- 24 Jul, 2020 2 commits
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Baolin Wang authored
Now the ARM page tables are always allocated by GFP_ATOMIC parameter, but the iommu_ops->map() function has been added a gfp_t parameter by commit 781ca2de ("iommu: Add gfp parameter to iommu_ops::map"), thus io_pgtable_ops->map() should use the gfp parameter passed from iommu_ops->map() to allocate page pages, which can avoid wasting the memory allocators atomic pools for some non-atomic contexts. Signed-off-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by:
Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/3093df4cb95497aaf713fca623ce4ecebb197c2e.1591930156.git.baolin.wang@linux.alibaba.comSigned-off-by:
Joerg Roedel <jroedel@suse.de>
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Baolin Wang authored
Now __iommu_map_sg() is used only in iommu.c file, so mark it static. Signed-off-by:
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- 22 Jul, 2020 1 commit
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Wei Yongjun authored
The sparse tool complains as follows: drivers/iommu/iommu.c:386:5: warning: symbol 'iommu_insert_resv_region' was not declared. Should it be static? drivers/iommu/iommu.c:2182:5: warning: symbol '__iommu_map' was not declared. Should it be static? Those functions are not used outside of iommu.c, so mark them static. Reported-by:
Hulk Robot <hulkci@huawei.com> Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Link: https://lore.kernel.org/r/20200713142542.50294-1-weiyongjun1@huawei.comSigned-off-by:
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- 10 Jul, 2020 2 commits
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Robin Murphy authored
This driver shouldn't need anything architecture-specific (that isn't under CONFIG_ARM protection already), and has already been accessible from certain x86 configurations by virtue of the previously-cleaned-up "ARM || IOMMU_DMA" dependency. Allow COMPILE_TEST for all architectures. Signed-off-by:
Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/1fe2006aa98f008a2e689adba6e8c96e9197f903.1593791968.git.robin.murphy@arm.comSigned-off-by:
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Robin Murphy authored
Wacky COMPILE_TEST dependencies based on who used to define dev_archdata.iommu can go. Dependencies on ARM or ARM64 already implied by the ARCH_* platform selection can go. The entire IOMMU_SUPPORT menu already depends on MMU, so those can go. IOMMU_DMA is for the architecture's DMA API implementation to choose, and its interface to IOMMU drivers is properly stubbed out if disabled, so dependencies on or selections of that can go (AMD_IOMMU is the current exception since the x86 drivers have to provide their own entire dma_map_ops implementation). Since commit ed6ccf10 ("dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA"), drivers which simply use the dma-mapping API should not need to depend on HAS_DMA, so those can go. And a long-dead option for code removed from the MSM driver 4 years ago can also go. Signed-off-by:
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- 30 Jun, 2020 17 commits
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Jerry Snitselaar authored
When include/uapi/linux/iommu.h was created it was never added to the file list in MAINTAINERS. Signed-off-by:
Jerry Snitselaar <jsnitsel@redhat.com> Cc: Joerg Roedel <jroedel@suse.de> Link: https://lore.kernel.org/r/20200605070025.216124-1-jsnitsel@redhat.comSigned-off-by:
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Marek Szyprowski authored
Move the recently added sg_table wrapper out of CONFIG_IOMMU_SUPPORT to let the client code copile also when IOMMU support is disabled. Fixes: 48530d9f ("iommu: add generic helper for mapping sgtable objects") Signed-off-by:
Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20200630081756.18526-1-m.szyprowski@samsung.comSigned-off-by:
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Joerg Roedel authored
There are no users left, so remove the pointer and save some memory. Signed-off-by:
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Joerg Roedel authored
There are no users left, all drivers have been converted to use the per-device private pointer offered by IOMMU core. Signed-off-by:
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Joerg Roedel authored
There are no users left, all drivers have been converted to use the per-device private pointer offered by IOMMU core. Signed-off-by:
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Joerg Roedel authored
There are no users left, all drivers have been converted to use the per-device private pointer offered by IOMMU core. Signed-off-by:
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Joerg Roedel authored
There are no users left, all drivers have been converted to use the per-device private pointer offered by IOMMU core. Signed-off-by:
Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20200625130836.1916-10-joro@8bytes.org
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Joerg Roedel authored
The iommu private pointer is already used in the Mediatek IOMMU v1 driver, so move the dma_iommu_mapping pointer into 'struct mtk_iommu_data' and do not use dev->archdata.iommu anymore. Signed-off-by:
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Joerg Roedel authored
Remove the use of dev->archdata.iommu_domain and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
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Joerg Roedel authored
