Re: Bug report: HiBMC crash

From: John Garry
Date: Fri Sep 21 2018 - 04:11:38 EST


On 21/09/2018 06:49, Liuxinliang (Matthew Liu) wrote:
Hi John,
Thank you for reporting bug.
I am now using 4.18.7. I haven't found this issue yet.
I will try linux-next and figure out what's wrong with it.

Thanks,
Xinliang



As mentioned in internal mail, the issue may be that the surface depth/bpp we were using the in the driver was previously invalid, but code has since been added in v4.19 to reject this. Specifically it looks like this patch:

commit 70109354fed232dfce8fb2c7cadf635acbe03e19
Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Date: Wed Sep 5 16:31:16 2018 +0100

drm: Reject unknown legacy bpp and depth for drm_mode_addfb ioctl


Thanks,
John

On 2018/9/20 19:23, John Garry wrote:
On 20/09/2018 11:04, John Garry wrote:
Hi,

I am seeing this crash below on linux-next (20 Sept).

This is on an arm64 D05 board, which includes the HiBMC device. D06 was
also crashing for what looked like same reason. I am using standard
defconfig, except DRM and DRM_HISI_HIBMC are built-in.

Is this a known issue? I tested v4.19-rc3 and it had no such crash.

The origin seems to be here, where pointer info is not checked for NULL
for safety:
static int framebuffer_check(struct drm_device *dev,
const struct drm_mode_fb_cmd2 *r)
{
...

/* now let the driver pick its own format info */
info = drm_get_format_info(dev, r);

...

for (i = 0; i < info->num_planes; i++) {
unsigned int width = fb_plane_width(r->width, info, i);
unsigned int height = fb_plane_height(r->height, info, i);
unsigned int cpp = info->cpp[i];



Upon closer inspection the crash is actually from hibmc probe error
handling path, specifically
hibmc_fbdev_destroy()->drm_framebuffer_put() is called with fb holding
the error value from hibmc_framebuffer_init(), as shown:

static int hibmc_drm_fb_create(struct drm_fb_helper *helper,
struct drm_fb_helper_surface_size *sizes)
{

...

hi_fbdev->fb = hibmc_framebuffer_init(priv->dev, &mode_cmd, gobj);
if (IS_ERR(hi_fbdev->fb)) {
ret = PTR_ERR(hi_fbdev->fb);

*** hi_fbdev->fb holds error code ***

DRM_ERROR("failed to initialize framebuffer: %d\n", ret);
goto out_release_fbi;
}


static void hibmc_fbdev_destroy(struct hibmc_fbdev *fbdev)
{
struct hibmc_framebuffer *gfb = fbdev->fb;
struct drm_fb_helper *fbh = &fbdev->helper;

drm_fb_helper_unregister_fbi(fbh);

drm_fb_helper_fini(fbh);

** &gfb->fb holds error code, not pointer ***

if (gfb)
drm_framebuffer_put(&gfb->fb);
}

This change fixes the crash for me:

hi_fbdev->fb = hibmc_framebuffer_init(priv->dev, &mode_cmd, gobj);
if (IS_ERR(hi_fbdev->fb)) {
ret = PTR_ERR(hi_fbdev->fb);
+ hi_fbdev->fb = NULL;
DRM_ERROR("failed to initialize framebuffer: %d\n", ret);
goto out_release_fbi;
}

Why we're hitting the error path at all, I don't know.

And, having said all that, the code I pointed out in
framebuffer_check() still does not seem safe for same reason I
mentioned originally.

