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Re: DEPT (the dependency tracker) as AI review prompt?

by Yunseong Kim

Hi Harry, On 5/23/26 16:34, Harry Yoo wrote: > > > On 5/23/26 11:00 PM, Yunseong Kim wrote: >> I've previously experimented with running DEPT alongside syzkaller fuzzing, >> and many hung tasks missed by lockdep are caught by DEPT, but the resulting >> high volume of reports makes it easy for issues to get lost in the massive >> log output. Sorting through that output manually is a huge bottleneck, so >> leveraging a well-crafted AI prompt to triage the warnings and filter out >> the false positives would be incredibly valuable. > > I mean both 1) detection of deadlock issues AND 2) false positive elimination with AI. I completely agree. Implanting DEPT's model into an AI review prompt is a great idea. As you suggested, the patterns we develop for the AI could provide valuable feedback to enhance DEPT's itself. > If the review prompt is only used to eliminate DEPT's false positives, I think that would be quite hard to get broad use. > > Someone would have to build out-of-tree DEPT, collect the reports, and then feed those back into the AI. I don't think building that kind of pipeline would actually work well in practice. I also have a huge dept report of DEPT reports, and manually reviewing all of them is makes me sigh. The constant kernel rebuilds required for lockup testing every time are also quite expensive. Thanks for the summary! Best Regards, Yunseong

3 weeks, 4 days

How to Hire a Hacker to remove unwanted information & files from all search engines linked on the internet

by lenarichmond49＠gmail.com

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3 weeks, 5 days

How to Hire a Hacker to remove unwanted information & files from all search engines linked on the internet

by lenarichmond49＠gmail.com

3 weeks, 5 days

How to Hire a Hacker to remove unwanted information & files from all search engines linked on the internet

by lenarichmond49＠gmail.com

3 weeks, 5 days

How to Hire a Hacker to remove unwanted information & files from all search engines linked on the internet

by lenarichmond49＠gmail.com

3 weeks, 5 days

[PATCH v5 0/2] dma-buf: heaps: system: add an option to allocate explicitly shared/decrypted memory

by Jiri Pirko

From: Jiri Pirko <jiri(a)nvidia.com> Confidential computing (CoCo) VMs/guests, such as AMD SEV and Intel TDX, run with private/encrypted memory which creates a challenge for devices that do not support DMA to it (no TDISP support). For kernel-only DMA operations, swiotlb bounce buffering provides a transparent solution by copying data through shared memory. However, the only way to get this memory into userspace is via the DMA API's dma_alloc_pages()/dma_mmap_pages() type interfaces which limits the use of the memory to a single DMA device, and is incompatible with pin_user_pages(). These limitations are particularly problematic for the RDMA subsystem which makes heavy use of pin_user_pages() and expects flexible memory usage between many different DMA devices. This patch series enables userspace to explicitly request shared (decrypted) memory allocations from new dma-buf system_cc_shared heap. Userspace can mmap this memory and pass the dma-buf fd to other existing importers such as RDMA or DRM devices to access the memory. The DMA API is improved to allow the dma heap exporter to DMA map the shared memory to each importing device. Based on dma-mapping-for-next e7442a68cd1ee797b585f045d348781e9c0dde0d Jiri Pirko (2): dma-mapping: introduce DMA_ATTR_CC_SHARED for shared memory dma-buf: heaps: system: add system_cc_shared heap for explicitly shared memory drivers/dma-buf/heaps/system_heap.c | 103 ++++++++++++++++++++++++++-- include/linux/dma-mapping.h | 10 +++ include/trace/events/dma.h | 3 +- kernel/dma/direct.h | 14 +++- kernel/dma/mapping.c | 13 +++- 5 files changed, 132 insertions(+), 11 deletions(-) -- 2.51.1

3 weeks, 6 days

What's Wave Rider game?

