right;
+		} else {
+			pr_debug("duplicated btf %u\n", btf_id);
+			goto out;
+		}
+	}
+
+	rb_link_node(&btf_node->rb_node, parent, p);
+	rb_insert_color(&btf_node->rb_node, &env->bpf_progs.btfs);
+out:
+	up_write(&env->bpf_progs.lock);
+}
+
+struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
+{
+	struct btf_node *node = NULL;
+	struct rb_node *n;
+
+	down_read(&env->bpf_progs.lock);
+	n = env->bpf_progs.btfs.rb_node;
+
+	while (n) {
+		node = rb_entry(n, struct btf_node, rb_node);
+		if (btf_id < node->id)
+			n = n->rb_left;
+		else if (btf_id > node->id)
+			n = n->rb_right;
+		else
+			break;
+	}
+
+	up_read(&env->bpf_progs.lock);
+	return node;
+}
+
 /* purge data in bpf_progs.infos tree */
 static void perf_env__purge_bpf(struct perf_env *env)
 {
@@ -82,6 +133,19 @@ static void perf_env__purge_bpf(struct perf_env *env)
 		rb_erase_init(&node->rb_node, root);
 		free(node);
 	}
+
+	root = &env->bpf_progs.btfs;
+	next = rb_first(root);
+
+	while (next) {
+		struct btf_node *node;
+
+		node = rb_entry(next, struct btf_node, rb_node);
+		next = rb_next(&node->rb_node);
+		rb_erase_init(&node->rb_node, root);
+		free(node);
+	}
+
 	up_write(&env->bpf_progs.lock);
 }
 
@@ -119,6 +183,7 @@ void perf_env__exit(struct perf_env *env)
 void perf_env__init(struct perf_env *env)
 {
 	env->bpf_progs.infos = RB_ROOT;
+	env->bpf_progs.btfs = RB_ROOT;
 	init_rwsem(&env->bpf_progs.lock);
 }
 
diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
index e034e5b438e3..c3e48504e834 100644
--- a/tools/perf/util/env.h
+++ b/tools/perf/util/env.h
@@ -74,10 +74,12 @@ struct perf_env {
 	struct {
 		struct rw_semaphore	lock;
 		struct rb_root		infos;
+		struct rb_root		btfs;
 	} bpf_progs;
 };
 
 struct bpf_prog_info_node;
+struct btf_node;
 
 extern struct perf_env perf_env;
 
@@ -98,4 +100,6 @@ void perf_env__insert_bpf_prog_info(struct perf_env *env,
 				    struct bpf_prog_info_node *info_node);
 struct bpf_prog_info_node *perf_env__find_bpf_prog_info(struct perf_env *env,
 							__u32 prog_id);
+void perf_env__insert_btf(struct perf_env *env, struct btf_node *btf_node);
+struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id);
 #endif /* __PERF_ENV_H */
-- 
2.17.1

[PATCH v5 perf,bpf 09/15] perf, bpf: save btf information as headers to perf.data

[Song Liu]

This patch enables perf-record to save btf information as headers to
perf.data A new header type HEADER_BPF_BTF is introduced for this data.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/header.c | 108 ++++++++++++++++++++++++++++++++++++++-
 tools/perf/util/header.h |   1 +
 2 files changed, 108 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 16f5bedb0b7d..3df8428c4c91 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1121,6 +1121,45 @@ static int write_bpf_prog_info(struct feat_fd *ff,
 	return ret;
 }
 
+static int write_bpf_btf(struct feat_fd *ff,
+			 struct perf_evlist *evlist __maybe_unused)
+{
+	struct perf_env *env = &ff->ph->env;
+	struct rb_root *root;
+	struct rb_node *next;
+	u32 count = 0;
+	int ret;
+
+	down_read(&env->bpf_progs.lock);
+
+	root = &env->bpf_progs.btfs;
+	next = rb_first(root);
+	while (next) {
+		++count;
+		next = rb_next(next);
+	}
+
+	ret = do_write(ff, &count, sizeof(count));
+
+	if (ret < 0)
+		goto out;
+
+	next = rb_first(root);
+	while (next) {
+		struct btf_node *node;
+
+		node = rb_entry(next, struct btf_node, rb_node);
+		next = rb_next(&node->rb_node);
+		ret = do_write(ff, &node->id,
+			       sizeof(u32) * 2 + node->data_size);
+		if (ret < 0)
+			goto out;
+	}
+out:
+	up_read(&env->bpf_progs.lock);
+	return ret;
+}
+
 static int cpu_cache_level__sort(const void *a, const void *b)
 {
 	struct cpu_cache_level *cache_a = (struct cpu_cache_level *)a;
@@ -1624,6 +1663,28 @@ static void print_bpf_prog_info(struct feat_fd *ff, FILE *fp)
 	up_read(&env->bpf_progs.lock);
 }
 
+static void print_bpf_btf(struct feat_fd *ff, FILE *fp)
+{
+	struct perf_env *env = &ff->ph->env;
+	struct rb_root *root;
+	struct rb_node *next;
+
+	down_read(&env->bpf_progs.lock);
+
+	root = &env->bpf_progs.btfs;
+	next = rb_first(root);
+
+	while (next) {
+		struct btf_node *node;
+
+		node = rb_entry(next, struct btf_node, rb_node);
+		next = rb_next(&node->rb_node);
+		fprintf(fp, "# btf info of id %u\n", node->id);
+	}
+
+	up_read(&env->bpf_progs.lock);
+}
+
 static void free_event_desc(struct perf_evsel *events)
 {
 	struct perf_evsel *evsel;
@@ -2726,6 +2787,50 @@ static int process_bpf_prog_info(struct feat_fd *ff,
 	return err;
 }
 
+static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused)
+{
+	struct perf_env *env = &ff->ph->env;
+	u32 count, i;
+
+	if (do_read_u32(ff, &count))
+		return -1;
+
+	down_write(&env->bpf_progs.lock);
+
+	for (i = 0; i < count; ++i) {
+		struct btf_node *node;
+		u32 id, data_size;
+
+		if (do_read_u32(ff, &id))
+			return -1;
+		if (do_read_u32(ff, &data_size))
+			return -1;
+
+		node = malloc(sizeof(struct btf_node) + data_size);
+		if (!node)
+			return -1;
+
+		node->id = id;
+		node->data_size = data_size;
+
+		if (__do_read(ff, node->data, data_size)) {
+			free(node);
+			return -1;
+		}
+
+		/* endian mismatch, drop the btf, continue */
+		if (ff->ph->needs_swap) {
+			free(node);
+			continue;
+		}
+
+		perf_env__insert_btf(env, node);
+	}
+
+	up_write(&env->bpf_progs.lock);
+	return 0;
+}
+
 struct feature_ops {
 	int (*write)(struct feat_fd *ff, struct perf_evlist *evlist);
 	void (*print)(struct feat_fd *ff, FILE *fp);
@@ -2786,7 +2891,8 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
 	FEAT_OPR(SAMPLE_TIME,	sample_time,	false),
 	FEAT_OPR(MEM_TOPOLOGY,	mem_topology,	true),
 	FEAT_OPR(CLOCKID,       clockid,        false),
-	FEAT_OPR(BPF_PROG_INFO, bpf_prog_info,  false)
+	FEAT_OPR(BPF_PROG_INFO, bpf_prog_info,  false),
+	FEAT_OPR(BPF_BTF,       bpf_btf,        false)
 };
 
 struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 0785c91b4c3a..9e7d931f7c0d 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -40,6 +40,7 @@ enum {
 	HEADER_MEM_TOPOLOGY,
 	HEADER_CLOCKID,
 	HEADER_BPF_PROG_INFO,
+	HEADER_BPF_BTF,
 	HEADER_LAST_FEATURE,
 	HEADER_FEAT_BITS	= 256,
 };
-- 
2.17.1

[PATCH v5 perf,bpf 10/15] perf-top: add option --no-bpf-event

[Song Liu]

bpf events should be tracked by default for perf-top. This patch makes it
on by default, and adds option to disable bpf events.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/builtin-top.c | 3 +++
 tools/perf/util/top.h    | 1 +
 2 files changed, 4 insertions(+)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 27d8d42e0a4d..ccdf5689452f 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1492,6 +1492,7 @@ int cmd_top(int argc, const char **argv)
 		    "Display raw encoding of assembly instructions (default)"),
 	OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
 		    "Enable kernel symbol demangling"),
+	OPT_BOOLEAN(0, "no-bpf-event", &top.no_bpf_event, "do not record bpf events"),
 	OPT_STRING(0, "objdump", &top.annotation_opts.objdump_path, "path",
 		    "objdump binary to use for disassembly and annotations"),
 	OPT_STRING('M', "disassembler-style", &top.annotation_opts.disassembler_style, "disassembler style",
@@ -1651,6 +1652,8 @@ int cmd_top(int argc, const char **argv)
 		signal(SIGWINCH, winch_sig);
 	}
 
+	top.record_opts.bpf_event = !top.no_bpf_event;
+
 	status = __cmd_top(&top);
 
 out_delete_evlist:
diff --git a/tools/perf/util/top.h b/tools/perf/util/top.h
index 19f95eaf75c8..862a37bd27ea 100644
--- a/tools/perf/util/top.h
+++ b/tools/perf/util/top.h
@@ -32,6 +32,7 @@ struct perf_top {
 	bool		   use_tui, use_stdio;
 	bool		   vmlinux_warned;
 	bool		   dump_symtab;
+	bool		   no_bpf_event;
 	struct hist_entry  *sym_filter_entry;
 	struct perf_evsel  *sym_evsel;
 	struct perf_session *session;
-- 
2.17.1

[PATCH v5 perf,bpf 11/15] perf: add -lopcodes to feature-libbfd

[Song Liu]

Both libbfd and libopcodes are distributed with binutil-dev/devel. When
libbfd presents, it is OK to assume libopcodes also presents. This has
been a safe assumption for bpftool.