John

John

[ 9.220446] pci 0007:90:00.0: can't derive routing for PCI INT A
[ 9.226517] hibmc-drm 0007:91:00.0: PCI INT A: no GSI
[ 9.231847] [TTM] Zone kernel: Available graphics memory:
16297696 kiB
[ 9.238536] [TTM] Zone dma32: Available graphics memory: 2097152
kiB
[ 9.245133] [TTM] Initializing pool allocator
[ 9.249536] [TTM] Initializing DMA pool allocator
[ 9.254340] [drm] Supports vblank timestamp caching Rev 2
(21.10.2013).
[ 9.261026] [drm] No driver support for vblank timestamp query.
[ 9.272431] WARNING: CPU: 16 PID: 293 at
drivers/gpu/drm/drm_fourcc.c:221 drm_format_info.part.1+0x0/0x8
[ 9.282014] Modules linked in:
[ 9.285095] CPU: 16 PID: 293 Comm: kworker/16:1 Not tainted
4.19.0-rc4-next-20180920-00001-g9b0012c #322
[ 9.294677] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 IT21 Nemo 2.0 RC0 04/18/2018
[ 9.303915] Workqueue: events work_for_cpu_fn
[ 9.308314] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 9.313150] pc : drm_format_info.part.1+0x0/0x8
[ 9.317724] lr : drm_get_format_info+0x90/0x98
[ 9.322208] sp : ffff00000af1baf0
[ 9.325549] x29: ffff00000af1baf0 x28: 0000000000000000
[ 9.330915] x27: ffff00000af1bcb0 x26: ffff8017d3018800
[ 9.336279] x25: ffff8017d28a0018 x24: ffff8017d2f80018
[ 9.341644] x23: ffff8017d3018670 x22: ffff00000af1bbf0
[ 9.347009] x21: ffff8017d3018a70 x20: ffff00000af1bbf0
[ 9.352373] x19: ffff00000af1bbf0 x18: ffffffffffffffff
[ 9.357737] x17: 0000000000000000 x16: 0000000000000000
[ 9.363102] x15: ffff0000092296c8 x14: ffff000009074000
[ 9.368466] x13: 0000000000000000 x12: 0000000000000000
[ 9.373831] x11: ffff8017fbffe008 x10: ffff8017db9307e8
[ 9.379195] x9 : 0000000000000000 x8 : ffff8017b517c800
[ 9.384560] x7 : 0000000000000000 x6 : 000000000000003f
[ 9.389924] x5 : 0000000000000040 x4 : 0000000000000000
[ 9.395289] x3 : ffff000008d04000 x2 : 0000000056555941
[ 9.400654] x1 : ffff000008d04f70 x0 : 0000000000000044
[ 9.406019] Call trace:
[ 9.408483] drm_format_info.part.1+0x0/0x8
[ 9.412705] drm_helper_mode_fill_fb_struct+0x20/0x80
[ 9.417807] hibmc_framebuffer_init+0x48/0xd0
[ 9.422204] hibmc_drm_fb_create+0x1ec/0x3c8
[ 9.426513] __drm_fb_helper_initial_config_and_unlock+0x1cc/0x418
[ 9.432756] drm_fb_helper_initial_config+0x3c/0x48
[ 9.437681] hibmc_fbdev_init+0xb4/0x198
[ 9.441638] hibmc_pci_probe+0x2f4/0x3c8
[ 9.445598] local_pci_probe+0x3c/0xb0
[ 9.449379] work_for_cpu_fn+0x18/0x28
[ 9.453161] process_one_work+0x1e0/0x318
[ 9.457207] worker_thread+0x228/0x450
[ 9.460988] kthread+0x128/0x130
[ 9.464244] ret_from_fork+0x10/0x18
[ 9.467850] ---[ end trace 2695ffa0af5be373 ]---
[ 9.472525] WARNING: CPU: 16 PID: 293 at
drivers/gpu/drm/drm_framebuffer.c:730 drm_framebuffer_init+0x18/0x110
[ 9.482634] Modules linked in:
[ 9.485714] CPU: 16 PID: 293 Comm: kworker/16:1 Tainted: G W
4.19.0-rc4-next-20180920-00001-g9b0012c #322
[ 9.496702] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 IT21 Nemo 2.0 RC0 04/18/2018
[ 9.505936] Workqueue: events work_for_cpu_fn
[ 9.510333] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 9.515170] pc : drm_framebuffer_init+0x18/0x110
[ 9.519831] lr : hibmc_framebuffer_init+0x60/0xd0
[ 9.524578] sp : ffff00000af1baf0
[ 9.527920] x29: ffff00000af1baf0 x28: 0000000000000000
[ 9.533284] x27: ffff00000af1bcb0 x26: ffff8017d3018800
[ 9.538649] x25: ffff8017d28a0018 x24: ffff8017d2f80018
[ 9.544014] x23: ffff8017d3018670 x22: ffff00000af1bbf0
[ 9.549378] x21: ffff8017d3018a70 x20: ffff8017d2420000
[ 9.554743] x19: ffff8017b517c700 x18: ffffffffffffffff
[ 9.560108] x17: 0000000000000000 x16: 0000000000000000
[ 9.565472] x15: ffff0000092296c8 x14: ffff000009074000
[ 9.570837] x13: 0000000000000000 x12: 0000000000000000