by Leo Enda

Wave Rider surprised me more than I expected. The game looks simple at first, but once the speed increases and the waves become unstable, every run starts feeling intense. Unlike many endless runner games that rely only on fast movement, Wave Rider creates pressure through unpredictable water physics and constantly changing obstacle patterns. Play Wave Rider online at https://wave-rider.io The gameplay is built around survival. Your board moves forward automatically while you focus on steering through dangerous sections of water. Floating barriers, underwater mines, sharp turns, and narrow lanes appear quickly, forcing players to react within seconds. What I liked most is how the game balances smooth surfing movement with sudden moments of chaos. Sometimes the water feels calm, then everything changes when multiple obstacles appear together. Wave Rider also rewards risky decisions. Pearls are often hidden near dangerous routes, making players choose between safe movement and higher scores. I found myself taking bigger risks after every run just to see how far I could push the distance counter. The durability system adds even more tension because repeated small crashes slowly reduce your chance of surviving longer sessions. Game Controls Left Arrow / A: Move left Right Arrow / D: Move right Spacebar or Up Arrow: Jump or glide over obstacles The controls are easy to learn, but mastering the timing takes practice. Quick reactions help, but smooth movement and patience usually lead to better runs. Players who panic and change direction too aggressively often crash faster than expected. Overall, Wave Rider feels like a solid arcade experience for anyone who enjoys reaction-based gameplay. The combination of flowing water, rising speed, and nonstop danger makes every session feel fresh and competitive.