This patch adds -lopcodes to perf/Makefile.config. libopcodes will be
used in the next commit for bpf annotation.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/Makefile.config | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index b441c88cafa1..e0bafbc273af 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -701,7 +701,7 @@ else
 endif
 
 ifeq ($(feature-libbfd), 1)
-  EXTLIBS += -lbfd
+  EXTLIBS += -lbfd -lopcodes
 else
   # we are on a system that requires -liberty and (maybe) -lz
   # to link against -lbfd; test each case individually here
-- 
2.17.1

[PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Song Liu]

This patch enables the annotation of bpf program.

A new dso type DSO_BINARY_TYPE__BPF_PROG_INFO is introduced to for BPF
programs. In symbol__disassemble(), DSO_BINARY_TYPE__BPF_PROG_INFO dso
calls into a new function symbol__disassemble_bpf(), where annotation
line information is filled based bpf_prog_info and btf saved in given
perf_env.

symbol__disassemble_bpf() uses libbfd to disassemble bpf programs.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/build/Makefile.feature |   6 +-
 tools/perf/Makefile.config   |   4 +
 tools/perf/util/annotate.c   | 150 ++++++++++++++++++++++++++++++++++-
 tools/perf/util/dso.c        |   1 +
 tools/perf/util/dso.h        |  33 +++++---
 tools/perf/util/symbol.c     |   1 +
 6 files changed, 181 insertions(+), 14 deletions(-)

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 5467c6bf9ceb..4f35e9ff1e00 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -71,7 +71,8 @@ FEATURE_TESTS_BASIC :=                  \
         sdt				\
         setns				\
         libopencsd			\
-        libaio
+        libaio				\
+        disassembler-four-args
 
 # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list
 # of all feature tests
@@ -118,7 +119,8 @@ FEATURE_DISPLAY ?=              \
          lzma                   \
          get_cpuid              \
          bpf			\
-         libaio
+         libaio			\
+         disassembler-four-args
 
 # Set FEATURE_CHECK_(C|LD)FLAGS-all for all FEATURE_TESTS features.
 # If in the future we need per-feature checks/flags for features not
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index e0bafbc273af..ab223239f1fb 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -796,6 +796,10 @@ ifdef HAVE_KVM_STAT_SUPPORT
     CFLAGS += -DHAVE_KVM_STAT_SUPPORT
 endif
 
+ifeq ($(feature-disassembler-four-args), 1)
+    CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
+endif
+
 ifeq (${IS_64_BIT}, 1)
   ifndef NO_PERF_READ_VDSO32
     $(call feature_check,compile-32)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 70de8f6b3aee..e467aa0ef0c2 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -9,6 +9,10 @@
 
 #include <errno.h>
 #include <inttypes.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+#include <linux/btf.h>
 #include "util.h"
 #include "ui/ui.h"
 #include "sort.h"
@@ -22,6 +26,7 @@
 #include "annotate.h"
 #include "evsel.h"
 #include "evlist.h"
+#include "bpf-event.h"
 #include "block-range.h"
 #include "string2.h"
 #include "arch/common.h"
@@ -29,6 +34,9 @@
 #include <pthread.h>
 #include <linux/bitops.h>
 #include <linux/kernel.h>
+#include <bfd.h>
+#include <dis-asm.h>
+#include <bpf/libbpf.h>
 
 /* FIXME: For the HE_COLORSET */
 #include "ui/browser.h"
@@ -1672,6 +1680,144 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
 	return 0;
 }
 
+static int symbol__disassemble_bpf(struct symbol *sym,
+				   struct annotate_args *args)
+{
+	struct annotation *notes = symbol__annotation(sym);
+	struct annotation_options *opts = args->options;
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_linfo *prog_linfo = NULL;
+	struct bpf_prog_info_node *info_node;
+	int len = sym->end - sym->start;
+	disassembler_ftype disassemble;
+	struct map *map = args->ms.map;
+	struct disassemble_info info;
+	struct dso *dso = map->dso;
+	int pc = 0, count, sub_id;
+	struct btf *btf = NULL;
+	char tpath[PATH_MAX];
+	size_t buf_size;
+	int nr_skip = 0;
+	int ret = -1;
+	char *buf;
+	bfd *bfdf;
+	FILE *s;
+
+	if (dso->binary_type != DSO_BINARY_TYPE__BPF_PROG_INFO)
+		return -1;
+
+	pr_debug("%s: handling sym %s addr %lx len %lx\n", __func__,
+		 sym->name, sym->start, sym->end - sym->start);
+
+	memset(tpath, 0, sizeof(tpath));
+	perf_exe(tpath, sizeof(tpath));
+
+	bfdf = bfd_openr(tpath, NULL);
+	assert(bfdf);
+	assert(bfd_check_format(bfdf, bfd_object));
+
+	s = open_memstream(&buf, &buf_size);
+	if (!s)
+		goto out;
+	init_disassemble_info(&info, s,
+			      (fprintf_ftype) fprintf);
+
+	info.arch = bfd_get_arch(bfdf);
+	info.mach = bfd_get_mach(bfdf);
+
+	info_node = perf_env__find_bpf_prog_info(dso->bpf_prog.env,
+						 dso->bpf_prog.id);
+	if (!info_node)
+		goto out;
+	info_linear = info_node->info_linear;
+	sub_id = dso->bpf_prog.sub_id;
+
+	info.buffer = (void *)(info_linear->info.jited_prog_insns);
+	info.buffer_length = info_linear->info.jited_prog_len;
+
+	if (info_linear->info.nr_line_info)
+		prog_linfo = bpf_prog_linfo__new(&info_linear->info);
+
+	if (info_linear->info.btf_id) {
+		struct btf_node *node;
+
+		node = perf_env__find_btf(dso->bpf_prog.env,
+					  info_linear->info.btf_id);
+		if (node)
+			btf = btf__new((__u8 *)(node->data),
+				       node->data_size);
+	}
+
+	disassemble_init_for_target(&info);
+
+#ifdef DISASM_FOUR_ARGS_SIGNATURE
+	disassemble = disassembler(info.arch,
+				   bfd_big_endian(bfdf),
+				   info.mach,
+				   bfdf);
+#else
+	disassemble = disassembler(bfdf);
+#endif
+	assert(disassemble);
+
+	fflush(s);
+	do {
+		const struct bpf_line_info *linfo = NULL;
+		struct disasm_line *dl;
+		size_t prev_buf_size;
+		const char *srcline;
+		u64 addr;
+
+		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
+		count = disassemble(pc, &info);
+
+		if (prog_linfo)
+			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
+								addr, sub_id,
+								nr_skip);
+
+		if (linfo && btf) {
+			srcline = btf__name_by_offset(btf, linfo->line_off);
+			nr_skip++;
+		} else
+			srcline = NULL;
+
+		fprintf(s, "\n");
+		prev_buf_size = buf_size;
+		fflush(s);
+
+		if (!opts->hide_src_code && srcline) {
+			args->offset = -1;
+			args->line = strdup(srcline);
+			args->line_nr = 0;
+			args->ms.sym  = sym;
+			dl = disasm_line__new(args);
+			if (dl) {
+				annotation_line__add(&dl->al,
+						     &notes->src->source);
+			}
+		}
+
+		args->offset = pc;
+		args->line = buf + prev_buf_size;
+		args->line_nr = 0;
+		args->ms.sym  = sym;
+		dl = disasm_line__new(args);
+		if (dl)
+			annotation_line__add(&dl->al, &notes->src->source);
+
+		pc += count;
+	} while (count > 0 && pc < len);
+
+	ret = 0;
+out:
+	free(prog_linfo);
+	free(btf);
+	fclose(s);
+	bfd_close(bfdf);
+	return ret;
+}
+
 static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 {
 	struct annotation_options *opts = args->options;
@@ -1699,7 +1845,9 @@ static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 	pr_debug("annotating [%p] %30s : [%p] %30s\n",
 		 dso, dso->long_name, sym, sym->name);
 
-	if (dso__is_kcore(dso)) {
+	if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO) {
+		return symbol__disassemble_bpf(sym, args);
+	} else if (dso__is_kcore(dso)) {
 		kce.kcore_filename = symfs_filename;
 		kce.addr = map__rip_2objdump(map, sym->start);
 		kce.offs = sym->start;
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 62c8cf622607..1798192bf0f9 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -181,6 +181,7 @@ int dso__read_binary_type_filename(const struct dso *dso,
 	case DSO_BINARY_TYPE__KALLSYMS:
 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
 	case DSO_BINARY_TYPE__JAVA_JIT:
+	case DSO_BINARY_TYPE__BPF_PROG_INFO:
 	case DSO_BINARY_TYPE__NOT_FOUND:
 		ret = -1;
 		break;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 8c8a7abe809d..f20d319463f1 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -14,6 +14,8 @@
 #include "namespaces.h"
 #include "build-id.h"
 
+struct perf_env;
+
 enum dso_binary_type {
 	DSO_BINARY_TYPE__KALLSYMS = 0,
 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
@@ -34,6 +36,7 @@ enum dso_binary_type {
 	DSO_BINARY_TYPE__KCORE,
 	DSO_BINARY_TYPE__GUEST_KCORE,
 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
+	DSO_BINARY_TYPE__BPF_PROG_INFO,
 	DSO_BINARY_TYPE__NOT_FOUND,
 };
 
@@ -177,17 +180,25 @@ struct dso {
 	struct auxtrace_cache *auxtrace_cache;
 	int		 comp;
 
-	/* dso data file */
-	struct {
-		struct rb_root	 cache;
-		int		 fd;
-		int		 status;
-		u32		 status_seen;
-		size_t		 file_size;
-		struct list_head open_entry;
-		u64		 debug_frame_offset;
-		u64		 eh_frame_hdr_offset;
-	} data;
+	union {
+		/* dso data file */
+		struct {
+			struct rb_root	 cache;
+			int		 fd;
+			int		 status;
+			u32		 status_seen;
+			size_t		 file_size;
+			struct list_head open_entry;
+			u64		 debug_frame_offset;
+			u64		 eh_frame_hdr_offset;
+		} data;
+		/* bpf prog information */
+		struct {
+			u32		id;
+			u32		sub_id;
+			struct perf_env	*env;
+		} bpf_prog;
+	};
 
 	union { /* Tool specific area */
 		void	 *priv;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 48efad6d0f90..33ae59e89da2 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1441,6 +1441,7 @@ static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
 		return true;
 