[ 9.576201] x11: ffff8017fbffe008 x10: ffff8017db9307e8
[ 9.581566] x9 : 0000000000000000 x8 : ffff8017b517c800
[ 9.586930] x7 : 0000000000000000 x6 : 000000000000003f
[ 9.592295] x5 : 0000000000000040 x4 : 0000000000000000
[ 9.597660] x3 : ffff00000af1bc24 x2 : ffff000008d23f50
[ 9.603024] x1 : ffff8017b517c700 x0 : 0000000000000000
[ 9.608389] Call trace:
[ 9.610852] drm_framebuffer_init+0x18/0x110
[ 9.615161] hibmc_framebuffer_init+0x60/0xd0
[ 9.619558] hibmc_drm_fb_create+0x1ec/0x3c8
[ 9.623867] __drm_fb_helper_initial_config_and_unlock+0x1cc/0x418
[ 9.630110] drm_fb_helper_initial_config+0x3c/0x48
[ 9.635034] hibmc_fbdev_init+0xb4/0x198
[ 9.638991] hibmc_pci_probe+0x2f4/0x3c8
[ 9.642949] local_pci_probe+0x3c/0xb0
[ 9.646731] work_for_cpu_fn+0x18/0x28
[ 9.650513] process_one_work+0x1e0/0x318
[ 9.654558] worker_thread+0x228/0x450
[ 9.658339] kthread+0x128/0x130
[ 9.661594] ret_from_fork+0x10/0x18
[ 9.665199] ---[ end trace 2695ffa0af5be374 ]---
[ 9.669868] [drm:hibmc_framebuffer_init] *ERROR* drm_framebuffer_init
failed: -22
[ 9.677434] [drm:hibmc_drm_fb_create] *ERROR* failed to initialize
framebuffer: -22
[ 9.685182] [drm:hibmc_fbdev_init] *ERROR* failed to setup initial
conn config: -22
[ 9.692926] [drm:hibmc_pci_probe] *ERROR* failed to initialize fbdev:
-22
[ 9.699791] Unable to handle kernel NULL pointer dereference at
virtual address 000000000000001a
[ 9.708672] Mem abort info:
[ 9.711489] ESR = 0x96000004
[ 9.714570] Exception class = DABT (current EL), IL = 32 bits
[ 9.720551] SET = 0, FnV = 0
[ 9.723631] EA = 0, S1PTW = 0
[ 9.726799] Data abort info:
[ 9.729702] ISV = 0, ISS = 0x00000004
[ 9.733573] CM = 0, WnR = 0
[ 9.736566] [000000000000001a] user address but active_mm is swapper
[ 9.742987] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 9.748614] Modules linked in:
[ 9.751694] CPU: 16 PID: 293 Comm: kworker/16:1 Tainted: G W
4.19.0-rc4-next-20180920-00001-g9b0012c #322
[ 9.762681] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 IT21 Nemo 2.0 RC0 04/18/2018
[ 9.771915] Workqueue: events work_for_cpu_fn
[ 9.776312] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 9.781150] pc : drm_mode_object_put+0x0/0x20
[ 9.785547] lr : hibmc_fbdev_fini+0x40/0x58
[ 9.789767] sp : ffff00000af1bcf0
[ 9.793108] x29: ffff00000af1bcf0 x28: 0000000000000000
[ 9.798473] x27: 0000000000000000 x26: ffff000008f66630
[ 9.803838] x25: 0000000000000000 x24: ffff0000095abb98
[ 9.809203] x23: ffff8017db92fe00 x22: ffff8017d2b13000
[ 9.814568] x21: ffffffffffffffea x20: ffff8017d2f80018
[ 9.819933] x19: ffff8017d28a0018 x18: ffffffffffffffff
[ 9.825297] x17: 0000000000000000 x16: 0000000000000000
[ 9.830662] x15: ffff0000092296c8 x14: ffff00008939970f
[ 9.836026] x13: ffff00000939971d x12: ffff000009229940
[ 9.841391] x11: ffff0000085f8fc0 x10: ffff00000af1b9a0
[ 9.846756] x9 : 000000000000000d x8 : 6620657a696c6169
[ 9.852121] x7 : ffff8017d3340580 x6 : ffff8017d4168000
[ 9.857486] x5 : 0000000000000000 x4 : ffff8017db92fb20
[ 9.862850] x3 : 0000000000002690 x2 : ffff8017d3340480
[ 9.868214] x1 : 0000000000000028 x0 : 0000000000000002
[ 9.873580] Process kworker/16:1 (pid: 293, stack limit =
0x(____ptrval____))
[ 9.880788] Call trace:
[ 9.883252] drm_mode_object_put+0x0/0x20
[ 9.887297] hibmc_unload+0x1c/0x80
[ 9.890815] hibmc_pci_probe+0x170/0x3c8
[ 9.894773] local_pci_probe+0x3c/0xb0
[ 9.898555] work_for_cpu_fn+0x18/0x28
[ 9.902337] process_one_work+0x1e0/0x318
[ 9.906382] worker_thread+0x228/0x450
[ 9.910164] kthread+0x128/0x130
[ 9.913418] ret_from_fork+0x10/0x18
[ 9.917024] Code: a94153f3 a8c27bfd d65f03c0 d503201f (f9400c01)
[ 9.923180] ---[ end trace 2695ffa0af5be375 ]---

