- 12 Apr, 2019 4 commits
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Lu Baolu authored
By default, for performance consideration, Intel IOMMU driver won't flush IOTLB immediately after a buffer is unmapped. It schedules a thread and flushes IOTLB in a batched mode. This isn't suitable for untrusted device since it still can access the memory even if it isn't supposed to do so. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by:
Lu Baolu <baolu.lu@linux.intel.com> Tested-by:
Xu Pengfei <pengfei.xu@intel.com> Tested-by:
Mika Westerberg <mika.westerberg@intel.com> Signed-off-by:
Joerg Roedel <jroedel@suse.de>
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Lu Baolu authored
This adds the support to determine the isolation type of a mediated device group by checking whether it has an iommu device. If an iommu device exists, an iommu domain will be allocated and then attached to the iommu device. Otherwise, keep the same behavior as it is. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
Sanjay Kumar <sanjay.k.kumar@intel.com> Signed-off-by:
Liu Yi L <yi.l.liu@intel.com> Signed-off-by:
Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Reviewed-by:
Kirti Wankhede <kwankhede@nvidia.com> Acked-by:
Alex Williamson <alex.williamson@redhat.com> Signed-off-by:
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Lu Baolu authored
This adds helpers to attach or detach a domain to a group. This will replace iommu_attach_group() which only works for non-mdev devices. If a domain is attaching to a group which includes the mediated devices, it should attach to the iommu device (a pci device which represents the mdev in iommu scope) instead. The added helper supports attaching domain to groups for both pci and mdev devices. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
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Lu Baolu authored
A parent device might create different types of mediated devices. For example, a mediated device could be created by the parent device with full isolation and protection provided by the IOMMU. One usage case could be found on Intel platforms where a mediated device is an assignable subset of a PCI, the DMA requests on behalf of it are all tagged with a PASID. Since IOMMU supports PASID-granular translations (scalable mode in VT-d 3.0), this mediated device could be individually protected and isolated by an IOMMU. This patch adds a new member in the struct mdev_device to indicate that the mediated device represented by mdev could be isolated and protected by attaching a domain to a device represented by mdev->iommu_device. It also adds a helper to add or set the iommu device. * mdev_device->iommu_device - This, if set, indicates that the mediated device could be fully isolated and protected by IOMMU via attaching an iommu domain to this device. If empty, it indicates using vendor defined isolation, hence bypass IOMMU. * mdev_set/get_iommu_device(dev, iommu_device) - Set or get the iommu device which represents this mdev in IOMMU's device scope. Drivers don't need to set the iommu device if it uses vendor defined isolation. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Liu Yi L <yi.l.liu@intel.com> Suggested-by:Kevin Tian <kevin.tian@intel.com> Suggested-by:
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- 11 Apr, 2019 11 commits
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Christoph Hellwig authored
We already do this in the caller. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Christoph Hellwig authored
The intel-iommu driver currently has a partial reimplementation of the direct mapping code for devices that use pass through mode. Replace that code with calls to the relevant dma_direct routines at the highest level. This means we have exactly the same behvior as the dma direct code itself, and can prepare for eventually only attaching the intel_iommu ops to devices that actually need dynamic iommu mappings. Signed-off-by:
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Christoph Hellwig authored
Invert the return value to avoid double negatives, use a bool instead of int as the return value, and reduce some indentation after early returns. Signed-off-by:
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Lu Baolu authored
This adds support to return the default pasid associated with an auxiliary domain. The PCI device which is bound with this domain should use this value as the pasid for all DMA requests of the subset of device which is isolated and protected with this domain. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
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Lu Baolu authored
