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-rw-r--r--meta/recipes-kernel/lttng/lttng-modules/0001-fix-sched-tracing-Append-prev_state-to-tp-args-inste.patch59
1 files changed, 59 insertions, 0 deletions
diff --git a/meta/recipes-kernel/lttng/lttng-modules/0001-fix-sched-tracing-Append-prev_state-to-tp-args-inste.patch b/meta/recipes-kernel/lttng/lttng-modules/0001-fix-sched-tracing-Append-prev_state-to-tp-args-inste.patch
new file mode 100644
index 0000000000..b41053b6bc
--- /dev/null
+++ b/meta/recipes-kernel/lttng/lttng-modules/0001-fix-sched-tracing-Append-prev_state-to-tp-args-inste.patch
@@ -0,0 +1,59 @@
+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
+