2019-03-07 18:00:56

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 00/15] perf annotation of BPF programs

Changes v6 to v7:
1. Fix minor issues suggested by Jiri.

Changes v5 to v6:
1. Improve side band evlist interface;
2. Minor style fixes.

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 | 9 +-
tools/perf/builtin-top.c | 12 +-
tools/perf/perf.c | 1 +
tools/perf/util/annotate.c | 150 +++++++++++++++-
tools/perf/util/bpf-event.c | 327 ++++++++++++++++++++++++++---------
tools/perf/util/bpf-event.h | 33 +++-
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 | 113 ++++++++++++
tools/perf/util/evlist.h | 12 ++
tools/perf/util/evsel.h | 6 +
tools/perf/util/header.c | 250 +++++++++++++++++++++++++-
tools/perf/util/header.h | 2 +
tools/perf/util/session.c | 1 +
tools/perf/util/symbol.c | 1 +
tools/perf/util/top.h | 1 +
25 files changed, 1410 insertions(+), 311 deletions(-)

--
2.17.1


2019-03-07 17:59:18

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 01/15] perf, bpf: consider events with attr.bpf_event as side-band events

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 <[email protected]>
---
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 f1a26c8f15b3..4a59cb9b29ee 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


2019-03-07 17:59:24

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 03/15] bpf: bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump()

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

Cc: Daniel Borkmann <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Signed-off-by: Song Liu <[email protected]>
---
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 8ef80d65a474..d2be5a06c339 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


2019-03-07 18:00:05

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 14/15] perf: introduce side band thread

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.

To use side band thread, we need to:

1. add side band event(s) by calling perf_evlist__add_sb_event();
2. calls perf_evlist__start_sb_thread();
3. at the end of perf run, perf_evlist__stop_sb_thread().

In the next patch, we use this thread to handle PERF_RECORD_BPF_EVENT.

Signed-off-by: Song Liu <[email protected]>
---
tools/perf/builtin-record.c | 5 ++
tools/perf/builtin-top.c | 5 ++
tools/perf/util/evlist.c | 113 ++++++++++++++++++++++++++++++++++++
tools/perf/util/evlist.h | 12 ++++
tools/perf/util/evsel.h | 6 ++
5 files changed, 141 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 2355e0a9eda0..435b94f1f3b3 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_evlist = NULL;
int fd;

atexit(record__sig_exit);
@@ -1206,6 +1207,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
goto out_child;
}

+ perf_evlist__start_sb_thread(sb_evlist, &rec->opts.target);
+
err = record__synthesize(rec, false);
if (err < 0)
goto out_child;
@@ -1456,6 +1459,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)

out_delete_session:
perf_session__delete(session);
+
+ perf_evlist__stop_sb_thread(sb_evlist);
return status;
}

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index ccdf5689452f..ec69eb040933 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_evlist = NULL;
const char * const top_usage[] = {
"perf top [<options>]",
NULL
@@ -1654,8 +1655,12 @@ int cmd_top(int argc, const char **argv)

top.record_opts.bpf_event = !top.no_bpf_event;

+ perf_evlist__start_sb_thread(sb_evlist, target);
+
status = __cmd_top(&top);

+ perf_evlist__stop_sb_thread(sb_evlist);
+
out_delete_evlist:
perf_evlist__delete(top.evlist);

