Commit d509db04 authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo

perf tools: Compile scriptlets to BPF objects when passing '.c' to --event

This patch provides infrastructure for 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.

Introduces a bpf-script-example.c so we can manually test it:

 # perf record --clang-opt "-DLINUX_VERSION_CODE=0x40200" --event ./bpf-script-example.c sleep 1

Note that '--clang-opt' must put before '--event'.

Futher patches will merge it into a testcase so can be tested automatically.
Signed-off-by: default avatarWang Nan <wangnan0@huawei.com>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1444826502-49291-10-git-send-email-wangnan0@huawei.comSigned-off-by: default avatarHe Kuang <hekuang@huawei.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 71dc2326
#ifndef LINUX_VERSION_CODE
# error Need LINUX_VERSION_CODE
# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
#endif
#define BPF_ANY 0
#define BPF_MAP_TYPE_ARRAY 2
#define BPF_FUNC_map_lookup_elem 1
#define BPF_FUNC_map_update_elem 2
static void *(*bpf_map_lookup_elem)(void *map, void *key) =
(void *) BPF_FUNC_map_lookup_elem;
static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
(void *) BPF_FUNC_map_update_elem;
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};
#define SEC(NAME) __attribute__((section(NAME), used))
struct bpf_map_def SEC("maps") flip_table = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};
SEC("func=sys_epoll_pwait")
int bpf_func__sys_epoll_pwait(void *ctx)
{
int ind =0;
int *flag = bpf_map_lookup_elem(&flip_table, &ind);
int new_flag;
if (!flag)
return 0;
/* flip flag and store back */
new_flag = !*flag;
bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
return new_flag;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
......@@ -12,6 +12,7 @@
#include "bpf-loader.h"
#include "probe-event.h"
#include "probe-finder.h" // for MAX_PROBES
#include "llvm-utils.h"
#define DEFINE_PRINT_FN(name, level) \
static int libbpf_##name(const char *fmt, ...) \
......@@ -33,7 +34,7 @@ struct bpf_prog_priv {
struct perf_probe_event pev;
};
struct bpf_object *bpf__prepare_load(const char *filename)
struct bpf_object *bpf__prepare_load(const char *filename, bool source)
{
struct bpf_object *obj;
static bool libbpf_initialized;
......@@ -45,7 +46,19 @@ struct bpf_object *bpf__prepare_load(const char *filename)
libbpf_initialized = true;
}
if (source) {
int err;
void *obj_buf;
size_t obj_buf_sz;
err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
if (err)
return ERR_PTR(err);
obj = bpf_object__open_buffer(obj_buf, obj_buf_sz, filename);
free(obj_buf);
} else
obj = bpf_object__open(filename);
if (!obj) {
pr_debug("bpf: failed to load %s\n", filename);
return ERR_PTR(-EINVAL);
......
......@@ -18,7 +18,7 @@ typedef int (*bpf_prog_iter_callback_t)(struct probe_trace_event *tev,
int fd, void *arg);
#ifdef HAVE_LIBBPF_SUPPORT
struct bpf_object *bpf__prepare_load(const char *filename);
struct bpf_object *bpf__prepare_load(const char *filename, bool source);
void bpf__clear(void);
......@@ -34,7 +34,8 @@ int bpf__foreach_tev(struct bpf_object *obj,
bpf_prog_iter_callback_t func, void *arg);
#else
static inline struct bpf_object *
bpf__prepare_load(const char *filename __maybe_unused)
bpf__prepare_load(const char *filename __maybe_unused,
bool source __maybe_unused)
{
pr_debug("ERROR: eBPF object loading is disabled during compiling.\n");
return ERR_PTR(-ENOTSUP);
......
......@@ -626,11 +626,12 @@ int parse_events_load_bpf_obj(struct parse_events_evlist *data,
int parse_events_load_bpf(struct parse_events_evlist *data,
struct list_head *list,
char *bpf_file_name)
char *bpf_file_name,
bool source)
{
struct bpf_object *obj;
obj = bpf__prepare_load(bpf_file_name);
obj = bpf__prepare_load(bpf_file_name, source);
if (IS_ERR(obj) || !obj) {
char errbuf[BUFSIZ];
int err;
......
......@@ -125,7 +125,8 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
struct list_head *head_config);
int parse_events_load_bpf(struct parse_events_evlist *data,
struct list_head *list,
char *bpf_file_name);
char *bpf_file_name,
bool source);
/* Provide this function for perf test */
struct bpf_object;
int parse_events_load_bpf_obj(struct parse_events_evlist *data,
......
......@@ -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);
......@@ -269,6 +271,7 @@ r{num_raw_hex} { return raw(yyscanner); }
{modifier_event} { return str(yyscanner, PE_MODIFIER_EVENT); }
{bpf_object} { return str(yyscanner, PE_BPF_OBJECT); }
{bpf_source} { return str(yyscanner, PE_BPF_SOURCE); }
{name} { return pmu_str_check(yyscanner); }
"/" { BEGIN(config); return '/'; }
- { return '-'; }
......
......@@ -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
......@@ -461,7 +462,17 @@ PE_BPF_OBJECT
struct list_head *list;
ALLOC_LIST(list);
ABORT_ON(parse_events_load_bpf(data, list, $1));
ABORT_ON(parse_events_load_bpf(data, list, $1, false));
$$ = list;
}
|
PE_BPF_SOURCE
{
struct parse_events_evlist *data = _data;
struct list_head *list;
ALLOC_LIST(list);
ABORT_ON(parse_events_load_bpf(data, list, $1, true));
$$ = list;
}
......
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