kernel/linux.git/drivers/dma/idxd/cdev.c, branch v6.12.80

dmaengine: idxd: Fix freeing the allocated ida too late

2026-04-02T11:09:52+00:00

[ Upstream commit c311f5e9248471a950f0a524c2fd736414d98900 ] It can happen that when the cdev .release() is called, the driver already called ida_destroy(). Move ida_free() to the _del() path. We see with DEBUG_KOBJECT_RELEASE enabled and forcing an early PCI unbind. Fixes: 04922b7445a1 ("dmaengine: idxd: fix cdev setup and free device lifetime issues") Reviewed-by: Dave Jiang Signed-off-by: Vinicius Costa Gomes Link: https://patch.msgid.link/20260121-idxd-fix-flr-on-kernel-queues-v3-v3-9-7ed70658a9d1@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: idxd: Check availability of workqueue allocated by idxd wq driver before using

2025-07-06T09:01:33+00:00

[ Upstream commit 17502e7d7b7113346296f6758324798d536c31fd ] Running IDXD workloads in a container with the /dev directory mounted can trigger a call trace or even a kernel panic when the parent process of the container is terminated. This issue occurs because, under certain configurations, Docker does not properly propagate the mount replica back to the original mount point. In this case, when the user driver detaches, the WQ is destroyed but it still calls destroy_workqueue() attempting to completes all pending work. It's necessary to check wq->wq and skip the drain if it no longer exists. Signed-off-by: Yi Sun Reviewed-by: Dave Jiang Reviewed-by: Anil S Keshavamurthy Link: https://lore.kernel.org/r/20250509000304.1402863-1-yi.sun@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: idxd: cdev: Fix uninitialized use of sva in idxd_cdev_open

2025-06-04T12:43:52+00:00

[ Upstream commit 97994333de2b8062d2df4e6ce0dc65c2dc0f40dc ] Fix Smatch-detected issue: drivers/dma/idxd/cdev.c:321 idxd_cdev_open() error: uninitialized symbol 'sva'. 'sva' pointer may be used uninitialized in error handling paths. Specifically, if PASID support is enabled and iommu_sva_bind_device() returns an error, the code jumps to the cleanup label and attempts to call iommu_sva_unbind_device(sva) without ensuring that sva was successfully assigned. This triggers a Smatch warning about an uninitialized symbol. Initialize sva to NULL at declaration and add a check using IS_ERR_OR_NULL() before unbinding the device. This ensures the function does not use an invalid or uninitialized pointer during cleanup. Signed-off-by: Purva Yeshi Reviewed-by: Dave Jiang Acked-by: Vinicius Costa Gomes Link: https://lore.kernel.org/r/20250410110216.21592-1-purvayeshi550@gmail.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: idxd: Fix ->poll() return value

2025-05-29T09:03:15+00:00

[ Upstream commit ae74cd15ade833adc289279b5c6f12e78f64d4d7 ] The fix to block access from different address space did not return a correct value for ->poll() change. kernel test bot reported that a return value of type __poll_t is expected rather than int. Fix to return POLLNVAL to indicate invalid request. Fixes: 8dfa57aabff6 ("dmaengine: idxd: Fix allowing write() from different address spaces") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202505081851.rwD7jVxg-lkp@intel.com/ Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/20250508170548.2747425-1-dave.jiang@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: idxd: Fix allowing write() from different address spaces

2025-05-29T09:03:14+00:00

[ Upstream commit 8dfa57aabff625bf445548257f7711ef294cd30e ] Check if the process submitting the descriptor belongs to the same address space as the one that opened the file, reject otherwise. Fixes: 6827738dc684 ("dmaengine: idxd: add a write() method for applications to submit work") Signed-off-by: Vinicius Costa Gomes Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/20250421170337.3008875-1-dave.jiang@intel.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

Merge tag 'dmaengine-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine

2024-05-21T18:15:56+00:00

Pull dmaengine updates from Vinod Koul: "New HW support: - Freescale i.MX8ULP edma support in edma driver - StarFive JH8100 DMA support in Synopsis axi-dmac driver Updates: - Tracing support for freescale edma driver, updates to dpaa2 driver - Remove unused QCom hidma DT support - Support for i2c dma in imx-sdma - Maintainers update for idxd and edma drivers" * tag 'dmaengine-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (42 commits) MAINTAINERS: Update role for IDXD driver dmaengine: fsl-edma: use _Generic to handle difference type dmaengine: fsl-edma: add trace event support dmaengine: idxd: Avoid unnecessary destruction of file_ida dmaengine: xilinx: xdma: fix module autoloading dt-bindings: dma: fsl-edma: allow 'power-domains' property dt-bindings: dma: fsl-edma: remove 'clocks' from required dmaengine: fsl-dpaa2-qdma: Fix kernel-doc check warning dmaengine: imx-sdma: Add i2c dma support dmaengine: imx-sdma: utilize compiler to calculate ADDRS_ARRAY_SIZE_V dt-bindings: fsl-imx-sdma: Add I2C peripheral types ID dt-bindings: fsl-dma: fsl-edma: clean up unused "fsl,imx8qm-adma" compatible string dmaengine: fsl-edma: clean up unused "fsl,imx8qm-adma" compatible string dt-bindings: dma: Drop unused QCom hidma binding dmaengine: qcom: Drop hidma DT support dmaengine: pl08x: Use kcalloc() instead of kzalloc() dmaengine: fsl-dpaa2-qdma: Update DPDMAI interfaces to version 3 dmaengine: fsl-edma: fix miss mutex unlock at an error return path dmaengine: pch_dma: remove unused function chan2parent dmaengine: fsl-dpaa2-qdma: Add dpdmai_cmd_open ...

