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authorMarcin Slusarz <marcin.slusarz@gmail.com>2011-11-09 22:20:35 +0100
committerEugeni Dodonov <eugeni.dodonov@intel.com>2012-02-08 18:23:22 -0200
commit20124ee77c3142f99934664dc76b50c66dd4f6ab (patch)
tree9036db68560353aa3abf29db2131e6fc6c4511d0
parente0ea9abc2c9c20b9546c0904c63adbe806118252 (diff)
drm: serialize access to list of debugfs files
Nouveau, when configured with debugfs, creates debugfs files for every channel, so structure holding list of files needs to be protected from simultaneous changes by multiple threads. Without this patch it's possible to hit kernel oops in drm_debugfs_remove_files just by running a couple of xterms with looped glxinfo. Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
-rw-r--r--drivers/gpu/drm/drm_debugfs.c12
-rw-r--r--drivers/gpu/drm/i915/i915_debugfs.c5
-rw-r--r--include/drm/drmP.h4
3 files changed, 16 insertions, 5 deletions
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index 9d8c892d07c..8ac18c46aa8 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -118,7 +118,10 @@ int drm_debugfs_create_files(struct drm_info_list *files, int count,
tmp->minor = minor;
tmp->dent = ent;
tmp->info_ent = &files[i];
- list_add(&(tmp->list), &(minor->debugfs_nodes.list));
+
+ mutex_lock(&minor->debugfs_lock);
+ list_add(&tmp->list, &minor->debugfs_list);
+ mutex_unlock(&minor->debugfs_lock);
}
return 0;
@@ -146,7 +149,8 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
char name[64];
int ret;
- INIT_LIST_HEAD(&minor->debugfs_nodes.list);
+ INIT_LIST_HEAD(&minor->debugfs_list);
+ mutex_init(&minor->debugfs_lock);
sprintf(name, "%d", minor_id);
minor->debugfs_root = debugfs_create_dir(name, root);
if (!minor->debugfs_root) {
@@ -192,8 +196,9 @@ int drm_debugfs_remove_files(struct drm_info_list *files, int count,
struct drm_info_node *tmp;
int i;
+ mutex_lock(&minor->debugfs_lock);
for (i = 0; i < count; i++) {
- list_for_each_safe(pos, q, &minor->debugfs_nodes.list) {
+ list_for_each_safe(pos, q, &minor->debugfs_list) {
tmp = list_entry(pos, struct drm_info_node, list);
if (tmp->info_ent == &files[i]) {
debugfs_remove(tmp->dent);
@@ -202,6 +207,7 @@ int drm_debugfs_remove_files(struct drm_info_list *files, int count,
}
}
}
+ mutex_unlock(&minor->debugfs_lock);
return 0;
}
EXPORT_SYMBOL(drm_debugfs_remove_files);
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 8e95d66800b..a5a5eff18b5 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1505,7 +1505,10 @@ drm_add_fake_info_node(struct drm_minor *minor,
node->minor = minor;
node->dent = ent;
node->info_ent = (void *) key;
- list_add(&node->list, &minor->debugfs_nodes.list);
+
+ mutex_lock(&minor->debugfs_lock);
+ list_add(&node->list, &minor->debugfs_list);
+ mutex_unlock(&minor->debugfs_lock);
return 0;
}
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 40aaebf50af..581d6ec7b10 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -987,7 +987,9 @@ struct drm_minor {
struct proc_dir_entry *proc_root; /**< proc directory entry */
struct drm_info_node proc_nodes;
struct dentry *debugfs_root;
- struct drm_info_node debugfs_nodes;
+
+ struct list_head debugfs_list;
+ struct mutex debugfs_lock; /* Protects debugfs_list. */
struct drm_master *master; /* currently active master for this node */
struct list_head master_list;