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linux-next/samples/bpf/task_fd_query_user.c
Toke Høiland-Jørgensen 7cf245a37e samples/bpf: Use consistent include paths for libbpf
Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.

To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.

Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 16:37:45 -08:00

384 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <stdbool.h>
#include <string.h>
#include <stdint.h>
#include <fcntl.h>
#include <linux/bpf.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/perf_event.h>
#include <bpf/libbpf.h>
#include "bpf_load.h"
#include "bpf_util.h"
#include "perf-sys.h"
#include "trace_helpers.h"
#define CHECK_PERROR_RET(condition) ({ \
int __ret = !!(condition); \
if (__ret) { \
printf("FAIL: %s:\n", __func__); \
perror(" "); \
return -1; \
} \
})
#define CHECK_AND_RET(condition) ({ \
int __ret = !!(condition); \
if (__ret) \
return -1; \
})
static __u64 ptr_to_u64(void *ptr)
{
return (__u64) (unsigned long) ptr;
}
#define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type"
static int bpf_find_probe_type(const char *event_type)
{
char buf[256];
int fd, ret;
ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type);
CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
fd = open(buf, O_RDONLY);
CHECK_PERROR_RET(fd < 0);
ret = read(fd, buf, sizeof(buf));
close(fd);
CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
errno = 0;
ret = (int)strtol(buf, NULL, 10);
CHECK_PERROR_RET(errno);
return ret;
}
#define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe"
static int bpf_get_retprobe_bit(const char *event_type)
{
char buf[256];
int fd, ret;
ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type);
CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
fd = open(buf, O_RDONLY);
CHECK_PERROR_RET(fd < 0);
ret = read(fd, buf, sizeof(buf));
close(fd);
CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
CHECK_PERROR_RET(strlen(buf) < strlen("config:"));
errno = 0;
ret = (int)strtol(buf + strlen("config:"), NULL, 10);
CHECK_PERROR_RET(errno);
return ret;
}
static int test_debug_fs_kprobe(int prog_fd_idx, const char *fn_name,
__u32 expected_fd_type)
{
__u64 probe_offset, probe_addr;
__u32 len, prog_id, fd_type;
char buf[256];
int err;
len = sizeof(buf);
err = bpf_task_fd_query(getpid(), event_fd[prog_fd_idx], 0, buf, &len,
&prog_id, &fd_type, &probe_offset,
&probe_addr);
if (err < 0) {
printf("FAIL: %s, for event_fd idx %d, fn_name %s\n",
__func__, prog_fd_idx, fn_name);
perror(" :");
return -1;
}
if (strcmp(buf, fn_name) != 0 ||
fd_type != expected_fd_type ||
probe_offset != 0x0 || probe_addr != 0x0) {
printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n",
prog_fd_idx);
printf("buf: %s, fd_type: %u, probe_offset: 0x%llx,"
" probe_addr: 0x%llx\n",
buf, fd_type, probe_offset, probe_addr);
return -1;
}
return 0;
}
static int test_nondebug_fs_kuprobe_common(const char *event_type,
const char *name, __u64 offset, __u64 addr, bool is_return,
char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
__u64 *probe_offset, __u64 *probe_addr)
{
int is_return_bit = bpf_get_retprobe_bit(event_type);
int type = bpf_find_probe_type(event_type);
struct perf_event_attr attr = {};
int fd;
if (type < 0 || is_return_bit < 0) {
printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n",
__func__, type, is_return_bit);
return -1;
}
attr.sample_period = 1;
attr.wakeup_events = 1;
if (is_return)
attr.config |= 1 << is_return_bit;
if (name) {
attr.config1 = ptr_to_u64((void *)name);
attr.config2 = offset;
} else {
attr.config1 = 0;
attr.config2 = addr;
}
attr.size = sizeof(attr);
attr.type = type;
fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
CHECK_PERROR_RET(fd < 0);
CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) < 0);
CHECK_PERROR_RET(ioctl(fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0);
CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len,
prog_id, fd_type, probe_offset, probe_addr) < 0);
return 0;
}
static int test_nondebug_fs_probe(const char *event_type, const char *name,
__u64 offset, __u64 addr, bool is_return,
__u32 expected_fd_type,
__u32 expected_ret_fd_type,
char *buf, __u32 buf_len)
{
__u64 probe_offset, probe_addr;
__u32 prog_id, fd_type;
int err;
err = test_nondebug_fs_kuprobe_common(event_type, name,
offset, addr, is_return,
buf, &buf_len, &prog_id,
&fd_type, &probe_offset,
&probe_addr);
if (err < 0) {
printf("FAIL: %s, "
"for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n",
__func__, name ? name : "", offset, addr, is_return);
perror(" :");
return -1;
}
if ((is_return && fd_type != expected_ret_fd_type) ||
(!is_return && fd_type != expected_fd_type)) {
printf("FAIL: %s, incorrect fd_type %u\n",
__func__, fd_type);
return -1;
}
if (name) {
if (strcmp(name, buf) != 0) {
printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
return -1;
}
if (probe_offset != offset) {
printf("FAIL: %s, incorrect probe_offset 0x%llx\n",
__func__, probe_offset);
return -1;
}
