From d0cabbb021bee5c4b831a0235af9534ad07f8d3d Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 10 May 2018 10:24:40 -0700 Subject: [PATCH] tools: bpf: move the event reading loop to libbpf There are two copies of event reading loop - in bpftool and trace_helpers "library". Consolidate them and move the code to libbpf. Return codes from trace_helpers are kept, but renamed to include LIBBPF prefix. Suggested-by: Alexei Starovoitov Signed-off-by: Jakub Kicinski Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- samples/bpf/Makefile | 8 ++ samples/bpf/trace_output_user.c | 6 +- tools/bpf/bpftool/map_perf_ring.c | 66 ++++------------ tools/lib/bpf/Makefile | 2 +- tools/lib/bpf/libbpf.c | 61 +++++++++++++++ tools/lib/bpf/libbpf.h | 13 +++ tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/test_progs.c | 6 +- tools/testing/selftests/bpf/trace_helpers.c | 87 +++++++-------------- tools/testing/selftests/bpf/trace_helpers.h | 11 +-- 10 files changed, 139 insertions(+), 123 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 79cdb66a5ea723..8ce72d211c3e4d 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -165,6 +165,14 @@ HOSTCFLAGS += -I$(srctree)/tools/lib/ -I$(srctree)/tools/include HOSTCFLAGS += -I$(srctree)/tools/perf HOSTCFLAGS_bpf_load.o += -I$(objtree)/usr/include -Wno-unused-variable +HOSTCFLAGS_trace_helpers.o += -I$(srctree)/tools/lib/bpf/ + +HOSTCFLAGS_trace_output_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_offwaketime_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_spintest_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_trace_event_user.o += -I$(srctree)/tools/lib/bpf/ +HOSTCFLAGS_sampleip_user.o += -I$(srctree)/tools/lib/bpf/ + HOSTLOADLIBES_test_lru_dist += -lelf HOSTLOADLIBES_sock_example += -lelf HOSTLOADLIBES_fds_example += -lelf diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c index 5e78c2ecd08dc8..da98be721001d2 100644 --- a/samples/bpf/trace_output_user.c +++ b/samples/bpf/trace_output_user.c @@ -48,7 +48,7 @@ static int print_bpf_output(void *data, int size) if (e->cookie != 0x12345678) { printf("BUG pid %llx cookie %llx sized %d\n", e->pid, e->cookie, size); - return PERF_EVENT_ERROR; + return LIBBPF_PERF_EVENT_ERROR; } cnt++; @@ -56,10 +56,10 @@ static int print_bpf_output(void *data, int size) if (cnt == MAX_CNT) { printf("recv %lld events per sec\n", MAX_CNT * 1000000000ll / (time_get_ns() - start_time)); - return PERF_EVENT_DONE; + return LIBBPF_PERF_EVENT_DONE; } - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } static void test_bpf_perf_event(void) diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c index 9ae4bb8a2cadb5..1832100d1b274d 100644 --- a/tools/bpf/bpftool/map_perf_ring.c +++ b/tools/bpf/bpftool/map_perf_ring.c @@ -50,14 +50,15 @@ static void int_exit(int signo) stop = true; } -static void -print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) +static enum bpf_perf_event_ret print_bpf_output(void *event, void *priv) { + struct event_ring_info *ring = priv; + struct perf_event_sample *e = event; struct { struct perf_event_header header; __u64 id; __u64 lost; - } *lost = (void *)e; + } *lost = event; if (json_output) { jsonw_start_object(json_wtr); @@ -96,60 +97,23 @@ print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e) e->header.type, e->header.size); } } + + return LIBBPF_PERF_EVENT_CONT; } static void perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len) { - volatile struct perf_event_mmap_page *header = ring->mem; - __u64 buffer_size = MMAP_PAGE_CNT * get_page_size(); - __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - void *base, *begin, *end; - - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return; - - base = ((char *)header) + get_page_size(); - - begin = base + data_tail % buffer_size; - end = base + data_head % buffer_size; - - while (begin != end) { - struct perf_event_sample *e; - - e = begin; - if (begin + e->header.size > base + buffer_size) { - long len = base + buffer_size - begin; - - if (*buf_len < e->header.size) { - free(*buf); - *buf = malloc(e->header.size); - if (!