From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Thu, 10 May 2018 10:24:40 -0700
Subject: tools: bpf: move the event reading loop to libbpf
Patch-mainline: v4.18-rc1
Git-commit: d0cabbb021bee5c4b831a0235af9534ad07f8d3d
References: bsc#1109837
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 <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
samples/bpf/Makefile | 8 ++
samples/bpf/trace_output_user.c | 6 -
tools/bpf/bpftool/map_perf_ring.c | 64 ++++----------------
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/trace_helpers.c | 87 +++++++++-------------------
tools/testing/selftests/bpf/trace_helpers.h | 11 +--
9 files changed, 135 insertions(+), 119 deletions(-)
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -163,6 +163,14 @@ HOSTCFLAGS += -I$(srctree)/tools/lib/ -I
HOSTCFLAGS += -I$(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
--- 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,
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,
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)
--- 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
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;
- }
+ enum bpf_perf_event_ret ret;
- print_bpf_output(ring, e);
+ 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)
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -68,7 +68,7 @@ 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
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -31,6 +31,7 @@
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
+#include <perf-sys.h>
#include <asm/unistd.h>
#include <linux/err.h>
#include <linux/kernel.h>
@@ -2196,3 +2197,63 @@ int bpf_prog_load_xattr(const struct bpf
*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;
+}
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -267,4 +267,17 @@ int bpf_prog_load(const char *file, enum
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
--- 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
--- 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;
}
--- 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 <libbpf.h>
+
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