3 weeks, 6 days

[PATCH v4] drm/virtio: use uninterruptible resv lock for plane updates

by Deepanshu Kartikey

virtio_gpu_cursor_plane_update() and virtio_gpu_resource_flush() lock the framebuffer BO's dma_resv via virtio_gpu_array_lock_resv() and ignore its return value. The function can fail with -EINTR from dma_resv_lock_interruptible() (signal during lock wait) or with -ENOMEM from dma_resv_reserve_fences() (fence slot allocation), leaving the resv lock not held. The queue path then walks the object array and calls dma_resv_add_fence(), which requires the lock held; with lockdep enabled this trips dma_resv_assert_held(): WARNING: drivers/dma-buf/dma-resv.c:296 at dma_resv_add_fence+0x71e/0x840 Call Trace: virtio_gpu_array_add_fence virtio_gpu_queue_ctrl_sgs virtio_gpu_queue_fenced_ctrl_buffer virtio_gpu_cursor_plane_update drm_atomic_helper_commit_planes drm_atomic_helper_commit_tail commit_tail drm_atomic_helper_commit drm_atomic_commit drm_atomic_helper_update_plane __setplane_atomic drm_mode_cursor_universal drm_mode_cursor_common drm_mode_cursor_ioctl drm_ioctl __x64_sys_ioctl Beyond the WARN, mutating the dma_resv fence list without the lock races with concurrent readers/writers and can corrupt the list. Both call sites run inside the .atomic_update plane callback, which DRM atomic helpers do not allow to fail (by the time it runs, the commit has been signed off to userspace and there is no clean rollback path). Moving the lock acquisition to .prepare_fb was rejected because the broader lock scope deadlocks against other BO locking paths in the same atomic commit. Introduce virtio_gpu_lock_one_resv_uninterruptible() that uses dma_resv_lock() instead of dma_resv_lock_interruptible(). This eliminates the -EINTR failure mode -- the realistic syzbot trigger -- without extending the lock hold across the commit. The helper locks a single BO and rejects nents > 1 with -EINVAL; both fix sites lock exactly one BO. Use it from virtio_gpu_cursor_plane_update() and virtio_gpu_resource_flush(); check the return value to handle the remaining -ENOMEM case from dma_resv_reserve_fences() by freeing the objs and skipping the plane update for that frame. The framebuffer BOs touched here are not shared with other contexts and lock contention is expected to be brief, so the loss of signal-interruptibility is acceptable. Other callers of virtio_gpu_array_lock_resv() (the ioctl paths) continue to use the interruptible variant. The bug was reported by syzbot, triggered via fault injection (fail_nth) on the DRM_IOCTL_MODE_CURSOR path, which forces the -ENOMEM branch in dma_resv_reserve_fences(). Reported-by: syzbot+72bd3dd3a5d5f39a0271(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=72bd3dd3a5d5f39a0271 Fixes: 5cfd31c5b3a3 ("drm/virtio: fix virtio_gpu_cursor_plane_update().") Cc: stable(a)vger.kernel.org Signed-off-by: Deepanshu Kartikey <kartikey406(a)gmail.com> --- v4: Rename the helper to virtio_gpu_lock_one_resv_uninterruptible() and reject objs->nents > 1 with -EINVAL. The v3 helper's multi-object branch used drm_gem_lock_reservations(), which is interruptible, contradicting the "uninterruptible" name; both fix sites lock a single BO so the multi-object path is dropped. (Dmitry Osipenko) v3: Drop the prepare_fb/cleanup_fb approach from v2 (it deadlocked against virtio_gpu_resource_flush(), which also locks the BO in the same atomic commit). Instead add an uninterruptible variant of the resv lock helper and use it in both virtio_gpu_cursor_plane_update() and virtio_gpu_resource_flush(). (Dmitry Osipenko) v2: Move resv lock acquisition from .atomic_update (which must not fail) to .prepare_fb (which may), per maintainer review of v1. The v1 approach of silently skipping the cursor update on lock failure violated the atomic-commit contract with userspace. --- drivers/gpu/drm/virtio/virtgpu_drv.h | 1 + drivers/gpu/drm/virtio/virtgpu_gem.c | 17 +++++++++++++++++ drivers/gpu/drm/virtio/virtgpu_plane.c | 10 ++++++++-- 3 files changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h index f17660a71a3e..2f3531950aa4 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.h +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h @@ -317,6 +317,7 @@ virtio_gpu_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents void virtio_gpu_array_add_obj(struct virtio_gpu_object_array *objs, struct drm_gem_object *obj); int virtio_gpu_array_lock_resv(struct virtio_gpu_object_array *objs); +int virtio_gpu_lock_one_resv_uninterruptible(struct virtio_gpu_object_array *objs); void virtio_gpu_array_unlock_resv(struct virtio_gpu_object_array *objs); void virtio_gpu_array_add_fence(struct virtio_gpu_object_array *objs, struct dma_fence *fence); diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c index f22dc5c21cd4..435d37d36034 100644 --- a/drivers/gpu/drm/virtio/virtgpu_gem.c +++ b/drivers/gpu/drm/virtio/virtgpu_gem.c @@ -238,6 +238,23 @@ int virtio_gpu_array_lock_resv(struct virtio_gpu_object_array *objs) return ret; } +int virtio_gpu_lock_one_resv_uninterruptible(struct virtio_gpu_object_array *objs) +{ + int ret; + + if (objs->nents != 1) + return -EINVAL; + + dma_resv_lock(objs->objs[0]->resv, NULL); + + ret = dma_resv_reserve_fences(objs->objs[0]->resv, 1); + if (ret) { + virtio_gpu_array_unlock_resv(objs); + return ret; + } + return 0; +} + void virtio_gpu_array_unlock_resv(struct virtio_gpu_object_array *objs) { if (objs->nents == 1) { diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c index a126d1b25f46..652352424744 100644 --- a/drivers/gpu/drm/virtio/virtgpu_plane.c +++ b/drivers/gpu/drm/virtio/virtgpu_plane.c @@ -215,7 +215,10 @@ static void virtio_gpu_resource_flush(struct drm_plane *plane, if (!objs) return; virtio_gpu_array_add_obj(objs, vgfb->base.obj[0]); - virtio_gpu_array_lock_resv(objs); + if (virtio_gpu_lock_one_resv_uninterruptible(objs)) { + virtio_gpu_array_put_free(objs); + return; + } virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle, x, y, width, height, objs, vgplane_st->fence); @@ -459,7 +462,10 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane, if (!objs) return; virtio_gpu_array_add_obj(objs, vgfb->base.obj[0]); - virtio_gpu_array_lock_resv(objs); + if (virtio_gpu_lock_one_resv_uninterruptible(objs)) { + virtio_gpu_array_put_free(objs); + return; + } virtio_gpu_cmd_transfer_to_host_2d (vgdev, 0, plane->state->crtc_w, -- 2.43.0

