Orange Pi5 kernel

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
// Copyright (C) 2018 Facebook
// Author: Yonghong Song <yhs@fb.com>
 
#define _GNU_SOURCE
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <ftw.h>
 
#include <bpf/bpf.h>
 
#include "main.h"
 
/* 0: undecided, 1: supported, 2: not supported */
static int perf_query_supported;
static bool has_perf_query_support(void)
{
<------>__u64 probe_offset, probe_addr;
<------>__u32 len, prog_id, fd_type;
<------>char buf[256];
<------>int fd;
 
<------>if (perf_query_supported)
<------><------>goto out;
 
<------>fd = open("/", O_RDONLY);
<------>if (fd < 0) {
<------><------>p_err("perf_query_support: cannot open directory \"/\" (%s)",
<------><------>      strerror(errno));
<------><------>goto out;
<------>}
 
<------>/* the following query will fail as no bpf attachment,
<------> * the expected errno is ENOTSUPP
<------> */
<------>errno = 0;
<------>len = sizeof(buf);
<------>bpf_task_fd_query(getpid(), fd, 0, buf, &len, &prog_id,
<------><------><------>  &fd_type, &probe_offset, &probe_addr);
 
<------>if (errno == 524 /* ENOTSUPP */) {
<------><------>perf_query_supported = 1;
<------><------>goto close_fd;
<------>}
 
<------>perf_query_supported = 2;
<------>p_err("perf_query_support: %s", strerror(errno));
<------>fprintf(stderr,
<------><------>"HINT: non root or kernel doesn't support TASK_FD_QUERY\n");
 
close_fd:
<------>close(fd);
out:
<------>return perf_query_supported == 1;
}
 
static void print_perf_json(int pid, int fd, __u32 prog_id, __u32 fd_type,
<------><------><------>    char *buf, __u64 probe_offset, __u64 probe_addr)
{
<------>jsonw_start_object(json_wtr);
<------>jsonw_int_field(json_wtr, "pid", pid);
<------>jsonw_int_field(json_wtr, "fd", fd);
<------>jsonw_uint_field(json_wtr, "prog_id", prog_id);
<------>switch (fd_type) {
<------>case BPF_FD_TYPE_RAW_TRACEPOINT:
<------><------>jsonw_string_field(json_wtr, "fd_type", "raw_tracepoint");
<------><------>jsonw_string_field(json_wtr, "tracepoint", buf);
<------><------>break;
<------>case BPF_FD_TYPE_TRACEPOINT:
<------><------>jsonw_string_field(json_wtr, "fd_type", "tracepoint");
<------><------>jsonw_string_field(json_wtr, "tracepoint", buf);
<------><------>break;
<------>case BPF_FD_TYPE_KPROBE:
<------><------>jsonw_string_field(json_wtr, "fd_type", "kprobe");
<------><------>if (buf[0] != '\0') {
<------><------><------>jsonw_string_field(json_wtr, "func", buf);
<------><------><------>jsonw_lluint_field(json_wtr, "offset", probe_offset);
<------><------>} else {
<------><------><------>jsonw_lluint_field(json_wtr, "addr", probe_addr);
<------><------>}
<------><------>break;
<------>case BPF_FD_TYPE_KRETPROBE:
<------><------>jsonw_string_field(json_wtr, "fd_type", "kretprobe");
<------><------>if (buf[0] != '\0') {
<------><------><------>jsonw_string_field(json_wtr, "func", buf);
<------><------><------>jsonw_lluint_field(json_wtr, "offset", probe_offset);
<------><------>} else {
<------><------><------>jsonw_lluint_field(json_wtr, "addr", probe_addr);
<------><------>}
<------><------>break;
<------>case BPF_FD_TYPE_UPROBE:
<------><------>jsonw_string_field(json_wtr, "fd_type", "uprobe");
<------><------>jsonw_string_field(json_wtr, "filename", buf);
<------><------>jsonw_lluint_field(json_wtr, "offset", probe_offset);
<------><------>break;
<------>case BPF_FD_TYPE_URETPROBE:
<------><------>jsonw_string_field(json_wtr, "fd_type", "uretprobe");
<------><------>jsonw_string_field(json_wtr, "filename", buf);
<------><------>jsonw_lluint_field(json_wtr, "offset", probe_offset);
<------><------>break;
<------>default:
<------><------>break;
<------>}
<------>jsonw_end_object(json_wtr);
}
 