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 8c902276d4b4..a06a4f54b083 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 +1842,115 @@ struct perf_evsel *perf_evlist__reset_weak_group(struct perf_evlist *evsel_list,
}
return leader;
}
+
+int perf_evlist__add_sb_event(struct perf_evlist **evlist,
+ struct perf_event_attr *attr,
+ perf_evsel__sb_cb_t cb,
+ void *data)
+{
+ struct perf_evsel *evsel;
+ bool new_evlist = (*evlist) == NULL;
+
+ if (*evlist == NULL)
+ *evlist = perf_evlist__new();
+ if (*evlist == NULL)
+ return -1;
+
+ if (!attr->sample_id_all) {
+ pr_warning("enabling sample_id_all for all side band events\n");
+ attr->sample_id_all = 1;
+ }
+
+ evsel = perf_evsel__new_idx(attr, (*evlist)->nr_entries);
+ if (!evsel)
+ goto out_err;
+
+ evsel->side_band.cb = cb;
+ evsel->side_band.data = data;
+ perf_evlist__add(*evlist, evsel);
+ return 0;
+
+out_err:
+ if (new_evlist) {
+ perf_evlist__delete(*evlist);
+ *evlist = NULL;
+ }
+ return -1;
+}
+
+static void *perf_evlist__poll_thread(void *arg)
+{
+ struct perf_evlist *evlist = arg;
+ int i;
+
+ while (!(evlist->thread.done)) {
+ perf_evlist__poll(evlist, 1000);
+
+ for (i = 0; i < evlist->nr_mmaps; i++) {
+ struct perf_mmap *map = &evlist->mmap[i];
+ union perf_event *event;
+
+ if (perf_mmap__read_init(map))
+ continue;
+ while ((event = perf_mmap__read_event(map)) != NULL) {
+ struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event);
+
+ if (evsel && evsel->side_band.cb)
+ evsel->side_band.cb(event, evsel->side_band.data);
+ else
+ pr_warning("cannot locate proper evsel for the side band event\n");
+
+ perf_mmap__consume(map);
+ }
+ perf_mmap__read_done(map);
+ }
+ }
+ return NULL;
+}
+
+int perf_evlist__start_sb_thread(struct perf_evlist *evlist,
+ struct target *target)
+{
+ struct perf_evsel *counter;
+
+ if (!evlist)
+ return 0;
+
+ if (perf_evlist__create_maps(evlist, target))
+ goto out_delete_evlist;
+
+ evlist__for_each_entry(evlist, counter) {
+ if (perf_evsel__open(counter, evlist->cpus,
+ evlist->threads) < 0)
+ goto out_delete_evlist;
+ }
+
+ if (perf_evlist__mmap(evlist, UINT_MAX))
+ goto out_delete_evlist;
+
+ evlist__for_each_entry(evlist, counter) {
+ if (perf_evsel__enable(counter))
+ goto out_delete_evlist;
+ }
+
+ evlist->thread.done = 0;
+ if (pthread_create(&evlist->thread.th, NULL, perf_evlist__poll_thread, evlist))
+ goto out_delete_evlist;
+
+ return 0;
+
+out_delete_evlist:
+ perf_evlist__delete(evlist);
+ evlist = NULL;
+ return -1;
+}
+
+void perf_evlist__stop_sb_thread(struct perf_evlist *evlist)
+{
+ if (!evlist)
+ return;
+ evlist->thread.done = 1;
+ pthread_join(evlist->thread.th, NULL);
+ perf_evlist__exit(evlist);
+ evlist = NULL;
+}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 868294491194..07395fbb4b3b 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -51,6 +51,10 @@ struct perf_evlist {
struct perf_env *env;
u64 first_sample_time;
u64 last_sample_time;
+ struct {
+ pthread_t th;
+ volatile int done;
+ } thread;
};

struct perf_evsel_str_handler {
@@ -84,6 +88,14 @@ int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,

int perf_evlist__add_dummy(struct perf_evlist *evlist);

+int perf_evlist__add_sb_event(struct perf_evlist **evlist,
+ struct perf_event_attr *attr,
+ perf_evsel__sb_cb_t cb,
+ void *data);
+int perf_evlist__start_sb_thread(struct perf_evlist *evlist,
+ struct target *target);
+void perf_evlist__stop_sb_thread(struct perf_evlist *evlist);
+
int perf_evlist__add_newtp(struct perf_evlist *evlist,
const char *sys, const char *name, void *handler);

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 29c5eb68c44b..94232ba9acce 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -73,6 +73,8 @@ struct perf_evsel_config_term {

struct perf_stat_evsel;

+typedef int (perf_evsel__sb_cb_t)(union perf_event *event, void *data);
+
/** struct perf_evsel - event selector
*
* @evlist - evlist this evsel is in, if it is in one.
@@ -151,6 +153,10 @@ struct perf_evsel {
bool collect_stat;
bool weak_group;
const char *pmu_name;
+ struct {
+ perf_evsel__sb_cb_t *cb;
+ void *data;
+ } side_band;
};

union u64_swap {
--
2.17.1


2019-03-07 18:00:15

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 13/15] perf, bpf: process PERF_BPF_EVENT_PROG_LOAD for annotation

