commit 08765a9a0ba8dc9c38ec7dff05fa1734cf43866f
author Hengqi Chen <chenhengqi@outlook.com> Sun Oct 31 23:20:10 2021 +0800
committer yonghong-song <ys114321@gmail.com> Mon Nov 01 08:07:53 2021 -0700
tree 288ede71ad7cd518fb8a8b49869c2ef2c8b570af
parent 8270cf28bcd41107b71160fa609ec6a50b405f0a

bcc/tools: Fix renaming of the state field of task_struct

Kernel commit 2f064a59a1 ("sched: Change task_struct::state") changes
the name of task_struct::state to task_struct::__state, which breaks
several bcc tools. Fix this issue by checking field existence in vmlinux
BTF. Since this change was intruduce in kernel v5.14, we should have
BTF support. Closes #3658 .

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

tools/offcputime.py

diff --git a/tools/offcputime.py b/tools/offcputime.py
index 128c649..c9b1e6e 100755
--- a/tools/offcputime.py
+++ b/tools/offcputime.py
@@ -116,8 +116,8 @@
 #define MAXBLOCK_US    MAXBLOCK_US_VALUEULL
 
 struct key_t {
-    u32 pid;
-    u32 tgid;
+    u64 pid;
+    u64 tgid;
     int user_stack_id;
     int kernel_stack_id;
     char name[TASK_COMM_LEN];
@@ -205,14 +205,18 @@
     thread_context = "all threads"
     thread_filter = '1'
 if args.state == 0:
-    state_filter = 'prev->state == 0'
+    state_filter = 'prev->STATE_FIELD == 0'
 elif args.state:
     # these states are sometimes bitmask checked
-    state_filter = 'prev->state & %d' % args.state
+    state_filter = 'prev->STATE_FIELD & %d' % args.state
 else:
     state_filter = '1'
 bpf_text = bpf_text.replace('THREAD_FILTER', thread_filter)
 bpf_text = bpf_text.replace('STATE_FILTER', state_filter)
+if BPF.kernel_struct_has_field(b'task_struct', b'__state') == 1:
+    bpf_text = bpf_text.replace('STATE_FIELD', '__state')
+else:
+    bpf_text = bpf_text.replace('STATE_FIELD', 'state')
 
 # set stack storage size
 bpf_text = bpf_text.replace('STACK_STORAGE_SIZE', str(args.stack_storage_size))