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Date: Thu, 15 Oct 2015 00:45:26 +0900
From: Namhyung Kim <namhyung@...nel.org>
To: Wang Nan <wangnan0@...wei.com>
Cc: acme@...nel.org, ast@...mgrid.com, brendan.d.gregg@...il.com,
a.p.zijlstra@...llo.nl, daniel@...earbox.net, dsahern@...il.com,
hekuang@...wei.com, jolsa@...nel.org, lizefan@...wei.com,
masami.hiramatsu.pt@...achi.com, paulus@...ba.org,
linux-kernel@...r.kernel.org, pi3orama@....com,
xiakaixu@...wei.com, Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: Re: [PATCH 09/31] perf tools: Compile scriptlets to BPF objects when
passing '.c' to --event
On Wed, Oct 14, 2015 at 12:41:20PM +0000, Wang Nan wrote:
> 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: Wang Nan <wangnan0@...wei.com>
> Signed-off-by: He Kuang <hekuang@...wei.com>
> Acked-by: Alexei Starovoitov <ast@...mgrid.com>
> Cc: Brendan Gregg <brendan.d.gregg@...il.com>
> Cc: Daniel Borkmann <daniel@...earbox.net>
> Cc: David Ahern <dsahern@...il.com>
> Cc: Jiri Olsa <jolsa@...nel.org>
> Cc: Kaixu Xia <xiakaixu@...wei.com>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
> Cc: Namhyung Kim <namhyung@...nel.org>
> Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
> Cc: Zefan Li <lizefan@...wei.com>
> Cc: pi3orama@....com
> Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
> Link: http://lkml.kernel.org/n/ebpf-6yw9eg0ej3l4jnqhinngkw86@git.kernel.org
> ---
> tools/perf/tests/bpf-script-example.c | 44 +++++++++++++++++++++++++++++++++++
> tools/perf/util/bpf-loader.c | 17 ++++++++++++--
> tools/perf/util/bpf-loader.h | 5 ++--
> tools/perf/util/parse-events.c | 5 ++--
> tools/perf/util/parse-events.h | 3 ++-
> tools/perf/util/parse-events.l | 3 +++
> tools/perf/util/parse-events.y | 15 ++++++++++--
> 7 files changed, 83 insertions(+), 9 deletions(-)
> create mode 100644 tools/perf/tests/bpf-script-example.c
>
> diff --git a/tools/perf/tests/bpf-script-example.c b/tools/perf/tests/bpf-script-example.c
> new file mode 100644
> index 0000000..410a70b
> --- /dev/null
> +++ b/tools/perf/tests/bpf-script-example.c
Shouldn't it be a part of the next patch?
Thanks,
Namhyung
> @@ -0,0 +1,44 @@
> +#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;
> diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
> index aa784a4..ba6f752 100644
> --- a/tools/perf/util/bpf-loader.c
> +++ b/tools/perf/util/bpf-loader.c
> @@ -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;
> }
>
> - obj = bpf_object__open(filename);
> + 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);
> diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
> index a8f25ee..ccd8d7f 100644
> --- a/tools/perf/util/bpf-loader.h
> +++ b/tools/perf/util/bpf-loader.h
> @@ -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);
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 5087023..4849dbd 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -626,11 +626,12 @@ errout:
>
> 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;
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index fbb16c7..8f17c83 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -123,7 +123,8 @@ 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,
> diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
> index 5e5d31a..eeea4e1 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);
> @@ -267,6 +269,7 @@ 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 '-'; }
> diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
> index 497f19b..ad37996 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
> @@ -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;
> }
>
> --
> 1.8.3.4
>
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