static void print_perf_plain(int pid, int fd, __u32 prog_id, __u32 fd_type,
<------><------><------>     char *buf, __u64 probe_offset, __u64 probe_addr)
{
<------>printf("pid %d  fd %d: prog_id %u  ", pid, fd, prog_id);
<------>switch (fd_type) {
<------>case BPF_FD_TYPE_RAW_TRACEPOINT:
<------><------>printf("raw_tracepoint  %s\n", buf);
<------><------>break;
<------>case BPF_FD_TYPE_TRACEPOINT:
<------><------>printf("tracepoint  %s\n", buf);
<------><------>break;
<------>case BPF_FD_TYPE_KPROBE:
<------><------>if (buf[0] != '\0')
<------><------><------>printf("kprobe  func %s  offset %llu\n", buf,
<------><------><------>       probe_offset);
<------><------>else
<------><------><------>printf("kprobe  addr %llu\n", probe_addr);
<------><------>break;
<------>case BPF_FD_TYPE_KRETPROBE:
<------><------>if (buf[0] != '\0')
<------><------><------>printf("kretprobe  func %s  offset %llu\n", buf,
<------><------><------>       probe_offset);
<------><------>else
<------><------><------>printf("kretprobe  addr %llu\n", probe_addr);
<------><------>break;
<------>case BPF_FD_TYPE_UPROBE:
<------><------>printf("uprobe  filename %s  offset %llu\n", buf, probe_offset);
<------><------>break;
<------>case BPF_FD_TYPE_URETPROBE:
<------><------>printf("uretprobe  filename %s  offset %llu\n", buf,
<------><------>       probe_offset);
<------><------>break;
<------>default:
<------><------>break;
<------>}
}
 
static int show_proc(const char *fpath, const struct stat *sb,
<------><------>     int tflag, struct FTW *ftwbuf)
{
<------>__u64 probe_offset, probe_addr;
<------>__u32 len, prog_id, fd_type;
<------>int err, pid = 0, fd = 0;
<------>const char *pch;
<------>char buf[4096];
 
<------>/* prefix always /proc */
<------>pch = fpath + 5;
<------>if (*pch == '\0')
<------><------>return 0;
 
<------>/* pid should be all numbers */
<------>pch++;
<------>while (isdigit(*pch)) {
<------><------>pid = pid * 10 + *pch - '0';
<------><------>pch++;
<------>}
<------>if (*pch == '\0')
<------><------>return 0;
<------>if (*pch != '/')
<------><------>return FTW_SKIP_SUBTREE;
 
<------>/* check /proc/<pid>/fd directory */
<------>pch++;
<------>if (strncmp(pch, "fd", 2))
<------><------>return FTW_SKIP_SUBTREE;
<------>pch += 2;
<------>if (*pch == '\0')
<------><------>return 0;
<------>if (*pch != '/')
<------><------>return FTW_SKIP_SUBTREE;
 
<------>/* check /proc/<pid>/fd/<fd_num> */
<------>pch++;
<------>while (isdigit(*pch)) {
<------><------>fd = fd * 10 + *pch - '0';
<------><------>pch++;
<------>}
<------>if (*pch != '\0')
<------><------>return FTW_SKIP_SUBTREE;
 
<------>/* query (pid, fd) for potential perf events */
<------>len = sizeof(buf);
<------>err = bpf_task_fd_query(pid, fd, 0, buf, &len, &prog_id, &fd_type,
<------><------><------><------>&probe_offset, &probe_addr);
<------>if (err < 0)
<------><------>return 0;
 
<------>if (json_output)
<------><------>print_perf_json(pid, fd, prog_id, fd_type, buf, probe_offset,
<------><------><------><------>probe_addr);
<------>else
<------><------>print_perf_plain(pid, fd, prog_id, fd_type, buf, probe_offset,
<------><------><------><------> probe_addr);
 
<------>return 0;
}
 
static int do_show(int argc, char **argv)
{
<------>int flags = FTW_ACTIONRETVAL | FTW_PHYS;
<------>int err = 0, nopenfd = 16;
 
<------>if (!has_perf_query_support())
<------><------>return -1;
 
<------>if (json_output)
<------><------>jsonw_start_array(json_wtr);
<------>if (nftw("/proc", show_proc, nopenfd, flags) == -1) {
<------><------>p_err("%s", strerror(errno));
<------><------>err = -1;
<------>}
<------>if (json_output)
<------><------>jsonw_end_array(json_wtr);
 
<------>return err;
}
 
static int do_help(int argc, char **argv)
{
<------>fprintf(stderr,
<------><------>"Usage: %1$s %2$s { show | list | help }\n"
<------><------>"",
<------><------>bin_name, argv[-2]);
 
<------>return 0;
}
 
static const struct cmd cmds[] = {
<------>{ "show",	do_show },
<------>{ "list",	do_show },
<------>{ "help",	do_help },
<------>{ 0 }
};
 
int do_perf(int argc, char **argv)
{
<------>return cmd_select(cmds, argc, argv, do_help);
}