On Thu, 20 Sep 2018 at 10:06, John Garry <john.garry2@xxxxxxxxxxx>
wrote:
[ 9.196615] arm-smmu-v3 arm-smmu-v3.4.auto: ias 44-bit, oas 44-bit
(features 0x00000f0d)
[ 9.206296] arm-smmu-v3 arm-smmu-v3.4.auto: no evtq irq - events will
not be reported!
[ 9.214302] arm-smmu-v3 arm-smmu-v3.4.auto: no gerr irq - errors will
not be reported!
[ 9.222673] pci 0007:90:00.0: can't derive routing for PCI INT A
[ 9.228746] hibmc-drm 0007:91:00.0: PCI INT A: no GSI
[ 9.234073] [TTM] Zone kernel: Available graphics memory:
16297696 kiB
[ 9.240763] [TTM] Zone dma32: Available graphics memory: 2097152
kiB
[ 9.247361] [TTM] Initializing pool allocator
[ 9.251763] [TTM] Initializing DMA pool allocator
[ 9.256565] [drm] Supports vblank timestamp caching Rev 2
(21.10.2013).
[ 9.263250] [drm] No driver support for vblank timestamp query.
[ 9.274661] WARNING: CPU: 16 PID: 293 at
drivers/gpu/drm/drm_fourcc.c:221 drm_format_info.part.1+0x0/0x8
[ 9.284244] Modules linked in:
[ 9.287326] CPU: 16 PID: 293 Comm: kworker/16:1 Not tainted
4.19.0-rc4-next-20180919-00001-gcb2f9f4-dirty #321
[ 9.297435] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 IT21 Nemo 2.0 RC0 04/18/2018
[ 9.306674] Workqueue: events work_for_cpu_fn
[ 9.311072] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 9.315909] pc : drm_format_info.part.1+0x0/0x8
[ 9.320482] lr : drm_get_format_info+0x90/0x98
[ 9.324966] sp : ffff00000af1baf0
[ 9.328307] x29: ffff00000af1baf0 x28: 0000000000000000
[ 9.333673] x27: ffff00000af1bcb0 x26: ffff8017b4d78800
[ 9.339037] x25: ffff8017b4d68018 x24: ffff8017b4d94018
[ 9.344402] x23: ffff8017b4d78670 x22: ffff00000af1bbf0
[ 9.349767] x21: ffff8017b4d78a70 x20: ffff00000af1bbf0
[ 9.355131] x19: ffff00000af1bbf0 x18: ffffffffffffffff
[ 9.360495] x17: 0000000000000000 x16: 0000000000000000
[ 9.365860] x15: ffff0000092296c8 x14: ffff000009074000
[ 9.371225] x13: 0000000000000000 x12: 0000000000000000
[ 9.376589] x11: ffff8017fbffe008 x10: ffff8017db9307e8
[ 9.381954] x9 : 0000000000000000 x8 : ffff8017b4d66800
[ 9.387319] x7 : 0000000000000000 x6 : 000000000000003f
[ 9.392683] x5 : 0000000000000040 x4 : 0000000000000000
[ 9.398048] x3 : ffff000008d04000 x2 : 0000000056555941
[ 9.403412] x1 : ffff000008d04f30 x0 : 0000000000000044
[ 9.408777] Call trace:
[ 9.411241] drm_format_info.part.1+0x0/0x8
[ 9.415462] drm_helper_mode_fill_fb_struct+0x20/0x80
[ 9.420564] hibmc_framebuffer_init+0x48/0xd0
[ 9.424961] hibmc_drm_fb_create+0x1ec/0x3c8
[ 9.429271] __drm_fb_helper_initial_config_and_unlock+0x1cc/0x418
[ 9.435513] drm_fb_helper_initial_config+0x3c/0x48