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 <[email protected]>
---
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 4ef7c833830c..c0a316af5c2a 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,
+ 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


2019-03-07 18:00:19

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 06/15] perf, bpf: save bpf_prog_info in a rbtree in perf_env

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 <[email protected]>
---
tools/perf/perf.c | 1 +
tools/perf/util/bpf-event.c | 30 ++++++++++++-
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, 139 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..3ae60f74339b 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 +179,22 @@ 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));
+ if (!info_node) {
+ err = -1;
+ goto out;
+ }
+
+ 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..6e037a9660ca 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(&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


2019-03-07 18:00:43

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 04/15] perf, bpf: synthesize bpf events with bpf_program__get_prog_info_linear()

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 <[email protected]>
---
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


2019-03-07 18:01:10

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 08/15] perf, bpf: save btf in a rbtree in perf_env

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

Signed-off-by: Song Liu <[email protected]>
---
tools/perf/util/bpf-event.c | 23 +++++++++++++
tools/perf/util/bpf-event.h | 7 ++++
tools/perf/util/env.c | 65 +++++++++++++++++++++++++++++++++++++
tools/perf/util/env.h | 4 +++
4 files changed, 99 insertions(+)

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index 3ae60f74339b..4ef7c833830c 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -34,6 +34,28 @@ 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 +135,7 @@ 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 6e037a9660ca..d9b1299b8a6d 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(&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(&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


2019-03-07 18:01:15

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 11/15] perf: add -lopcodes to feature-libbfd

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 <[email protected]>
---
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


2019-03-07 18:01:22

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

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 <[email protected]>
---
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


2019-03-07 18:01:25

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 05/15] perf: change prototype of perf_event__synthesize_bpf_events()

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 <[email protected]>
---
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


2019-03-07 18:01:47

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 02/15] bpf: libbpf: introduce bpf_program__get_prog_info_linear()

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 <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Signed-off-by: Song Liu <[email protected]>
---
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 f5eb60379c8d..ca00ce5cbae0 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 b4652aa1a58a..c7645a5e1ac0 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -377,6 +377,69 @@ 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


2019-03-07 18:01:58

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

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 <[email protected]>
---
tools/perf/util/header.c | 145 ++++++++++++++++++++++++++++++++++++++-
tools/perf/util/header.h | 1 +
2 files changed, 145 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 4b88de5e9192..f0708188211e 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 +1076,54 @@ 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);
+ /*
+ * translate back to address even when do_write() fails,
+ * so that this function never changes the data.
+ */
+ 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 +1604,29 @@ 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 +2659,75 @@ 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 (ff->ph->needs_swap) {
+ pr_warning("interpreting bpf_prog_info from systems with endianity is not yet supported\n");
+ return 0;
+ }
+
+ 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;
+
+ 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 +2787,8 @@ 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


2019-03-07 18:02:55

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 10/15] perf-top: add option --no-bpf-event

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 <[email protected]>
---
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


2019-03-07 18:03:55

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 09/15] perf, bpf: save btf information as headers to perf.data

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 <[email protected]>
---
tools/perf/util/header.c | 107 ++++++++++++++++++++++++++++++++++++++-
tools/perf/util/header.h | 1 +
2 files changed, 107 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index f0708188211e..e31344de20c4 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -1124,6 +1124,45 @@ 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;
@@ -1627,6 +1666,28 @@ 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;
@@ -2728,6 +2789,49 @@ 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 (ff->ph->needs_swap) {
+ pr_warning("interpreting btf from systems with endianity is not yet supported\n");
+ return 0;
+ }
+
+ 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;
+ }
+
+ 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);
@@ -2788,7 +2892,8 @@ 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


2019-03-07 18:04:23

by Song Liu

[permalink] [raw]
Subject: [PATCH v7 perf,bpf 15/15] perf, bpf: save bpf_prog_info and btf of short living bpf programs

