lttng-modules: support kernel 5.18+

Backporting changes from lttng master to support building against
the 5.18+ kernel. No changes required to the patches. Once a new
-stable 2.13.x is released, we can drop these patches. To enable
newer kernel development against the LTS, it is worth pulling these
in while we wait for an upstream release.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 8a7237a47488442513741930ea55d69dd6bd7be4)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>

1 files changed, 183 insertions, 0 deletions

diff --git a/meta/recipes-kernel/lttng/lttng-modules/0003-fix-sched-tracing-Don-t-re-read-p-state-when-emittin.patch b/meta/recipes-kernel/lttng/lttng-modules/0003-fix-sched-tracing-Don-t-re-read-p-state-when-emittin.patch
new file mode 100644
index 0000000000..afe514de82
--- /dev/null
+++ b/meta/recipes-kernel/lttng/lttng-modules/0003-fix-sched-tracing-Don-t-re-read-p-state-when-emittin.patch
@@ -0,0 +1,183 @@
+From 8e52fd71e693619f7a58de2692e59f0c826e9988 Mon Sep 17 00:00:00 2001
+From: Michael Jeanson <mjeanson@efficios.com>
+Date: Mon, 4 Apr 2022 13:52:57 -0400
+Subject: [PATCH 03/10] fix: sched/tracing: Don't re-read p->state when
+ emitting sched_switch event (v5.18)
+
+See upstream commit :
+
+  commit fa2c3254d7cfff5f7a916ab928a562d1165f17bb
+  Author: Valentin Schneider <valentin.schneider@arm.com>
+  Date:   Thu Jan 20 16:25:19 2022 +0000
+
+    sched/tracing: Don't re-read p->state when emitting sched_switch event
+
+    As of commit
+
+      c6e7bd7afaeb ("sched/core: Optimize ttwu() spinning on p->on_cpu")
+
+    the following sequence becomes possible:
+
+                          p->__state = TASK_INTERRUPTIBLE;
+                          __schedule()
+                            deactivate_task(p);
+      ttwu()
+        READ !p->on_rq
+        p->__state=TASK_WAKING
+                            trace_sched_switch()
+                              __trace_sched_switch_state()
+                                task_state_index()
+                                  return 0;
+
+    TASK_WAKING isn't in TASK_REPORT, so the task appears as TASK_RUNNING in
+    the trace event.
+
+    Prevent this by pushing the value read from __schedule() down the trace
+    event.
+
+Upstream-Status: Backport
+
+Change-Id: I46743cd006be4b4d573cae2d77df7d6d16744d04
+Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
+Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+---
+ include/instrumentation/events/sched.h | 88 +++++++++++++++++++++++---
+ 1 file changed, 78 insertions(+), 10 deletions(-)
+
+diff --git a/include/instrumentation/events/sched.h b/include/instrumentation/events/sched.h
+index 91953a6f..339bec94 100644
+--- a/include/instrumentation/events/sched.h
++++ b/include/instrumentation/events/sched.h
+@@ -20,7 +20,37 @@
+ #ifndef _TRACE_SCHED_DEF_
+ #define _TRACE_SCHED_DEF_
+ 
+-#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,15,0))
++#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0))
++
++static inline long __trace_sched_switch_state(bool preempt,
++		unsigned int prev_state,
++		struct task_struct *p)
++{
++        unsigned int state;
++
++#ifdef CONFIG_SCHED_DEBUG
++        BUG_ON(p != current);
++#endif /* CONFIG_SCHED_DEBUG */
++
++        /*
++         * Preemption ignores task state, therefore preempted tasks are always
++         * RUNNING (we will not have dequeued if state != RUNNING).
++         */
++        if (preempt)
++                return TASK_REPORT_MAX;
++
++        /*
++         * task_state_index() uses fls() and returns a value from 0-8 range.
