static struct request *
noop_former_request(struct request_queue *q, struct request *rq)
{
struct noop_data *nd = q->elevator->elevator_data;
if (rq->queuelist.prev == &nd->queue)
return NULL;
return list_prev_entry(rq, queuelist);
}
/*
* coresight_disable_path_from : Disable components in the given path beyond
* @nd in the list. If @nd is NULL, all the components, except the SOURCE are
* disabled.
*/
static void coresight_disable_path_from(struct list_head *path,
struct coresight_node *nd)
{
u32 type;
struct coresight_device *csdev, *parent, *child;
if (!nd)
nd = list_first_entry(path, struct coresight_node, link);
list_for_each_entry_continue(nd, path, link) {
csdev = nd->csdev;
type = csdev->type;
/*
* ETF devices are tricky... They can be a link or a sink,
* depending on how they are configured. If an ETF has been
* "activated" it will be configured as a sink, otherwise
* go ahead with the link configuration.
*/
if (type == CORESIGHT_DEV_TYPE_LINKSINK)
type = (csdev == coresight_get_sink(path)) ?
CORESIGHT_DEV_TYPE_SINK :
CORESIGHT_DEV_TYPE_LINK;
switch (type) {
case CORESIGHT_DEV_TYPE_SINK:
coresight_disable_sink(csdev);
break;
case CORESIGHT_DEV_TYPE_SOURCE:
/*
* We skip the first node in the path assuming that it
* is the source. So we don't expect a source device in
* the middle of a path.
*/
WARN_ON(1);
break;
case CORESIGHT_DEV_TYPE_LINK:
parent = list_prev_entry(nd, link)->csdev;
child = list_next_entry(nd, link)->csdev;
coresight_disable_link(csdev, parent, child);
break;
default:
break;
}
}
void coresight_disable_path(struct list_head *path)
{
u32 type;
struct coresight_node *nd;
struct coresight_device *csdev, *parent, *child;
list_for_each_entry(nd, path, link) {
csdev = nd->csdev;
type = csdev->type;
/*
* ETF devices are tricky... They can be a link or a sink,
* depending on how they are configured. If an ETF has been
* "activated" it will be configured as a sink, otherwise
* go ahead with the link configuration.
*/
if (type == CORESIGHT_DEV_TYPE_LINKSINK)
type = (csdev == coresight_get_sink(path)) ?
CORESIGHT_DEV_TYPE_SINK :
CORESIGHT_DEV_TYPE_LINK;
switch (type) {
case CORESIGHT_DEV_TYPE_SINK:
coresight_disable_sink(csdev);
break;
case CORESIGHT_DEV_TYPE_SOURCE:
/* sources are disabled from either sysFS or Perf */
break;
case CORESIGHT_DEV_TYPE_LINK:
parent = list_prev_entry(nd, link)->csdev;
child = list_next_entry(nd, link)->csdev;
coresight_disable_link(csdev, parent, child);
break;
default:
break;
}
}
static int __klp_enable_patch(struct klp_patch *patch)
{
struct klp_object *obj;
int ret;
if (klp_transition_patch)
return -EBUSY;
if (WARN_ON(patch->enabled))
return -EINVAL;
/* enforce stacking: only the first disabled patch can be enabled */
if (patch->list.prev != &klp_patches &&
!list_prev_entry(patch, list)->enabled)
return -EBUSY;
/*
* A reference is taken on the patch module to prevent it from being
* unloaded.
*/
if (!try_module_get(patch->mod))
return -ENODEV;
pr_notice("enabling patch '%s'\n", patch->mod->name);
klp_init_transition(patch, KLP_PATCHED);
/*
* Enforce the order of the func->transition writes in
* klp_init_transition() and the ops->func_stack writes in
* klp_patch_object(), so that klp_ftrace_handler() will see the
* func->transition updates before the handler is registered and the
* new funcs become visible to the handler.
*/
smp_wmb();
klp_for_each_object(patch, obj) {
if (!klp_is_object_loaded(obj))
continue;
ret = klp_pre_patch_callback(obj);
if (ret) {
pr_warn("pre-patch callback failed for object '%s'\n",
klp_is_module(obj) ? obj->name : "vmlinux");
goto err;
}
ret = klp_patch_object(obj);
if (ret) {
pr_warn("failed to patch object '%s'\n",
klp_is_module(obj) ? obj->name : "vmlinux");
goto err;
}
}
klp_start_transition();
klp_try_complete_transition();
patch->enabled = true;
return 0;
err:
pr_warn("failed to enable patch '%s'\n", patch->mod->name);
klp_cancel_transition();
return ret;
}