[ 9.440438] hibmc_fbdev_init+0xb4/0x198
[ 9.444395] hibmc_pci_probe+0x2f4/0x3c8
[ 9.448356] local_pci_probe+0x3c/0xb0
[ 9.452137] work_for_cpu_fn+0x18/0x28
[ 9.455919] process_one_work+0x1e0/0x318
[ 9.459964] worker_thread+0x228/0x450
[ 9.463746] kthread+0x128/0x130
[ 9.467002] ret_from_fork+0x10/0x18
[ 9.470608] ---[ end trace b05497eb4d842ec0 ]---
[ 9.475285] WARNING: CPU: 16 PID: 293 at
drivers/gpu/drm/drm_framebuffer.c:730 drm_framebuffer_init+0x18/0x110
[ 9.485394] Modules linked in:
[ 9.488474] CPU: 16 PID: 293 Comm: kworker/16:1 Tainted: G W
4.19.0-rc4-next-20180919-00001-gcb2f9f4-dirty #321
[ 9.499989] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 IT21 Nemo 2.0 RC0 04/18/2018
[ 9.509223] Workqueue: events work_for_cpu_fn
[ 9.513621] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 9.518457] pc : drm_framebuffer_init+0x18/0x110
[ 9.523118] lr : hibmc_framebuffer_init+0x60/0xd0
[ 9.527865] sp : ffff00000af1baf0
[ 9.531207] x29: ffff00000af1baf0 x28: 0000000000000000
[ 9.536571] x27: ffff00000af1bcb0 x26: ffff8017b4d78800
[ 9.541936] x25: ffff8017b4d68018 x24: ffff8017b4d94018
[ 9.547301] x23: ffff8017b4d78670 x22: ffff00000af1bbf0
[ 9.552666] x21: ffff8017b4d78a70 x20: ffff8017b4d48000
[ 9.558030] x19: ffff8017b4d66700 x18: ffffffffffffffff
[ 9.563395] x17: 0000000000000000 x16: 0000000000000000
[ 9.568760] x15: ffff0000092296c8 x14: ffff000009074000
[ 9.574124] x13: 0000000000000000 x12: 0000000000000000
[ 9.579489] x11: ffff8017fbffe008 x10: ffff8017db9307e8
[ 9.584854] x9 : 0000000000000000 x8 : ffff8017b4d66800
[ 9.590218] x7 : 0000000000000000 x6 : 000000000000003f
[ 9.595582] x5 : 0000000000000040 x4 : 0000000000000000
[ 9.600946] x3 : ffff00000af1bc24 x2 : ffff000008d23f10
[ 9.606311] x1 : ffff8017b4d66700 x0 : 0000000000000000
[ 9.611675] Call trace:
[ 9.614138] drm_framebuffer_init+0x18/0x110
[ 9.618447] hibmc_framebuffer_init+0x60/0xd0
[ 9.622845] hibmc_drm_fb_create+0x1ec/0x3c8
[ 9.627154] __drm_fb_helper_initial_config_and_unlock+0x1cc/0x418
[ 9.633397] drm_fb_helper_initial_config+0x3c/0x48
[ 9.638321] hibmc_fbdev_init+0xb4/0x198
[ 9.642278] hibmc_pci_probe+0x2f4/0x3c8
[ 9.646236] local_pci_probe+0x3c/0xb0
[ 9.650018] work_for_cpu_fn+0x18/0x28
[ 9.653800] process_one_work+0x1e0/0x318
[ 9.657845] worker_thread+0x228/0x450
[ 9.661627] kthread+0x128/0x130
[ 9.664881] ret_from_fork+0x10/0x18
[ 9.668486] ---[ end trace b05497eb4d842ec1 ]---
[ 9.673153] [drm:hibmc_framebuffer_init] *ERROR* drm_framebuffer_init
failed: -22
[ 9.680720] [drm:hibmc_drm_fb_create] *ERROR* failed to initialize
framebuffer: -22
