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authorAlexander Shishkin <alexander.shishkin@linux.intel.com>2015-10-06 12:47:17 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-10-10 22:24:47 +0300
commit0df771dedf67622b9135709fe4cbfb3222481997 (patch)
tree85ec2ce5e1b233cd2782fe1077bb66e78ad552f6 /drivers/hwtracing
parentfab6266e82a8981cccec55af47589665daf69fb6 (diff)
downloadlinux-0df771dedf67622b9135709fe4cbfb3222481997.tar.xz
stm class: Mark src::link __rcu
Source device's link is protected with srcu, mark it as such to have proper build-time validation of accesses to this field. The update side that's dereferencing it under an update lock also needs an accessor to dereference this field to keep sparse happy. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/stm/core.c9
-rw-r--r--drivers/hwtracing/stm/stm.h2
2 files changed, 7 insertions, 4 deletions
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index b79c42c62557..b6445d9e5453 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -781,17 +781,20 @@ fail_detach:
static void __stm_source_link_drop(struct stm_source_device *src,
struct stm_device *stm)
{
+ struct stm_device *link;
+
spin_lock(&src->link_lock);
- if (WARN_ON_ONCE(src->link != stm)) {
+ link = srcu_dereference_check(src->link, &stm_source_srcu, 1);
+ if (WARN_ON_ONCE(link != stm)) {
spin_unlock(&src->link_lock);
return;
}
- stm_output_free(src->link, &src->output);
+ stm_output_free(link, &src->output);
/* caller must hold stm::link_lock */
list_del_init(&src->link_entry);
/* matches stm_find_device() from stm_source_link_store() */
- stm_put_device(src->link);
+ stm_put_device(link);
rcu_assign_pointer(src->link, NULL);
spin_unlock(&src->link_lock);
diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h
index cf33bf976abe..95ece0292c99 100644
--- a/drivers/hwtracing/stm/stm.h
+++ b/drivers/hwtracing/stm/stm.h
@@ -74,7 +74,7 @@ struct stm_source_device {
struct device dev;
struct stm_source_data *data;
spinlock_t link_lock;
- struct stm_device *link;
+ struct stm_device __rcu *link;
struct list_head link_entry;
/* one output per stm_source device */
struct stp_policy_node *policy_node;