*buf) { - fprintf(stderr, - "can't allocate memory"); - stop = true; - return; - } - *buf_len = e->header.size; - } - - memcpy(*buf, begin, len); - memcpy(*buf + len, base, e->header.size - len); - e = (void *)*buf; - begin = base + e->header.size - len; - } else if (begin + e->header.size == base + buffer_size) { - begin = base; - } else { - begin += e->header.size; - } - - print_bpf_output(ring, e); + enum bpf_perf_event_ret ret; + + ret = bpf_perf_event_read_simple(ring->mem, + MMAP_PAGE_CNT * get_page_size(), + get_page_size(), buf, buf_len, + print_bpf_output, ring); + if (ret != LIBBPF_PERF_EVENT_CONT) { + fprintf(stderr, "perf read loop failed with %d\n", ret); + stop = true; } - - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_head; } static int perf_mmap_size(void) diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile index e6d5f8d1477fbc..f3fab4af4260e9 100644 --- a/tools/lib/bpf/Makefile +++ b/tools/lib/bpf/Makefile @@ -69,7 +69,7 @@ FEATURE_USER = .libbpf FEATURE_TESTS = libelf libelf-getphdrnum libelf-mmap bpf FEATURE_DISPLAY = libelf bpf -INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi +INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi -I$(srctree)/tools/perf FEATURE_CHECK_CFLAGS-bpf = $(INCLUDES) check_feat := 1 diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7bcdca13083a22..ce96f1fe3f3730 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -2210,3 +2211,63 @@ int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, *prog_fd = bpf_program__fd(first_prog); return 0; } + +enum bpf_perf_event_ret +bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, void *priv) +{ + volatile struct perf_event_mmap_page *header = mem; + __u64 data_tail = header->data_tail; + __u64 data_head = header->data_head; + void *base, *begin, *end; + int ret; + + asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ + if (data_head == data_tail) + return LIBBPF_PERF_EVENT_CONT; + + base = ((char *)header) + page_size; + + begin = base + data_tail % size; + end = base + data_head % size; + + while (begin != end) { + struct perf_event_header *ehdr; + + ehdr = begin; + if (begin + ehdr->size > base + size) { + long len = base + size - begin; + + if (*buf_len < ehdr->size) { + free(*buf); + *buf = malloc(ehdr->size); + if (!*buf) { + ret = LIBBPF_PERF_EVENT_ERROR; + break; + } + *buf_len = ehdr->size; + } + + memcpy(*buf, begin, len); + memcpy(*buf + len, base, ehdr->size - len); + ehdr = (void *)*buf; + begin = base + ehdr->size - len; + } else if (begin + ehdr->size == base + size) { + begin = base; + } else { + begin += ehdr->size; + } + + ret = fn(ehdr, priv); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; + + data_tail += ehdr->size; + } + + __sync_synchronize(); /* smp_mb() */ + header->data_tail = data_tail; + + return ret; +} diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 197f9ce2248c59..ce681097584e3c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -267,4 +267,17 @@ int bpf_prog_load(const char *file, enum bpf_prog_type type, struct bpf_object **pobj, int *prog_fd); int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); + +enum bpf_perf_event_ret { + LIBBPF_PERF_EVENT_DONE = 0, + LIBBPF_PERF_EVENT_ERROR = -1, + LIBBPF_PERF_EVENT_CONT = -2, +}; + +typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event, + void *priv); +int bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, + void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, void *priv); #endif diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 79d29d6cc7192a..438d4f93875bfa 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -10,7 +10,7 @@ ifneq ($(wildcard $(GENHDR)),) GENFLAGS := -DHAVE_GENHDR endif -CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include +CFLAGS += -Wall -O2 -I$(APIDIR) -I$(LIBDIR) -I$(BPFDIR) -I$(GENDIR) $(GENFLAGS) -I../../../include LDLIBS += -lcap -lelf -lrt -lpthread TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index ed197eef1cfc72..f7731973ec682f 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -1337,12 +1337,12 @@ static int get_stack_print_output(void *data, int