Hi
Am 06.05.22 um 16:01 schrieb Noralf Trønnes:
> Hi Thomas,
>
> I'm getting this on Ubuntu 22.04:
>
> [ 0.000000] Linux version 5.15.0-27-generic (buildd@ubuntu) (gcc
> (Ubuntu 11.2.0-19ubuntu1) 11.2.0, GNU ld (GNU Binutils for Ubuntu) 2.38)
> #28-Ubuntu SMP Thu Apr 14 04:55:28 UTC 2022 (Ubuntu 5.15.0-27.28-generic
> 5.15.30)
>
> [ 4.830866] usb 2-3.1: new high-speed USB device number 4 using xhci_hcd
> [ 4.935546] usb 2-3.1: New USB device found, idVendor=1d50,
> idProduct=614d, bcdDevice= 1.00
> [ 4.935553] usb 2-3.1: New USB device strings: Mfr=1, Product=2,
> SerialNumber=3
> [ 4.935556] usb 2-3.1: Product: Raspberry Pi 4 Display Gadget
> [ 4.935558] usb 2-3.1: Manufacturer: Raspberry Pi
> [ 4.935560] usb 2-3.1: SerialNumber: 100000003b40d6c6
>
> [ 7.497361] [drm] Initialized gud 1.0.0 20200422 for 2-3.1:1.0 on minor 0
>
> [ 7.573048] gud 2-3.1:1.0: [drm] fb1: guddrmfb frame buffer device
>
> [ 9.199402]
> ================================================================================
> [ 9.199411] UBSAN: invalid-load in
> /build/linux-HMZHpV/linux-5.15.0/include/linux/dma-buf-map.h:224:9
> [ 9.199416] load of value 226 is not a valid value for type '_Bool'
> [ 9.199420] CPU: 0 PID: 113 Comm: kworker/0:2 Not tainted
> 5.15.0-27-generic #28-Ubuntu
> [ 9.199424] Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991,
> BIOS L71 Ver. 01.44 04/12/2018
> [ 9.199427] Workqueue: events_long gud_flush_work [gud]
> [ 9.199440] Call Trace:
> [ 9.199443]
> [ 9.199447] show_stack+0x52/0x58
> [ 9.199456] dump_stack_lvl+0x4a/0x5f
> [ 9.199464] dump_stack+0x10/0x12
> [ 9.199468] ubsan_epilogue+0x9/0x45
> [ 9.199473] __ubsan_handle_load_invalid_value.cold+0x44/0x49
> [ 9.199478] drm_gem_fb_vmap.cold+0x10/0x3d [drm_kms_helper]
> [ 9.199519] gud_prep_flush+0xaa/0x410 [gud]
> [ 9.199525] ? check_preempt_curr+0x5d/0x70
> [ 9.199533] ? update_load_avg+0x82/0x620
> [ 9.199540] ? set_next_entity+0xb7/0x200
> [ 9.199545] gud_flush_work+0x1e0/0x430 [gud]
> [ 9.199551] ? psi_task_switch+0x1e7/0x220
> [ 9.199557] process_one_work+0x22b/0x3d0
> [ 9.199564] worker_thread+0x53/0x410
> [ 9.199570] ? process_one_work+0x3d0/0x3d0
> [ 9.199575] kthread+0x12a/0x150
> [ 9.199579] ? set_kthread_struct+0x50/0x50
> [ 9.199584] ret_from_fork+0x22/0x30
> [ 9.199593]
> [ 9.199595]
> ================================================================================
>
> [ 9.199598]
> ================================================================================
> [ 9.199600] UBSAN: invalid-load in
> /build/linux-HMZHpV/linux-5.15.0/include/linux/dma-buf-map.h:194:9
> [ 9.199604] load of value 226 is not a valid value for type '_Bool'
> [ 9.199606] CPU: 0 PID: 113 Comm: kworker/0:2 Not tainted
> 5.15.0-27-generic #28-Ubuntu
> [ 9.199610] Hardware name: Hewlett-Packard HP EliteBook 820 G1/1991,
> BIOS L71 Ver. 01.44 04/12/2018
> [ 9.199612] Workqueue: events_long gud_flush_work [gud]
> [ 9.199618] Call Trace:
> [ 9.199619]
> [ 9.199621] show_stack+0x52/0x58
> [ 9.199627] dump_stack_lvl+0x4a/0x5f
> [ 9.199633] dump_stack+0x10/0x12
> [ 9.199637] ubsan_epilogue+0x9/0x45
> [ 9.199641] __ubsan_handle_load_invalid_value.cold+0x44/0x49
> [ 9.199646] drm_gem_fb_vmap.cold+0x24/0x3d [drm_kms_helper]
> [ 9.199675] gud_prep_flush+0xaa/0x410 [gud]
> [ 9.199682] ? check_preempt_curr+0x5d/0x70
> [ 9.199688] ? update_load_avg+0x82/0x620
> [ 9.199693] ? update_load_avg+0x82/0x620
> [ 9.199697] gud_flush_work+0x1e0/0x430 [gud]
> [ 9.199702] ? psi_task_switch+0x1e7/0x220
> [ 9.199706] process_one_work+0x22b/0x3d0
> [ 9.199713] worker_thread+0x53/0x410
> [ 9.199718] ? process_one_work+0x3d0/0x3d0
> [ 9.199723] kthread+0x12a/0x150
> [ 9.199728] ? set_kthread_struct+0x50/0x50
> [ 9.199732] ret_from_fork+0x22/0x30
> [ 9.199741]
> [ 9.199743]
> ================================================================================
>
> It's the "if (map->is_iomem)" statement in dma_buf_map_clear() and
> dma_buf_map_is_null() that triggers this.
