Hi Noralf Am 06.05.22 um 16:11 schrieb Thomas Zimmermann:
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] <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.cindex 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.
iomap_sys_clear() assumes that the instance is already initialized. Hence, calling it at [1] with un-zeroed, stack-allocated memory operates on undefined state. It doesn't matter for the result, though. I guess the semantics of iosys_sys_clear() are not stellar.
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.
I have posted that patchset at [2]. If you have the time, I'd appreciate if you could give it a test run.
Best regards Thomas[1] https://elixir.bootlin.com/linux/v5.17.5/source/drivers/gpu/drm/drm_gem_framebuffer_helper.c#L348 [2] https://lore.kernel.org/dri-devel/20220509081602.474-1-tzimmermann@xxxxxxx/T/#t
If we need a quick fix, we could do the zeroing everywhere. Best regards ThomasNoralf.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
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