++         * Decrement it by 1 (except TASK_RUNNING state i.e 0) before using
++         * it for left shift operation to get the correct task->state
++         * mapping.
++         */
++	state = __task_state_index(prev_state, p->exit_state);
++
++        return state ? (1 << (state - 1)) : state;
++}
++
++#elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,15,0))
+ 
+ static inline long __trace_sched_switch_state(bool preempt, struct task_struct *p)
+ {
+@@ -321,43 +351,81 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE(sched_wakeup_template, sched_wakeup_new,
+ /*
+  * Tracepoint for task switches, performed by the scheduler:
+  */
++
++#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,18,0))
+ LTTNG_TRACEPOINT_EVENT(sched_switch,
+ 
+-#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,4,0))
+ 	TP_PROTO(bool preempt,
+-		 struct task_struct *prev,
+-		 struct task_struct *next),
++		unsigned int prev_state,
++		struct task_struct *prev,
++		struct task_struct *next),
+ 
+-	TP_ARGS(preempt, prev, next),
++	TP_ARGS(preempt, prev_state, prev, next),
++
++	TP_FIELDS(
++		ctf_array_text(char, prev_comm,	prev->comm, TASK_COMM_LEN)
++		ctf_integer(pid_t, prev_tid, prev->pid)
++		ctf_integer(int, prev_prio, prev->prio - MAX_RT_PRIO)
++#ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
++		ctf_enum(task_state, long, prev_state, __trace_sched_switch_state(preempt, prev_state, prev))
+ #else
+-	TP_PROTO(struct task_struct *prev,
++		ctf_integer(long, prev_state, __trace_sched_switch_state(preempt, prev_state, prev))
++#endif
++		ctf_array_text(char, next_comm, next->comm, TASK_COMM_LEN)
++		ctf_integer(pid_t, next_tid, next->pid)
++		ctf_integer(int, next_prio, next->prio - MAX_RT_PRIO)
++	)
++)
++
++#elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,4,0))
++
++LTTNG_TRACEPOINT_EVENT(sched_switch,
++
++	TP_PROTO(bool preempt,
++		 struct task_struct *prev,
+ 		 struct task_struct *next),
+ 
+-	TP_ARGS(prev, next),
+-#endif /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,4,0)) */
++	TP_ARGS(preempt, prev, next),
+ 
+ 	TP_FIELDS(
+ 		ctf_array_text(char, prev_comm,	prev->comm, TASK_COMM_LEN)
+ 		ctf_integer(pid_t, prev_tid, prev->pid)
+ 		ctf_integer(int, prev_prio, prev->prio - MAX_RT_PRIO)
+-#if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,4,0))
+ #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
+ 		ctf_enum(task_state, long, prev_state, __trace_sched_switch_state(preempt, prev))
+ #else
+ 		ctf_integer(long, prev_state, __trace_sched_switch_state(preempt, prev))
+ #endif
++		ctf_array_text(char, next_comm, next->comm, TASK_COMM_LEN)
++		ctf_integer(pid_t, next_tid, next->pid)
++		ctf_integer(int, next_prio, next->prio - MAX_RT_PRIO)
++	)
++)
++
+ #else
++
++LTTNG_TRACEPOINT_EVENT(sched_switch,
++
++	TP_PROTO(struct task_struct *prev,
++		 struct task_struct *next),
++
++	TP_ARGS(prev, next),
++
++	TP_FIELDS(
++		ctf_array_text(char, prev_comm,	prev->comm, TASK_COMM_LEN)
++		ctf_integer(pid_t, prev_tid, prev->pid)
++		ctf_integer(int, prev_prio, prev->prio - MAX_RT_PRIO)
+ #ifdef CONFIG_LTTNG_EXPERIMENTAL_BITWISE_ENUM
+ 		ctf_enum(task_state, long, prev_state, __trace_sched_switch_state(prev))
+ #else
+ 		ctf_integer(long, prev_state, __trace_sched_switch_state(prev))
+-#endif
+ #endif
+ 		ctf_array_text(char, next_comm, next->comm, TASK_COMM_LEN)
+ 		ctf_integer(pid_t, next_tid, next->pid)
+ 		ctf_integer(int, next_prio, next->prio - MAX_RT_PRIO)
+ 	)
+ )
++#endif
+ 
+ /*
+  * Tracepoint for a task being migrated:
+-- 
+2.19.1
+