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authorNoralf Trønnes <noralf@tronnes.org>2019-04-23 16:53:53 +0200
committerNoralf Trønnes <noralf@tronnes.org>2019-04-24 15:57:43 +0200
commit1de7259275ca4ebc66459de6620558d3e38d4142 (patch)
treeacdb8a9f6a5920784b3e93185de4b9393f0f94a7
parentb8c7d7bc8386924f57aac0a745ae3240f07b743b (diff)
drm/fb-helper: Fix drm_fb_helper_firmware_config() NULL pointer derefdrm-misc-next-fixes-2019-04-24
Non-atomic drivers like ast doesn't have connector->state set resulting in a NULL pointer deref: [ 29.609593] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 29.609619] Call Trace: [ 29.609630] ? drm_helper_probe_single_connector_modes+0x27f/0x680 [ 29.609640] drm_setup_crtcs+0x431/0xd80 [drm_kms_helper] [ 29.753065] __drm_fb_helper_initial_config_and_unlock+0x6f/0x6a0 [ 29.753160] ? drm_modeset_unlock_all+0x31/0x50 [drm] [ 29.765758] ast_fbdev_init+0xa8/0xc0 [ast] [ 29.765762] ast_driver_load.cold.7+0x2b3/0xe11 [ast] [ 29.765775] drm_dev_register+0x111/0x150 [drm] Fix by bailing out if the driver does not support atomic modesetting. Fixes: 09ded8af57bc ("drm/i915/fbdev: Move intel_fb_initial_config() to fbdev helper") Reported-by: Thomas Zimmermann <tzimmermann@suse.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Tested-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20190423145353.30158-1-noralf@tronnes.org
-rw-r--r--drivers/gpu/drm/drm_fb_helper.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 226c0910ba91..498f95c3e81d 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2588,6 +2588,9 @@ static bool drm_fb_helper_firmware_config(struct drm_fb_helper *fb_helper,
int num_connectors_detected = 0;
struct drm_modeset_acquire_ctx ctx;
+ if (!drm_drv_uses_atomic_modeset(dev))
+ return false;
+
save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL);
if (!save_enabled)
return false;