Linaro-mm-sig

linaro-mm-sig@lists.linaro.org

26 participants
6411 discussions

[PATCH RFC 0/5] memcg: dma-buf per-cgroup accounting via pid_fd

by Albert Esteve

This RFC builds on T.J. Mercier's earlier series [1] which added a memory.stat counter for exported dma-bufs and a binder-backed mechanism to transfer charges between cgroups. The first commit is taken almost verbatim from TJ's series: it introduces MEMCG_DMABUF as a dedicated per-cgroup stat, so that the total exported dma-buf footprint is visible both system-wide (via the root cgroup) and per-application (via per-process cgroups). This avoids the overhead of DMABUF_SYSFS_STATS and integrates naturally into the existing cgroup memory hierarchy. The rest of the series departs from TJ's approach. While the first commit introduces the memcg stat infrastructure for dmabufs, the export-time charging it introduces in dma_buf_export() is then superseded: we charge at dma_heap_ioctl_allocate() time, using a new charge_pid_fd field in struct dma_heap_allocation_data. The allocator opens a pidfd for its client (e.g., from binder's sender_pid), passes it to the ioctl, and the kernel charges the buffer directly to the client's cgroup at allocation time, so no transfer step is needed. This decouples the accounting path from binder entirely: any allocator that knows its client's PID can use the pid_fd mechanism regardless of the IPC transport in use. The cross-cgroup charging capability requires access control. Patches #3 and #4 add a generic LSM hook (security_dma_heap_alloc) and an SELinux implementation based on a new dma_heap object class with a charge_to permission, so policy authors can express which domains are allowed to charge memory to another domain's cgroup. Last patch adds some tests to verify the new charge_pid_fd field. We are sending it as an RFC to spark broader discussion. It may or may not be the right path forward, and we welcome feedback on the trade-offs. Collision note: Eric Chanudet's series [2] adds __GFP_ACCOUNT to system_heap page allocations as an opt-in module parameter. That approach charges pages to the allocator's own kmem, which overlaps with MEMCG_DMABUF. This series explicitly removes __GFP_ACCOUNT from system heap allocations and routes all accounting through the MEMCG_DMABUF path to avoid double-counting. [1] https://lore.kernel.org/cgroups/20230109213809.418135-1-tjmercier@google.co… [2] https://lore.kernel.org/r/20260113-dmabuf-heap-system-memcg-v2-0-e85722cc2f… Signed-off-by: Albert Esteve <aesteve(a)redhat.com> --- Albert Esteve (4): dma-heap: charge dma-buf memory via explicit memcg security: dma-heap: Add dma_heap_alloc LSM hook selinux: Restrict cross-cgroup dma-heap charging selftests/dmabuf-heaps: Add dma-buf memcg accounting tests T.J. Mercier (1): memcg: Track exported dma-buffers Documentation/admin-guide/cgroup-v2.rst | 5 + drivers/dma-buf/dma-buf.c | 7 + drivers/dma-buf/dma-heap.c | 54 +++++- drivers/dma-buf/heaps/system_heap.c | 2 - include/linux/dma-buf.h | 4 + include/linux/lsm_hook_defs.h | 1 + include/linux/memcontrol.h | 37 ++++ include/linux/security.h | 7 + include/uapi/linux/dma-heap.h | 6 + mm/memcontrol.c | 19 ++ security/security.c | 16 ++ security/selinux/hooks.c | 7 + security/selinux/include/classmap.h | 1 + tools/testing/selftests/cgroup/Makefile | 2 +- tools/testing/selftests/cgroup/test_memcontrol.c | 143 +++++++++++++- tools/testing/selftests/dmabuf-heaps/config | 1 + tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 126 ++++++++++++- tools/testing/selftests/dmabuf-heaps/vmtest.sh | 205 +++++++++++++++++++++ 18 files changed, 633 insertions(+), 10 deletions(-) --- base-commit: 74fe02ce122a6103f207d29fafc8b3a53de6abaf change-id: 20260508-v2_20230123_tjmercier_google_com-f44fcfb16530 Best regards, -- Albert Esteve <aesteve(a)redhat.com>

