1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
From 9c5b8de32b5745f3ff31079c02da64595e101bee Mon Sep 17 00:00:00 2001
From: Michael Jeanson <mjeanson@efficios.com>
Date: Tue, 17 May 2022 11:46:29 -0400
Subject: [PATCH] fix: sched/tracing: Append prev_state to tp args instead
(v5.18)
See upstream commit :
commit 9c2136be0878c88c53dea26943ce40bb03ad8d8d
Author: Delyan Kratunov <delyank@fb.com>
Date: Wed May 11 18:28:36 2022 +0000
sched/tracing: Append prev_state to tp args instead
Commit fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting
sched_switch event, 2022-01-20) added a new prev_state argument to the
sched_switch tracepoint, before the prev task_struct pointer.
This reordering of arguments broke BPF programs that use the raw
tracepoint (e.g. tp_btf programs). The type of the second argument has
changed and existing programs that assume a task_struct* argument
(e.g. for bpf_task_storage access) will now fail to verify.
If we instead append the new argument to the end, all existing programs
would continue to work and can conditionally extract the prev_state
argument on supported kernel versions.
Upstream-Status: Backport
Change-Id: Ife2ec88a8bea2743562590cbd357068d7773863f
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
include/instrumentation/events/sched.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/instrumentation/events/sched.h b/include/instrumentation/events/sched.h
index 339bec94..c1c3df15 100644
--- a/include/instrumentation/events/sched.h
+++ b/include/instrumentation/events/sched.h
@@ -356,11 +356,11 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE(sched_wakeup_template, sched_wakeup_new,
LTTNG_TRACEPOINT_EVENT(sched_switch,
TP_PROTO(bool preempt,
- unsigned int prev_state,
struct task_struct *prev,
- struct task_struct *next),
+ struct task_struct *next,
+ unsigned int prev_state),
- TP_ARGS(preempt, prev_state, prev, next),
+ TP_ARGS(preempt, prev, next, prev_state),
TP_FIELDS(
ctf_array_text(char, prev_comm, prev->comm, TASK_COMM_LEN)
--
2.19.1
|
