scsi: remove unused kobj map for sd devie to avoid memleak

hulk inclusion
category: bugfix
bugzilla: 168625
CVE: NA

-------------------------------------------------

After calling add_disk, we have register new kobj map for sd device,
then we can remove old unused kobj map which probed by sd_remove.
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

block/genhd.c

@@ -663,6 +663,14 @@ void blk_unregister_region(dev_t devt, unsigned long range)
 
 EXPORT_SYMBOL(blk_unregister_region);
 
+void blk_delete_region(dev_t devt, unsigned long range,
+			struct kobject *(*probe)(dev_t, int *, void *))
+{
+	kobj_delete(bdev_map, devt, range, probe);
+}
+
+EXPORT_SYMBOL(blk_delete_region);
+
 static struct kobject *exact_match(dev_t devt, int *partno, void *data)
 {
 	struct gendisk *p = data;

drivers/base/map.c

@@ -92,6 +92,34 @@ void kobj_unmap(struct kobj_map *domain, dev_t dev, unsigned long range)
 	kfree(found);
 }
 
+void kobj_delete(struct kobj_map *domain, dev_t dev, unsigned long range,
+		kobj_probe_t *probe)
+{
+	unsigned n = MAJOR(dev + range - 1) - MAJOR(dev) + 1;
+	unsigned index = MAJOR(dev);
+	unsigned i;
+	struct probe *found = NULL;
+
+	if (n > 255)
+		n = 255;
+
+	mutex_lock(domain->lock);
+	for (i = 0; i < n; i++, index++) {
+		struct probe **s;
+		for (s = &domain->probes[index % 255]; *s; s = &(*s)->next) {
+			struct probe *p = *s;
+			if (p->dev == dev && p->range == range && p->get == probe) {
+				*s = p->next;
+				if (!found)
+					found = p;
+				break;
+			}
+		}
+	}
+	mutex_unlock(domain->lock);
+	kfree(found);
+}
+
 struct kobject *kobj_lookup(struct kobj_map *domain, dev_t dev, int *index)
 {
 	struct kobject *kobj;

drivers/scsi/sd.c

@@ -3488,6 +3488,7 @@ static int sd_probe(struct device *dev)
 			sdp->host->hostt->rpm_autosuspend_delay);
 	}
 	device_add_disk(dev, gd, NULL);
+	blk_delete_region(disk_devt(sdkp->disk), SD_MINORS, sd_default_probe);
 	if (sdkp->capacity)
 		sd_dif_config_host(sdkp);
 

include/linux/genhd.h

@@ -349,6 +349,8 @@ extern void blk_register_region(dev_t devt, unsigned long range,
 			int (*lock)(dev_t, void *),
 			void *data);
 extern void blk_unregister_region(dev_t devt, unsigned long range);
+extern void blk_delete_region(dev_t devt, unsigned long range,
+			struct kobject *(*probe)(dev_t, int *, void *));
 
 #define alloc_disk_node(minors, node_id)				\
 ({									\

include/linux/kobj_map.h

@@ -14,6 +14,8 @@ struct kobj_map;
 int kobj_map(struct kobj_map *, dev_t, unsigned long, struct module *,
 	     kobj_probe_t *, int (*)(dev_t, void *), void *);
 void kobj_unmap(struct kobj_map *, dev_t, unsigned long);
+void kobj_delete(struct kobj_map *, dev_t, unsigned long,
+		kobj_probe_t *);
 struct kobject *kobj_lookup(struct kobj_map *, dev_t, int *);
 struct kobj_map *kobj_map_init(kobj_probe_t *, struct mutex *);