9 hours, 46 minutes

Re: [PATCH 4/8] drm/panthor: Add support for protected memory allocation in panthor

by Liviu Dudau

On Tue, May 12, 2026 at 04:11:11PM +0200, Boris Brezillon wrote: > On Tue, 12 May 2026 14:47:27 +0100 > Liviu Dudau <liviu.dudau(a)arm.com> wrote: > > > On Thu, May 07, 2026 at 01:53:56PM +0200, Boris Brezillon wrote: > > > On Thu, 7 May 2026 11:02:26 +0200 > > > Marcin Ślusarz <marcin.slusarz(a)arm.com> wrote: > > > > > > > On Tue, May 05, 2026 at 06:15:23PM +0200, Boris Brezillon wrote: > > > > > > @@ -277,9 +286,21 @@ int panthor_device_init(struct panthor_device *ptdev) > > > > > > return ret; > > > > > > } > > > > > > > > > > > > + /* If a protected heap name is specified but not found, defer the probe until created */ > > > > > > + if (protected_heap_name && strlen(protected_heap_name)) { > > > > > > > > > > Do we really need this strlen() > 0? Won't dma_heap_find() fail is the > > > > > name is "" already? > > > > > > > > If dma_heap_find() will fail, then the whole probe with fail too. > > > > This check prevents that. > > > > > > Yeah, that's also a questionable design choice. I mean, we can > > > currently probe and boot the FW even though we never setup the > > > protected FW sections, so why should we defer the probe here? Can't we > > > just retry the next time a group with the protected bit is created and > > > fail if we can find a protected heap? > > > > The problem we have with the current firmware is that it does a number of setup steps at "boot" > > time only. One of the steps is preparing its internal structures for when it enters protected > > mode and it stores them in the buffer passed in at firmware loading. We cannot later run the > > process when we have a group with protected mode set. > > No, but we can force a full/slow reset and have that thing > re-initialized, can't we? I mean, that's basically what we do when a > fast reset fails: we re-initialize all the sections and reset again, at > which point the FW should start from a fresh state, and be able to > properly initialize the protected-related stuff if protected sections > are populated. Am I missing something? Right, we can do that. For some reason I keep associating the reset with the error handling and not with "normal" operations. Best regards, Liviu -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯

13 hours, 1 minute

Obtain BCSP certifications without an exam in California

by Jamestoah113＠gmail.com

(certifitasap(a)gmail.com) Certified Safety Professional! #csp #safety #bcsp Certification is a designation awarded by the Board of Certified Safety Professionals (BCSP). We issue legit and verified BCSP certifications online with or without exams. The certificates are all available online. Buy Valid CSP Certification in the USA, Real BCSP Certifications in Mexico - USA BCSP Certifications. Learn how to become a Certified Safety Professional (CSP) with BCSP, a credential that demonstrates comprehensive knowledge and skills in safety practice. Find out the education, experience, examination, and maintenance requirements for CSP certification. Buy a Certified Safety Professional in the USA #csp #bcsp #ehs #safety #hse #workplacesafety #development #certification #growth Contact us via Teams ID-- (Jacob JB) Email....(certifitasap(a)gmail.com) WhatsApp...+1 (226) 894-5014 We are seeking a NEBOSH Diploma holder or equivalent for the role of HSE/Safety Officer on the Riyadh Metro Project. NEBOSH IGC, OSHA, and IOSH certifications with QR codes for easy verification of authenticity. No Exam: When you buy a genuine Certification, there will be no need to take the exams. Convenience: Many people have tight schedules and lack sufficient time to complete the exams or the testing process. https://safetycertificationsonline.blogspot.com/ We provide Official certifications with registration into the database and actual center stamps for customers interested in obtaining the certificate without taking the test. Certifitasap(a)gmail.com Apply for BCSP Certifications without exams 2026, Apply for CSHM Certification without exams, Apply for MSP Certification without exams in Australia, Apply for CSD Certification without exams in Bahrain, Apply for ASP Certification without exams in British, Apply for OHST Certification without exams in Canada, Apply for CHST Certification without exams in Dubai|, Apply for BCSP Certification without exams, Apply for CSP Certification without exams 2026, Apply for STS Certification without exams in Azerbaijan, Apply for CIH Certification without exams, Apply for CHMM without exam, Apply for NEBOSH Certification without exam in Bahrain #safety #bcsp #occupationalsafety #safetyexam #csp #industrialhygiene #safetypro #workersafety #jobsitesafety #osh #safetyprofessional #construction #safeworkplace #constructionsafety #safetymanager #ucm #ucmsafetyscience Certified Safety Professional (CSP) certification is a designation awarded by the Board of Certified Safety Professionals (BCSP) to individuals who demonstrate competency in safety management, occupational health, risk assessment, and regulatory compliance. https://generalhealthandsafety.blogspot.com/ The Certified Safety Professional (CSP) Certificate Course is one of the most sought-after certifications in the field of occupational health and safety. It demonstrates a high level of expertise in safety management. Certified Safety Professional (CSP) certification is a designation awarded by the Board of Certified Safety Professionals (BCSP). We issue legit and verified BCSP certifications online with or without exams. The certificates are all available online. Acquire BCSP certifications online without an Exam in Minnesota Obtain BCSP certifications without an exam in California Order a real, legit (STSC) certification online in Oklahoma Obtain (STS) certification online without an Exam in Nebraska Buy a real, legit CSP certification online in Montana Purchase (ASP) certification online without an Exam in Pennsylvania Apply for (SMS)certification online without an Exam in Massachusetts Apply for Certification without exam in Georgia, Apply for BCSP Certification without exam in Jeddah, Apply for NEBOSH Certification without exam in Jordan, Apply for Diplomas Certification without exam in Lebanon, Apply for IELTS Certification without exam in UK, Apply for BCSP Certification without exam in India, Apply for NEBOSH Diplomas without exam online, Apply for BCSP Certification without exam online in Libya Acquire BCSP Certification Without Exam | CSP Certificate USA without Exam Real BCSP Certifications in India - USA Valid CSD Certification Without Exam - USA Original OHST Certification in UAE - USA Registered CHST Certification Without Exam - Valid CSP Certification in USA - UK Genuine CIH Certification - USA STS Certification Online -USA CHMM Certification in the UK -USA Buy a Certified Safety Professional in the USA Update (CSP) certification online in Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming. Contact us via Teams ID-- (Jacob JB) Email....certifitasap(a)gmail.com WhatsApp...