[DTrace-devel] [PATCH] Fix arg3 for sched enqueue and dequeue probes

[eugene.loh at oracle.com]

From: Eugene Loh <eugene.loh at oracle.com>

For sched enqueue and dequeue probes, arg3 should be an int
for enqueue and not exist for dequeue.  In the code it was
the other way around.  Fix this and the associated tests.

The trampoline was already set up to get this argument correct.

Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
---
 libdtrace/dt_prov_sched.c            | 3 ++-
 test/unittest/sched/tst.lv-dequeue.r | 1 -
 test/unittest/sched/tst.lv-enqueue.r | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/libdtrace/dt_prov_sched.c b/libdtrace/dt_prov_sched.c
index 125d58917..3a218f3cb 100644
--- a/libdtrace/dt_prov_sched.c
+++ b/libdtrace/dt_prov_sched.c
@@ -46,10 +46,10 @@ static probe_arg_t probe_args[] = {
 	{ "dequeue", 0, { 0, 0, "struct task_struct *", "lwpsinfo_t *" } },
 	{ "dequeue", 1, { 0, 0, "struct task_struct *", "psinfo_t *" } },
 	{ "dequeue", 2, { 1, 0, "cpuinfo_t *", } },
-	{ "dequeue", 3, { 2, 0, "int", } },
 	{ "enqueue", 0, { 0, 0, "struct task_struct *", "lwpsinfo_t *" } },
 	{ "enqueue", 1, { 0, 0, "struct task_struct *", "psinfo_t *" } },
 	{ "enqueue", 2, { 1, 0, "cpuinfo_t *", } },
+	{ "enqueue", 3, { 2, 0, "int", } },
 	{ "off-cpu", 0, { 0, 0, "struct task_struct *", "lwpsinfo_t *" } },
 	{ "off-cpu", 1, { 0, 0, "struct task_struct *", "psinfo_t *" } },
 	{ "on-cpu", },
@@ -128,6 +128,7 @@ static int trampoline(dt_pcb_t *pcb, uint_t exitlbl)
 		 *	  associated with the runqueue.
 		 */
 		emit(dlp, BPF_STORE_IMM(BPF_DW, BPF_REG_7, DMST_ARG(1), 0));
+
 		emit(dlp, BPF_LOAD(BPF_DW, BPF_REG_0, BPF_REG_7, DMST_ARG(2)));
 		emit(dlp, BPF_ALU64_IMM(BPF_AND, BPF_REG_0, ENQUEUE_HEAD));
 		emit(dlp, BPF_STORE(BPF_DW, BPF_REG_7, DMST_ARG(2), BPF_REG_0));
diff --git a/test/unittest/sched/tst.lv-dequeue.r b/test/unittest/sched/tst.lv-dequeue.r
index 7580a8abc..657667f34 100644
--- a/test/unittest/sched/tst.lv-dequeue.r
+++ b/test/unittest/sched/tst.lv-dequeue.r
@@ -14,5 +14,4 @@ PROBE sched vmlinux dequeue
 		args[0]: lwpsinfo_t *
 		args[1]: psinfo_t *
 		args[2]: cpuinfo_t *
-		args[3]: int
 
diff --git a/test/unittest/sched/tst.lv-enqueue.r b/test/unittest/sched/tst.lv-enqueue.r
index edc5e2c4c..2f5efa30c 100644
--- a/test/unittest/sched/tst.lv-enqueue.r
+++ b/test/unittest/sched/tst.lv-enqueue.r
@@ -14,4 +14,5 @@ PROBE sched vmlinux enqueue
 		args[0]: lwpsinfo_t *
 		args[1]: psinfo_t *
 		args[2]: cpuinfo_t *
+		args[3]: int
 
-- 
2.43.5