} else {
if (buf_len != 0) {
printf("FAIL: %s, incorrect buf %p\n",
__func__, buf);
return -1;
}
if (probe_addr != addr) {
printf("FAIL: %s, incorrect probe_addr 0x%llx\n",
__func__, probe_addr);
return -1;
}
}
return 0;
}
static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return)
{
const char *event_type = "uprobe";
struct perf_event_attr attr = {};
char buf[256], event_alias[sizeof("test_1234567890")];
__u64 probe_offset, probe_addr;
__u32 len, prog_id, fd_type;
int err, res, kfd, efd;
ssize_t bytes;
snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/%s_events",
event_type);
kfd = open(buf, O_WRONLY | O_APPEND, 0);
CHECK_PERROR_RET(kfd < 0);
res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid());
CHECK_PERROR_RET(res < 0 || res >= sizeof(event_alias));
res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx",
is_return ? 'r' : 'p', event_type, event_alias,
binary_path, offset);
CHECK_PERROR_RET(res < 0 || res >= sizeof(buf));
CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0);
close(kfd);
kfd = -1;
snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
event_type, event_alias);
efd = open(buf, O_RDONLY, 0);
CHECK_PERROR_RET(efd < 0);
bytes = read(efd, buf, sizeof(buf));
CHECK_PERROR_RET(bytes <= 0 || bytes >= sizeof(buf));
close(efd);
buf[bytes] = '\0';
attr.config = strtol(buf, NULL, 0);
attr.type = PERF_TYPE_TRACEPOINT;
attr.sample_period = 1;
attr.wakeup_events = 1;
kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
CHECK_PERROR_RET(kfd < 0);
CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) < 0);
CHECK_PERROR_RET(ioctl(kfd, PERF_EVENT_IOC_ENABLE, 0) < 0);
len = sizeof(buf);
err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len,
&prog_id, &fd_type, &probe_offset,
&probe_addr);
if (err < 0) {
printf("FAIL: %s, binary_path %s\n", __func__, binary_path);
perror(" :");
return -1;
}
if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) ||
(!is_return && fd_type != BPF_FD_TYPE_UPROBE)) {
printf("FAIL: %s, incorrect fd_type %u\n", __func__,
fd_type);
return -1;
}
if (strcmp(binary_path, buf) != 0) {
printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
return -1;
}
if (probe_offset != offset) {
printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__,
probe_offset);
return -1;
}
close(kfd);
return 0;
}
int main(int argc, char **argv)
{
struct rlimit r = {1024*1024, RLIM_INFINITY};
extern char __executable_start;
char filename[256], buf[256];
__u64 uprobe_file_offset;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
if (setrlimit(RLIMIT_MEMLOCK, &r)) {
perror("setrlimit(RLIMIT_MEMLOCK)");
return 1;
}
if (load_kallsyms()) {
printf("failed to process /proc/kallsyms\n");
return 1;
}
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
/* test two functions in the corresponding *_kern.c file */
CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
BPF_FD_TYPE_KPROBE));
CHECK_AND_RET(test_debug_fs_kprobe(1, "blk_account_io_completion",
BPF_FD_TYPE_KRETPROBE));
/* test nondebug fs kprobe */
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
false, BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
buf, sizeof(buf)));
#ifdef __x86_64__
/* set a kprobe on "bpf_check + 0x5", which is x64 specific */
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0,
false, BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
buf, sizeof(buf)));
#endif
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
true, BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
buf, sizeof(buf)));
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
ksym_get_addr("bpf_check"), false,
BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
buf, sizeof(buf)));
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
ksym_get_addr("bpf_check"), false,
BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
NULL, 0));
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
ksym_get_addr("bpf_check"), true,
BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
buf, sizeof(buf)));
CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
ksym_get_addr("bpf_check"), true,
BPF_FD_TYPE_KPROBE,
BPF_FD_TYPE_KRETPROBE,
0, 0));
/* test nondebug fs uprobe */
/* the calculation of uprobe file offset is based on gcc 7.3.1 on x64
* and the default linker script, which defines __executable_start as
* the start of the .text section. The calculation could be different
* on different systems with different compilers. The right way is
* to parse the ELF file. We took a shortcut here.
*/
uprobe_file_offset = (__u64)main - (__u64)&__executable_start;
CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
uprobe_file_offset, 0x0, false,
BPF_FD_TYPE_UPROBE,
BPF_FD_TYPE_URETPROBE,
buf, sizeof(buf)));
CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
uprobe_file_offset, 0x0, true,
BPF_FD_TYPE_UPROBE,
BPF_FD_TYPE_URETPROBE,
buf, sizeof(buf)));
/* test debug fs uprobe */
CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
false));
CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
true));
return 0;
}