drm/vmwgfx: Fix a destoy-while-held mutex problem.
commit 73a88250b70954a8f27c2444e1c2411bba3c29d9 upstream.
When validating legacy surfaces, the backup bo might be destroyed at
surface validate time. However, the kms resource validation code may have
the bo reserved, so we will destroy a locked mutex. While there shouldn't
be any other users of that mutex when it is destroyed, it causes a lock
leak and thus throws a lockdep error.
Fix this by having the kms resource validation code hold a reference to
the bo while we have it reserved. We do this by introducing a validation
context which might come in handy when the kms code is extended to validate
multiple resources or buffers.
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index bf28ccc..87086af 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -27,7 +27,6 @@
#include "vmwgfx_kms.h"
-
/* Might need a hrtimer here? */
#define VMWGFX_PRESENT_RATE ((HZ / 60 > 0) ? HZ / 60 : 1)
@@ -1933,9 +1932,12 @@
* Helper to be used if an error forces the caller to undo the actions of
* vmw_kms_helper_resource_prepare.
*/
-void vmw_kms_helper_resource_revert(struct vmw_resource *res)
+void vmw_kms_helper_resource_revert(struct vmw_validation_ctx *ctx)
{
- vmw_kms_helper_buffer_revert(res->backup);
+ struct vmw_resource *res = ctx->res;
+
+ vmw_kms_helper_buffer_revert(ctx->buf);
+ vmw_dmabuf_unreference(&ctx->buf);
vmw_resource_unreserve(res, false, NULL, 0);
mutex_unlock(&res->dev_priv->cmdbuf_mutex);
}
@@ -1952,10 +1954,14 @@
* interrupted by a signal.
*/
int vmw_kms_helper_resource_prepare(struct vmw_resource *res,
- bool interruptible)
+ bool interruptible,
+ struct vmw_validation_ctx *ctx)
{
int ret = 0;
+ ctx->buf = NULL;
+ ctx->res = res;
+
if (interruptible)
ret = mutex_lock_interruptible(&res->dev_priv->cmdbuf_mutex);
else
@@ -1974,6 +1980,8 @@
res->dev_priv->has_mob);
if (ret)
goto out_unreserve;
+
+ ctx->buf = vmw_dmabuf_reference(res->backup);
}
ret = vmw_resource_validate(res);
if (ret)
@@ -1981,7 +1989,7 @@
return 0;
out_revert:
- vmw_kms_helper_buffer_revert(res->backup);
+ vmw_kms_helper_buffer_revert(ctx->buf);
out_unreserve:
vmw_resource_unreserve(res, false, NULL, 0);
out_unlock:
@@ -1997,11 +2005,13 @@
* @out_fence: Optional pointer to a fence pointer. If non-NULL, a
* ref-counted fence pointer is returned here.
*/
-void vmw_kms_helper_resource_finish(struct vmw_resource *res,
- struct vmw_fence_obj **out_fence)
+void vmw_kms_helper_resource_finish(struct vmw_validation_ctx *ctx,
+ struct vmw_fence_obj **out_fence)
{
- if (res->backup || out_fence)
- vmw_kms_helper_buffer_finish(res->dev_priv, NULL, res->backup,
+ struct vmw_resource *res = ctx->res;
+
+ if (ctx->buf || out_fence)
+ vmw_kms_helper_buffer_finish(res->dev_priv, NULL, ctx->buf,
out_fence, NULL);
vmw_resource_unreserve(res, false, NULL, 0);
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
index ff4803c..2dd0539 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
@@ -183,6 +183,11 @@
int set_gui_y;
};
+struct vmw_validation_ctx {
+ struct vmw_resource *res;
+ struct vmw_dma_buffer *buf;
+};
+
#define vmw_crtc_to_du(x) \
container_of(x, struct vmw_display_unit, crtc)
#define vmw_connector_to_du(x) \
@@ -233,9 +238,10 @@
struct drm_vmw_fence_rep __user *
user_fence_rep);
int vmw_kms_helper_resource_prepare(struct vmw_resource *res,
- bool interruptible);
-void vmw_kms_helper_resource_revert(struct vmw_resource *res);
-void vmw_kms_helper_resource_finish(struct vmw_resource *res,
+ bool interruptible,
+ struct vmw_validation_ctx *ctx);
+void vmw_kms_helper_resource_revert(struct vmw_validation_ctx *ctx);
+void vmw_kms_helper_resource_finish(struct vmw_validation_ctx *ctx,
struct vmw_fence_obj **out_fence);
int vmw_kms_readback(struct vmw_private *dev_priv,
struct drm_file *file_priv,
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
index f423590..a6ca218 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
@@ -753,12 +753,13 @@
struct vmw_framebuffer_surface *vfbs =
container_of(framebuffer, typeof(*vfbs), base);
struct vmw_kms_sou_surface_dirty sdirty;
+ struct vmw_validation_ctx ctx;
int ret;
if (!srf)
srf = &vfbs->surface->res;
- ret = vmw_kms_helper_resource_prepare(srf, true);
+ ret = vmw_kms_helper_resource_prepare(srf, true, &ctx);
if (ret)
return ret;
@@ -777,7 +778,7 @@
ret = vmw_kms_helper_dirty(dev_priv, framebuffer, clips, vclips,
dest_x, dest_y, num_clips, inc,
&sdirty.base);
- vmw_kms_helper_resource_finish(srf, out_fence);
+ vmw_kms_helper_resource_finish(&ctx, out_fence);
return ret;
}
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
index 94ad8d2..8b91450 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -977,12 +977,13 @@
struct vmw_framebuffer_surface *vfbs =
container_of(framebuffer, typeof(*vfbs), base);
struct vmw_stdu_dirty sdirty;
+ struct vmw_validation_ctx ctx;
int ret;
if (!srf)
srf = &vfbs->surface->res;
- ret = vmw_kms_helper_resource_prepare(srf, true);
+ ret = vmw_kms_helper_resource_prepare(srf, true, &ctx);
if (ret)
return ret;
@@ -1005,7 +1006,7 @@
dest_x, dest_y, num_clips, inc,
&sdirty.base);
out_finish:
- vmw_kms_helper_resource_finish(srf, out_fence);
+ vmw_kms_helper_resource_finish(&ctx, out_fence);
return ret;
}