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 <[email protected]>
---
tools/perf/builtin-record.c | 2 +
tools/perf/builtin-top.c | 2 +
tools/perf/util/bpf-event.c | 95 +++++++++++++++++++++++++++++++++++++
tools/perf/util/bpf-event.h | 15 ++++++
4 files changed, 114 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 435b94f1f3b3..8d197762a499 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1207,6 +1207,8 @@ static int __cmd_record(struct record *rec, int argc, const char **argv)
goto out_child;
}

+ if (opts->bpf_event)
+ bpf_event__add_sb_event(&sb_evlist, &session->header.env);
perf_evlist__start_sb_thread(sb_evlist, &rec->opts.target);

err = record__synthesize(rec, false);
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index ec69eb040933..0d0da834dd9d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1655,6 +1655,8 @@ 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_sb_event(&sb_evlist, &perf_env);
perf_evlist__start_sb_thread(sb_evlist, target);

status = __cmd_top(&top);
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index c0a316af5c2a..32766341e111 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))

@@ -329,3 +330,97 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
free(event);
return err;
}
+
+static 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);
+}
+
+static int bpf_event__sb_cb(union perf_event *event, void *data)
+{
+ struct perf_env *env = data;
+
+ if (event->header.type != PERF_RECORD_BPF_EVENT)
+ return -1;
+
+ switch (event->bpf_event.type) {
+ case PERF_BPF_EVENT_PROG_LOAD:
+ perf_env__add_bpf_info(env, event->bpf_event.id);
+
+ 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;
+}
+
+int bpf_event__add_sb_event(struct perf_evlist **evlist,
+ struct perf_env *env)
+{
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_SOFTWARE,
+ .config = PERF_COUNT_SW_DUMMY,
+ .sample_id_all = 1,
+ .watermark = 1,
+ .bpf_event = 1,
+ .wakeup_watermark = 1,
+ .size = sizeof(attr), /* to capture ABI version */
+ };
+
+ return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env);
+}
diff --git a/tools/perf/util/bpf-event.h b/tools/perf/util/bpf-event.h
index b9ec394dc7c7..249909c826e7 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_sb_event(struct perf_evlist **evlist,
+ struct perf_env *env);
+
#else
static inline int machine__process_bpf_event(struct machine *machine __maybe_unused,
union perf_event *event __maybe_unused,
@@ -46,5 +54,12 @@ static inline int perf_event__synthesize_bpf_events(struct perf_session *session
{
return 0;
}
+
+static int bpf_event__add_sb_event(struct perf_evlist **evlist __maybe_unused,
+ struct perf_env *env __maybe_unused)
+{
+ return 0;
+}
+
#endif // HAVE_LIBBPF_SUPPORT
#endif
--
2.17.1


2019-03-07 23:27:10

by Stanislav Fomichev

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 11/15] perf: add -lopcodes to feature-libbfd

On 03/07, Song Liu wrote:
> 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 <[email protected]>
> ---
> 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
I think you need to add -lopcodes to the other feature checks as
well (to work on the systems which require -liberty and/or -lz for
libfd):

--

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index b441c88cafa1..3fa2f5d7d54f 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
@@ -712,10 +712,10 @@ else
$(call feature_check,libbfd-liberty-z)

ifeq ($(feature-libbfd-liberty), 1)
- EXTLIBS += -lbfd -liberty
+ EXTLIBS += -lbfd -lopcodes -liberty
else
ifeq ($(feature-libbfd-liberty-z), 1)
- EXTLIBS += -lbfd -liberty -lz
+ EXTLIBS += -lbfd -lopcodes -liberty -lz
endif
endif
endif

> else
> # we are on a system that requires -liberty and (maybe) -lz
> # to link against -lbfd; test each case individually here
> --
> 2.17.1
>

2019-03-07 23:48:47

by Song Liu

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 11/15] perf: add -lopcodes to feature-libbfd