size) good_user_stack = true; } if (!good_kern_stack || !good_user_stack) - return PERF_EVENT_ERROR; + return LIBBPF_PERF_EVENT_ERROR; if (cnt == MAX_CNT_RAWTP) - return PERF_EVENT_DONE; + return LIBBPF_PERF_EVENT_DONE; - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } static void test_get_stack_raw_tp(void) diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index ad025bd75f1caf..8fb4fe8686e4d9 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -74,7 +74,7 @@ struct ksym *ksym_search(long key) static int page_size; static int page_cnt = 8; -static volatile struct perf_event_mmap_page *header; +static struct perf_event_mmap_page *header; int perf_event_mmap(int fd) { @@ -107,74 +107,47 @@ struct perf_event_sample { char data[]; }; -static int perf_event_read(perf_event_print_fn fn) +static enum bpf_perf_event_ret bpf_perf_event_print(void *event, void *priv) { - __u64 data_tail = header->data_tail; - __u64 data_head = header->data_head; - __u64 buffer_size = page_cnt * page_size; - void *base, *begin, *end; - char buf[256]; + struct perf_event_sample *e = event; + perf_event_print_fn fn = priv; int ret; - asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */ - if (data_head == data_tail) - return PERF_EVENT_CONT; - - base = ((char *)header) + page_size; - - begin = base + data_tail % buffer_size; - end = base + data_head % buffer_size; - - while (begin != end) { - struct perf_event_sample *e; - - e = begin; - if (begin + e->header.size > base + buffer_size) { - long len = base + buffer_size - begin; - - assert(len < e->header.size); - memcpy(buf, begin, len); - memcpy(buf + len, base, e->header.size - len); - e = (void *) buf; - begin = base + e->header.size - len; - } else if (begin + e->header.size == base + buffer_size) { - begin = base; - } else { - begin += e->header.size; - } - - if (e->header.type == PERF_RECORD_SAMPLE) { - ret = fn(e->data, e->size); - if (ret != PERF_EVENT_CONT) - return ret; - } else if (e->header.type == PERF_RECORD_LOST) { - struct { - struct perf_event_header header; - __u64 id; - __u64 lost; - } *lost = (void *) e; - printf("lost %lld events\n", lost->lost); - } else { - printf("unknown event type=%d size=%d\n", - e->header.type, e->header.size); - } + if (e->header.type == PERF_RECORD_SAMPLE) { + ret = fn(e->data, e->size); + if (ret != LIBBPF_PERF_EVENT_CONT) + return ret; + } else if (e->header.type == PERF_RECORD_LOST) { + struct { + struct perf_event_header header; + __u64 id; + __u64 lost; + } *lost = (void *) e; + printf("lost %lld events\n", lost->lost); + } else { + printf("unknown event type=%d size=%d\n", + e->header.type, e->header.size); } - __sync_synchronize(); /* smp_mb() */ - header->data_tail = data_head; - return PERF_EVENT_CONT; + return LIBBPF_PERF_EVENT_CONT; } int perf_event_poller(int fd, perf_event_print_fn output_fn) { - int ret; + enum bpf_perf_event_ret ret; + void *buf = NULL; + size_t len = 0; for (;;) { perf_event_poll(fd); - ret = perf_event_read(output_fn); - if (ret != PERF_EVENT_CONT) - return ret; + ret = bpf_perf_event_read_simple(header, page_cnt * page_size, + page_size, &buf, &len, + bpf_perf_event_print, + output_fn); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; } + free(buf); - return PERF_EVENT_DONE; + return ret; } diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index fe3eefd21e861d..36d90e3b1ea9c4 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -2,6 +2,8 @@ #ifndef __TRACE_HELPER_H #define __TRACE_HELPER_H +#include + struct ksym { long addr; char *name; @@ -10,14 +12,9 @@ struct ksym { int load_kallsyms(void); struct ksym *ksym_search(long key); -typedef int (*perf_event_print_fn)(void *data, int size); - -/* return code for perf_event_print_fn */ -#define PERF_EVENT_DONE 0 -#define PERF_EVENT_ERROR -1 -#define PERF_EVENT_CONT -2 +typedef enum bpf_perf_event_ret (*perf_event_print_fn)(void *data, int size); int perf_event_mmap(int fd); -/* return PERF_EVENT_DONE or PERF_EVENT_ERROR */ +/* return LIBBPF_PERF_EVENT_DONE or LIBBPF_PERF_EVENT_ERROR */ int perf_event_poller(int fd, perf_event_print_fn output_fn); #endif