v4.19.13 snapshot.
diff --git a/tools/bpf/bpftool/perf.c b/tools/bpf/bpftool/perf.c
new file mode 100644
index 0000000..b76b77d
--- /dev/null
+++ b/tools/bpf/bpftool/perf.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0+
+// 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.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;
+ }
+ 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;
+ }
+}
+
+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: %s %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);
+}