+	case DSO_BINARY_TYPE__BPF_PROG_INFO:
 	case DSO_BINARY_TYPE__NOT_FOUND:
 	default:
 		return false;
-- 
2.17.1

[PATCH v5 perf,bpf 13/15] perf, bpf: process PERF_BPF_EVENT_PROG_LOAD for annotation

[Song Liu]

This patch adds processing of PERF_BPF_EVENT_PROG_LOAD, which sets proper
DSO type/id/etc of memory regions mapped to BPF programs to
DSO_BINARY_TYPE__BPF_PROG_INFO

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/bpf-event.c | 53 +++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 370b830f2433..048ef00371ad 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -25,12 +25,65 @@ static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
 	return ret;
 }
 
+static int machine__process_bpf_event_load(struct machine *machine __maybe_unused,
+					   union perf_event *event,
+					   struct perf_sample *sample __maybe_unused)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info_node *info_node;
+	struct perf_env *env = machine->env;
+	int id = event->bpf_event.id;
+	unsigned int i;
+
+	/* perf-record, no need to handle bpf-event */
+	if (env == NULL)
+		return 0;
+
+	info_node = perf_env__find_bpf_prog_info(env, id);
+	if (!info_node)
+		return 0;
+	info_linear = info_node->info_linear;
+
+	for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
+		u64 *addrs = (u64 *)(info_linear->info.jited_ksyms);
+		u64 addr = addrs[i];
+		struct map *map;
+
+		map = map_groups__find(&machine->kmaps, addr);
+
+		if (map) {
+			map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
+			map->dso->bpf_prog.id = id;
+			map->dso->bpf_prog.sub_id = i;
+			map->dso->bpf_prog.env = env;
+		}
+	}
+	return 0;
+}
+
 int machine__process_bpf_event(struct machine *machine __maybe_unused,
 			       union perf_event *event,
 			       struct perf_sample *sample __maybe_unused)
 {
 	if (dump_trace)
 		perf_event__fprintf_bpf_event(event, stdout);
+
+	switch (event->bpf_event.type) {
+	case PERF_BPF_EVENT_PROG_LOAD:
+		return machine__process_bpf_event_load(machine, event, sample);
+
+	case PERF_BPF_EVENT_PROG_UNLOAD:
+		/*
+		 * Do not free bpf_prog_info and btf of the program here,
+		 * as annotation still need them. They will be freed at
+		 * the end of the session.
+		 */
+		break;
+	default:
+		pr_debug("unexpected bpf_event type of %d\n",
+			 event->bpf_event.type);
+		break;
+	}
 	return 0;
 }
 
-- 
2.17.1

[PATCH v5 perf,bpf 14/15] perf: introduce side band thread

[Song Liu]

This patch introduces side band thread that captures extended information
for events like PERF_RECORD_BPF_EVENT.

This new thread uses its own evlist that uses ring buffer with very low
watermark for lower latency. In the next patch, we uses this thread to
handle PERF_RECORD_BPF_EVENT.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/builtin-record.c |   7 +++
 tools/perf/builtin-top.c    |   7 +++
 tools/perf/util/evlist.c    | 100 ++++++++++++++++++++++++++++++++++++
 tools/perf/util/evlist.h    |  13 +++++
 4 files changed, 127 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 2355e0a9eda0..d10c1d5a9e89 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1106,6 +1106,7 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 	struct perf_data *data = &rec->data;
 	struct perf_session *session;
 	bool disabled = false, draining = false;
+	struct perf_evlist_sb_poll_args poll_args;
 	int fd;
 
 	atexit(record__sig_exit);
@@ -1206,6 +1207,10 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 		goto out_child;
 	}
 
+	poll_args.env = &session->header.env;
+	poll_args.done = &done;
+	perf_evlist__start_polling_thread(&rec->opts.target, &poll_args);
+
 	err = record__synthesize(rec, false);
 	if (err < 0)
 		goto out_child;
@@ -1456,6 +1461,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 
 out_delete_session:
 	perf_session__delete(session);
+
+	perf_evlist__stop_polling_thread();
 	return status;
 }
 
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index ccdf5689452f..f41545445917 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1524,6 +1524,7 @@ int cmd_top(int argc, const char **argv)
 			"number of thread to run event synthesize"),
 	OPT_END()
 	};
+	struct perf_evlist_sb_poll_args poll_args;
 	const char * const top_usage[] = {
 		"perf top [<options>]",
 		NULL
@@ -1654,8 +1655,14 @@ int cmd_top(int argc, const char **argv)
 
 	top.record_opts.bpf_event = !top.no_bpf_event;
 
+	poll_args.env = &perf_env;
+	poll_args.done = &done;
+	perf_evlist__start_polling_thread(target, &poll_args);
+
 	status = __cmd_top(&top);
 
+	perf_evlist__stop_polling_thread();
+
 out_delete_evlist:
 	perf_evlist__delete(top.evlist);
 
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 8c902276d4b4..61b87c8111e6 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -19,6 +19,7 @@
 #include "debug.h"
 #include "units.h"
 #include "asm/bug.h"
+#include "bpf-event.h"
 #include <signal.h>
 #include <unistd.h>
 
@@ -1841,3 +1842,102 @@ struct perf_evsel *perf_evlist__reset_weak_group(struct perf_evlist *evsel_list,
 	}
 	return leader;
 }
+
+static struct perf_evlist *sb_evlist;
+pthread_t poll_thread;
+
+int perf_evlist__new_side_band_event(struct perf_event_attr *attr)
+{
+	struct perf_evsel *evsel;
+
+	if (!sb_evlist)
+		sb_evlist = perf_evlist__new();
+
+	if (!sb_evlist)
+		return -1;
+
+	evsel = perf_evsel__new_idx(attr, sb_evlist->nr_entries);
+	if (!evsel)
+		goto out_err;
+
+	perf_evlist__add(sb_evlist, evsel);
+	return 0;
+
+out_err:
+	perf_evlist__delete(sb_evlist);
+	return -1;
+}
+
+static void *perf_evlist__poll_thread(void *arg)
+{
+	struct perf_evlist_sb_poll_args *args = arg;
+	int i;
+
+	while (!*(args->done)) {
+		perf_evlist__poll(sb_evlist, 1000);
+
+		for (i = 0; i < sb_evlist->nr_mmaps; i++) {
+			struct perf_mmap *map = &sb_evlist->mmap[i];
+			union perf_event *event;
+
+			if (perf_mmap__read_init(map))
+				continue;
+			while ((event = perf_mmap__read_event(map)) != NULL) {
+				pr_debug("processing vip event of type %d\n",
+					 event->header.type);
+				switch (event->header.type) {
+				default:
+					break;
+				}
+				perf_mmap__consume(map);
+			}
+			perf_mmap__read_done(map);
+		}
+	}
+	return NULL;
+}
+
+int perf_evlist__start_polling_thread(struct target *target,
+				      struct perf_evlist_sb_poll_args *args)
+{
+	struct perf_evsel *counter;
+
+	if (sb_evlist == NULL)
+		return 0;
+
+	if (perf_evlist__create_maps(sb_evlist, target))
+		goto out_delete_evlist;
+
+	evlist__for_each_entry(sb_evlist, counter) {
+		if (perf_evsel__open(counter, sb_evlist->cpus,
+				     sb_evlist->threads) < 0)
+			goto out_delete_evlist;
+	}
+
+	if (perf_evlist__mmap(sb_evlist, UINT_MAX))
+		goto out_delete_evlist;
+
+	evlist__for_each_entry(sb_evlist, counter) {
+		if (perf_evsel__enable(counter))
+			goto out_delete_evlist;
+	}
+
+	if (pthread_create(&poll_thread, NULL, perf_evlist__poll_thread, args))
+		goto out_delete_evlist;
+
+	return 0;
+
+out_delete_evlist:
+	perf_evlist__delete(sb_evlist);
+	sb_evlist = NULL;
+	return -1;
+}
+
+void perf_evlist__stop_polling_thread(void)
+{
+	if (!sb_evlist)
+		return;
+	pthread_join(poll_thread, NULL);
+	perf_evlist__exit(sb_evlist);
+	sb_evlist = NULL;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 868294491194..4182e50659e0 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -58,6 +58,12 @@ struct perf_evsel_str_handler {
 	void	   *handler;
 };
 
+struct perf_evlist_sb_poll_args {
+	struct perf_env	*env;
+
+	volatile int	*done;
+};
+
 struct perf_evlist *perf_evlist__new(void);
 struct perf_evlist *perf_evlist__new_default(void);
 struct perf_evlist *perf_evlist__new_dummy(void);
@@ -84,6 +90,13 @@ int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
 
 int perf_evlist__add_dummy(struct perf_evlist *evlist);
 
+int perf_evlist__new_side_band_event(struct perf_event_attr *attr);
+
+int perf_evlist__start_polling_thread(struct target *target,
+				      struct perf_evlist_sb_poll_args *args);
+
+void perf_evlist__stop_polling_thread(void);
+
 int perf_evlist__add_newtp(struct perf_evlist *evlist,
 			   const char *sys, const char *name, void *handler);
 
-- 
2.17.1

[PATCH v5 perf,bpf 15/15] perf, bpf: save bpf_prog_info and btf of short living bpf programs

[Song Liu]

To fully annotate BPF programs with source code mapping, 4 different
information are needed:
    1) PERF_RECORD_KSYMBOL
    2) PERF_RECORD_BPF_EVENT
    3) bpf_prog_info
    4) btf

