This is a note to let you know that I've just added the patch titled
drm/syncobj: Stop reusing the same struct file for all syncobj -> fd
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: drm-syncobj-stop-reusing-the-same-struct-file-for-all-syncobj-fd.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31 Mon Sep 17 00:00:00 2001
From: Chris Wilson chris@chris-wilson.co.uk Date: Tue, 19 Dec 2017 12:07:00 +0000 Subject: drm/syncobj: Stop reusing the same struct file for all syncobj -> fd
From: Chris Wilson chris@chris-wilson.co.uk
commit e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31 upstream.
The vk cts test: dEQP-VK.api.external.semaphore.opaque_fd.export_multiple_times_temporary
triggers a lot of VFS: Close: file count is 0
Dave pointed out that clearing the syncobj->file from drm_syncobj_file_release() was sufficient to silence the test, but that opens a can of worm since we assumed that the syncobj->file was never unset. Stop trying to reuse the same struct file for every fd pointing to the drm_syncobj, and allocate one file for each fd instead.
v2: Fixup return handling of drm_syncobj_fd_to_handle v2.1: [airlied: fix possible syncobj ref race] v2.2: [jekstrand: back-port to 4.14]
Reported-by: Dave Airlie airlied@redhat.com Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Tested-by: Dave Airlie airlied@redhat.com Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Dave Airlie airlied@redhat.com Signed-off-by: Jason Ekstrand jason@jlekstrand.net Tested-by: Clayton Craft clayton.a.craft@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/drm_syncobj.c | 81 +++++++++++++++--------------------------- include/drm/drm_syncobj.h | 5 -- 2 files changed, 30 insertions(+), 56 deletions(-)
--- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -328,28 +328,11 @@ static const struct file_operations drm_ .release = drm_syncobj_file_release, };
-static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj) -{ - struct file *file = anon_inode_getfile("syncobj_file", - &drm_syncobj_file_fops, - syncobj, 0); - if (IS_ERR(file)) - return PTR_ERR(file); - - drm_syncobj_get(syncobj); - if (cmpxchg(&syncobj->file, NULL, file)) { - /* lost the race */ - fput(file); - } - - return 0; -} - static int drm_syncobj_handle_to_fd(struct drm_file *file_private, u32 handle, int *p_fd) { struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle); - int ret; + struct file *file; int fd;
if (!syncobj) @@ -361,46 +344,40 @@ static int drm_syncobj_handle_to_fd(stru return fd; }
- if (!syncobj->file) { - ret = drm_syncobj_alloc_file(syncobj); - if (ret) - goto out_put_fd; + file = anon_inode_getfile("syncobj_file", + &drm_syncobj_file_fops, + syncobj, 0); + if (IS_ERR(file)) { + put_unused_fd(fd); + drm_syncobj_put(syncobj); + return PTR_ERR(file); } - fd_install(fd, syncobj->file); - drm_syncobj_put(syncobj); + + drm_syncobj_get(syncobj); + fd_install(fd, file); + *p_fd = fd; return 0; -out_put_fd: - put_unused_fd(fd); - drm_syncobj_put(syncobj); - return ret; }
-static struct drm_syncobj *drm_syncobj_fdget(int fd) -{ - struct file *file = fget(fd); - - if (!file) - return NULL; - if (file->f_op != &drm_syncobj_file_fops) - goto err; - - return file->private_data; -err: - fput(file); - return NULL; -}; - static int drm_syncobj_fd_to_handle(struct drm_file *file_private, int fd, u32 *handle) { - struct drm_syncobj *syncobj = drm_syncobj_fdget(fd); + struct drm_syncobj *syncobj; + struct file *file; int ret;
- if (!syncobj) + file = fget(fd); + if (!file) + return -EINVAL; + + if (file->f_op != &drm_syncobj_file_fops) { + fput(file); return -EINVAL; + }
/* take a reference to put in the idr */ + syncobj = file->private_data; drm_syncobj_get(syncobj);
idr_preload(GFP_KERNEL); @@ -409,12 +386,14 @@ static int drm_syncobj_fd_to_handle(stru spin_unlock(&file_private->syncobj_table_lock); idr_preload_end();
- if (ret < 0) { - fput(syncobj->file); - return ret; - } - *handle = ret; - return 0; + if (ret > 0) { + *handle = ret; + ret = 0; + } else + drm_syncobj_put(syncobj); + + fput(file); + return ret; }
int drm_syncobj_import_sync_file_fence(struct drm_file *file_private, --- a/include/drm/drm_syncobj.h +++ b/include/drm/drm_syncobj.h @@ -60,11 +60,6 @@ struct drm_syncobj { * locks cb_list and write-locks fence. */ spinlock_t lock; - /** - * @file: - * a file backing for this syncobj. - */ - struct file *file; };
typedef void (*drm_syncobj_func_t)(struct drm_syncobj *syncobj,
Patches currently in stable-queue which might be from chris@chris-wilson.co.uk are
queue-4.14/drm-syncobj-stop-reusing-the-same-struct-file-for-all-syncobj-fd.patch