From 4089e272ac61603931beb024d4d640de2cb390e0 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Thu, 10 Jan 2019 19:19:31 +0900
Subject: [PATCH] gpu/drm: Fix lock held when returning to user space.
We need to call drm_modeset_acquire_fini() when drm_atomic_state_alloc()
failed or call drm_modeset_acquire_init() after drm_atomic_state_alloc()
succeeded.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+6ea337c427f5083ebdf2@syzkaller.appspotmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1547115571-21219-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
---
drivers/gpu/drm/drm_atomic_uapi.c | 3 +--
drivers/gpu/drm/drm_mode_object.c | 4 ++--
2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index c40889888a16b..9a1f41adfc674 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -1296,12 +1296,11 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
(arg->flags & DRM_MODE_PAGE_FLIP_EVENT))
return -EINVAL;
- drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
-
state = drm_atomic_state_alloc(dev);
if (!state)
return -ENOMEM;
+ drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
state->acquire_ctx = &ctx;
state->allow_modeset = !!(arg->flags & DRM_MODE_ATOMIC_ALLOW_MODESET);
diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
index cd9bc0ce9be07..004191d017722 100644
--- a/drivers/gpu/drm/drm_mode_object.c
+++ b/drivers/gpu/drm/drm_mode_object.c
@@ -459,11 +459,11 @@ static int set_property_atomic(struct drm_mode_object *obj,
struct drm_modeset_acquire_ctx ctx;
int ret;
- drm_modeset_acquire_init(&ctx, 0);
-
state = drm_atomic_state_alloc(dev);
if (!state)
return -ENOMEM;
+
+ drm_modeset_acquire_init(&ctx, 0);
state->acquire_ctx = &ctx;
retry:
if (prop == state->dev->mode_config.dpms_property) {
--
2.30.2