This patch handles 3) and 4) for short living BPF programs. For timely
process of these information, a dedicated event is added to the side
band evlist. When PERF_RECORD_BPF_EVENT is received via the side band
event, the polling thread gathers 3) and 4) vis sys_bpf and store them
in perf_env. These information are saved to perf.data at the end of
perf-record.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/builtin-record.c |  3 ++
 tools/perf/builtin-top.c    |  3 ++
 tools/perf/util/bpf-event.c | 66 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/bpf-event.h | 18 ++++++++++
 tools/perf/util/evlist.c    |  5 +++
 5 files changed, 95 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index d10c1d5a9e89..ce26d37c2871 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1207,6 +1207,9 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
 		goto out_child;
 	}
 
+	if (opts->bpf_event)
+		bpf_event__add_polling_event();
+
 	poll_args.env = &session->header.env;
 	poll_args.done = &done;
 	perf_evlist__start_polling_thread(&rec->opts.target, &poll_args);
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index f41545445917..851c4dcce66f 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1655,6 +1655,9 @@ int cmd_top(int argc, const char **argv)
 
 	top.record_opts.bpf_event = !top.no_bpf_event;
 
+	if (top.record_opts.bpf_event)
+		bpf_event__add_polling_event();
+
 	poll_args.env = &perf_env;
 	poll_args.done = &done;
 	perf_evlist__start_polling_thread(target, &poll_args);
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 048ef00371ad..664906237ffb 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -12,6 +12,7 @@
 #include "machine.h"
 #include "env.h"
 #include "session.h"
+#include "evlist.h"
 
 #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
 
@@ -332,3 +333,68 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
 	free(event);
 	return err;
 }
+
+void perf_env__add_bpf_info(struct perf_env *env, u32 id)
+{
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_info_node *info_node;
+	struct btf *btf = NULL;
+	u64 arrays;
+	u32 btf_id;
+	int fd;
+
+	fd = bpf_prog_get_fd_by_id(id);
+	if (fd < 0)
+		return;
+
+	arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS;
+	arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS;
+	arrays |= 1UL << BPF_PROG_INFO_LINE_INFO;
+	arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO;
+
+	info_linear = bpf_program__get_prog_info_linear(fd, arrays);
+	if (IS_ERR_OR_NULL(info_linear)) {
+		pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
+		goto out;
+	}
+
+	btf_id = info_linear->info.btf_id;
+
+	info_node = malloc(sizeof(struct bpf_prog_info_node));
+	if (info_node) {
+		info_node->info_linear = info_linear;
+		perf_env__insert_bpf_prog_info(env, info_node);
+	} else
+		free(info_linear);
+
+	if (btf_id == 0)
+		goto out;
+
+	if (btf__get_from_id(btf_id, &btf)) {
+		pr_debug("%s: failed to get BTF of id %u, aborting\n",
+			 __func__, btf_id);
+		goto out;
+	}
+	perf_env__fetch_btf(env, btf_id, btf);
+
+out:
+	free(btf);
+	close(fd);
+}
+
+int bpf_event__add_polling_event(void)
+{
+	struct perf_event_attr attr = {
+		.type	          = PERF_TYPE_SOFTWARE,
+		.config           = PERF_COUNT_SW_DUMMY,
+		.watermark        = 1,
+		.bpf_event        = 1,
+		.wakeup_watermark = 1,
+		.size	   = sizeof(attr), /* to capture ABI version */
+	};
+
+	return perf_evlist__new_side_band_event(&attr);
+}
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index b9ec394dc7c7..03a6f018e219 100644
--- a/tools/perf/util/bpf-event.h
+++ b/tools/perf/util/bpf-event.h
@@ -4,12 +4,17 @@
 
 #include <linux/compiler.h>
 #include <linux/rbtree.h>
+#include <pthread.h>
+#include <api/fd/array.h>
 #include "event.h"
 
 struct machine;
 union perf_event;
+struct perf_env;
 struct perf_sample;
 struct record_opts;
+struct evlist;
+struct target;
 
 struct bpf_prog_info_node {
 	struct bpf_prog_info_linear	*info_linear;
@@ -31,6 +36,9 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
 				      perf_event__handler_t process,
 				      struct machine *machine,
 				      struct record_opts *opts);
+int bpf_event__add_polling_event(void);
+void perf_env__add_bpf_info(struct perf_env *env, u32 id);
+
 #else
 static inline int machine__process_bpf_event(struct machine *machine __maybe_unused,
 					     union perf_event *event __maybe_unused,
@@ -46,5 +54,15 @@ static inline int perf_event__synthesize_bpf_events(struct perf_session *session
 {
 	return 0;
 }
+
+static inline int bpf_event__add_polling_event(void)
+{
+	return 0;
+}
+
+void perf_env__add_bpf_info(struct perf_env *env __maybe_unused,
+			    u32 id __maybe_unused)
+{
+}
 #endif // HAVE_LIBBPF_SUPPORT
 #endif
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 61b87c8111e6..58ac42878c0a 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1886,6 +1886,11 @@ static void *perf_evlist__poll_thread(void *arg)
 				pr_debug("processing vip event of type %d\n",
 					 event->header.type);
 				switch (event->header.type) {
+				case PERF_RECORD_BPF_EVENT:
+					if (event->bpf_event.type != PERF_BPF_EVENT_PROG_LOAD)
+						break;
+					perf_env__add_bpf_info(args->env, event->bpf_event.id);
+					break;
 				default:
 					break;
 				}
-- 
2.17.1

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:

SNIP

> +#ifdef DISASM_FOUR_ARGS_SIGNATURE
> +	disassemble = disassembler(info.arch,
> +				   bfd_big_endian(bfdf),
> +				   info.mach,
> +				   bfdf);
> +#else
> +	disassemble = disassembler(bfdf);
> +#endif
> +	assert(disassemble);
> +
> +	fflush(s);
> +	do {
> +		const struct bpf_line_info *linfo = NULL;
> +		struct disasm_line *dl;
> +		size_t prev_buf_size;
> +		const char *srcline;
> +		u64 addr;
> +
> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
> +		count = disassemble(pc, &info);
> +
> +		if (prog_linfo)
> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
> +								addr, sub_id,
> +								nr_skip);
> +
> +		if (linfo && btf) {
> +			srcline = btf__name_by_offset(btf, linfo->line_off);
> +			nr_skip++;
> +		} else
> +			srcline = NULL;
> +
> +		fprintf(s, "\n");
> +		prev_buf_size = buf_size;
> +		fflush(s);
> +
> +		if (!opts->hide_src_code && srcline) {
> +			args->offset = -1;
> +			args->line = strdup(srcline);
> +			args->line_nr = 0;
> +			args->ms.sym  = sym;
> +			dl = disasm_line__new(args);
> +			if (dl) {
> +				annotation_line__add(&dl->al,
> +						     &notes->src->source);
> +			}
> +		}

are you adding the line twice? (code up and down)

> +
> +		args->offset = pc;
> +		args->line = buf + prev_buf_size;
> +		args->line_nr = 0;

also could you please explain why line_nr is not use

thanks,
jirka

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:

SNIP

> +static int process_bpf_prog_info(struct feat_fd *ff,
> +				 void *data __maybe_unused)
> +{
> +	struct bpf_prog_info_linear *info_linear;
> +	struct bpf_prog_info_node *info_node;
> +	struct perf_env *env = &ff->ph->env;
> +	u32 count, i;
> +	int err = -1;
> +
> +	if (do_read_u32(ff, &count))
> +		return -1;
> +
> +	down_write(&env->bpf_progs.lock);
> +
> +	for (i = 0; i < count; ++i) {
> +		u32 info_len, data_len;
> +
> +		info_linear = NULL;
> +		info_node = NULL;
> +		if (do_read_u32(ff, &info_len))
> +			goto out;
> +		if (do_read_u32(ff, &data_len))
> +			goto out;
> +
> +		if (info_len > sizeof(struct bpf_prog_info)) {
> +			pr_warning("detected invalid bpf_prog_info\n");
> +			goto out;
> +		}
> +
> +		info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
> +				     data_len);
> +		if (!info_linear)
> +			goto out;
> +		info_linear->info_len = sizeof(struct bpf_prog_info);
> +		info_linear->data_len = data_len;
> +		if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
> +			goto out;
> +		if (__do_read(ff, &info_linear->info, info_len))
> +			goto out;
> +		if (info_len < sizeof(struct bpf_prog_info))
> +			memset(((void *)(&info_linear->info)) + info_len, 0,
> +			       sizeof(struct bpf_prog_info) - info_len);
> +
> +		if (__do_read(ff, info_linear->data, data_len))
> +			goto out;
> +
> +		/* endian mismatch, drop the info, continue */
> +		if (ff->ph->needs_swap) {
> +			free(info_linear);
> +			continue;
> +		}

so in this case we can check for needs_swap in the begining
of the function and bail out without reading all the data

also please display soem error message saying we don't support
ebpf progs data report over the different endianity

jirka

Re: [PATCH v5 perf,bpf 09/15] perf, bpf: save btf information as headers to perf.data

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:37PM -0800, Song Liu wrote:

