Robin Murphy 747e5a5ff2 drm: hdlcd: Fix cleanup order ... If hdlcd_drm_bind() fails at drm_fbdev_cma_init(), its cleanup will call drm_mode_config_cleanup() as if to balance drm_mode_config_reset(). The net result is that drm_connector_cleanup() will clean up the active connectors long before component_unbind_all() gets called, so when the connector later tries to clean up itself after being unbound, Bad Things can happen: [ 4.121888] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 4.129951] pgd = ffffff80091e0000 [ 4.133345] [00000000] *pgd=00000009ffffe003, *pud=00000009ffffe003, *pmd=0000000000000000 [ 4.141613] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 4.147144] Modules linked in: [ 4.150188] CPU: 0 PID: 122 Comm: kworker/u12:2 Not tainted 4.8.0-rc2+ #989 [ 4.157097] Hardware name: ARM Juno development board (r1) (DT) [ 4.162981] Workqueue: deferwq deferred_probe_work_func [ 4.168173] task: ffffffc975d93200 task.stack: ffffffc975dac000 [ 4.174055] PC is at drm_connector_cleanup+0x58/0x1c0 [ 4.179074] LR is at tda998x_unbind+0x24/0x40 [ 4.183401] pc : [<ffffff80084c46f0>] lr : [<ffffff800850414c>] pstate: 00000045 [ 4.190750] sp : ffffffc975dafa10 [ 4.194041] x29: ffffffc975dafa10 x28: ffffffc9768152a8 [ 4.199325] x27: ffffffc97ff46450 x26: ffffff8008d99000 [ 4.204608] x25: dead000000000100 x24: dead000000000200 [ 4.209891] x23: ffffffc976bf91e8 x22: 0000000000000000 [ 4.215172] x21: ffffffc976bf9170 x20: ffffffc976bf9170 [ 4.220454] x19: ffffffc976bf9018 x18: 0000000000000000 [ 4.225737] x17: 0000000074ce71ee x16: 000000008ff5d35f [ 4.231019] x15: ffffffc97681e91c x14: ffffffffffffffff [ 4.236301] x13: ffffffc97681e185 x12: 0000000000000038 [ 4.241583] x11: 0101010101010101 x10: 0000000000000000 [ 4.246866] x9 : 0000000040000000 x8 : 0000000000210d00 [ 4.252148] x7 : ffffffc97fea8c00 x6 : 000000000000001b [ 4.257430] x5 : ffffff80084b7b8c x4 : 0000000000000080 [ 4.262712] x3 : ffffff8008504128 x2 : ffffffc975df3800 [ 4.267993] x1 : 0000000000000000 x0 : 0000000000000000 ... [ 4.750937] [<ffffff80084c46f0>] drm_connector_cleanup+0x58/0x1c0 [ 4.756990] [<ffffff800850414c>] tda998x_unbind+0x24/0x40 [ 4.762354] [<ffffff8008507918>] component_unbind.isra.4+0x28/0x50 [ 4.768492] [<ffffff8008507a0c>] component_unbind_all+0xcc/0xd8 [ 4.774373] [<ffffff80084d5adc>] hdlcd_drm_bind+0x234/0x418 [ 4.779909] [<ffffff8008507b58>] try_to_bring_up_master+0x140/0x1a0 [ 4.786133] [<ffffff8008507c50>] component_add+0x98/0x170 [ 4.791496] [<ffffff8008504b90>] tda998x_probe+0x18/0x20 [ 4.796774] [<ffffff80086bf914>] i2c_device_probe+0x164/0x258 [ 4.802481] [<ffffff800850d094>] driver_probe_device+0x204/0x2b0 [ 4.808447] [<ffffff800850d28c>] __device_attach_driver+0x9c/0xf8 [ 4.814498] [<ffffff800850b108>] bus_for_each_drv+0x58/0x98 [ 4.820033] [<ffffff800850cd64>] __device_attach+0xc4/0x138 [ 4.825567] [<ffffff800850d338>] device_initial_probe+0x10/0x18 [ 4.831446] [<ffffff800850c124>] bus_probe_device+0x94/0xa0 [ 4.836981] [<ffffff800850c5b0>] deferred_probe_work_func+0x78/0xb0 [ 4.843207] [<ffffff80080d2998>] process_one_work+0x118/0x378 [ 4.848914] [<ffffff80080d2c40>] worker_thread+0x48/0x498 [ 4.854276] [<ffffff80080d8918>] kthread+0xd0/0xe8 [ 4.859036] [<ffffff8008082e90>] ret_from_fork+0x10/0x40 [ 4.864314] Code: f2fbd5b9 f2fbd5b8 f8478ee0 eb17001f (f9400013) [ 4.870472] ---[ end trace a643cfe4ce1d838b ]--- Fix this by moving the drm_mode_config_cleanup() much later such that it correctly balances drm_mode_config_init(). Suggested-by: Russell King <linux@armlinux.org.uk> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>		2016-11-25 15:51:57 +00:00
..
drm	drm: hdlcd: Fix cleanup order	2016-11-25 15:51:57 +00:00
host1x	drm/tegra: dsi: Enhance runtime power management	2016-08-24 15:58:57 +02:00
ipu-v3	gpu: ipu-v3: Use ERR_CAST instead of ERR_PTR(PTR_ERR())	2016-10-17 08:21:53 +02:00
vga	vgaarbiter: rst-ifiy and polish kerneldoc	2016-08-16 18:49:56 +02:00
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