> On Mar 7, 2019, at 3:26 PM, Stanislav Fomichev <[email protected]> wrote:
>
> On 03/07, Song Liu wrote:
>> 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 <[email protected]>
>> ---
>> 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 ($(feature-libbfd), 1)
>> - EXTLIBS += -lbfd
>> + EXTLIBS += -lbfd -lopcodes
> I think you need to add -lopcodes to the other feature checks as
> well (to work on the systems which require -liberty and/or -lz for
> libfd):
>
> --
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index b441c88cafa1..3fa2f5d7d54f 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -701,7 +701,7 @@ else
> endif
>
> ifeq ($(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
> @@ -712,10 +712,10 @@ else
> $(call feature_check,libbfd-liberty-z)
>
> ifeq ($(feature-libbfd-liberty), 1)
> - EXTLIBS += -lbfd -liberty
> + EXTLIBS += -lbfd -lopcodes -liberty
> else
> ifeq ($(feature-libbfd-liberty-z), 1)
> - EXTLIBS += -lbfd -liberty -lz
> + EXTLIBS += -lbfd -lopcodes -liberty -lz
> endif
> endif
> endif

Good point! I will fix it in next version.

Thanks,
Song

>
>> else
>> # we are on a system that requires -liberty and (maybe) -lz
>> # to link against -lbfd; test each case individually here
>> --
>> 2.17.1


2019-03-11 14:02:03

by Jiri Olsa

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 00/15] perf annotation of BPF programs

On Thu, Mar 07, 2019 at 09:57:55AM -0800, Song Liu wrote:

SNIP

> ===================== 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

could you please update the branch? it seems to have still the old version

thanks,
jirka

2019-03-11 14:17:45

by Song Liu

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 00/15] perf annotation of BPF programs



> On Mar 11, 2019, at 6:59 AM, Jiri Olsa <[email protected]> wrote:
>
> On Thu, Mar 07, 2019 at 09:57:55AM -0800, Song Liu wrote:
>
> SNIP
>
>> ===================== 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
>
> could you please update the branch? it seems to have still the old version
>
> thanks,
> jirka

Just updated. Sorry for the confusion.

Song

2019-03-11 17:57:25

by Jiri Olsa

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 12/15] perf, bpf: enable annotation of bpf program

On Thu, Mar 07, 2019 at 09:58:07AM -0800, Song Liu wrote:

SNIP

> + 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);
> + }
> + }

I still miss answer for why is the line added twice for
!opts->hide_src_code && srcline ? code up and down

jirka

> +
> + 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);

SNIP

2019-03-11 17:57:34

by Jiri Olsa

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 09/15] perf, bpf: save btf information as headers to perf.data

On Thu, Mar 07, 2019 at 09:58:04AM -0800, Song Liu wrote:
> 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 <[email protected]>
> ---
> tools/perf/util/header.c | 107 ++++++++++++++++++++++++++++++++++++++-
> tools/perf/util/header.h | 1 +
> 2 files changed, 107 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index f0708188211e..e31344de20c4 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -1124,6 +1124,45 @@ 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);
> + }

same here.. why you don't keep btf count in perf_env::bpf_progs::btfs_cnt ?

jirka

> +
> + 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;
> @@ -1627,6 +1666,28 @@ 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;
> @@ -2728,6 +2789,49 @@ 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 (ff->ph->needs_swap) {
> + pr_warning("interpreting btf from systems with endianity is not yet supported\n");
> + return 0;
> + }
> +
> + 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;
> + }
> +
> + 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);
> @@ -2788,7 +2892,8 @@ 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
>

2019-03-11 17:57:47

by Jiri Olsa

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data

On Thu, Mar 07, 2019 at 09:58:02AM -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 <[email protected]>
> ---
> tools/perf/util/header.c | 145 ++++++++++++++++++++++++++++++++++++++-
> tools/perf/util/header.h | 1 +
> 2 files changed, 145 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index 4b88de5e9192..f0708188211e 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 +1076,54 @@ 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);
> + }

sry I did not se this before, but why you don't keep program count
in perf_env::bpf_progs::infos_cnt ?

jirka

2019-03-11 17:59:58

by Jiri Olsa

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 14/15] perf: introduce side band thread

On Thu, Mar 07, 2019 at 09:58:09AM -0800, Song Liu wrote:

SNIP

> +static void *perf_evlist__poll_thread(void *arg)
> +{
> + struct perf_evlist *evlist = arg;
> + int i;
> +
> + while (!(evlist->thread.done)) {
> + perf_evlist__poll(evlist, 1000);
> +
> + for (i = 0; i < evlist->nr_mmaps; i++) {
> + struct perf_mmap *map = &evlist->mmap[i];
> + union perf_event *event;
> +
> + if (perf_mmap__read_init(map))
> + continue;
> + while ((event = perf_mmap__read_event(map)) != NULL) {
> + struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event);
> +
> + if (evsel && evsel->side_band.cb)
> + evsel->side_band.cb(event, evsel->side_band.data);
> + else
> + pr_warning("cannot locate proper evsel for the side band event\n");
> +
> + perf_mmap__consume(map);
> + }
> + perf_mmap__read_done(map);
> + }

shouldn't you drain the map before leaving?

SNIP

> +out_delete_evlist:
> + perf_evlist__delete(evlist);
> + evlist = NULL;
> + return -1;
> +}
> +
> +void perf_evlist__stop_sb_thread(struct perf_evlist *evlist)
> +{
> + if (!evlist)
> + return;
> + evlist->thread.done = 1;
> + pthread_join(evlist->thread.th, NULL);
> + perf_evlist__exit(evlist);
> + evlist = NULL;

I think the interface is ok, but please let this function
undo whatever perf_evlist__start_sb_thread did, so disable
and close events and cleanup maps

thanks,
jirka

2019-03-11 18:06:13

by Song Liu

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 12/15] perf, bpf: enable annotation of bpf program



> On Mar 11, 2019, at 10:56 AM, Jiri Olsa <[email protected]> wrote:
>
> On Thu, Mar 07, 2019 at 09:58:07AM -0800, Song Liu wrote:
>
> SNIP
>
>> + 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);
>> + }
>> + }
>
> I still miss answer for why is the line added twice for
> !opts->hide_src_code && srcline ? code up and down
>
> jirka

The line above (under "!hide_src_code && srcline") is the src code
line; while the one below is the disassemble output. We only show the
source code when "!hide_src_code && srcline" is true.

Thanks,
Song

>> +
>> + 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);
>
> SNIP


2019-03-11 18:08:31

by Song Liu

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 07/15] perf, bpf: save bpf_prog_info information as headers to perf.data



> On Mar 11, 2019, at 10:56 AM, Jiri Olsa <[email protected]> wrote:
>
> On Thu, Mar 07, 2019 at 09:58:02AM -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 <[email protected]>
>> ---
>> tools/perf/util/header.c | 145 ++++++++++++++++++++++++++++++++++++++-
>> tools/perf/util/header.h | 1 +
>> 2 files changed, 145 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
>> index 4b88de5e9192..f0708188211e 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 +1076,54 @@ 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);
>> + }
>
> sry I did not se this before, but why you don't keep program count
> in perf_env::bpf_progs::infos_cnt ?
>
> jirka

Good idea... I didn't think about this carefully. Will fix in next
version.

Thanks,
Song


2019-03-11 18:27:15

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 02/15] bpf: libbpf: introduce bpf_program__get_prog_info_linear()

Em Thu, Mar 07, 2019 at 09:57:57AM -0800, Song Liu escreveu:
> 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 <[email protected]>
> Cc: Alexei Starovoitov <[email protected]>

Daniel, are you ok with these changes to libbpf and bpftool? Perhaps
those should be detached from this patchkit and submitted sooner,
eroding the size of this kit.

Alternatively, if you're ok with it, please provide your Acked-by and
I'll process as soon as I get back to it after Jiri is done reviewing.

- Arnaldo

> Signed-off-by: Song Liu <[email protected]>
> ---
> 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 f5eb60379c8d..ca00ce5cbae0 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 b4652aa1a58a..c7645a5e1ac0 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -377,6 +377,69 @@ 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

--

- Arnaldo

2019-03-11 20:46:32

by Daniel Borkmann

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 02/15] bpf: libbpf: introduce bpf_program__get_prog_info_linear()

On 03/11/2019 07:26 PM, Arnaldo Carvalho de Melo wrote:
> Em Thu, Mar 07, 2019 at 09:57:57AM -0800, Song Liu escreveu:
>> 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 <[email protected]>
>> Cc: Alexei Starovoitov <[email protected]>
>
> Daniel, are you ok with these changes to libbpf and bpftool? Perhaps
> those should be detached from this patchkit and submitted sooner,
> eroding the size of this kit.
>
> Alternatively, if you're ok with it, please provide your Acked-by and
> I'll process as soon as I get back to it after Jiri is done reviewing.

Overall looks okay. Are you planning to get these in for 5.1 window? If
yes, that would be great, otherwise we might need to cherry-pick the libbpf
and bpftool ones from your tree into bpf-next as well since there's just
too much going on in this area where we'd potentially run into complex
merge conflicts. In the latter case, libbpf.map would need to be fixed up
to LIBBPF_0.0.3 as convention is that this is in line with kernel release.

Thanks,
Daniel

> - Arnaldo

2019-03-11 20:59:13

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 02/15] bpf: libbpf: introduce bpf_program__get_prog_info_linear()

Em Mon, Mar 11, 2019 at 09:45:49PM +0100, Daniel Borkmann escreveu:
> On 03/11/2019 07:26 PM, Arnaldo Carvalho de Melo wrote:
> > Em Thu, Mar 07, 2019 at 09:57:57AM -0800, Song Liu escreveu:
> >> 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 <[email protected]>
> >> Cc: Alexei Starovoitov <[email protected]>
> >
> > Daniel, are you ok with these changes to libbpf and bpftool? Perhaps
> > those should be detached from this patchkit and submitted sooner,
> > eroding the size of this kit.
> >
> > Alternatively, if you're ok with it, please provide your Acked-by and
> > I'll process as soon as I get back to it after Jiri is done reviewing.
>
> Overall looks okay. Are you planning to get these in for 5.1 window? If

I hope so.

> yes, that would be great, otherwise we might need to cherry-pick the libbpf

So I'll try and grab those for my next pull req to Ingo, this week,
will add your Acked-by, ok?

> and bpftool ones from your tree into bpf-next as well since there's just
> too much going on in this area where we'd potentially run into complex
> merge conflicts. In the latter case, libbpf.map would need to be fixed up
> to LIBBPF_0.0.3 as convention is that this is in line with kernel release.

BTW, while running my build tests I had to add this to today's batch,
should be trivial when merging, I think, ok?


commit dfcbc2f2994b8a3af3605a26dc29c07ad7378bf4
Author: Arnaldo Carvalho de Melo <[email protected]>
Date: Mon Mar 11 17:07:52 2019 -0300

tools lib bpf: Fix the build by adding a missing stdarg.h include

The libbpf_print_fn_t typedef uses va_list without including the header
where that type is defined, stdarg.h, breaking in places where we're
unlucky for that type not to be already defined by some previously
included header.

Noticed while building on fedora 24 cross building tools/perf to the ARC
architecture using the uClibc C library:

28 fedora:24-x-ARC-uClibc : FAIL arc-linux-gcc (ARCompact ISA Linux uClibc toolchain 2017.09-rc2) 7.1.1 20170710

CC /tmp/build/perf/tests/llvm.o
In file included from tests/llvm.c:3:0:
/git/linux/tools/lib/bpf/libbpf.h:57:20: error: unknown type name 'va_list'
const char *, va_list ap);
^~~~~~~
/git/linux/tools/lib/bpf/libbpf.h:59:34: error: unknown type name 'libbpf_print_fn_t'
LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn);
^~~~~~~~~~~~~~~~~
mv: cannot stat '/tmp/build/perf/tests/.llvm.o.tmp': No such file or directory

Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Quentin Monnet <[email protected]>
Cc: Stanislav Fomichev <[email protected]>
Cc: Yonghong Song <[email protected]>
Fixes: a8a1f7d09cfc ("libbpf: fix libbpf_print")
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index b4652aa1a58a..aa1521a51687 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -10,6 +10,7 @@
#ifndef __LIBBPF_LIBBPF_H
#define __LIBBPF_LIBBPF_H

+#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>

2019-03-12 11:21:10

by Daniel Borkmann

[permalink] [raw]
Subject: Re: [PATCH v7 perf,bpf 02/15] bpf: libbpf: introduce bpf_program__get_prog_info_linear()