SNIP

>  
> +static int process_bpf_btf(struct feat_fd *ff, void *data __maybe_unused)
> +{
> +	struct perf_env *env = &ff->ph->env;
> +	u32 count, i;
> +
> +	if (do_read_u32(ff, &count))
> +		return -1;
> +
> +	down_write(&env->bpf_progs.lock);
> +
> +	for (i = 0; i < count; ++i) {
> +		struct btf_node *node;
> +		u32 id, data_size;
> +
> +		if (do_read_u32(ff, &id))
> +			return -1;
> +		if (do_read_u32(ff, &data_size))
> +			return -1;
> +
> +		node = malloc(sizeof(struct btf_node) + data_size);
> +		if (!node)
> +			return -1;
> +
> +		node->id = id;
> +		node->data_size = data_size;
> +
> +		if (__do_read(ff, node->data, data_size)) {
> +			free(node);
> +			return -1;
> +		}
> +
> +		/* endian mismatch, drop the btf, continue */
> +		if (ff->ph->needs_swap) {
> +			free(node);
> +			continue;
> +		}

again, we can check for needs_swap in the begining,
display warning and skip the loop in here

perhaps we should warn just once for all the bpf data
missed when needs_swap is set

jirka

Re: [PATCH v5 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:36PM -0800, Song Liu wrote:
> btf contains information necessary to annotate bpf programs. This patch
> saves btf for bpf programs loaded in the system.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/bpf-event.c | 24 ++++++++++++++
>  tools/perf/util/bpf-event.h |  7 ++++
>  tools/perf/util/env.c       | 65 +++++++++++++++++++++++++++++++++++++
>  tools/perf/util/env.h       |  4 +++
>  4 files changed, 100 insertions(+)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index ce81b2c43a51..370b830f2433 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -34,6 +34,29 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
>  	return 0;
>  }
>  
> +static int perf_env__fetch_btf(struct perf_env *env,
> +			       u32 btf_id,
> +			       struct btf *btf)
> +{
> +	struct btf_node *node;
> +	u32 data_size;
> +	const void *data;
> +
> +	data = btf__get_raw_data(btf, &data_size);
> +
> +	node = malloc(data_size + sizeof(struct btf_node));
> +
> +	if (!node)
> +		return -1;
> +
> +	node->id = btf_id;
> +	node->data_size = data_size;
> +	memcpy(node->data, data, data_size);

why don't we store just struct btf itself?

thanks,
jirka

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:

SNIP

> +static int process_bpf_prog_info(struct feat_fd *ff,
> +				 void *data __maybe_unused)
> +{
> +	struct bpf_prog_info_linear *info_linear;
> +	struct bpf_prog_info_node *info_node;
> +	struct perf_env *env = &ff->ph->env;
> +	u32 count, i;
> +	int err = -1;
> +
> +	if (do_read_u32(ff, &count))
> +		return -1;
> +
> +	down_write(&env->bpf_progs.lock);
> +
> +	for (i = 0; i < count; ++i) {
> +		u32 info_len, data_len;
> +
> +		info_linear = NULL;
> +		info_node = NULL;
> +		if (do_read_u32(ff, &info_len))
> +			goto out;
> +		if (do_read_u32(ff, &data_len))
> +			goto out;
> +
> +		if (info_len > sizeof(struct bpf_prog_info)) {
> +			pr_warning("detected invalid bpf_prog_info\n");
> +			goto out;
> +		}
> +
> +		info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
> +				     data_len);
> +		if (!info_linear)
> +			goto out;
> +		info_linear->info_len = sizeof(struct bpf_prog_info);
> +		info_linear->data_len = data_len;
> +		if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
> +			goto out;
> +		if (__do_read(ff, &info_linear->info, info_len))
> +			goto out;
> +		if (info_len < sizeof(struct bpf_prog_info))
> +			memset(((void *)(&info_linear->info)) + info_len, 0,
> +			       sizeof(struct bpf_prog_info) - info_len);
> +
> +		if (__do_read(ff, info_linear->data, data_len))
> +			goto out;
> +
> +		/* endian mismatch, drop the info, continue */
> +		if (ff->ph->needs_swap) {
> +			free(info_linear);
> +			continue;
> +		}

same here, please check this on the beginning
and add a warning message

thanks,
jrika

> +
> +		info_node = malloc(sizeof(struct bpf_prog_info_node));
> +		if (!info_node)
> +			goto out;
> +
> +		/* after reading from file, translate offset to address */
> +		bpf_program__bpil_offs_to_addr(info_linear);
> +		info_node->info_linear = info_linear;
> +		perf_env__insert_bpf_prog_info(env, info_node);
> +	}

SNIP

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
> This patch enables perf-record to save bpf_prog_info information as
> headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
> introduced for this data.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/header.c | 143 ++++++++++++++++++++++++++++++++++++++-
>  tools/perf/util/header.h |   1 +
>  2 files changed, 143 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 4b88de5e9192..16f5bedb0b7d 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -18,6 +18,7 @@
>  #include <sys/utsname.h>
>  #include <linux/time64.h>
>  #include <dirent.h>
> +#include <bpf/libbpf.h>
>  
>  #include "evlist.h"
>  #include "evsel.h"
> @@ -39,6 +40,7 @@
>  #include "tool.h"
>  #include "time-utils.h"
>  #include "units.h"
> +#include "bpf-event.h"
>  
>  #include "sane_ctype.h"
>  
> @@ -1074,6 +1076,51 @@ static int write_clockid(struct feat_fd *ff,
>  			sizeof(ff->ph->env.clockid_res_ns));
>  }
>  
> +static int write_bpf_prog_info(struct feat_fd *ff,
> +			       struct perf_evlist *evlist __maybe_unused)
> +{
> +	struct perf_env *env = &ff->ph->env;
> +	struct rb_root *root;
> +	struct rb_node *next;
> +	u32 count = 0;
> +	int ret;
> +
> +	down_read(&env->bpf_progs.lock);
> +
> +	root = &env->bpf_progs.infos;
> +	next = rb_first(root);
> +	while (next) {
> +		++count;
> +		next = rb_next(next);
> +	}
> +
> +	ret = do_write(ff, &count, sizeof(count));
> +
> +	if (ret < 0)
> +		goto out;
> +
> +	next = rb_first(root);
> +	while (next) {
> +		struct bpf_prog_info_node *node;
> +		size_t len;
> +
> +		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
> +		next = rb_next(&node->rb_node);
> +		len = sizeof(struct bpf_prog_info_linear) +
> +			node->info_linear->data_len;
> +
> +		/* before writing to file, translate address to offset */
> +		bpf_program__bpil_addr_to_offs(node->info_linear);
> +		ret = do_write(ff, node->info_linear, len);
> +		bpf_program__bpil_offs_to_addr(node->info_linear);

what's the reason to call this before the error check?

thanks,
jirka

> +		if (ret < 0)
> +			goto out;
> +	}
> +out:
> +	up_read(&env->bpf_progs.lock);
> +	return ret;
> +}

SNIP

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
> This patch enables perf-record to save bpf_prog_info information as
> headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
> introduced for this data.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/header.c | 143 ++++++++++++++++++++++++++++++++++++++-
>  tools/perf/util/header.h |   1 +
>  2 files changed, 143 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 4b88de5e9192..16f5bedb0b7d 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -18,6 +18,7 @@
>  #include <sys/utsname.h>
>  #include <linux/time64.h>
>  #include <dirent.h>
> +#include <bpf/libbpf.h>
>  
>  #include "evlist.h"
>  #include "evsel.h"
> @@ -39,6 +40,7 @@
>  #include "tool.h"
>  #include "time-utils.h"
>  #include "units.h"
> +#include "bpf-event.h"
>  
>  #include "sane_ctype.h"
>  
> @@ -1074,6 +1076,51 @@ static int write_clockid(struct feat_fd *ff,
>  			sizeof(ff->ph->env.clockid_res_ns));
>  }
>  
> +static int write_bpf_prog_info(struct feat_fd *ff,
> +			       struct perf_evlist *evlist __maybe_unused)
> +{
> +	struct perf_env *env = &ff->ph->env;
> +	struct rb_root *root;
> +	struct rb_node *next;
> +	u32 count = 0;
> +	int ret;
> +
> +	down_read(&env->bpf_progs.lock);
> +
> +	root = &env->bpf_progs.infos;
> +	next = rb_first(root);
> +	while (next) {
> +		++count;
> +		next = rb_next(next);
> +	}
> +
> +	ret = do_write(ff, &count, sizeof(count));
> +

extra new line

> +	if (ret < 0)
> +		goto out;
> +
> +	next = rb_first(root);
> +	while (next) {
> +		struct bpf_prog_info_node *node;
> +		size_t len;
> +
> +		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
> +		next = rb_next(&node->rb_node);
> +		len = sizeof(struct bpf_prog_info_linear) +
> +			node->info_linear->data_len;
> +
> +		/* before writing to file, translate address to offset */
> +		bpf_program__bpil_addr_to_offs(node->info_linear);
> +		ret = do_write(ff, node->info_linear, len);
> +		bpf_program__bpil_offs_to_addr(node->info_linear);
> +		if (ret < 0)
> +			goto out;
> +	}
> +out:
> +	up_read(&env->bpf_progs.lock);
> +	return ret;
> +}

SNIP

Re: [PATCH v5 perf,bpf 13/15] perf, bpf: process PERF_BPF_EVENT_PROG_LOAD for annotation

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:41PM -0800, Song Liu wrote:
> This patch adds processing of PERF_BPF_EVENT_PROG_LOAD, which sets proper
> DSO type/id/etc of memory regions mapped to BPF programs to
> DSO_BINARY_TYPE__BPF_PROG_INFO
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/bpf-event.c | 53 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index 370b830f2433..048ef00371ad 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -25,12 +25,65 @@ static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
>  	return ret;
>  }
>  
> +static int machine__process_bpf_event_load(struct machine *machine __maybe_unused,

machine is used 

jirka

> +					   union perf_event *event,
> +					   struct perf_sample *sample __maybe_unused)
> +{
> +	struct bpf_prog_info_linear *info_linear;
> +	struct bpf_prog_info_node *info_node;
> +	struct perf_env *env = machine->env;
> +	int id = event->bpf_event.id;
> +	unsigned int i;
> +
> +	/* perf-record, no need to handle bpf-event */
> +	if (env == NULL)
> +		return 0;
> +
> +	info_node = perf_env__find_bpf_prog_info(env, id);
> +	if (!info_node)
> +		return 0;
> +	info_linear = info_node->info_linear;
> +
> +	for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
> +		u64 *addrs = (u64 *)(info_linear->info.jited_ksyms);
> +		u64 addr = addrs[i];
> +		struct map *map;
> +
> +		map = map_groups__find(&machine->kmaps, addr);
> +
> +		if (map) {
> +			map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
> +			map->dso->bpf_prog.id = id;
> +			map->dso->bpf_prog.sub_id = i;
> +			map->dso->bpf_prog.env = env;
> +		}
> +	}
> +	return 0;
> +}
> +
>  int machine__process_bpf_event(struct machine *machine __maybe_unused,
>  			       union perf_event *event,
>  			       struct perf_sample *sample __maybe_unused)
>  {
>  	if (dump_trace)
>  		perf_event__fprintf_bpf_event(event, stdout);
> +
> +	switch (event->bpf_event.type) {
> +	case PERF_BPF_EVENT_PROG_LOAD:
> +		return machine__process_bpf_event_load(machine, event, sample);
> +
> +	case PERF_BPF_EVENT_PROG_UNLOAD:
> +		/*
> +		 * Do not free bpf_prog_info and btf of the program here,
> +		 * as annotation still need them. They will be freed at
> +		 * the end of the session.
> +		 */
> +		break;
> +	default:
> +		pr_debug("unexpected bpf_event type of %d\n",
> +			 event->bpf_event.type);
> +		break;
> +	}
>  	return 0;
>  }
>  
> -- 
> 2.17.1
> 

