From 59a4e7ea490f78ba289c1ba461bfe1fce9e7ef19 Mon Sep 17 00:00:00 2001

From: Hengqi Chen <chenhengqi@outlook.com>

Date: Sat, 11 Dec 2021 17:36:17 +0800

Subject: [PATCH] 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]: https://github.com/torvalds/linux/commit/be6bfe36db1795babe9d92178a47b2e02193cb0f

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

---

 tools/biolatency.py | 12 ++++++++----

 tools/biolatpcts.py |  5 ++++-

 tools/biosnoop.py   | 11 ++++++++---

 tools/biotop.py     | 11 ++++++++---

 4 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/tools/biolatency.py b/tools/biolatency.py

index 0599609b..2e75a5de 100755

--- a/tools/biolatency.py

+++ b/tools/biolatency.py

@@ -168,13 +168,18 @@ bpf_text = bpf_text.replace("STORE", store_str)

 # 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 @@ dist = b.get_table("dist")

     countdown -= 1

     if exiting or countdown == 0:

         exit()

-

diff --git a/tools/biolatpcts.py b/tools/biolatpcts.py

index 5ab8aa5f..a2f59592 100755

--- a/tools/biolatpcts.py

+++ b/tools/biolatpcts.py

@@ -142,7 +142,10 @@ bpf_source = bpf_source.replace('__MAJOR__', str(major))

 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

diff --git a/tools/biosnoop.py b/tools/biosnoop.py

index 333949b5..2b954ac9 100755

--- a/tools/biosnoop.py

+++ b/tools/biosnoop.py

@@ -163,12 +163,17 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)

 # 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",

diff --git a/tools/biotop.py b/tools/biotop.py

index 596f0076..0ebfef0e 100755

--- a/tools/biotop.py

+++ b/tools/biotop.py

@@ -180,12 +180,17 @@ int trace_req_completion(struct pt_regs *ctx, struct request *req)

     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)

-- 

2.35.1