+1 (226) 894-5014 BCSP operates the following certifications: Certified Safety Professional (CSP) Safety Management Specialist (SMS) Associate Safety Professional® (ASP) Occupational Hygiene and Safety Technologist (OHST) Construction Health and Safety Technician (CHST) Safety Trained Supervisor (STS) Safety Trained Supervisor Construction (STSC) Certified Instructional Trainer (CIT) Designations: Graduate Safety Practitioner (GSP) Transitional Safety Practitioner (TSP) NEBOSH Diplomas Certificates Online in Egypt Original NEBOSH Certificate Without Exam in United Arab Emirates, UAE, Dubai Original NEBOSH course Certificate Without Exam in Jordan neboshigc03(a)yahoo.com original NEBOSH Diplomas Without Exam in Saudi Arabia Original NEBOSH Certificate Without Exam in Jordan NEBOSH Diplomas Certificate Without Exam in Saudi Arabia https://neboshigc03.wixsite.com/website/services https://neboshigc03.wixsite.com/website/about https://neboshigc03.wixs....com/website/book-online https://neboshigc03.wixsite.com/website/contact https://neboshigc03.wixsite.com/website/products Neboshigc03(a)yahoo.com Purchase Original NEBOSH Diplomas Online Exam in Jordan, Apply for Original NEBOSH Certificates Online in United Arab Emirates Acquire Original NEBOSH Certificates Exam Online in Bahrain, Apply for Original NEBOSH Diplomas Exam Online in Algeria, Order Original NEBOSH Certificates Online Exam in Saudi Arabia Obtain Original NEBOSH Diplomas Exam Online in Middle East, Obtain Original NEBOSH IGC online Certificates Exam in Kuwait, Apply for Original NEBOSH Certificates Online Exam in Qatar, Obtain Original NEBOSH IGC Certificates Online Exam in Jordan, Order Original NEBOSH Diplomas Exam Online in Egypt Apply for Original NEBOSH Certificate Exam in UAE, Dubai Order Original NEBOSH Certificate Exam in Jordan, Apply for Original NEBOSH Diplomas Exam in Saudi Arabia Original NEBOSH Certificate Exam in Jordan NEBOSH Diplomas Certificate Exam in Saudi Arabia >>We are fast, reliable and flexible >>We are popular and trusted >>We are highly experienced in documentation >>We have excellent pass into database. https://generalhealthandsafety.blogspot.com/ https://certifiedsafetyprofessional.blogspot.com/ https://safetycertificationsonline.blogspot.com/ https://isc2certified.blogspot.com/ https://buycybersecurity...ifications.blogspot.com/ https://t.me/neboshigcdiploma https://t.me/odkhs https://t.me/+UfhkuxkiJsw5NWEx https://t.me/neboshigcdiploma https://t.me/+9YNbYISd1zo2ZmFh https://t.me/+IKqMHjQRhzllZmUx https://t.me/+LCKaaTSZ0Ws4Njlh https://t.me/+6wM4t3pxC1Q5NTMx https://t.me/modkx https://t.me/iscdk https://t.me/odkhs https://www.tiktok.com/@isc2cissp Contact us via Teams ID-- (Jacob JB) Apply for ASP Certification without exams, Apply for MSP Certification without exams in Saudi Arabia, Apply for CHST Certification without exams, Apply for OHST Certification without exams, Apply for CSD Certification without exams, Apply for Diplomas without exams in Bahrain, Apply for BCSP Certification without exams test in india, Apply for NEBOSH Diplomas without test in London, Apply for Diplomas without test in melbourne, Apply for NEBOSH Certification without test in Riyadh, Apply for CSHM Certification without test in sydney, Apply for CHMM Certification without test online, Apply for CIH Certification without test online in India, Apply for STS Certification without test online in London #ApplyforCSPCertificationwithoutexams #ApplyforCHSTCertificationwithoutexams #ApplyforOHSTCertificationwithoutexams #ApplyforASPCertificationwithoutexams #ApplyforCSDCertificationwithoutexams #ApplyforMSPCertificationwithoutexams #ApplyforNEBOSHCertificationwithouttest #ApplyforNEBOSHDiplomaswithouttest Contact us via Teams ID-- (Jacob JB) Email....certifitasap(a)gmail.com WhatsApp...+1 (226) 894-5014