3 weeks, 6 days

[PATCH V1] Revert "accel/amdxdna: Support read-only user-pointer BO mappings"

by Lizhi Hou

This reverts commit f649e63d4a6423eda8eb208638849fd6396aedd7. The read-only feature requires further consideration. Signed-off-by: Lizhi Hou <lizhi.hou(a)amd.com> --- drivers/accel/amdxdna/amdxdna_ubuf.c | 29 ++-------------------------- 1 file changed, 2 insertions(+), 27 deletions(-) diff --git a/drivers/accel/amdxdna/amdxdna_ubuf.c b/drivers/accel/amdxdna/amdxdna_ubuf.c index 3769210c55cc..4c0647057759 100644 --- a/drivers/accel/amdxdna/amdxdna_ubuf.c +++ b/drivers/accel/amdxdna/amdxdna_ubuf.c @@ -125,26 +125,6 @@ static const struct dma_buf_ops amdxdna_ubuf_dmabuf_ops = { .vunmap = amdxdna_ubuf_vunmap, }; -static int readonly_va_entry(struct amdxdna_drm_va_entry *va_ent) -{ - struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; - int ret; - - mmap_read_lock(mm); - - vma = find_vma(mm, va_ent->vaddr); - if (!vma || - vma->vm_start > va_ent->vaddr || - vma->vm_end - va_ent->vaddr < va_ent->len) - ret = -ENOENT; - else - ret = vma->vm_flags & VM_WRITE ? 0 : 1; - - mmap_read_unlock(mm); - return ret; -} - struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev, u32 num_entries, void __user *va_entries) { @@ -154,7 +134,6 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev, struct amdxdna_ubuf_priv *ubuf; u32 npages, start = 0; struct dma_buf *dbuf; - bool readonly = true; int i, ret; DEFINE_DMA_BUF_EXPORT_INFO(exp_info); @@ -193,10 +172,6 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev, ret = -EINVAL; goto free_ent; } - - /* Pin pages as writable as long as not all entries are read-only. */ - if (readonly && readonly_va_entry(&va_ent[i]) != 1) - readonly = false; } ubuf->nr_pages = exp_info.size >> PAGE_SHIFT; @@ -219,7 +194,7 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev, npages = va_ent[i].len >> PAGE_SHIFT; ret = pin_user_pages_fast(va_ent[i].vaddr, npages, - (readonly ? 0 : FOLL_WRITE) | FOLL_LONGTERM, + FOLL_WRITE | FOLL_LONGTERM, &ubuf->pages[start]); if (ret >= 0) { start += ret; @@ -236,7 +211,7 @@ struct dma_buf *amdxdna_get_ubuf(struct drm_device *dev, exp_info.ops = &amdxdna_ubuf_dmabuf_ops; exp_info.priv = ubuf; - exp_info.flags = (readonly ? O_RDONLY : O_RDWR) | O_CLOEXEC; + exp_info.flags = O_RDWR | O_CLOEXEC; dbuf = dma_buf_export(&exp_info); if (IS_ERR(dbuf)) { -- 2.34.1

3 weeks, 6 days

About five nights at freddy's 2 game

by lindanina1199＠gmail.com

In FNAF 2, players work as a night security guard at Freddy Fazbear’s Pizza, a children’s restaurant filled with animatronic characters. Unlike normal robots, these animatronics become dangerous at night and try to attack anyone they see. The player must survive from midnight until 6 a.m. by monitoring security cameras, using a flashlight, and wearing a Freddy Fazbear mask to trick the animatronics. Play now: https://fnaf-2.io

3 weeks, 6 days

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