// 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;}