When multiple domains per device has been enabled by the device driver, the device will tag the default PASID for the domain to all DMA traffics out of the subset of this device; and the IOMMU should translate the DMA requests in PASID granularity. This adds the intel_iommu_aux_attach/detach_device() ops to support managing PASID granular translation structures when the device driver has enabled multiple domains per device. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
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Lu Baolu authored
This part of code could be used by both normal and aux domain specific attach entries. Hence move them into a common function to avoid duplication. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
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Lu Baolu authored
This adds the iommu ops entries for aux-domain per-device feature query and enable/disable. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
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Lu Baolu authored
This moves intel_iommu_enable_pasid() out of the scope of CONFIG_INTEL_IOMMU_SVM with more and more features requiring pasid function. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Signed-off-by:
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Joerg Roedel authored
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Jean-Philippe Brucker authored
Add bind() and unbind() operations to the IOMMU API. iommu_sva_bind_device() binds a device to an mm, and returns a handle to the bond, which is released by calling iommu_sva_unbind_device(). Each mm bound to devices gets a PASID (by convention, a 20-bit system-wide ID representing the address space), which can be retrieved with iommu_sva_get_pasid(). When programming DMA addresses, device drivers include this PASID in a device-specific manner, to let the device access the given address space. Since the process memory may be paged out, device and IOMMU must support I/O page faults (e.g. PCI PRI). Using iommu_sva_set_ops(), device drivers provide an mm_exit() callback that is called by the IOMMU driver if the process exits before the device driver called unbind(). In mm_exit(), device driver should disable DMA from the given context, so that the core IOMMU can reallocate the PASID. Whether the process exited or nor, the device driver should always release the handle with unbind(). To use these functions, device driver must first enable the IOMMU_DEV_FEAT_SVA device feature with iommu_dev_enable_feature(). Signed-off-by:
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Lu Baolu authored
Sharing a physical PCI device in a finer-granularity way is becoming a consensus in the industry. IOMMU vendors are also engaging efforts to support such sharing as well as possible. Among the efforts, the capability of support finer-granularity DMA isolation is a common requirement due to the security consideration. With finer-granularity DMA isolation, subsets of a PCI function can be isolated from each others by the IOMMU. As a result, there is a request in software to attach multiple domains to a physical PCI device. One example of such use model is the Intel Scalable IOV [1] [2]. The Intel vt-d 3.0 spec [3] introduces the scalable mode which enables PASID granularity DMA isolation. This adds the APIs to support multiple domains per device. In order to ease the discussions, we call it 'a domain in auxiliary mode' or simply 'auxiliary domain' when multiple domains are attached to a physical device. The APIs include: * iommu_dev_has_feature(dev, IOMMU_DEV_FEAT_AUX) - Detect both IOMMU and PCI endpoint devices supporting the feature (aux-domain here) without the host driver dependency. * iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) - Check the enabling status of the feature (aux-domain here). The aux-domain interfaces are available only if this returns true. * iommu_dev_enable/disable_feature(dev, IOMMU_DEV_FEAT_AUX) - Enable/disable device specific aux-domain feature. * iommu_aux_attach_device(domain, dev) - Attaches @domain to @dev in the auxiliary mode. Multiple domains could be attached to a single device in the auxiliary mode with each domain representing an isolated address space for an assignable subset of the device. * iommu_aux_detach_device(domain, dev) - Detach @domain which has been attached to @dev in the auxiliary mode. * iommu_aux_get_pasid(domain, dev) - Return ID used for finer-granularity DMA translation. For the Intel Scalable IOV usage model, this will be a PASID. The device which supports Scalable IOV needs to write this ID to the device register so that DMA requests could be tagged with a right PASID prefix. This has been updated with the latest proposal from Joerg posted here [5]. Many people involved in discussions of this design. Kevin Tian <kevin.tian@intel.com> Liu Yi L <yi.l.liu@intel.com> Ashok Raj <ashok.raj@intel.com> Sanjay Kumar <sanjay.k.kumar@intel.com> Jacob Pan <jacob.jun.pan@linux.intel.com> Alex Williamson <alex.williamson@redhat.com> Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Joerg Roedel <joro@8bytes.org> and some discussions can be found here [4] [5]. [1] https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification [2] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf [3] https://software.intel.com/en-us/download/intel-virtualization-technology-for-directed-io-architecture-specification [4] https://lkml.org/lkml/2018/7/26/4 [5] https://www.spinics.net/lists/iommu/msg31874.html Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Liu Yi L <yi.l.liu@intel.com> Suggested-by:
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- 08 Apr, 2019 1 commit
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Linus Torvalds authored
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- 07 Apr, 2019 15 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds authored
Pull ARM SoC fixes from Olof Johansson: "A collection of fixes from the last few weeks. Most of them are smaller tweaks and fixes to DT and hardware descriptions for boards. Some of the more significant ones are: - eMMC and RGMII stability tweaks for rk3288 - DDC fixes for Rock PI 4 - Audio fixes for two TI am335x eval boards - D_CAN clock fix for am335x - Compilation fixes for clang - !HOTPLUG_CPU compilation fix for one of the new platforms this release (milbeaut) - A revert of a gpio fix for nomadik that instead was fixed in the gpio subsystem - Whitespace fix for the DT JSON schema (no tabs allowed)" * tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (25 commits) ARM: milbeaut: fix build with !CONFIG_HOTPLUG_CPU ARM: iop: don't use using 64-bit DMA masks ARM: orion: don't use using 64-bit DMA masks Revert "ARM: dts: nomadik: Fix polarity of SPI CS" dt-bindings: cpu: Fix JSON schema arm/mach-at91/pm : fix possible object reference leak ARM: dts: at91: Fix typo in ISC_D0 on PC9 ARM: dts: Fix dcan clkctrl clock for am3 reset: meson-audio-arb: Fix missing .owner setting of reset_controller_dev dt-bindings: reset: meson-g12a: Add missing USB2 PHY resets ARM: dts: rockchip: Remove #address/#size-cells from rk3288-veyron gpio-keys ARM: dts: rockchip: Remove #address/#size-cells from rk3288 mipi_dsi ARM: dts: rockchip: Fix gpu opp node names for rk3288 ARM: dts: am335x-evmsk: Correct the regulators for the audio codec ARM: dts: am335x-evm: Correct the regulators for the audio codec ARM: OMAP2+: add missing of_node_put after of_device_is_available ARM: OMAP1: ams-delta: Fix broken GPIO ID allocation arm64: dts: stratix10: add the sysmgr-syscon property from the gmac's arm64: dts: rockchip: fix rk3328 sdmmc0 write errors arm64: dts: rockchip: fix rk3328 rgmii high tx error rate ... -
git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block fixes from Jens Axboe: - Fixups for the pf/pcd queue handling (YueHaibing) - Revert of the three direct issue changes as they have been proven to cause an issue with dm-mpath (Bart) - Plug rq_count reset fix (Dongli) - io_uring double free in fileset registration error handling (me) - Make null_blk handle bad numa node passed in (John) - BFQ ifdef fix (Konstantin) - Flush queue leak fix (Shenghui) - Plug trace fix (Yufen) * tag 'for-linus-20190407' of git://git.kernel.dk/linux-block: xsysace: Fix error handling in ace_setup null_blk: prevent crash from bad home_node value block: Revert v5.0 blk_mq_request_issue_directly() changes paride/pcd: Fix potential NULL pointer dereference and mem leak blk-mq: do not reset plug->rq_count before the list is sorted paride/pf: Fix potential NULL pointer dereference io_uring: fix double free in case of fileset regitration failure blk-mq: add trace block plug and unplug for multiple queues block: use blk_free_flush_queue() to free hctx->fq in blk_mq_init_hctx block/bfq: fix ifdef for CONFIG_BFQ_GROUP_IOSCHED=y
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Arnd Bergmann authored
When HOTPLUG_CPU is disabled, some fields in the smp operations are not available or needed: arch/arm/mach-milbeaut/platsmp.c:90:3: error: field designator 'cpu_die' does not refer to any field in type 'struct smp_operations' .cpu_die = m10v_cpu_die, ^ arch/arm/mach-milbeaut/platsmp.c:91:3: error: field designator 'cpu_kill' does not refer to any field in type 'struct smp_operations' .cpu_kill = m10v_cpu_kill, ^ Hide them in an #ifdef like the other platforms do. Fixes: 9fb29c73 ("ARM: milbeaut: Add basic support for Milbeaut m10v SoC") Signed-off-by:Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Olof Johansson <olof@lixom.net>
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Arnd Bergmann authored
