1 files changed, 109 insertions, 0 deletions

diff --git a/meta/recipes-kernel/systemtap/systemtap/scheduler-stp.patch b/meta/recipes-kernel/systemtap/systemtap/scheduler-stp.patch
new file mode 100644
index 0000000000..9897e481a3
--- /dev/null
+++ b/meta/recipes-kernel/systemtap/systemtap/scheduler-stp.patch
@@ -0,0 +1,109 @@
+scheduler.stp: Handle missing symbols.
+
+Compiler output code optimization leads to missing debug data for some
+target variables, in particular some inline functions parameters, e.g.
+context_switch.
+
+Handle this by testing for variable name resolvability and provide default
+variable values in case no suitable target data is available through variable
+name. Affected functions: ctxswitch,wakeup.
+
+This fix does not affect the intended context switch tracing.
+
+
+Upstream-Status: Pending
+
+Signed-off-by: George Nita <george.nita@enea.com>
+
+
+diff --git a/tapset/linux/scheduler.stp b/tapset/linux/scheduler.stp
+index 7596a46..539a0f1 100644
+--- a/tapset/linux/scheduler.stp
++++ b/tapset/linux/scheduler.stp
+@@ -120,7 +120,7 @@ probe scheduler.ctxswitch = kernel.trace("sched_switch") !,
+ %( arch != "x86_64" && arch != "ia64" && arch != "arm" %?
+        kernel.function("__switch_to")
+ %:
+-       kernel.function("context_switch")
++       kernel.function("prepare_task_switch")
+ %)
+ {
+        name = "ctxswitch"
+@@ -140,7 +140,7 @@ probe scheduler.ctxswitch = kernel.trace("sched_switch") !,
+                prev_task_name = task_execname($prev_p)
+                prevtsk_state = $prev_p->state
+        }
+-       else {
++       else if (@defined($prev)) {
+                prev_priority = $prev->prio
+                prev_pid = $prev->tgid
+                prev_tid = $prev->pid
+@@ -148,6 +148,15 @@ probe scheduler.ctxswitch = kernel.trace("sched_switch") !,
+                prev_task_name = task_execname($prev)
+                prevtsk_state = $prev->state
+        }
++       else {
++               prev_priority = 0
++               prev_pid = 0
++               prev_tid = 0
++               /* No prev_task, dummy */
++               prev_task = task_current()
++               prev_task_name = "UNAVAILABLE"
++               prevtsk_state = 0
++       }
+ 
+        if (@defined($next)) {
+                next_priority = $next->prio
+@@ -165,7 +174,7 @@ probe scheduler.ctxswitch = kernel.trace("sched_switch") !,
+                next_task_name = task_execname($next_p)
+                nexttsk_state = $next_p->state
+        }
+-       else {
++       else if (@defined($new)) {
+                next_priority = $new->prio
+                next_pid = $new->tgid
+                next_tid = $new->pid
+@@ -173,6 +182,14 @@ probe scheduler.ctxswitch = kernel.trace("sched_switch") !,
+                next_task_name = task_execname($new)
+                nexttsk_state = $new->state
+        }
++       else {
++               next_task = task_current()
++               next_priority = task_prio(next_task)
++               next_pid = task_pid(next_task)
++               next_tid = task_tid(next_task)
++               next_task_name = task_execname(next_task)
++               nexttsk_state = task_state(next_task)
++       }
+ }
+ 
+ 
+@@ -254,12 +271,22 @@ probe scheduler.wakeup =
+        kernel.function("try_to_wake_up")
+ {
+        name = "wakeup"
+-       task = $p
+-       task_pid = $p->tgid
+-       task_tid = $p->pid
+-       task_priority = $p->prio
+-       task_cpu = task_cpu($p)
+-       task_state = task_state($p)
++       if (@defined($p)) {
++               task = $p
++               task_pid = $p->tgid
++               task_tid = $p->pid
++               task_priority = $p->prio
++               task_cpu = task_cpu($p)
++               task_state = task_state($p)
++       }
++       else {
++               task = task_current()
++               task_pid = task_pid(task)
++               task_tid = task_tid(task)
++               task_priority = task_prio(task)
++               task_cpu = task_cpu(task)
++               task_state = task_state(task)
++       }
+ }
+ 
+ /**