dmaengine: idxd: add a write() method for applications to submit work

2024-05-13T14:07:45+00:00

After the patch to restrict the use of mmap() to CAP_SYS_RAWIO for the currently existing devices, most applications can no longer make use of the accelerators as in production "you don't run things as root". To keep the DSA and IAA accelerators usable, hook up a write() method so that applications can still submit work. In the write method, sufficient input validation is performed to avoid the security issue that required the mmap CAP_SYS_RAWIO check. One complication is that the DSA device allows for indirect ("batched") descriptors. There is no reasonable way to do the input validation on these indirect descriptors so the write() method will not allow these to be submitted to the hardware on affected hardware, and the sysfs enumeration of support for the opcode is also removed. Early performance data shows that the performance delta for most common cases is within the noise. Signed-off-by: Nikhil Rao Signed-off-by: Arjan van de Ven

dmaengine: idxd: add a new security check to deal with a hardware erratum

2024-05-13T14:07:40+00:00

On Sapphire Rapids and related platforms, the DSA and IAA devices have an erratum that causes direct access (for example, by using the ENQCMD or MOVDIR64 instructions) from untrusted applications to be a security problem. To solve this, add a flag to the PCI device enumeration and device structures to indicate the presence/absence of this security exposure. In the mmap() method of the device, this flag is then used to enforce that the user has the CAP_SYS_RAWIO capability. In a future patch, a write() based method will be added that allows untrusted applications submit work to the accelerator, where the kernel can do sanity checking on the user input to ensure secure operation of the accelerator. Signed-off-by: Arjan van de Ven

dmaengine: idxd: Avoid unnecessary destruction of file_ida

2024-05-04T12:22:04+00:00

file_ida is allocated during cdev open and is freed accordingly during cdev release. This sequence is guaranteed by driver file operations. Therefore, there is no need to destroy an already empty file_ida when the WQ cdev is removed. Worse, ida_free() in cdev release may happen after destruction of file_ida per WQ cdev. This can lead to accessing an id in file_ida after it has been destroyed, resulting in a kernel panic. Remove ida_destroy(&file_ida) to address these issues. Fixes: e6fd6d7e5f0f ("dmaengine: idxd: add a device to represent the file opened") Signed-off-by: Lijun Pan Signed-off-by: Fenghua Yu Reviewed-by: Dave Jiang Link: https://lore.kernel.org/r/20240130013954.2024231-1-fenghua.yu@intel.com Signed-off-by: Vinod Koul

dmaengine: idxd: Convert spinlock to mutex to lock evl workqueue

2024-04-07T08:01:44+00:00

drain_workqueue() cannot be called safely in a spinlocked context due to possible task rescheduling. In the multi-task scenario, calling queue_work() while drain_workqueue() will lead to a Call Trace as pushing a work on a draining workqueue is not permitted in spinlocked context. Call Trace: ? __warn+0x7d/0x140 ? __queue_work+0x2b2/0x440 ? report_bug+0x1f8/0x200 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? __queue_work+0x2b2/0x440 queue_work_on+0x28/0x30 idxd_misc_thread+0x303/0x5a0 [idxd] ? __schedule+0x369/0xb40 ? __pfx_irq_thread_fn+0x10/0x10 ? irq_thread+0xbc/0x1b0 irq_thread_fn+0x21/0x70 irq_thread+0x102/0x1b0 ? preempt_count_add+0x74/0xa0 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0x103/0x140 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 The current implementation uses a spinlock to protect event log workqueue and will lead to the Call Trace due to potential task rescheduling. To address the locking issue, convert the spinlock to mutex, allowing the drain_workqueue() to be called in a safe mutex-locked context. This change ensures proper synchronization when accessing the event log workqueue, preventing potential Call Trace and improving the overall robustness of the code. Fixes: c40bd7d9737b ("dmaengine: idxd: process user page faults for completion record") Signed-off-by: Rex Zhang Reviewed-by: Dave Jiang Reviewed-by: Fenghua Yu Reviewed-by: Lijun Pan Link: https://lore.kernel.org/r/20240404223949.2885604-1-fenghua.yu@intel.com Signed-off-by: Vinod Koul