clang warns about statically defined DMA masks from the DMA_BIT_MASK macro with length 64: arch/arm/mach-iop13xx/setup.c:303:35: error: shift count >= width of type [-Werror,-Wshift-count-overflow] static u64 iop13xx_adma_dmamask = DMA_BIT_MASK(64); ^~~~~~~~~~~~~~~~ include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK' #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) ^ ~~~ The ones in iop shouldn't really be 64 bit masks, so changing them to what the driver can support avoids the warning. Signed-off-by: -
Arnd Bergmann authored
clang warns about statically defined DMA masks from the DMA_BIT_MASK macro with length 64: arch/arm/plat-orion/common.c:625:29: error: shift count >= width of type [-Werror,-Wshift-count-overflow] .coherent_dma_mask = DMA_BIT_MASK(64), ^~~~~~~~~~~~~~~~ include/linux/dma-mapping.h:141:54: note: expanded from macro 'DMA_BIT_MASK' #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) The ones in orion shouldn't really be 64 bit masks, so changing them to what the driver can support avoids the warning. Signed-off-by: -
Olof Johansson authored
This reverts commit fa946356. Per Linus Walleij: Dear ARM SoC maintainers, can you please revert this patch. It was the wrong solution to the wrong problem, and I must have acted in stress. Andrey fixed the real bug in a proper way in these commits: commit e5545c94 "gpio: of: Check propname before applying "cs-gpios" quirks" commit 7ce40277 "gpio: of: Check for "spi-cs-high" in child instead of parent node" Signed-off-by:
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Olof Johansson authored
Merge tag 'omap-for-v5.1/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into arm/fixes Fixes for omaps for v5.1-rc cycle Few small fixes for omap variants: - Fix ams-delta gpio IDs - Add missing of_node_put for omapdss platform init code - Fix unconfigured audio regulators for two am335x boards - Fix use of wrong offset for am335x d_can clocks * tag 'omap-for-v5.1/fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: ARM: dts: Fix dcan clkctrl clock for am3 ARM: dts: am335x-evmsk: Correct the regulators for the audio codec ARM: dts: am335x-evm: Correct the regulators for the audio codec ARM: OMAP2+: add missing of_node_put after of_device_is_available ARM: OMAP1: ams-delta: Fix broken GPIO ID allocation Signed-off-by:
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Olof Johansson authored
Merge tag 'at91-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux into arm/fixes AT91 fixes for 5.1 - fix a typo in sama5d2 pinmuxing which concerns the ISC data 0 signal - fix a kobject reference leak * tag 'at91-5.1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/at91/linux: arm/mach-at91/pm : fix possible object reference leak ARM: dts: at91: Fix typo in ISC_D0 on PC9 Signed-off-by:
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Olof Johansson authored
Merge tag 'v5.1-rockchip-dtfixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip into arm/fixes Fixes for dtc warnings, fixes for ethernet transfers on rk3328, sd-card related fixes on both rk3328 ans rk3288-tinker and a regulator fix on rock64 and making ddc actually work on the Rock PI 4 due to missing the ddc bus. * tag 'v5.1-rockchip-dtfixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip: ARM: dts: rockchip: Remove #address/#size-cells from rk3288-veyron gpio-keys ARM: dts: rockchip: Remove #address/#size-cells from rk3288 mipi_dsi ARM: dts: rockchip: Fix gpu opp node names for rk3288 arm64: dts: rockchip: fix rk3328 sdmmc0 write errors arm64: dts: rockchip: fix rk3328 rgmii high tx error rate ARM: dts: rockchip: Fix SD card detection on rk3288-tinker arm64: dts: rockchip: Fix vcc_host1_5v GPIO polarity on rk3328-rock64 ARM: dts: rockchip: fix rk3288 cpu opp node reference arm64: dts: rockchip: add DDC bus on Rock Pi 4 arm64: dts: rockchip: fix rk3328-roc-cc gmac2io tx/rx_delay Signed-off-by:
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Olof Johansson authored
Merge tag 'stratix10_fix_for_v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux into arm/fixes arm64: dts: stratix10: fix emac loading warning - Add missing "altr,sysmgr-syscon" property to all gmac nodes * tag 'stratix10_fix_for_v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/dinguyen/linux: arm64: dts: stratix10: add the sysmgr-syscon property from the gmac's Signed-off-by:
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git://git.pengutronix.de/pza/linuxOlof Johansson authored
Reset controller fixes for v5.1 This tag adds missing USB PHY reset lines to the Meson G12A reset controller header and fixes the Meson Audio ARB driver to prevent module unloading while it is in use. * tag 'reset-fixes-for-v5.1' of git://git.pengutronix.de/pza/linux: reset: meson-audio-arb: Fix missing .owner setting of reset_controller_dev dt-bindings: reset: meson-g12a: Add missing USB2 PHY resets Signed-off-by:
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Maxime Ripard authored