On 03/11/2019 09:57 PM, Arnaldo Carvalho de Melo wrote:
> Em Mon, Mar 11, 2019 at 09:45:49PM +0100, Daniel Borkmann escreveu:
>> On 03/11/2019 07:26 PM, Arnaldo Carvalho de Melo wrote:
>>> Em Thu, Mar 07, 2019 at 09:57:57AM -0800, Song Liu escreveu:
>>>> 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 <[email protected]>
>>>> Cc: Alexei Starovoitov <[email protected]>
>>>
>>> Daniel, are you ok with these changes to libbpf and bpftool? Perhaps
>>> those should be detached from this patchkit and submitted sooner,
>>> eroding the size of this kit.
>>>
>>> Alternatively, if you're ok with it, please provide your Acked-by and
>>> I'll process as soon as I get back to it after Jiri is done reviewing.
>>
>> Overall looks okay. Are you planning to get these in for 5.1 window? If
>
> I hope so.
>
>> yes, that would be great, otherwise we might need to cherry-pick the libbpf
>
> So I'll try and grab those for my next pull req to Ingo, this week,
> will add your Acked-by, ok?

Please do, thanks.

>> and bpftool ones from your tree into bpf-next as well since there's just
>> too much going on in this area where we'd potentially run into complex
>> merge conflicts. In the latter case, libbpf.map would need to be fixed up
>> to LIBBPF_0.0.3 as convention is that this is in line with kernel release.
>
> BTW, while running my build tests I had to add this to today's batch,
> should be trivial when merging, I think, ok?

That's fine as well, ack, lets shoot for getting it in during merge window
such that we don't need to duplicate these dependencies in bpf trees.

> commit dfcbc2f2994b8a3af3605a26dc29c07ad7378bf4
> Author: Arnaldo Carvalho de Melo <[email protected]>
> Date: Mon Mar 11 17:07:52 2019 -0300
>
> tools lib bpf: Fix the build by adding a missing stdarg.h include
>
> The libbpf_print_fn_t typedef uses va_list without including the header
> where that type is defined, stdarg.h, breaking in places where we're
> unlucky for that type not to be already defined by some previously
> included header.
>
> Noticed while building on fedora 24 cross building tools/perf to the ARC
> architecture using the uClibc C library:
>
> 28 fedora:24-x-ARC-uClibc : FAIL arc-linux-gcc (ARCompact ISA Linux uClibc toolchain 2017.09-rc2) 7.1.1 20170710
>
> CC /tmp/build/perf/tests/llvm.o
> In file included from tests/llvm.c:3:0:
> /git/linux/tools/lib/bpf/libbpf.h:57:20: error: unknown type name 'va_list'
> const char *, va_list ap);
> ^~~~~~~
> /git/linux/tools/lib/bpf/libbpf.h:59:34: error: unknown type name 'libbpf_print_fn_t'
> LIBBPF_API void libbpf_set_print(libbpf_print_fn_t fn);
> ^~~~~~~~~~~~~~~~~
> mv: cannot stat '/tmp/build/perf/tests/.llvm.o.tmp': No such file or directory
>
> Cc: Alexei Starovoitov <[email protected]>
> Cc: Daniel Borkmann <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Namhyung Kim <[email protected]>
> Cc: Quentin Monnet <[email protected]>
> Cc: Stanislav Fomichev <[email protected]>
> Cc: Yonghong Song <[email protected]>
> Fixes: a8a1f7d09cfc ("libbpf: fix libbpf_print")
> Link: https://lkml.kernel.org/n/[email protected]
> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
>
> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> index b4652aa1a58a..aa1521a51687 100644
> --- a/tools/lib/bpf/libbpf.h
> +++ b/tools/lib/bpf/libbpf.h
> @@ -10,6 +10,7 @@
> #ifndef __LIBBPF_LIBBPF_H
> #define __LIBBPF_LIBBPF_H
>
> +#include <stdarg.h>
> #include <stdio.h>
> #include <stdint.h>
> #include <stdbool.h>
>

Thanks,
Daniel