>
> I tried 5.18.0-rc5 and the problem is still present.
>
> UBSAN entries in the config:
>
> CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL=y
> CONFIG_UBSAN=y
> # CONFIG_UBSAN_TRAP is not set
> CONFIG_CC_HAS_UBSAN_BOUNDS=y
> CONFIG_UBSAN_BOUNDS=y
> CONFIG_UBSAN_ONLY_BOUNDS=y
> CONFIG_UBSAN_SHIFT=y
> # CONFIG_UBSAN_DIV_ZERO is not set
> CONFIG_UBSAN_BOOL=y
> CONFIG_UBSAN_ENUM=y
> # CONFIG_UBSAN_ALIGNMENT is not set
> CONFIG_UBSAN_SANITIZE_ALL=y
> # CONFIG_TEST_UBSAN is not set
>
> Continuing further down.
>
>
> Den 30.07.2021 20.35, skrev Thomas Zimmermann:
>> Abstract the framebuffer details by mapping its BOs with a call
>> to drm_gem_fb_vmap(). Unmap with drm_gem_fb_vunmap().
>>
>> The call to drm_gem_fb_vmap() ensures that all BOs are mapped
>> correctly. Gud still only supports single-plane formats.
>>
>> No functional changes.
>>
>> Signed-off-by: Thomas Zimmermann
>> Acked-by: Noralf Trønnes
>> Acked-by: Sam Ravnborg
>> ---
>> drivers/gpu/drm/gud/gud_pipe.c | 10 +++++-----
>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
>> index 4d7a26b68a2e..7e009f562b30 100644
>> --- a/drivers/gpu/drm/gud/gud_pipe.c
>> +++ b/drivers/gpu/drm/gud/gud_pipe.c
>> @@ -14,8 +14,8 @@
>> #include
>> #include
>> #include
>> +#include
>> #include
>> -#include
>> #include
>> #include
>> #include
>> @@ -152,7 +152,7 @@ static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
>> {
>> struct dma_buf_attachment *import_attach = fb->obj[0]->import_attach;
>> u8 compression = gdrm->compression;
>> - struct dma_buf_map map;
>> + struct dma_buf_map map[DRM_FORMAT_MAX_PLANES];
>
> Zeroing map solves the problem:
>
> struct iosys_map map[DRM_FORMAT_MAX_PLANES] = {};
>
> I don't understand the conditional clearing in
> dma_buf_map_clear/iosys_map_clear(), the doc says: Clears all fields to
> zero. If I zero the whole structure unconditionally this also keeps
> UBSAN happy.
Thanks for debugging this problem. It's uninitialized and some of the
internal helpers look at all planes, even if they are empty. I have a
patchset to fix that throughout the DRM modules. I'll post on Monday.
If we need a quick fix, we could do the zeroing everywhere.
Best regards
Thomas
>
> Noralf.
>
>> void *vaddr, *buf;
>> size_t pitch, len;
>> int ret = 0;
>> @@ -162,11 +162,11 @@ static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
>> if (len > gdrm->bulk_len)
>> return -E2BIG;
>>
>> - ret = drm_gem_shmem_vmap(fb->obj[0], &map);
>> + ret = drm_gem_fb_vmap(fb, map);
>> if (ret)
>> return ret;
>>
>> - vaddr = map.vaddr + fb->offsets[0];
>> + vaddr = map[0].vaddr + fb->offsets[0];
>>
>> ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
>> if (ret)
>> @@ -225,7 +225,7 @@ static int gud_prep_flush(struct gud_device *gdrm, struct drm_framebuffer *fb,
>> end_cpu_access:
>> drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
>> vunmap:
>> - drm_gem_shmem_vunmap(fb->obj[0], &map);
>> + drm_gem_fb_vunmap(fb, map);
>>
>> return ret;
>> }
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev