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] <TASK>
[ 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] </TASK>
[ 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] <TASK>
[ 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] </TASK>
[ 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 <tzimmermann@xxxxxxx>
> Acked-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> ---
> 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 <drm/drm_format_helper.h>
> #include <drm/drm_fourcc.h>
> #include <drm/drm_framebuffer.h>
> +#include <drm/drm_gem.h>
> #include <drm/drm_gem_framebuffer_helper.h>
> -#include <drm/drm_gem_shmem_helper.h>
> #include <drm/drm_print.h>
> #include <drm/drm_rect.h>
> #include <drm/drm_simple_kms_helper.h>
> @@ -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.
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;
> }