Commit fd73403a ("dt-bindings: arm: Add SMP enable-method for Milbeaut") added support for a new cpu enable-method, but did so using tabulations to ident. This is however invalid in the syntax, and resulted in a failure when trying to use that schemas for validation. Use spaces instead of tabs to indent to fix this. Fixes: fd73403a ("dt-bindings: arm: Add SMP enable-method for Milbeaut") Signed-off-by:
Maxime Ripard <maxime.ripard@bootlin.com> Reviewed-by:
Rob Herring <robh@kernel.org> Acked-by:
Sugaya Taichi <sugaya.taichi@socionext.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds authored
Pull xen fixes from Juergen Gross: "One minor fix and a small cleanup for the xen privcmd driver" * tag 'for-linus-5.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Prevent buffer overflow in privcmd ioctl xen: use struct_size() helper in kzalloc()
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git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linuxLinus Torvalds authored
Pull MTD fix from Richard Weinberger: "A single fix for a possible infinite loop in the cfi_cmdset_0002 driver" * tag 'mtd/fixes-for-5.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux: mtd: cfi: fix deadloop in cfi_cmdset_0002.c do_write_buffer
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Five small fixes. Four in three drivers: qedi, lpfc and storvsc. The final one is labelled core, but merely adds a dh rdac entry for Lenovo systems" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: lpfc: Fix missing wakeups on abort threads scsi: storvsc: Reduce default ring buffer size to 128 Kbytes scsi: storvsc: Fix calculation of sub-channel count scsi: core: add new RDAC LENOVO/DE_Series device scsi: qedi: remove declaration of nvm_image from stack
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- 06 Apr, 2019 9 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fix from Wolfram Sang: "A simple but wanted driver bugfix" * 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: imx: don't leak the i2c adapter on error
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git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linuxLinus Torvalds authored
Pull parisc fixes from Helge Deller: "A 32-bit boot regression fix introduced in the merge window, a QEMU detection fix and two fixes by Sven regarding ptrace & kprobes" * 'parisc-5.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Detect QEMU earlier in boot process parisc: also set iaoq_b in instruction_pointer_set() parisc: regs_return_value() should return gpr28 Revert: parisc: Use F_EXTEND() macro in iosapic code
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Helge Deller authored
While adding LASI support to QEMU, I noticed that the QEMU detection in the kernel happens much too late. For example, when a LASI chip is found by the kernel, it registers the LASI LED driver as well. But when we run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so we need to access the running_on_QEMU flag earlier than before. This patch now makes the QEMU detection the fist task of the Linux kernel by moving it to where the kernel enters the C-coding. Fixes: 310d8278 ("parisc: qemu idle sleep support") Signed-off-by:
Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org # v4.14+
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Sven Schnelle authored
When setting the instruction pointer on PA-RISC we also need to set the back of the instruction queue to the new offset, otherwise we will execute on instruction from the new location, and jumping back to the old location stored in iaoq_b. Signed-off-by:
Sven Schnelle <svens@stackframe.org> Signed-off-by:
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Sven Schnelle authored
While working on kretprobes for PA-RISC I was wondering while the kprobes sanity test always fails on kretprobes. This is caused by returning gpr20 instead of gpr28. Signed-off-by:
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Helge Deller authored
Revert parts of commit 97d7e2e3 ("parisc: Use F_EXTEND() macro in iosapic code"). It breaks booting the 32-bit kernel on some machines. Reported-by:
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Kirill Smelkov authoredfs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock Commit 9c225f26 ("vfs: atomic f_pos accesses as per POSIX") added locking for file.f_pos access and in particular made concurrent read and write not possible - now both those functions take f_pos lock for the whole run, and so if e.g. a read is blocked waiting for data, write will deadlock waiting for that read to complete. This caused regression for stream-like files where previously read and write could run simultaneously, but after that patch could not do so anymore. See e.g. commit 581d21a2 ("xenbus: fix deadlock on writes to /proc/xen/xenbus") which fixes such regression for particular case of /proc/xen/xenbus. The patch that added f_pos lock in 2014 did so to guarantee POSIX thread safety for read/write/lseek and added the locking to file descriptors of all regular files. In 2014 that thread-safety problem was not new as it was already discussed earlier in 2006. However even though 2006'th version of Linus's patch was adding f_pos locking "only for files that are marked seekable with FMODE_LSEEK (thus avoiding the stream-like objects like pipes and sockets)", the 2014 version - the one that actually made it into the tree as 9c225f26 - is doing so irregardless of whether a file is seekable or not. See https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/ https://lwn.net/Articles/180387 https://lwn.net/Articles/180396 for historic context. The reason that it did so is, probably, that there are many files that are marked non-seekable, but e.g. their read implementation actually depends on knowing current position to correctly handle the read. Some examples: kernel/power/user.c snapshot_read fs/debugfs/file.c u32_array_read fs/fuse/control.c fuse_conn_waiting_read + ... drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read arch/s390/hypfs/inode.c hypfs_read_iter ... Despite that, many nonseekable_open users implement read and write with pure stream semantics - they don't depend on passed ppos at all. And for those cases where read could wait for something inside, it creates a situation similar to xenbus - the write could be never made to go until read is done, and read is waiting for some, potentially external, event, for potentially unbounded time -> deadlock. Besides xenbus, there are 14 such places in the kernel that I've found with semantic patch (see below): drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write() drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write() drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write() drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write() net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write() drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write() drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write() drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write() net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write() drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write() drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write() drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write() drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write() drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write() In addition to the cases above another regression caused by f_pos locking is that now FUSE filesystems that implement open with FOPEN_NONSEEKABLE flag, can no longer implement bidirectional stream-like files - for the same reason as above e.g. read can deadlock write locking on file.f_pos in the kernel. FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990 ("fuse: implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and write routines not depending on current position at all, and with both read and write being potentially blocking operations: See https://github.com/libfuse/osspd https://lwn.net/Articles/308445 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477 https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510 Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as "somewhat pipe-like files ..." with read handler not using offset. However that test implements only read without write and cannot exercise the deadlock scenario: https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163 https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216 I've actually hit the read vs write deadlock for real while implementing my FUSE filesystem where there is /head/watch file, for which open creates separate bidirectional socket-like stream in between filesystem and its user with both read and write being later performed simultaneously. And there it is semantically not easy to split the stream into two separate read-only and write-only channels: https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169 Let's fix this regression. The plan is: 1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS - doing so would break many in-kernel nonseekable_open users which actually use ppos in read/write handlers. 2. Add stream_open() to kernel to open stream-like non-seekable file descriptors. Read and write on such file descriptors would never use nor change ppos. And with that property on stream-like files read and write will be running without taking f_pos lock - i.e. read and write could be running simultaneously. 3. With semantic patch search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. 4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via steam_open if that bit is present in filesystem open reply. It was tempting to change fs/fuse/ open handler to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. 