Remove the use of dev->archdata.iommu and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
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Joerg Roedel authored
Remove the use of dev->archdata.iommu and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
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Joerg Roedel authored
Remove the use of dev->archdata.iommu and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
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Joerg Roedel authored
Remove the use of dev->archdata.iommu and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
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Joerg Roedel authored
Remove the use of dev->archdata.iommu and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20200625130836.1916-3-joro@8bytes.org
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Joerg Roedel authored
Remove the use of dev->archdata.iommu and use the private per-device pointer provided by IOMMU core code instead. Signed-off-by:
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Jean-Philippe Brucker authored
Some PCIe devices do not expect a PASID value in PRI Page Responses. If the "PRG Response PASID Required" bit in the PRI capability is zero, then the OS should not set the PASID field. Similarly on Arm SMMU, responses to stall events do not have a PASID. Currently iommu_page_response() systematically checks that the PASID in the page response corresponds to the one in the page request. This can't work with virtualization because a page response coming from a guest OS won't have a PASID if the passed-through device does not require one. Add a flag to page requests that declares whether the corresponding response needs to have a PASID. When this flag isn't set, allow page responses without PASID. Reported-by:
Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Signed-off-by:
Jean-Philippe Brucker <jean-philippe@linaro.org> Link: https://lore.kernel.org/r/20200616144712.748818-1-jean-philippe@linaro.orgSigned-off-by:
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Robin Murphy authored
Unlike the other instances which represent a complete loss of consistency within the rcache mechanism itself, or a fundamental and obvious misconfiguration by an IOMMU driver, the BUG_ON() in iova_magazine_free_pfns() can be provoked at more or less any time in a "spooky action-at-a-distance" manner by any old device driver passing nonsense to dma_unmap_*() which then propagates through to queue_iova(). Not only is this well outside the IOVA layer's control, it's also nowhere near fatal enough to justify panicking anyway - all that really achieves is to make debugging the offending driver more difficult. Let's simply WARN and otherwise ignore bogus PFNs. Reported-by:
Prakash Gupta <guptap@codeaurora.org> Signed-off-by:
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- 28 Jun, 2020 18 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds authored
Pull ARM OMAP fixes from Arnd Bergmann: "The OMAP developers are particularly active at hunting down regressions, so this is a separate branch with OMAP specific fixes for v5.8: As Tony explains "The recent display subsystem (DSS) related platform data changes caused display related regressions for suspend and resume. Looks like I only tested suspend and resume before dropping the legacy platform data, and forgot to test it after dropping it. Turns out the main issue was that we no longer have platform code calling pm_runtime_suspend for DSS like we did for the legacy platform data case, and that fix is still being discussed on the dri-devel list and will get merged separately. The DSS related testing exposed a pile other other display related issues that also need fixing though": - Fix ti-sysc optional clock handling and reset status checks for devices that reset automatically in idle like DSS - Ignore ti-sysc clockactivity bit unless separately requested to avoid unexpected performance issues - Init ti-sysc framedonetv_irq to true and disable for am4 - Avoid duplicate DSS reset for legacy mode with dts data - Remove LCD timings for am4 as they cause warnings now that we're using generic panels Other OMAP changes from Tony include: - Fix omap_prm reset deassert as we still have drivers setting the pm_runtime_irq_safe() flag - Flush posted write for ti-sysc enable and disable - Fix droid4 spi related errors with spi flags - Fix am335x USB range and a typo for softreset - Fix dra7 timer nodes for clocks for IPU and DSP - Drop duplicate mailboxes after mismerge for dra7 - Prevent pocketgeagle header line signal from accidentally setting micro-SD write protection signal by removing the default mux - Fix NFSroot flakeyness after resume for duover by switching the smsc911x gpio interrupt to back to level sensitive - Fix regression for omap4 clockevent source after recent system timer changes - Yet another ethernet regression fix for the "rgmii" vs "rgmii-rxid" phy-mode - One patch to convert am3/am4 DT files to use the regular sdhci-omap driver instead of the old hsmmc driver, this was meant for the merge window but got lost in the process" * tag 'arm-omap-fixes-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (21 commits) ARM: dts: am5729: beaglebone-ai: fix rgmii phy-mode ARM: dts: Fix omap4 system timer source clocks ARM: dts: Fix duovero smsc interrupt for suspend ARM: dts: am335x-pocketbeagle: Fix mmc0 Write Protect Revert "bus: ti-sysc: Increase max softreset wait" ARM: dts: am437x-epos-evm: remove lcd timings ARM: dts: am437x-gp-evm: remove lcd timings ARM: dts: am437x-sk-evm: remove lcd timings ARM: dts: dra7-evm-common: Fix duplicate mailbox nodes ARM: dts: dra7: Fix timer nodes properly for timer_sys_ck clocks ARM: dts: Fix am33xx.dtsi ti,sysc-mask wrong softreset flag ARM: dts: Fix am33xx.dtsi USB ranges length bus: ti-sysc: Increase max softreset wait ARM: OMAP2+: Fix legacy mode dss_reset bus: ti-sysc: Fix uninitialized framedonetv_irq bus: ti-sysc: Ignore clockactivity unless specified as a quirk bus: ti-sysc: Use optional clocks on for enable and wait for softreset bit ARM: dts: omap4-droid4: Fix spi configuration and increase rate bus: ti-sysc: Flush posted write on enable and disable soc: ti: omap-prm: use atomic iopoll instead of sleeping one ... -
