From d57a78580e6ef372324fdb5350563eaaec7c3478 Mon Sep 17 00:00:00 2001
From: Stephen Hurd <shurd@FreeBSD.org>
Date: Sat, 23 Sep 2017 01:39:16 +0000
Subject: [PATCH] Make struct grouptask gt_name member a char array

Previously, it was just a pointer which was copied, but
some callers pass in a stack variable which will go out of scope.
Add GROUPTASK_NAMELEN macro (32) and snprintf() the name into it,
using "grouptask" if name is NULL. We can now safely include
gtask->gt_name in console messages.

Reviewed by:	sbruno
Approved by:	sbruno (mentor)
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D12449
---
 sys/kern/subr_gtaskqueue.c | 12 ++++++------
 sys/sys/_task.h            |  3 ++-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/sys/kern/subr_gtaskqueue.c b/sys/kern/subr_gtaskqueue.c
index 5661a5d46abc..2a3ca8100557 100644
--- a/sys/kern/subr_gtaskqueue.c
+++ b/sys/kern/subr_gtaskqueue.c
@@ -666,7 +666,7 @@ taskqgroup_attach(struct taskqgroup *qgroup, struct grouptask *gtask,
 	int qid, error;
 
 	gtask->gt_uniq = uniq;
-	gtask->gt_name = name;
+	snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
 	gtask->gt_irq = irq;
 	gtask->gt_cpu = -1;
 	mtx_lock(&qgroup->tqg_lock);
@@ -703,7 +703,7 @@ taskqgroup_attach_deferred(struct taskqgroup *qgroup, struct grouptask *gtask)
 		error = intr_setaffinity(gtask->gt_irq, CPU_WHICH_IRQ, &mask);
 		mtx_lock(&qgroup->tqg_lock);
 		if (error)
-			printf("%s: setaffinity failed: %d\n", __func__, error);
+			printf("%s: %s setaffinity failed: %d\n", __func__, gtask->gt_name, error);
 
 	}
 	qgroup->tqg_queue[qid].tgc_cnt++;
@@ -724,7 +724,7 @@ taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
 
 	qid = -1;
 	gtask->gt_uniq = uniq;
-	gtask->gt_name = name;
+	snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
 	gtask->gt_irq = irq;
 	gtask->gt_cpu = cpu;
 	mtx_lock(&qgroup->tqg_lock);
@@ -736,7 +736,7 @@ taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
 			}
 		if (qid == -1) {
 			mtx_unlock(&qgroup->tqg_lock);
-			printf("%s: qid not found for %s cpu=%d\n", __func__, name, cpu);
+			printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
 			return (EINVAL);
 		}
 	} else
@@ -775,7 +775,7 @@ taskqgroup_attach_cpu_deferred(struct taskqgroup *qgroup, struct grouptask *gtas
 		}
 	if (qid == -1) {
 		mtx_unlock(&qgroup->tqg_lock);
-		printf("%s: qid not found for cpu=%d\n", __func__, cpu);
+		printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
 		return (EINVAL);
 	}
 	qgroup->tqg_queue[qid].tgc_cnt++;
@@ -805,7 +805,7 @@ taskqgroup_detach(struct taskqgroup *qgroup, struct grouptask *gtask)
 		if (qgroup->tqg_queue[i].tgc_taskq == gtask->gt_taskqueue)
 			break;
 	if (i == qgroup->tqg_cnt)
-		panic("taskqgroup_detach: task not in group\n");
+		panic("taskqgroup_detach: task %s not in group\n", gtask->gt_name);
 	qgroup->tqg_queue[i].tgc_cnt--;
 	LIST_REMOVE(gtask, gt_list);
 	mtx_unlock(&qgroup->tqg_lock);
diff --git a/sys/sys/_task.h b/sys/sys/_task.h
index d3be7198dc2f..d46659f43e87 100644
--- a/sys/sys/_task.h
+++ b/sys/sys/_task.h
@@ -65,7 +65,8 @@ struct grouptask {
 	void			*gt_taskqueue;
 	LIST_ENTRY(grouptask)	gt_list;
 	void			*gt_uniq;
-	char			*gt_name;
+#define GROUPTASK_NAMELEN	32
+	char			gt_name[GROUPTASK_NAMELEN];
 	int16_t			gt_irq;
 	int16_t			gt_cpu;
 };