5. Add stream_open and FOPEN_STREAM handling to stable kernels starting from v3.14+ (the kernel where 9c225f26 first appeared). This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in their open handler and this way avoid the deadlock on all kernel versions. This should work because fs/fuse/ ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. This patch adds stream_open, converts /proc/xen/xenbus to it and adds semantic patch to automatically locate in-kernel places that are either required to be converted due to read vs write deadlock, or that are just safe to be converted because read and write do not use ppos and there are no other funky methods in file_operations. Regarding semantic patch I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by:
Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Guenter Roeck authored
If xace hardware reports a bad version number, the error handling code in ace_setup() calls put_disk(), followed by queue cleanup. However, since the disk data structure has the queue pointer set, put_disk() also cleans and releases the queue. This results in blk_cleanup_queue() accessing an already released data structure, which in turn may result in a crash such as the following. [ 10.681671] BUG: Kernel NULL pointer dereference at 0x00000040 [ 10.681826] Faulting instruction address: 0xc0431480 [ 10.682072] Oops: Kernel access of bad area, sig: 11 [#1] [ 10.682251] BE PAGE_SIZE=4K PREEMPT Xilinx Virtex440 [ 10.682387] Modules linked in: [ 10.682528] CPU: 0 PID: 1 Comm: swapper Tainted: G W 5.0.0-rc6-next-20190218+ #2 [ 10.682733] NIP: c0431480 LR: c043147c CTR: c0422ad8 [ 10.682863] REGS: cf82fbe0 TRAP: 0300 Tainted: G W (5.0.0-rc6-next-20190218+) [ 10.683065] MSR: 00029000 <CE,EE,ME> CR: 22000222 XER: 00000000 [ 10.683236] DEAR: 00000040 ESR: 00000000 [ 10.683236] GPR00: c043147c cf82fc90 cf82ccc0 00000000 00000000 00000000 00000002 00000000 [ 10.683236] GPR08: 00000000 00000000 c04310bc 00000000 22000222 00000000 c0002c54 00000000 [ 10.683236] GPR16: 00000000 00000001 c09aa39c c09021b0 c09021dc 00000007 c0a68c08 00000000 [ 10.683236] GPR24: 00000001 ced6d400 ced6dcf0 c0815d9c 00000000 00000000 00000000 cedf0800 [ 10.684331] NIP [c0431480] blk_mq_run_hw_queue+0x28/0x114 [ 10.684473] LR [c043147c] blk_mq_run_hw_queue+0x24/0x114 [ 10.684602] Call Trace: [ 10.684671] [cf82fc90] [c043147c] blk_mq_run_hw_queue+0x24/0x114 (unreliable) [ 10.684854] [cf82fcc0] [c04315bc] blk_mq_run_hw_queues+0x50/0x7c [ 10.685002] [cf82fce0] [c0422b24] blk_set_queue_dying+0x30/0x68 [ 10.685154] [cf82fcf0] [c0423ec0] blk_cleanup_queue+0x34/0x14c [ 10.685306] [cf82fd10] [c054d73c] ace_probe+0x3dc/0x508 [ 10.685445] [cf82fd50] [c052d740] platform_drv_probe+0x4c/0xb8 [ 10.685592] [cf82fd70] [c052abb0] really_probe+0x20c/0x32c [ 10.685728] [cf82fda0] [c052ae58] driver_probe_device+0x68/0x464 [ 10.685877] [cf82fdc0] [c052b500] device_driver_attach+0xb4/0xe4 [ 10.686024] [cf82fde0] [c052b5dc] __driver_attach+0xac/0xfc [ 10.686161] [cf82fe00] [c0528428] bus_for_each_dev+0x80/0xc0 [ 10.686314] [cf82fe30] [c0529b3c] bus_add_driver+0x144/0x234 [ 10.686457] [cf82fe50] [c052c46c] driver_register+0x88/0x15c [ 10.686610] [cf82fe60] [c09de288] ace_init+0x4c/0xac [ 10.686742] [cf82fe80] [c0002730] do_one_initcall+0xac/0x330 [ 10.686888] [cf82fee0] [c09aafd0] kernel_init_freeable+0x34c/0x478 [ 10.687043] [cf82ff30] [c0002c6c] kernel_init+0x18/0x114 [ 10.687188] [cf82ff40] [c000f2f0] ret_from_kernel_thread+0x14/0x1c [ 10.687349] Instruction dump: [ 10.687435] 3863ffd4 4bfffd70 9421ffd0 7c0802a6 93c10028 7c9e2378 93e1002c 38810008 [ 10.687637] 7c7f1b78 90010034 4bfffc25 813f008c <81290040> 75290100 4182002c 80810008 [ 10.688056] ---[ end trace 13c9ff51d41b9d40 ]--- Fix the problem by setting the disk queue pointer to NULL before calling put_disk(). A more comprehensive fix might be to rearrange the code to check the hardware version before initializing data structures, but I don't know if this would have undesirable side effects, and it would increase the complexity of backporting the fix to older kernels. Fixes: 74489a91 ("Add support for Xilinx SystemACE CompactFlash interface") Acked-by:
Michal Simek <michal.simek@xilinx.com> Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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John Pittman authored
At module load, if the selected home_node value is greater than the available numa nodes, the system will crash in __alloc_pages_nodemask() due to a bad paging request. Prevent this user error crash by detecting the bad value, logging an error, and setting g_home_node back to the default of NUMA_NO_NODE. Signed-off-by:
John Pittman <jpittman@redhat.com> Signed-off-by:
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