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:

SNIP

> +
> +	disassemble_init_for_target(&info);
> +
> +#ifdef DISASM_FOUR_ARGS_SIGNATURE
> +	disassemble = disassembler(info.arch,
> +				   bfd_big_endian(bfdf),
> +				   info.mach,
> +				   bfdf);
> +#else
> +	disassemble = disassembler(bfdf);
> +#endif
> +	assert(disassemble);
> +
> +	fflush(s);

what's the reason for those fflush calls?

thanks,
jirka

> +	do {
> +		const struct bpf_line_info *linfo = NULL;
> +		struct disasm_line *dl;
> +		size_t prev_buf_size;
> +		const char *srcline;
> +		u64 addr;
> +
> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
> +		count = disassemble(pc, &info);
> +
> +		if (prog_linfo)
> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
> +								addr, sub_id,
> +								nr_skip);
> +
> +		if (linfo && btf) {
> +			srcline = btf__name_by_offset(btf, linfo->line_off);
> +			nr_skip++;
> +		} else
> +			srcline = NULL;
> +
> +		fprintf(s, "\n");
> +		prev_buf_size = buf_size;
> +		fflush(s);

SNIP

Re: [PATCH v5 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:36PM -0800, Song Liu wrote:
> btf contains information necessary to annotate bpf programs. This patch
> saves btf for bpf programs loaded in the system.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/bpf-event.c | 24 ++++++++++++++
>  tools/perf/util/bpf-event.h |  7 ++++
>  tools/perf/util/env.c       | 65 +++++++++++++++++++++++++++++++++++++
>  tools/perf/util/env.h       |  4 +++
>  4 files changed, 100 insertions(+)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index ce81b2c43a51..370b830f2433 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -34,6 +34,29 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
>  	return 0;
>  }
>  
> +static int perf_env__fetch_btf(struct perf_env *env,
> +			       u32 btf_id,
> +			       struct btf *btf)
> +{
> +	struct btf_node *node;
> +	u32 data_size;
> +	const void *data;
> +
> +	data = btf__get_raw_data(btf, &data_size);
> +
> +	node = malloc(data_size + sizeof(struct btf_node));
> +

extra new line

> +	if (!node)
> +		return -1;
> +
> +	node->id = btf_id;
> +	node->data_size = data_size;
> +	memcpy(node->data, data, data_size);
> +
> +	perf_env__insert_btf(env, node);
> +	return 0;
> +}

SNIP

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Jiri Olsa]

On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:

SNIP

> +	fflush(s);
> +	do {
> +		const struct bpf_line_info *linfo = NULL;
> +		struct disasm_line *dl;
> +		size_t prev_buf_size;
> +		const char *srcline;
> +		u64 addr;
> +
> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
> +		count = disassemble(pc, &info);
> +
> +		if (prog_linfo)
> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
> +								addr, sub_id,
> +								nr_skip);
> +
> +		if (linfo && btf) {
> +			srcline = btf__name_by_offset(btf, linfo->line_off);
> +			nr_skip++;
> +		} else
> +			srcline = NULL;
> +
> +		fprintf(s, "\n");
> +		prev_buf_size = buf_size;
> +		fflush(s);
> +
> +		if (!opts->hide_src_code && srcline) {
> +			args->offset = -1;

why's the offset not needed in here?

jirka

> +			args->line = strdup(srcline);
> +			args->line_nr = 0;
> +			args->ms.sym  = sym;
> +			dl = disasm_line__new(args);
> +			if (dl) {
> +				annotation_line__add(&dl->al,
> +						     &notes->src->source);
> +			}
> +		}

SNIP

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Song Liu]

> On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
> 
> SNIP
> 
>> +static int process_bpf_prog_info(struct feat_fd *ff,
>> +				 void *data __maybe_unused)
>> +{
>> +	struct bpf_prog_info_linear *info_linear;
>> +	struct bpf_prog_info_node *info_node;
>> +	struct perf_env *env = &ff->ph->env;
>> +	u32 count, i;
>> +	int err = -1;
>> +
>> +	if (do_read_u32(ff, &count))
>> +		return -1;
>> +
>> +	down_write(&env->bpf_progs.lock);
>> +
>> +	for (i = 0; i < count; ++i) {
>> +		u32 info_len, data_len;
>> +
>> +		info_linear = NULL;
>> +		info_node = NULL;
>> +		if (do_read_u32(ff, &info_len))
>> +			goto out;
>> +		if (do_read_u32(ff, &data_len))
>> +			goto out;
>> +
>> +		if (info_len > sizeof(struct bpf_prog_info)) {
>> +			pr_warning("detected invalid bpf_prog_info\n");
>> +			goto out;
>> +		}
>> +
>> +		info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
>> +				     data_len);
>> +		if (!info_linear)
>> +			goto out;
>> +		info_linear->info_len = sizeof(struct bpf_prog_info);
>> +		info_linear->data_len = data_len;
>> +		if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
>> +			goto out;
>> +		if (__do_read(ff, &info_linear->info, info_len))
>> +			goto out;
>> +		if (info_len < sizeof(struct bpf_prog_info))
>> +			memset(((void *)(&info_linear->info)) + info_len, 0,
>> +			       sizeof(struct bpf_prog_info) - info_len);
>> +
>> +		if (__do_read(ff, info_linear->data, data_len))
>> +			goto out;
>> +
>> +		/* endian mismatch, drop the info, continue */
>> +		if (ff->ph->needs_swap) {
>> +			free(info_linear);
>> +			continue;
>> +		}
> 
> so in this case we can check for needs_swap in the begining
> of the function and bail out without reading all the data

If we bail out, perf-record will fail. If we read all the data 
but ignore them, perf-record will continue without bpf annotation 
support. I think the latter is a better experience with little 
effort here. 

> 
> also please display soem error message saying we don't support
> ebpf progs data report over the different endianity

I will add a warning in the next version. 

Thanks,
Song

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Song Liu]

> On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
>> This patch enables perf-record to save bpf_prog_info information as
>> headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
>> introduced for this data.
>> 
>> Signed-off-by: Song Liu <songliubraving@fb.com>
>> ---
>> tools/perf/util/header.c | 143 ++++++++++++++++++++++++++++++++++++++-
>> tools/perf/util/header.h |   1 +
>> 2 files changed, 143 insertions(+), 1 deletion(-)
>> 
>> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
>> index 4b88de5e9192..16f5bedb0b7d 100644
>> --- a/tools/perf/util/header.c
>> +++ b/tools/perf/util/header.c
>> @@ -18,6 +18,7 @@
>> #include <sys/utsname.h>
>> #include <linux/time64.h>
>> #include <dirent.h>
>> +#include <bpf/libbpf.h>
>> 
>> #include "evlist.h"
>> #include "evsel.h"
>> @@ -39,6 +40,7 @@
>> #include "tool.h"
>> #include "time-utils.h"
>> #include "units.h"
>> +#include "bpf-event.h"
>> 
>> #include "sane_ctype.h"
>> 
>> @@ -1074,6 +1076,51 @@ static int write_clockid(struct feat_fd *ff,
>> 			sizeof(ff->ph->env.clockid_res_ns));
>> }
>> 
>> +static int write_bpf_prog_info(struct feat_fd *ff,
>> +			       struct perf_evlist *evlist __maybe_unused)
>> +{
>> +	struct perf_env *env = &ff->ph->env;
>> +	struct rb_root *root;
>> +	struct rb_node *next;
>> +	u32 count = 0;
>> +	int ret;
>> +
>> +	down_read(&env->bpf_progs.lock);
>> +
>> +	root = &env->bpf_progs.infos;
>> +	next = rb_first(root);
>> +	while (next) {
>> +		++count;
>> +		next = rb_next(next);
>> +	}
>> +
>> +	ret = do_write(ff, &count, sizeof(count));
>> +
>> +	if (ret < 0)
>> +		goto out;
>> +
>> +	next = rb_first(root);
>> +	while (next) {
>> +		struct bpf_prog_info_node *node;
>> +		size_t len;
>> +
>> +		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
>> +		next = rb_next(&node->rb_node);
>> +		len = sizeof(struct bpf_prog_info_linear) +
>> +			node->info_linear->data_len;
>> +
>> +		/* before writing to file, translate address to offset */
>> +		bpf_program__bpil_addr_to_offs(node->info_linear);
>> +		ret = do_write(ff, node->info_linear, len);
>> +		bpf_program__bpil_offs_to_addr(node->info_linear);
> 
> what's the reason to call this before the error check?

This will translate the all the pointers to the right address 
(instead of offsets). We only need the offsets when writing to 
files. With this approach, the data is not changed whether the
function succeeds or not. It is probably not necessary right 
now. But I think this may save us some debugging efforts in 
the future. 

