From d509db0473e40134286271b1d1adadccf42ac467 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Wed, 14 Oct 2015 12:41:20 +0000 Subject: [PATCH] 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: Wang Nan Acked-by: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1444826502-49291-10-git-send-email-wangnan0@huawei.com Signed-off-by: He Kuang Signed-off-by: Arnaldo Carvalho de Melo --- 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 000000000000..410a70b93b93 --- /dev/null +++ b/tools/perf/tests/bpf-script-example.c @@ -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 aa784a498c48..ba6f7526b282 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 a8f25ee06fc5..ccd8d7fd79d3 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 cee8c619ec7e..bee60583839a 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 765018a17448..f1a6db107241 100644 --- a/tools/perf/util/parse-events.h +++ b/tools/perf/util/parse-events.h @@ -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, diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l index cf330ebf812c..58c5831ffd5c 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); @@ -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 '-'; } diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y index 497f19b20f0b..ad379968d4c1 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 PE_TERM %type PE_NAME %type PE_BPF_OBJECT +%type PE_BPF_SOURCE %type PE_NAME_CACHE_TYPE %type PE_NAME_CACHE_OP_RESULT %type 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; }