[RFC PATCH v7 29/37] perf record: Compile scriptlets if pass '.c' to --event

Wang Nan
2015-06-12T05:38:43Z

This patch enables passing source files to --event directly using:

# perf record --event bpf-file.c command

This patch does following works:
1) Allow passing '.c' file to '--event'. parse_events_load_bpf() is
expanded to allow caller tell it whether the passed file is source
file or object.

2) llvm__compile_bpf() is called to compile the '.c' file, the result
is saved into memory. Use bpf_object__open_buffer() to load the
in-memory object.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/bpf-loader.c | 17 +++++++++++++++--
tools/perf/util/bpf-loader.h | 5 +++--
tools/perf/util/parse-events.c | 4 ++--
tools/perf/util/parse-events.h | 2 +-
tools/perf/util/parse-events.l | 3 +++
tools/perf/util/parse-events.y | 15 +++++++++++++--
6 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index e950baa..1083b3c 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -9,6 +9,7 @@
#include "perf.h"
#include "debug.h"
#include "bpf-loader.h"
+#include "llvm-utils.h"

#define DEFINE_PRINT_FN(name, level) \
static int libbpf_##name(const char *fmt, ...) \
@@ -28,7 +29,7 @@ DEFINE_PRINT_FN(debug, 1)

static bool libbpf_initialized = false;

-int bpf__prepare_load(const char *filename)
+int bpf__prepare_load(const char *filename, bool source)
{
struct bpf_object *obj;

@@ -37,7 +38,19 @@ int bpf__prepare_load(const char *filename)
libbpf_info,
libbpf_debug);

- obj = bpf_object__open(filename);
+ if (source) {
+ void *obj_buf;
+ size_t obj_buf_sz;
+ int err;
+
+ err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
+ if (err)
+ return err;
+ obj = bpf_object__open_buffer(obj_buf, obj_buf_sz);
+ free(obj_buf);
+ } else
+ obj = bpf_object__open(filename);
+
if (!obj) {
pr_err("bpf: failed to load %s\n", filename);
return -EINVAL;
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 39d8d1a..5566be0 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -9,11 +9,12 @@
#include "debug.h"

#ifdef HAVE_LIBBPF_SUPPORT
-int bpf__prepare_load(const char *filename);
+int bpf__prepare_load(const char *filename, bool source);

void bpf__clear(void);
#else
-static inline int bpf__prepare_load(const char *filename __maybe_unused)
+static inline int bpf__prepare_load(const char *filename __maybe_unused,
+ bool source __maybe_unused)
{
pr_err("ERROR: eBPF object loading is disabled during compiling.\n");
return -1;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 6f7a7b1..aaee24c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -475,7 +475,7 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,

int parse_events_load_bpf(struct list_head *list __maybe_unused,
int *idx __maybe_unused,
- char *bpf_file_name)
+ char *bpf_file_name, bool source)
{
/*
* Currently don't link any event to list. BPF object files
@@ -485,7 +485,7 @@ int parse_events_load_bpf(struct list_head *list __maybe_unused,
* problem. After that probe events file by file is possible.
* However, probing cost is still need to be considered.
*/
- return bpf__prepare_load(bpf_file_name);
+ return bpf__prepare_load(bpf_file_name, source);
}

static int
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 41b962a..5841d4f 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -115,7 +115,7 @@ int parse_events_name(struct list_head *list, char *name);
int parse_events_add_tracepoint(struct list_head *list, int *idx,
char *sys, char *event);
int parse_events_load_bpf(struct list_head *list, int *idx,
- char *bpf_file_name);
+ char *bpf_file_name, bool source);
int parse_events_add_numeric(struct parse_events_evlist *data,
struct list_head *list,
u32 type, u64 config,
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 4acea38..eb821d4 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -116,6 +116,7 @@ group [^,{}/]*[{][^}]*[}][^,{}/]*
event_pmu [^,{}/]+[/][^/]*[/][^,{}/]*
event [^,{}/]+
bpf_object .*\.(o|bpf)
+bpf_source .*\.c

num_dec [0-9]+
num_hex 0x[a-fA-F0-9]+
@@ -161,6 +162,7 @@ modifier_bp [rwx]{1,3}

{event_pmu} |
{bpf_object} |
+{bpf_source} |
{event} {
BEGIN(INITIAL);
REWIND(1);
@@ -265,6 +267,7 @@ r{num_raw_hex} { return raw(yyscanner); }
{modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
{name} { return pmu_str_check(yyscanner); }
{bpf_object} { return str(yyscanner, PE_BPF_OBJECT); }
+{bpf_source} { return str(yyscanner, PE_BPF_SOURCE); }
"/" { BEGIN(config); return '/'; }
- { return '-'; }
, { BEGIN(event); return ','; }
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 481f3cd..eeb9768 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -42,7 +42,7 @@ static inc_group_count(struct list_head *list,
%token PE_VALUE PE_VALUE_SYM_HW PE_VALUE_SYM_SW PE_RAW PE_TERM
%token PE_EVENT_NAME
%token PE_NAME
-%token PE_BPF_OBJECT
+%token PE_BPF_OBJECT PE_BPF_SOURCE
%token PE_MODIFIER_EVENT PE_MODIFIER_BP
%token PE_NAME_CACHE_TYPE PE_NAME_CACHE_OP_RESULT
%token PE_PREFIX_MEM PE_PREFIX_RAW PE_PREFIX_GROUP
@@ -55,6 +55,7 @@ static inc_group_count(struct list_head *list,
%type <num> PE_TERM
%type <str> PE_NAME
%type <str> PE_BPF_OBJECT
+%type <str> PE_BPF_SOURCE
%type <str> PE_NAME_CACHE_TYPE
%type <str> PE_NAME_CACHE_OP_RESULT
%type <str> PE_MODIFIER_EVENT
@@ -431,7 +432,17 @@ PE_BPF_OBJECT
struct list_head *list;

ALLOC_LIST(list);
- ABORT_ON(parse_events_load_bpf(list, &data->idx, $1));
+ ABORT_ON(parse_events_load_bpf(list, &data->idx, $1, false));
+ $$ = list;
+}
+|
+PE_BPF_SOURCE
+{
+ struct parse_events_evlist *data = _data;
+ struct list_head *list;
+
+ ALLOC_LIST(list);
+ ABORT_ON(parse_events_load_bpf(list, &data->idx, $1, true));
$$ = list;
}

--
1.8.3.4