Thanks,
Song

> 
> thanks,
> jirka
> 
>> +		if (ret < 0)
>> +			goto out;
>> +	}
>> +out:
>> +	up_read(&env->bpf_progs.lock);
>> +	return ret;
>> +}
> 
> SNIP

Re: [PATCH v5 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

[Song Liu]

> On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Feb 27, 2019 at 09:06:36PM -0800, Song Liu wrote:
>> btf contains information necessary to annotate bpf programs. This patch
>> saves btf for bpf programs loaded in the system.
>> 
>> Signed-off-by: Song Liu <songliubraving@fb.com>
>> ---
>> tools/perf/util/bpf-event.c | 24 ++++++++++++++
>> tools/perf/util/bpf-event.h |  7 ++++
>> tools/perf/util/env.c       | 65 +++++++++++++++++++++++++++++++++++++
>> tools/perf/util/env.h       |  4 +++
>> 4 files changed, 100 insertions(+)
>> 
>> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
>> index ce81b2c43a51..370b830f2433 100644
>> --- a/tools/perf/util/bpf-event.c
>> +++ b/tools/perf/util/bpf-event.c
>> @@ -34,6 +34,29 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
>> 	return 0;
>> }
>> 
>> +static int perf_env__fetch_btf(struct perf_env *env,
>> +			       u32 btf_id,
>> +			       struct btf *btf)
>> +{
>> +	struct btf_node *node;
>> +	u32 data_size;
>> +	const void *data;
>> +
>> +	data = btf__get_raw_data(btf, &data_size);
>> +
>> +	node = malloc(data_size + sizeof(struct btf_node));
>> +
>> +	if (!node)
>> +		return -1;
>> +
>> +	node->id = btf_id;
>> +	node->data_size = data_size;
>> +	memcpy(node->data, data, data_size);
> 
> why don't we store just struct btf itself?
> 
> thanks,
> jirka

In current libbpf design, definition of "struct btf" is private 
to tools/lib/bpf/btf.c. So we cannot copy the struct itself. 

Thanks,
Song

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Song Liu]

> On Mar 4, 2019, at 5:53 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:
> 
> SNIP
> 
>> +	fflush(s);
>> +	do {
>> +		const struct bpf_line_info *linfo = NULL;
>> +		struct disasm_line *dl;
>> +		size_t prev_buf_size;
>> +		const char *srcline;
>> +		u64 addr;
>> +
>> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
>> +		count = disassemble(pc, &info);
>> +
>> +		if (prog_linfo)
>> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
>> +								addr, sub_id,
>> +								nr_skip);
>> +
>> +		if (linfo && btf) {
>> +			srcline = btf__name_by_offset(btf, linfo->line_off);
>> +			nr_skip++;
>> +		} else
>> +			srcline = NULL;
>> +
>> +		fprintf(s, "\n");
>> +		prev_buf_size = buf_size;
>> +		fflush(s);
>> +
>> +		if (!opts->hide_src_code && srcline) {
>> +			args->offset = -1;
> 
> why's the offset not needed in here?

This is the source code line. Based on my understanding of annotation
code, we put -1 for source code line. Did I misunderstand something?

Thanks,
Song

> 
> jirka
> 
>> +			args->line = strdup(srcline);
>> +			args->line_nr = 0;
>> +			args->ms.sym  = sym;
>> +			dl = disasm_line__new(args);
>> +			if (dl) {
>> +				annotation_line__add(&dl->al,
>> +						     &notes->src->source);
>> +			}
>> +		}
> 
> SNIP

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Jiri Olsa]

On Mon, Mar 04, 2019 at 07:36:14PM +0000, Song Liu wrote:
> 
> 
> > On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> > 
> > On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
> > 
> > SNIP
> > 
> >> +static int process_bpf_prog_info(struct feat_fd *ff,
> >> +				 void *data __maybe_unused)
> >> +{
> >> +	struct bpf_prog_info_linear *info_linear;
> >> +	struct bpf_prog_info_node *info_node;
> >> +	struct perf_env *env = &ff->ph->env;
> >> +	u32 count, i;
> >> +	int err = -1;
> >> +
> >> +	if (do_read_u32(ff, &count))
> >> +		return -1;
> >> +
> >> +	down_write(&env->bpf_progs.lock);
> >> +
> >> +	for (i = 0; i < count; ++i) {
> >> +		u32 info_len, data_len;
> >> +
> >> +		info_linear = NULL;
> >> +		info_node = NULL;
> >> +		if (do_read_u32(ff, &info_len))
> >> +			goto out;
> >> +		if (do_read_u32(ff, &data_len))
> >> +			goto out;
> >> +
> >> +		if (info_len > sizeof(struct bpf_prog_info)) {
> >> +			pr_warning("detected invalid bpf_prog_info\n");
> >> +			goto out;
> >> +		}
> >> +
> >> +		info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
> >> +				     data_len);
> >> +		if (!info_linear)
> >> +			goto out;
> >> +		info_linear->info_len = sizeof(struct bpf_prog_info);
> >> +		info_linear->data_len = data_len;
> >> +		if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
> >> +			goto out;
> >> +		if (__do_read(ff, &info_linear->info, info_len))
> >> +			goto out;
> >> +		if (info_len < sizeof(struct bpf_prog_info))
> >> +			memset(((void *)(&info_linear->info)) + info_len, 0,
> >> +			       sizeof(struct bpf_prog_info) - info_len);
> >> +
> >> +		if (__do_read(ff, info_linear->data, data_len))
> >> +			goto out;
> >> +
> >> +		/* endian mismatch, drop the info, continue */
> >> +		if (ff->ph->needs_swap) {
> >> +			free(info_linear);
> >> +			continue;
> >> +		}
> > 
> > so in this case we can check for needs_swap in the begining
> > of the function and bail out without reading all the data
> 
> If we bail out, perf-record will fail. If we read all the data 
> but ignore them, perf-record will continue without bpf annotation 
> support. I think the latter is a better experience with little 
> effort here. 

i did not mean bail out with error, just return 0, warn and go on

jirka

> 
> > 
> > also please display soem error message saying we don't support
> > ebpf progs data report over the different endianity
> 
> I will add a warning in the next version. 
> 
> Thanks,
> Song
> 

Re: [PATCH v5 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

[Jiri Olsa]

On Mon, Mar 04, 2019 at 07:43:50PM +0000, Song Liu wrote:
> 
> 
> > On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> > 
> > On Wed, Feb 27, 2019 at 09:06:36PM -0800, Song Liu wrote:
> >> btf contains information necessary to annotate bpf programs. This patch
> >> saves btf for bpf programs loaded in the system.
> >> 
> >> Signed-off-by: Song Liu <songliubraving@fb.com>
> >> ---
> >> tools/perf/util/bpf-event.c | 24 ++++++++++++++
> >> tools/perf/util/bpf-event.h |  7 ++++
> >> tools/perf/util/env.c       | 65 +++++++++++++++++++++++++++++++++++++
> >> tools/perf/util/env.h       |  4 +++
> >> 4 files changed, 100 insertions(+)
> >> 
> >> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> >> index ce81b2c43a51..370b830f2433 100644
> >> --- a/tools/perf/util/bpf-event.c
> >> +++ b/tools/perf/util/bpf-event.c
> >> @@ -34,6 +34,29 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
> >> 	return 0;
> >> }
> >> 
> >> +static int perf_env__fetch_btf(struct perf_env *env,
> >> +			       u32 btf_id,
> >> +			       struct btf *btf)
> >> +{
> >> +	struct btf_node *node;
> >> +	u32 data_size;
> >> +	const void *data;
> >> +
> >> +	data = btf__get_raw_data(btf, &data_size);
> >> +
> >> +	node = malloc(data_size + sizeof(struct btf_node));
> >> +
> >> +	if (!node)
> >> +		return -1;
> >> +
> >> +	node->id = btf_id;
> >> +	node->data_size = data_size;
> >> +	memcpy(node->data, data, data_size);
> > 
> > why don't we store just struct btf itself?
> > 
> > thanks,
> > jirka
> 
> In current libbpf design, definition of "struct btf" is private 
> to tools/lib/bpf/btf.c. So we cannot copy the struct itself. 

ok

jirka

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Song Liu]

> On Mar 4, 2019, at 12:23 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Mon, Mar 04, 2019 at 07:36:14PM +0000, Song Liu wrote:
>> 
>> 
>>> On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
>>> 
>>> On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
>>> 
>>> SNIP
>>> 
>>>> +static int process_bpf_prog_info(struct feat_fd *ff,
>>>> +				 void *data __maybe_unused)
>>>> +{
>>>> +	struct bpf_prog_info_linear *info_linear;
>>>> +	struct bpf_prog_info_node *info_node;
>>>> +	struct perf_env *env = &ff->ph->env;
>>>> +	u32 count, i;
>>>> +	int err = -1;
>>>> +
>>>> +	if (do_read_u32(ff, &count))
>>>> +		return -1;
>>>> +
>>>> +	down_write(&env->bpf_progs.lock);
>>>> +
>>>> +	for (i = 0; i < count; ++i) {
>>>> +		u32 info_len, data_len;
>>>> +
>>>> +		info_linear = NULL;
>>>> +		info_node = NULL;
>>>> +		if (do_read_u32(ff, &info_len))
>>>> +			goto out;
>>>> +		if (do_read_u32(ff, &data_len))
>>>> +			goto out;
>>>> +
>>>> +		if (info_len > sizeof(struct bpf_prog_info)) {
>>>> +			pr_warning("detected invalid bpf_prog_info\n");
>>>> +			goto out;
>>>> +		}
>>>> +
>>>> +		info_linear = malloc(sizeof(struct bpf_prog_info_linear) +
>>>> +				     data_len);
>>>> +		if (!info_linear)
>>>> +			goto out;
>>>> +		info_linear->info_len = sizeof(struct bpf_prog_info);
>>>> +		info_linear->data_len = data_len;
>>>> +		if (do_read_u64(ff, (u64 *)(&info_linear->arrays)))
>>>> +			goto out;
>>>> +		if (__do_read(ff, &info_linear->info, info_len))
>>>> +			goto out;
>>>> +		if (info_len < sizeof(struct bpf_prog_info))
>>>> +			memset(((void *)(&info_linear->info)) + info_len, 0,
>>>> +			       sizeof(struct bpf_prog_info) - info_len);
>>>> +
>>>> +		if (__do_read(ff, info_linear->data, data_len))
>>>> +			goto out;
>>>> +
>>>> +		/* endian mismatch, drop the info, continue */
>>>> +		if (ff->ph->needs_swap) {
>>>> +			free(info_linear);
>>>> +			continue;
>>>> +		}
>>> 
>>> so in this case we can check for needs_swap in the begining
>>> of the function and bail out without reading all the data
>> 
>> If we bail out, perf-record will fail. If we read all the data 
>> but ignore them, perf-record will continue without bpf annotation 
>> support. I think the latter is a better experience with little 
>> effort here. 
> 
> i did not mean bail out with error, just return 0, warn and go on
> 
> jirka

In this case, do we need to read and discard all the data? If not, 
the next header type (or data) will interpret these data as 
something else, right? Or did I miss some protection against such
cases?

