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samples/bpf: move common-purpose trace functions to selftests 

There is no functionality change in this patch. The common-purpose
trace functions, including perf_event polling and ksym lookup,
are moved from trace_output_user.c and bpf_load.c to
selftests/bpf/trace_helpers.c so that these function can
be reused later in selftests.

Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Yonghong Song 2018-04-28 22:28:13 -07:00 committed by Alexei Starovoitov
parent de2ff05f48
commit 28dbf861de
10 changed files with 223 additions and 175 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
samples/bpf/Makefile
View File

@ -49,6 +49,7 @@ hostprogs-y += xdp_adjust_tail
# Libbpf dependencies
LIBBPF := ../../tools/lib/bpf/bpf.o ../../tools/lib/bpf/nlattr.o
CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
test_lru_dist-objs := test_lru_dist.o $(LIBBPF)
sock_example-objs := sock_example.o $(LIBBPF)
@ -65,10 +66,10 @@ tracex6-objs := bpf_load.o $(LIBBPF) tracex6_user.o
tracex7-objs := bpf_load.o $(LIBBPF) tracex7_user.o
load_sock_ops-objs := bpf_load.o $(LIBBPF) load_sock_ops.o
test_probe_write_user-objs := bpf_load.o $(LIBBPF) test_probe_write_user_user.o
trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o
trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o $(TRACE_HELPERS)
lathist-objs := bpf_load.o $(LIBBPF) lathist_user.o
offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o
spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o
offwaketime-objs := bpf_load.o $(LIBBPF) offwaketime_user.o $(TRACE_HELPERS)
spintest-objs := bpf_load.o $(LIBBPF) spintest_user.o $(TRACE_HELPERS)
map_perf_test-objs := bpf_load.o $(LIBBPF) map_perf_test_user.o
test_overhead-objs := bpf_load.o $(LIBBPF) test_overhead_user.o
test_cgrp2_array_pin-objs := $(LIBBPF) test_cgrp2_array_pin.o
@ -82,8 +83,8 @@ xdp2-objs := bpf_load.o $(LIBBPF) xdp1_user.o
xdp_router_ipv4-objs := bpf_load.o $(LIBBPF) xdp_router_ipv4_user.o
test_current_task_under_cgroup-objs := bpf_load.o $(LIBBPF) $(CGROUP_HELPERS) \
test_current_task_under_cgroup_user.o
trace_event-objs := bpf_load.o $(LIBBPF) trace_event_user.o
sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o
trace_event-objs := bpf_load.o $(LIBBPF) trace_event_user.o $(TRACE_HELPERS)
sampleip-objs := bpf_load.o $(LIBBPF) sampleip_user.o $(TRACE_HELPERS)
tc_l2_redirect-objs := bpf_load.o $(LIBBPF) tc_l2_redirect_user.o
lwt_len_hist-objs := bpf_load.o $(LIBBPF) lwt_len_hist_user.o
xdp_tx_iptunnel-objs := bpf_load.o $(LIBBPF) xdp_tx_iptunnel_user.o

63
samples/bpf/bpf_load.c
View File

@ -648,66 +648,3 @@ void read_trace_pipe(void)
}
}
}
#define MAX_SYMS 300000
static struct ksym syms[MAX_SYMS];
static int sym_cnt;
static int ksym_cmp(const void *p1, const void *p2)
{
return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
}
int load_kallsyms(void)
{
FILE *f = fopen("/proc/kallsyms", "r");
char func[256], buf[256];
char symbol;
void *addr;
int i = 0;
if (!f)
return -ENOENT;
while (!feof(f)) {
if (!fgets(buf, sizeof(buf), f))
break;
if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
break;
if (!addr)
continue;
syms[i].addr = (long) addr;
syms[i].name = strdup(func);
i++;
}
sym_cnt = i;
qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
return 0;
}
struct ksym *ksym_search(long key)
{
int start = 0, end = sym_cnt;
int result;
while (start < end) {
size_t mid = start + (end - start) / 2;
result = key - syms[mid].addr;
if (result < 0)
end = mid;
else if (result > 0)
start = mid + 1;
else
return &syms[mid];
}
if (start >= 1 && syms[start - 1].addr < key &&
key < syms[start].addr)
/* valid ksym */
return &syms[start - 1];
/* out of range. return _stext */
return &syms[0];
}

7
samples/bpf/bpf_load.h
View File

@ -54,12 +54,5 @@ int load_bpf_file(char *path);
int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map);
void read_trace_pipe(void);
struct ksym {
long addr;
char *name;
};
int load_kallsyms(void);
struct ksym *ksym_search(long key);
int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
#endif

1
samples/bpf/offwaketime_user.c
View File

@ -17,6 +17,7 @@
#include <sys/resource.h>
#include "libbpf.h"
#include "bpf_load.h"
#include "trace_helpers.h"
#define PRINT_RAW_ADDR 0

1
samples/bpf/sampleip_user.c
View File

@ -22,6 +22,7 @@
#include "libbpf.h"
#include "bpf_load.h"
#include "perf-sys.h"
#include "trace_helpers.h"
#define DEFAULT_FREQ 99
#define DEFAULT_SECS 5

1
samples/bpf/spintest_user.c
View File

@ -7,6 +7,7 @@
#include <sys/resource.h>
#include "libbpf.h"
#include "bpf_load.h"
#include "trace_helpers.h"
int main(int ac, char **argv)
{