[ 9.688468] [drm:hibmc_fbdev_init] *ERROR* failed to setup initial
conn config: -22
[ 9.696212] [drm:hibmc_pci_probe] *ERROR* failed to initialize fbdev:
-22
[ 9.703075] Unable to handle kernel NULL pointer dereference at
virtual address 000000000000001a
[ 9.711957] Mem abort info:
[ 9.714774] ESR = 0x96000004
[ 9.717855] Exception class = DABT (current EL), IL = 32 bits
[ 9.723835] SET = 0, FnV = 0
[ 9.726916] EA = 0, S1PTW = 0
[ 9.730084] Data abort info:
[ 9.732986] ISV = 0, ISS = 0x00000004
[ 9.736858] CM = 0, WnR = 0
[ 9.739850] [000000000000001a] user address but active_mm is swapper
[ 9.746271] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 9.751898] Modules linked in:
[ 9.754978] CPU: 16 PID: 293 Comm: kworker/16:1 Tainted: G W
4.19.0-rc4-next-20180919-00001-gcb2f9f4-dirty #321
[ 9.766493] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 IT21 Nemo 2.0 RC0 04/18/2018
[ 9.775727] Workqueue: events work_for_cpu_fn
[ 9.780124] pstate: 60000005 (nZCv daif -PAN -UAO)
[ 9.784962] pc : drm_mode_object_put+0x0/0x20
[ 9.789359] lr : hibmc_fbdev_fini+0x40/0x58
[ 9.793579] sp : ffff00000af1bcf0
[ 9.796920] x29: ffff00000af1bcf0 x28: 0000000000000000
[ 9.802285] x27: 0000000000000000 x26: ffff000008f66530
[ 9.807649] x25: 0000000000000000 x24: ffff0000095abb98
[ 9.813014] x23: ffff8017db92fe00 x22: ffff8017d2aeb000
[ 9.818378] x21: ffffffffffffffea x20: ffff8017b4d94018
[ 9.823742] x19: ffff8017b4d68018 x18: ffffffffffffffff
[ 9.829106] x17: 0000000000000000 x16: 0000000000000000
[ 9.834471] x15: ffff0000092296c8 x14: ffff00008939970f
[ 9.839835] x13: ffff00000939971d x12: ffff000009229940
[ 9.845200] x11: ffff0000085f8840 x10: ffff00000af1b9a0
[ 9.850564] x9 : 000000000000000d x8 : 696c616974696e69
[ 9.855929] x7 : ffff8017d2b96580 x6 : ffff8017d4168000
[ 9.861294] x5 : 0000000000000000 x4 : ffff8017db92fb20
[ 9.866659] x3 : 0000000000002650 x2 : ffff8017d2b96480
[ 9.872023] x1 : 0000000000000028 x0 : 0000000000000002
[ 9.877389] Process kworker/16:1 (pid: 293, stack limit =
0x(____ptrval____))
[ 9.884598] Call trace:
[ 9.887061] drm_mode_object_put+0x0/0x20
[ 9.891107] hibmc_unload+0x1c/0x80
[ 9.894625] hibmc_pci_probe+0x170/0x3c8
[ 9.898583] local_pci_probe+0x3c/0xb0
[ 9.902364] work_for_cpu_fn+0x18/0x28
[ 9.906146] process_one_work+0x1e0/0x318
[ 9.910192] worker_thread+0x228/0x450
[ 9.913973] kthread+0x128/0x130
[ 9.917227] ret_from_fork+0x10/0x18
[ 9.920833] Code: a94153f3 a8c27bfd d65f03c0 d503201f (f9400c01)
[ 9.926989] ---[ end trace b05497eb4d842ec2 ]---



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