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authorDaniel Vetter <daniel.vetter@ffwll.ch>2015-09-28 21:42:40 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-10-16 15:50:54 +0200
commitea487835e8876abf7ad909636e308c801a2bcda6 (patch)
treeead40458ef2c4f333228113e38d7facb01475a50
parent1c806a6e76795b72b09e2bf967d23b4ed791d0a2 (diff)
downloadop-kernel-dev-ea487835e8876abf7ad909636e308c801a2bcda6.zip
op-kernel-dev-ea487835e8876abf7ad909636e308c801a2bcda6.tar.gz
drm: Enforce unlocked ioctl operation for kms driver ioctls
With the prep patches for i915 all kms drivers either have DRM_UNLOCKED on all their ioctls. Or the ioctl always directly returns with an invariant return value when in modeset mode. But that's only the case for i915 and radeon. The drm core ioctls are unfortunately too much a mess still to dare this. Follow-up patches will remove DRM_UNLOCKED from all kms drivers to prove that this is indeed the case. Also update the documentation. v2: Really only do this for driver ioctls, spotted by David Herrmann. And drop spurious whitespace change. Cc: David Herrmann <dh.herrmann@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
-rw-r--r--Documentation/DocBook/drm.tmpl4
-rw-r--r--drivers/gpu/drm/drm_ioctl.c10
2 files changed, 11 insertions, 3 deletions
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 8d0cbf1..2bc6c80 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -3684,7 +3684,9 @@ int num_ioctls;</synopsis>
</para></listitem>
<listitem><para>
DRM_UNLOCKED - The ioctl handler will be called without locking
- the DRM global mutex
+ the DRM global mutex. This is the enforced default for kms drivers
+ (i.e. using the DRIVER_MODESET flag) and hence shouldn't be used
+ any more for new drivers.
</para></listitem>
</itemizedlist>
</para>
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 530c501..8ce2a0c 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -691,13 +691,16 @@ long drm_ioctl(struct file *filp,
char stack_kdata[128];
char *kdata = NULL;
unsigned int usize, asize, drv_size;
+ bool is_driver_ioctl;
dev = file_priv->minor->dev;
if (drm_device_is_unplugged(dev))
return -ENODEV;
- if (nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END) {
+ is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
+
+ if (is_driver_ioctl) {
/* driver ioctl */
if (nr - DRM_COMMAND_BASE >= dev->driver->num_ioctls)
goto err_i1;
@@ -756,7 +759,10 @@ long drm_ioctl(struct file *filp,
memset(kdata, 0, usize);
}
- if (ioctl->flags & DRM_UNLOCKED)
+ /* Enforce sane locking for kms driver ioctls. Core ioctls are
+ * too messy still. */
+ if ((drm_core_check_feature(dev, DRIVER_MODESET) && is_driver_ioctl) ||
+ (ioctl->flags & DRM_UNLOCKED))
retcode = func(dev, kdata, file_priv);
else {
mutex_lock(&drm_global_mutex);
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