13 hours, 37 minutes

Obtain BCSP certifications without an exam in California

by Jamestoah113＠gmail.com

13 hours, 38 minutes

Re: [PATCH 4/8] drm/panthor: Add support for protected memory allocation in panthor

by Liviu Dudau

On Thu, May 07, 2026 at 01:53:56PM +0200, Boris Brezillon wrote: > On Thu, 7 May 2026 11:02:26 +0200 > Marcin Ślusarz <marcin.slusarz(a)arm.com> wrote: > > > On Tue, May 05, 2026 at 06:15:23PM +0200, Boris Brezillon wrote: > > > > @@ -277,9 +286,21 @@ int panthor_device_init(struct panthor_device *ptdev) > > > > return ret; > > > > } > > > > > > > > + /* If a protected heap name is specified but not found, defer the probe until created */ > > > > + if (protected_heap_name && strlen(protected_heap_name)) { > > > > > > Do we really need this strlen() > 0? Won't dma_heap_find() fail is the > > > name is "" already? > > > > If dma_heap_find() will fail, then the whole probe with fail too. > > This check prevents that. > > Yeah, that's also a questionable design choice. I mean, we can > currently probe and boot the FW even though we never setup the > protected FW sections, so why should we defer the probe here? Can't we > just retry the next time a group with the protected bit is created and > fail if we can find a protected heap? The problem we have with the current firmware is that it does a number of setup steps at "boot" time only. One of the steps is preparing its internal structures for when it enters protected mode and it stores them in the buffer passed in at firmware loading. We cannot later run the process when we have a group with protected mode set. So unfortunately adding support for protected mode where the heap name is provided means we have to try our best to set it up at boot time, or otherwise disable protected mode support. Best regards, Liviu > > > I'm not sure why it's needed at all, but if > > it is really needed, then s/strlen(protected_heap_name)/protected_heap_name[0]/ > > would simplify this. > > It's not so much about how you do the test, and more about the case > you're trying to protect against. I guess here you assume that > panthor.protected_heap_name="" means "I don't have a protected heap for > you". If it's deemed acceptable, this should most certainly be > described somewhere. > > > > > > > + ptdev->protm.heap = dma_heap_find(protected_heap_name); > > > > + if (!ptdev->protm.heap) { > > > > + drm_warn(&ptdev->base, > > > > + "Protected heap \'%s\' not (yet) available - deferring probe", > > > > + protected_heap_name); > > > > + ret = -EPROBE_DEFER; > > > > + goto err_rpm_put; > > > > > > If you move the heap retrieval before the rpm enablement, you can get > > > rid of this goto err_rpm_put. > > > > > > > + } > > > > + } > > > > + > > > > ret = panthor_hw_init(ptdev); > > > > if (ret) > > > > - goto err_rpm_put; > > > > + goto err_dma_heap_put; > > > > > > > > ret = panthor_pwr_init(ptdev); > > > > if (ret) > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯

14 hours, 52 minutes

Re: [PATCH 3/8] drm/panthor: De-duplicate FW memory section sync

by Liviu Dudau

On Tue, May 05, 2026 at 04:05:09PM +0200, Ketil Johnsen wrote: > Handle the sync to device of FW memory sections inside > panthor_fw_init_section_mem() so that the callers do not have to. > > This small improvement is also critical for protected FW sections, > so we avoid issuing memory transactions to protected memory from > CPU running in normal mode. > > Signed-off-by: Ketil Johnsen <ketil.johnsen(a)arm.com> Reviewed-by: Liviu Dudau <liviu.dudau(a)arm.com> Best regards, Liviu > --- > drivers/gpu/drm/panthor/panthor_fw.c | 22 ++++++---------------- > 1 file changed, 6 insertions(+), 16 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c > index be0da5b1f3abf..0d07a133dc3af 100644 > --- a/drivers/gpu/drm/panthor/panthor_fw.c > +++ b/drivers/gpu/drm/panthor/panthor_fw.c > @@ -446,6 +446,7 @@ static void panthor_fw_init_section_mem(struct panthor_device *ptdev, > struct panthor_fw_section *section) > { > bool was_mapped = !!section->mem->kmap; > + struct sg_table *sgt; > int ret; > > if (!section->data.size && > @@ -464,6 +465,11 @@ static void panthor_fw_init_section_mem(struct panthor_device *ptdev, > > if (!was_mapped) > panthor_kernel_bo_vunmap(section->mem); > + > + /* An sgt should have been requested when the kernel BO was GPU-mapped. */ > + sgt = to_panthor_bo(section->mem->obj)->dmap.sgt; > + if (!drm_WARN_ON_ONCE(&ptdev->base, !sgt)) > + dma_sync_sgtable_for_device(ptdev->base.dev, sgt, DMA_TO_DEVICE); > } > > /** > @@ -626,7 +632,6 @@ static int panthor_fw_load_section_entry(struct panthor_device *ptdev, > section_size = hdr.va.end - hdr.va.start; > if (section_size) { > u32 cache_mode = hdr.flags & CSF_FW_BINARY_IFACE_ENTRY_CACHE_MODE_MASK; > - struct panthor_gem_object *bo; > u32 vm_map_flags = 0; > u64 va = hdr.va.start; > > @@ -663,14 +668,6 @@ static int panthor_fw_load_section_entry(struct panthor_device *ptdev, > } > > panthor_fw_init_section_mem(ptdev, section); > - > - bo = to_panthor_bo(section->mem->obj); > - > - /* An sgt should have been requested when the kernel BO was GPU-mapped. */ > - if (drm_WARN_ON_ONCE(&ptdev->base, !bo->dmap.sgt)) > - return -EINVAL; > - > - dma_sync_sgtable_for_device(ptdev->base.dev, bo->dmap.sgt, DMA_TO_DEVICE); > } > > if (hdr.va.start == CSF_MCU_SHARED_REGION_START) > @@ -724,17 +721,10 @@ panthor_reload_fw_sections(struct panthor_device *ptdev, bool full_reload) > struct panthor_fw_section *section; > > list_for_each_entry(section, &ptdev->fw->sections, node) { > - struct sg_table *sgt; > - > if (!full_reload && !(section->flags & CSF_FW_BINARY_IFACE_ENTRY_WR)) > continue; > > panthor_fw_init_section_mem(ptdev, section); > - > - /* An sgt should have been requested when the kernel BO was GPU-mapped. */ > - sgt = to_panthor_bo(section->mem->obj)->dmap.sgt; > - if (!drm_WARN_ON_ONCE(&ptdev->base, !sgt)) > - dma_sync_sgtable_for_device(ptdev->base.dev, sgt, DMA_TO_DEVICE); > } > } > > -- > 2.43.0 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯

15 hours, 2 minutes

Mastering the Quirky Fun of Drive Mad

by cold.puma.etfk＠hidingmail.net

Ever stumbled upon a game that, despite its simple premise, completely hooks you with its pure, unadulterated fun? That’s exactly the experience many players find with Drive Mad. This charmingly addictive browser game offers a delightful blend of physics-based challenges and surprisingly deep vehicle customization, making it a perfect quick pick-up-and-play for a few minutes or an hour. If you’re looking to dive into some lighthearted, yet engaging, gaming, then look no further than learning how to play and truly experience Drive Mad. What is Drive Mad? The Basics of Bouncing and Building https://drivemadfree.com At its core, Drive Mad is a physics-based driving game where your primary goal is to navigate a vehicle through increasingly outlandish courses. The controls are delightfully straightforward: typically just accelerator, brake, and often a way to tilt your vehicle forward or backward. What makes it interesting, however, is the emphasis on building. Before each level, you’re presented with a basic chassis and a limited budget to add various components: wheels of different sizes and grips, engines with varying power, and even structural elements to help you survive a crash or two. The magic lies in experimenting with these parts to create the most effective (or hilariously ineffective) contraption to tackle the upcoming obstacles. You can find this gem at Drive Mad. From Novice to Mad Driver: Gameplay and Progression The journey in Drive Mad starts simply. Early levels introduce you to basic inclines, gaps, and flat surfaces, allowing you to get a feel for the physics and how different vehicle builds respond. As you progress, the challenges escalate dramatically. You’ll encounter massive ramps, precarious bridges, explosive barrels, and even sections that require careful balancing on a single wheel. Each successful completion of a level earns you more in-game currency, which you can then use to unlock new vehicle parts, expanding your creative possibilities. The satisfaction of finally overcoming a particularly tricky level with a custom-built monster truck or a zippy, lightweight dune buggy is truly rewarding. Tips for Taming the Tracks: Your Guide to Success While Drive Mad is easy to pick up, mastering it requires a bit of strategy. Here are a few friendly tips to help you on your way: • Experiment with Wheels: Don't underestimate the power of different wheel types. Larger wheels offer better clearance and absorb impacts, while smaller wheels can be nimble. Experiment with combinations! • Balance is Key: Especially in later levels, maintaining balance is crucial. Use your tilt controls wisely to prevent your vehicle from flipping over, especially on steep ascents or descents. • Budget Wisely: While it's tempting to splurge on the most powerful engine, sometimes a more balanced build with good wheels and a sturdy frame is more effective than a top-heavy speed demon. • Learn from Crashes: Every glorious explosion or comical flip is a learning opportunity. Pay attention to what caused the failure and adjust your vehicle or driving style accordingly. • Sometimes Less is More: Don’t feel obligated to use every component you can. A simpler, more focused design can sometimes be more robust and effective than an over-engineered behemoth. Conclusion: Embrace the Madness Drive Mad is more than just a simple browser game; it's a testament to the joy of creative problem-solving and the sheer fun of physics-based chaos. Whether you're a seasoned gamer looking for a refreshing break or someone new to the world of digital entertainment, its approachable nature and engaging gameplay make it a fantastic choice. So, next time you have a few minutes to spare, why not hop into the driver's seat, build your dream machine, and see just how far you can drive yourself mad?