1
samples/bpf/trace_event_user.c
View File

@ -21,6 +21,7 @@
#include "libbpf.h"
#include "bpf_load.h"
#include "perf-sys.h"
#include "trace_helpers.h"
#define SAMPLE_FREQ 50

110
samples/bpf/trace_output_user.c
View File

@ -21,100 +21,10 @@
#include "libbpf.h"
#include "bpf_load.h"
#include "perf-sys.h"
#include "trace_helpers.h"
static int pmu_fd;
int page_size;
int page_cnt = 8;
volatile struct perf_event_mmap_page *header;
typedef void (*print_fn)(void *data, int size);
static int perf_event_mmap(int fd)
{
void *base;
int mmap_size;
page_size = getpagesize();
mmap_size = page_size * (page_cnt + 1);
base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (base == MAP_FAILED) {
printf("mmap err\n");
return -1;
}
header = base;
return 0;
}
static int perf_event_poll(int fd)
{
struct pollfd pfd = { .fd = fd, .events = POLLIN };
return poll(&pfd, 1, 1000);
}
struct perf_event_sample {
struct perf_event_header header;
__u32 size;
char data[];
};
static void perf_event_read(print_fn fn)
{
__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];
asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
if (data_head == data_tail)
return;
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) {
fn(e->data, e->size);
} 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;
}
static __u64 time_get_ns(void)
{
struct timespec ts;
@ -127,7 +37,7 @@ static __u64 start_time;
#define MAX_CNT 100000ll
static void print_bpf_output(void *data, int size)
static int print_bpf_output(void *data, int size)
{
static __u64 cnt;
struct {
@ -138,7 +48,7 @@ static void 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);
kill(0, SIGINT);
return PERF_EVENT_ERROR;
}
cnt++;
@ -146,8 +56,10 @@ static void 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));
kill(0, SIGINT);
return PERF_EVENT_DONE;
}
return PERF_EVENT_CONT;
}
static void test_bpf_perf_event(void)
@ -170,6 +82,7 @@ int main(int argc, char **argv)
{
char filename[256];
FILE *f;
int ret;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
@ -187,10 +100,7 @@ int main(int argc, char **argv)
(void) f;
start_time = time_get_ns();
for (;;) {
perf_event_poll(pmu_fd);
perf_event_read(print_bpf_output);
}
return 0;
ret = perf_event_poller(pmu_fd, print_bpf_output);
kill(0, SIGINT);
return ret;
}

180
tools/testing/selftests/bpf/trace_helpers.c Normal file
View File

@ -0,0 +1,180 @@
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <poll.h>
#include <unistd.h>
#include <linux/perf_event.h>
#include <sys/mman.h>
#include "trace_helpers.h"
#define MAX_SYMS 300000
static struct ksym syms[MAX_SYMS];
static int sym_cnt;
static int ksym_cmp(const void *p1, const void *p2)
{
return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
}
int load_kallsyms(void)
{
FILE *f = fopen("/proc/kallsyms", "r");
char func[256], buf[256];
char symbol;
void *addr;
int i = 0;
if (!f)
return -ENOENT;
while (!feof(f)) {
if (!fgets(buf, sizeof(buf), f))
break;
if (sscanf(buf, "%p %c %s", &addr, &symbol, func) != 3)
break;
if (!addr)
continue;
syms[i].addr = (long) addr;
syms[i].name = strdup(func);
i++;
}
sym_cnt = i;
qsort(syms, sym_cnt, sizeof(struct ksym), ksym_cmp);
return 0;
}
struct ksym *ksym_search(long key)
{
int start = 0, end = sym_cnt;
int result;
while (start < end) {
size_t mid = start + (end - start) / 2;
result = key - syms[mid].addr;
if (result < 0)
end = mid;
else if (result > 0)
start = mid + 1;
else
return &syms[mid];
}
if (start >= 1 && syms[start - 1].addr < key &&
key < syms[start].addr)
/* valid ksym */
return &syms[start - 1];
/* out of range. return _stext */
return &syms[0];
}
static int page_size;
static int page_cnt = 8;
static volatile struct perf_event_mmap_page *header;
int perf_event_mmap(int fd)
{
void *base;
int mmap_size;
page_size = getpagesize();
mmap_size = page_size * (page_cnt + 1);
base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (base == MAP_FAILED) {
printf("mmap err\n");
return -1;
}
header = base;
return 0;
}
static int perf_event_poll(int fd)
{
struct pollfd pfd = { .fd = fd, .events = POLLIN };
return poll(&pfd, 1, 1000);
}
struct perf_event_sample {
struct perf_event_header header;
__u32 size;
char data[];
};
static int perf_event_read(perf_event_print_fn fn)
{
__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];
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);
}
}
__sync_synchronize(); /* smp_mb() */
header->data_tail = data_head;
return PERF_EVENT_CONT;
}
int perf_event_poller(int fd, perf_event_print_fn output_fn)
{
int ret;
for (;;) {
perf_event_poll(fd);
ret = perf_event_read(output_fn);
if (ret != PERF_EVENT_CONT)
return ret;
}
return PERF_EVENT_DONE;
}

23
tools/testing/selftests/bpf/trace_helpers.h Normal file
View File

@ -0,0 +1,23 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __TRACE_HELPER_H
#define __TRACE_HELPER_H
struct ksym {
long addr;
char *name;
};
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
int perf_event_mmap(int fd);
/* return PERF_EVENT_DONE or PERF_EVENT_ERROR */
int perf_event_poller(int fd, perf_event_print_fn output_fn);
#endif