tools: Fix BCC bio tools with recent kernel change

Several BCC bio tools are broken due to kernel change ([0]).
blk_account_io_{start, done} were renamed to __blk_account_io_{start, done},
and the symbols gone from /proc/kallsyms. Fix them by checking symbol existence.

  [0]: torvalds/linux@be6bfe3

Signed-off-by: Hengqi Chen <[email protected]>

tools/biolatency.py

@@ -168,13 +168,18 @@
 # load BPF program
 b = BPF(text=bpf_text)
 if args.queued:
- b.attach_kprobe(event="blk_account_io_start", fn_name="trace_req_start")
+ if BPF.get_kprobe_functions(b'__blk_account_io_start'):
+ b.attach_kprobe(event="__blk_account_io_start", fn_name="trace_req_start")
+ else:
+ b.attach_kprobe(event="blk_account_io_start", fn_name="trace_req_start")
 else:
  if BPF.get_kprobe_functions(b'blk_start_request'):
  b.attach_kprobe(event="blk_start_request", fn_name="trace_req_start")
  b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_req_start")
-b.attach_kprobe(event="blk_account_io_done",
- fn_name="trace_req_done")
+if BPF.get_kprobe_functions(b'__blk_account_io_done'):
+ b.attach_kprobe(event="__blk_account_io_done", fn_name="trace_req_done")
+else:
+ b.attach_kprobe(event="blk_account_io_done", fn_name="trace_req_done")
 
 if not args.json:
  print("Tracing block device I/O... Hit Ctrl-C to end.")
@@ -277,4 +282,3 @@ def flags_print(flags):
  countdown -= 1
  if exiting or countdown == 0:
  exit()
-

tools/biolatpcts.py

@@ -142,7 +142,10 @@
 bpf_source = bpf_source.replace('__MINOR__', str(minor))
 
 bpf = BPF(text=bpf_source)
-bpf.attach_kprobe(event="blk_account_io_done", fn_name="kprobe_blk_account_io_done")
+if BPF.get_kprobe_functions(b'__blk_account_io_done'):
+ bpf.attach_kprobe(event="__blk_account_io_done", fn_name="kprobe_blk_account_io_done")
+else:
+ bpf.attach_kprobe(event="blk_account_io_done", fn_name="kprobe_blk_account_io_done")
 
 # times are in usecs
 MSEC = 1000

tools/biosnoop.py

@@ -163,12 +163,17 @@
 
 # initialize BPF
 b = BPF(text=bpf_text)
-b.attach_kprobe(event="blk_account_io_start", fn_name="trace_pid_start")
+if BPF.get_kprobe_functions(b'__blk_account_io_start'):
+ b.attach_kprobe(event="__blk_account_io_start", fn_name="trace_pid_start")
+else:
+ b.attach_kprobe(event="blk_account_io_start", fn_name="trace_pid_start")
 if BPF.get_kprobe_functions(b'blk_start_request'):
  b.attach_kprobe(event="blk_start_request", fn_name="trace_req_start")
 b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_req_start")
-b.attach_kprobe(event="blk_account_io_done",
- fn_name="trace_req_completion")
+if BPF.get_kprobe_functions(b'__blk_account_io_done'):
+ b.attach_kprobe(event="__blk_account_io_done", fn_name="trace_req_completion")
+else:
+ b.attach_kprobe(event="blk_account_io_done", fn_name="trace_req_completion")
 
 # header
 print("%-11s %-14s %-6s %-7s %-1s %-10s %-7s" % ("TIME(s)", "COMM", "PID",

tools/biotop.py

@@ -175,12 +175,17 @@
  exit()
 
 b = BPF(text=bpf_text)
-b.attach_kprobe(event="blk_account_io_start", fn_name="trace_pid_start")
+if BPF.get_kprobe_functions(b'__blk_account_io_start'):
+ b.attach_kprobe(event="__blk_account_io_start", fn_name="trace_pid_start")
+else:
+ b.attach_kprobe(event="blk_account_io_start", fn_name="trace_pid_start")
 if BPF.get_kprobe_functions(b'blk_start_request'):
  b.attach_kprobe(event="blk_start_request", fn_name="trace_req_start")
 b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_req_start")
-b.attach_kprobe(event="blk_account_io_done",
- fn_name="trace_req_completion")
+if BPF.get_kprobe_functions(b'__blk_account_io_done'):
+ b.attach_kprobe(event="__blk_account_io_done", fn_name="trace_req_completion")
+else:
+ b.attach_kprobe(event="blk_account_io_done", fn_name="trace_req_completion")
 
 print('Tracing... Output every %d secs. Hit Ctrl-C to end' % interval)