Thanks,
Song

> 
>> 
>>> 
>>> also please display soem error message saying we don't support
>>> ebpf progs data report over the different endianity
>> 
>> I will add a warning in the next version. 
>> 
>> Thanks,
>> Song
>> 

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Jiri Olsa]

On Mon, Mar 04, 2019 at 07:45:00PM +0000, Song Liu wrote:
> 
> 
> > On Mar 4, 2019, at 5:53 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> > 
> > On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:
> > 
> > SNIP
> > 
> >> +	fflush(s);
> >> +	do {
> >> +		const struct bpf_line_info *linfo = NULL;
> >> +		struct disasm_line *dl;
> >> +		size_t prev_buf_size;
> >> +		const char *srcline;
> >> +		u64 addr;
> >> +
> >> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
> >> +		count = disassemble(pc, &info);
> >> +
> >> +		if (prog_linfo)
> >> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
> >> +								addr, sub_id,
> >> +								nr_skip);
> >> +
> >> +		if (linfo && btf) {
> >> +			srcline = btf__name_by_offset(btf, linfo->line_off);
> >> +			nr_skip++;
> >> +		} else
> >> +			srcline = NULL;
> >> +
> >> +		fprintf(s, "\n");
> >> +		prev_buf_size = buf_size;
> >> +		fflush(s);
> >> +
> >> +		if (!opts->hide_src_code && srcline) {
> >> +			args->offset = -1;
> > 
> > why's the offset not needed in here?
> 
> This is the source code line. Based on my understanding of annotation
> code, we put -1 for source code line. Did I misunderstand something?

please double check, IIRC annotation_line__print will print
just more info if offset is present, together with the source,
but I haven't checked that code for some time, so I might be wrong

jirka

Re: [PATCH v5 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

[Jiri Olsa]

On Mon, Mar 04, 2019 at 07:41:10PM +0000, Song Liu wrote:
> 
> 
> > On Mar 4, 2019, at 5:52 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> > 
> > On Wed, Feb 27, 2019 at 09:06:35PM -0800, Song Liu wrote:
> >> This patch enables perf-record to save bpf_prog_info information as
> >> headers to perf.data. A new header type HEADER_BPF_PROG_INFO is
> >> introduced for this data.
> >> 
> >> Signed-off-by: Song Liu <songliubraving@fb.com>
> >> ---
> >> tools/perf/util/header.c | 143 ++++++++++++++++++++++++++++++++++++++-
> >> tools/perf/util/header.h |   1 +
> >> 2 files changed, 143 insertions(+), 1 deletion(-)
> >> 
> >> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> >> index 4b88de5e9192..16f5bedb0b7d 100644
> >> --- a/tools/perf/util/header.c
> >> +++ b/tools/perf/util/header.c
> >> @@ -18,6 +18,7 @@
> >> #include <sys/utsname.h>
> >> #include <linux/time64.h>
> >> #include <dirent.h>
> >> +#include <bpf/libbpf.h>
> >> 
> >> #include "evlist.h"
> >> #include "evsel.h"
> >> @@ -39,6 +40,7 @@
> >> #include "tool.h"
> >> #include "time-utils.h"
> >> #include "units.h"
> >> +#include "bpf-event.h"
> >> 
> >> #include "sane_ctype.h"
> >> 
> >> @@ -1074,6 +1076,51 @@ static int write_clockid(struct feat_fd *ff,
> >> 			sizeof(ff->ph->env.clockid_res_ns));
> >> }
> >> 
> >> +static int write_bpf_prog_info(struct feat_fd *ff,
> >> +			       struct perf_evlist *evlist __maybe_unused)
> >> +{
> >> +	struct perf_env *env = &ff->ph->env;
> >> +	struct rb_root *root;
> >> +	struct rb_node *next;
> >> +	u32 count = 0;
> >> +	int ret;
> >> +
> >> +	down_read(&env->bpf_progs.lock);
> >> +
> >> +	root = &env->bpf_progs.infos;
> >> +	next = rb_first(root);
> >> +	while (next) {
> >> +		++count;
> >> +		next = rb_next(next);
> >> +	}
> >> +
> >> +	ret = do_write(ff, &count, sizeof(count));
> >> +
> >> +	if (ret < 0)
> >> +		goto out;
> >> +
> >> +	next = rb_first(root);
> >> +	while (next) {
> >> +		struct bpf_prog_info_node *node;
> >> +		size_t len;
> >> +
> >> +		node = rb_entry(next, struct bpf_prog_info_node, rb_node);
> >> +		next = rb_next(&node->rb_node);
> >> +		len = sizeof(struct bpf_prog_info_linear) +
> >> +			node->info_linear->data_len;
> >> +
> >> +		/* before writing to file, translate address to offset */
> >> +		bpf_program__bpil_addr_to_offs(node->info_linear);
> >> +		ret = do_write(ff, node->info_linear, len);
> >> +		bpf_program__bpil_offs_to_addr(node->info_linear);
> > 
> > what's the reason to call this before the error check?
> 
> This will translate the all the pointers to the right address 
> (instead of offsets). We only need the offsets when writing to 
> files. With this approach, the data is not changed whether the
> function succeeds or not. It is probably not necessary right 
> now. But I think this may save us some debugging efforts in 
> the future. 

ok, please make comment with this

jirka

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Song Liu]

> On Mar 4, 2019, at 12:37 PM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Mon, Mar 04, 2019 at 07:45:00PM +0000, Song Liu wrote:
>> 
>> 
>>> On Mar 4, 2019, at 5:53 AM, Jiri Olsa <jolsa@redhat.com> wrote:
>>> 
>>> On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:
>>> 
>>> SNIP
>>> 
>>>> +	fflush(s);
>>>> +	do {
>>>> +		const struct bpf_line_info *linfo = NULL;
>>>> +		struct disasm_line *dl;
>>>> +		size_t prev_buf_size;
>>>> +		const char *srcline;
>>>> +		u64 addr;
>>>> +
>>>> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
>>>> +		count = disassemble(pc, &info);
>>>> +
>>>> +		if (prog_linfo)
>>>> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
>>>> +								addr, sub_id,
>>>> +								nr_skip);
>>>> +
>>>> +		if (linfo && btf) {
>>>> +			srcline = btf__name_by_offset(btf, linfo->line_off);
>>>> +			nr_skip++;
>>>> +		} else
>>>> +			srcline = NULL;
>>>> +
>>>> +		fprintf(s, "\n");
>>>> +		prev_buf_size = buf_size;
>>>> +		fflush(s);
>>>> +
>>>> +		if (!opts->hide_src_code && srcline) {
>>>> +			args->offset = -1;
>>> 
>>> why's the offset not needed in here?
>> 
>> This is the source code line. Based on my understanding of annotation
>> code, we put -1 for source code line. Did I misunderstand something?
> 
> please double check, IIRC annotation_line__print will print
> just more info if offset is present, together with the source,
> but I haven't checked that code for some time, so I might be wrong
> 
> jirka

In symbol__parse_objdump_line(), default offset is -1. And it is only 
updated if line_ip is not -1. And line_ip for src code line is -1, so 
offset for the source line is -1. 

It works fine in the tests when I toggle source code on/off with key
's'. 

Thanks
Song

Re: [PATCH v5 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

[Song Liu]

> On Mar 4, 2019, at 5:53 AM, Jiri Olsa <jolsa@redhat.com> wrote:
> 
> On Wed, Feb 27, 2019 at 09:06:40PM -0800, Song Liu wrote:
> 
> SNIP
> 
>> +
>> +	disassemble_init_for_target(&info);
>> +
>> +#ifdef DISASM_FOUR_ARGS_SIGNATURE
>> +	disassemble = disassembler(info.arch,
>> +				   bfd_big_endian(bfdf),
>> +				   info.mach,
>> +				   bfdf);
>> +#else
>> +	disassemble = disassembler(bfdf);
>> +#endif
>> +	assert(disassemble);
>> +
>> +	fflush(s);
> 
> what's the reason for those fflush calls?

fflush() updates buf_size for the stream. This one before the 
loop make sure we read proper buf_size (prev_buf_size = bud_size)
in the first iteration. Then, the fflush() in each iteration 
makes sure the next iteration reads proper prev_buf_size. 

Thanks,
Song


> 
> thanks,
> jirka
> 
>> +	do {
>> +		const struct bpf_line_info *linfo = NULL;
>> +		struct disasm_line *dl;
>> +		size_t prev_buf_size;
>> +		const char *srcline;
>> +		u64 addr;
>> +
>> +		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
>> +		count = disassemble(pc, &info);
>> +
>> +		if (prog_linfo)
>> +			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
>> +								addr, sub_id,
>> +								nr_skip);
>> +
>> +		if (linfo && btf) {
>> +			srcline = btf__name_by_offset(btf, linfo->line_off);
>> +			nr_skip++;
>> +		} else
>> +			srcline = NULL;
>> +
>> +		fprintf(s, "\n");
>> +		prev_buf_size = buf_size;
>> +		fflush(s);
> 
> SNIP