20 hours, 12 minutes

Re: [PATCH v3 00/10] Add dmabuf read/write via io_uring

by Christoph Hellwig

What tree is this against? I can't apply it against the usual candidates, even accounting for the time lag in getting to it. Can you provide a git tree?

21 hours, 39 minutes

Re: [PATCH v2] drm/virtio: move cursor resv lock acquisition to prepare_fb

by Dmitry Osipenko

On 5/12/26 05:07, Deepanshu Kartikey wrote: > virtio_gpu_cursor_plane_update() allocates a virtio_gpu_object_array, > locks its dma_resv, and queues a fenced transfer to the host. The > lock acquisition can fail in two ways: > > - dma_resv_lock_interruptible() returns -EINTR when a signal is > delivered while waiting for the reservation lock. > - dma_resv_reserve_fences() returns -ENOMEM if it fails to allocate > a fence slot; in this case lock_resv unlocks before returning. > > The return value was ignored, so the cursor path could proceed with > the resv lock not held. The queue path then walks the object array > and calls dma_resv_add_fence(), which requires the lock; 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. > > The DRM atomic helpers do not allow .atomic_update to fail: by the > time it runs, the commit has been signed off to userspace and there > is no clean rollback path. Move the fallible work -- objs allocation, > dma_resv locking, and fence slot reservation -- into > virtio_gpu_plane_prepare_fb, which is the designated callback for > resource acquisition and may return errors that the framework > handles by rolling back the commit. Stash the prepared object array > on virtio_gpu_plane_state so the update step can consume it. > > Make virtio_gpu_plane_cleanup_fb release the objs if the commit was > rolled back before update ran (i.e., objs not consumed). The queue > path already unlocks the resv after attaching the fence (vq.c:411) > and frees the array via put_free_delayed after host completion > (vq.c:271), so the update step only needs to clear vgplane_st->objs > to transfer ownership. > > Simplify virtio_gpu_cursor_plane_update to a no-fail queue submission > that hands the prepared, locked objs to the queue path. > > 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 > Link: https://lore.kernel.org/all/20260510053025.100224-1-kartikey406@gmail.com/T/ [v1] > Signed-off-by: Deepanshu Kartikey <kartikey406(a)gmail.com> > --- > v2: Move resv lock acquisition from .atomic_update (which must not > fail) to .prepare_fb (which may), per maintainer review of v1. > The previous 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_plane.c | 38 ++++++++++++++++++++------ > 2 files changed, 30 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h > index f17660a71a3e..e51f959dce46 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_drv.h > +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h > @@ -198,6 +198,7 @@ struct virtio_gpu_framebuffer { > struct virtio_gpu_plane_state { > struct drm_plane_state base; > struct virtio_gpu_fence *fence; > + struct virtio_gpu_object_array *objs; > }; > #define to_virtio_gpu_plane_state(x) \ > container_of(x, struct virtio_gpu_plane_state, base) > diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c > index a126d1b25f46..b0511ace89e6 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_plane.c > +++ b/drivers/gpu/drm/virtio/virtgpu_plane.c > @@ -381,6 +381,23 @@ static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane, > goto err_fence; > } > > + if (plane->type == DRM_PLANE_TYPE_CURSOR && bo->dumb) { > + struct virtio_gpu_object_array *objs; > + > + objs = virtio_gpu_array_alloc(1); > + if (!objs) { > + ret = -ENOMEM; > + goto err_fence; > + } > + virtio_gpu_array_add_obj(objs, vgfb->base.obj[0]); > + ret = virtio_gpu_array_lock_resv(objs); > + if (ret) { > + virtio_gpu_array_put_free(objs); > + goto err_fence; > + } > + vgplane_st->objs = objs; > + } > + > return 0; > > err_fence: > @@ -417,6 +434,12 @@ static void virtio_gpu_plane_cleanup_fb(struct drm_plane *plane, > vgplane_st->fence = NULL; > } > > + if (vgplane_st->objs) { > + virtio_gpu_array_unlock_resv(vgplane_st->objs); > + virtio_gpu_array_put_free(vgplane_st->objs); > + vgplane_st->objs = NULL; > + } > + > obj = state->fb->obj[0]; > if (drm_gem_is_imported(obj)) > virtio_gpu_cleanup_imported_obj(obj); > @@ -452,21 +475,18 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane, > } > > if (bo && bo->dumb && (plane->state->fb != old_state->fb)) { > - /* new cursor -- update & wait */ > - struct virtio_gpu_object_array *objs; > - > - objs = virtio_gpu_array_alloc(1); > - if (!objs) > - return; > - virtio_gpu_array_add_obj(objs, vgfb->base.obj[0]); > - virtio_gpu_array_lock_resv(objs); > + /* objs and fence were prepared in virtio_gpu_plane_prepare_fb; > + * the resv is already locked. The queue path takes ownership > + * of objs and unlocks the resv after attaching the fence. > + */ > virtio_gpu_cmd_transfer_to_host_2d > (vgdev, 0, > plane->state->crtc_w, > plane->state->crtc_h, > - 0, 0, objs, vgplane_st->fence); > + 0, 0, vgplane_st->objs, vgplane_st->fence); > virtio_gpu_notify(vgdev); > dma_fence_wait(&vgplane_st->fence->f, true); > + vgplane_st->objs = NULL; > } > > if (plane->state->fb != old_state->fb) { I'm getting lockup with this patch applied and now see that virtio_gpu_resource_flush() also locks BO. Easiest option might be to add uninterruptible variant of virtio_gpu_array_lock_resv(). Could you please try it for v3? -- Best regards, Dmitry

22 hours, 5 minutes

Re: [RFC PATCH 04/12] vfio/pci: Allow MMIO regions to be exported through dma-buf

by Jason Gunthorpe

On Tue, May 12, 2026 at 09:42:01AM +1000, Alexey Kardashevskiy wrote: > > true but either way dmabuf slicing will be directed by QEMU's msix-table > > emulation MR and this slicing needs to match the TDISP report so I'll > > have to teach QEMU these reports, right? > > Or TDISP devices are going to align MSIX BARs to 4K, and QEMU will > do the same and it should "just work", and if it does not - the host > won't crash. Can this work? Thanks, Host crashing stuff is a different issue, I think the plan was to revoke the entire MMIO space from userspace and remove it from the kernel mapping. Entire because we don't want to parse the TDISP report to figure out something more narrow. Therefore there is no way the host can crash. When qemu constructs the VM memory map it already has a scheme to insert a hole for a SW emulated page for MSI. That will keep working exactly as it is. When the VM validates the MMIO the hole has to fall within a T=0 space of the TDISP report or the VM will reject it. This means devices need to have a T=0 hole around their MSI-X/etc suitable for a 64K page size OS. This is already the case, if a device mixes MSIx with other things qemu will work but it becomes horribly slow and a little broken. Jason

1 day, 4 hours

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

Linaro-mm-sig