git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds authored
Pull ARM SoC fixes from Arnd Bergmann: "Here are a couple of bug fixes, mostly for devicetree files NXP i.MX: - Use correct voltage on some i.MX8M board device trees to avoid hardware damage - Code fixes for a compiler warning and incorrect reference counting, both harmless. - Fix the i.MX8M SoC driver to correctly identify imx8mp - Fix watchdog configuration in imx6ul-kontron device tree. Broadcom: - A small regression fix for the Raspberry-Pi firmware driver - A Kconfig change to use the correct timer driver on Northstar - A DT fix for the Luxul XWC-2000 machine - Two more DT fixes for NSP SoCs STmicroelectronics STI - Revert one broken patch for L2 cache configuration ARM Versatile Express: - Fix a regression by reverting a broken DT cleanup TEE drivers: - MAINTAINERS: change tee mailing list" * tag 'arm-fixes-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: Revert "ARM: sti: Implement dummy L2 cache's write_sec" soc: imx8m: fix build warning ARM: imx6: add missing put_device() call in imx6q_suspend_init() ARM: imx5: add missing put_device() call in imx_suspend_alloc_ocram() soc: imx8m: Correct i.MX8MP UID fuse offset ARM: dts: imx6ul-kontron: Change WDOG_ANY signal from push-pull to open-drain ARM: dts: imx6ul-kontron: Move watchdog from Kontron i.MX6UL/ULL board to SoM arm64: dts: imx8mm-beacon: Fix voltages on LDO1 and LDO2 arm64: dts: imx8mn-ddr4-evk: correct ldo1/ldo2 voltage range arm64: dts: imx8mm-evk: correct ldo1/ldo2 voltage range ARM: dts: NSP: Correct FA2 mailbox node ARM: bcm2835: Fix integer overflow in rpi_firmware_print_firmware_revision() MAINTAINERS: change tee mailing list ARM: dts: NSP: Disable PL330 by default, add dma-coherent property ARM: bcm: Select ARM_TIMER_SP804 for ARCH_BCM_NSP ARM: dts: BCM5301X: Add missing memory "device_type" for Luxul XWC-2000 arm: dts: vexpress: Move mcc node back into motherboard node -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer fix from Ingo Molnar: "A single DocBook fix" * tag 'timers-urgent-2020-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timekeeping: Fix kerneldoc system_device_crosststamp & al
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf fix from Ingo Molnar: "A single Kbuild dependency fix" * tag 'perf-urgent-2020-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/rapl: Fix RAPL config variable bug
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull EFI fixes from Ingo Molnar: - Fix build regression on v4.8 and older - Robustness fix for TPM log parsing code - kobject refcount fix for the ESRT parsing code - Two efivarfs fixes to make it behave more like an ordinary file system - Style fixup for zero length arrays - Fix a regression in path separator handling in the initrd loader - Fix a missing prototype warning - Add some kerneldoc headers for newly introduced stub routines - Allow support for SSDT overrides via EFI variables to be disabled - Report CPU mode and MMU state upon entry for 32-bit ARM - Use the correct stack pointer alignment when entering from mixed mode * tag 'efi-urgent-2020-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi/libstub: arm: Print CPU boot mode and MMU state at boot efi/libstub: arm: Omit arch specific config table matching array on arm64 efi/x86: Setup stack correctly for efi_pe_entry efi: Make it possible to disable efivar_ssdt entirely efi/libstub: Descriptions for stub helper functions efi/libstub: Fix path separator regression efi/libstub: Fix missing-prototype warning for skip_spaces() efi: Replace zero-length array and use struct_size() helper efivarfs: Don't return -EINTR when rate-limiting reads efivarfs: Update inode modification time for successful writes efi/esrt: Fix reference count leak in esre_create_sysfs_entry. efi/tpm: Verify event log header before parsing efi/x86: Fix build with gcc 4
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull scheduler fixes from Borislav Petkov: "The most anticipated fix in this pull request is probably the horrible build fix for the RANDSTRUCT fail that didn't make -rc2. Also included is the cleanup that removes those BUILD_BUG_ON()s and replaces it with ugly unions. Also included is the try_to_wake_up() race fix that was first triggered by Paul's RCU-torture runs, but was independently hit by Dave Chinner's fstest runs as well" * tag 'sched_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/cfs: change initial value of runnable_avg smp, irq_work: Continue smp_call_function*() and irq_work*() integration sched/core: s/WF_ON_RQ/WQ_ON_CPU/ sched/core: Fix ttwu() race sched/core: Fix PI boosting between RT and DEADLINE tasks sched/deadline: Initialize ->dl_boosted sched/core: Check cpus_mask, not cpus_ptr in __set_cpus_allowed_ptr(), to fix mask corruption sched/core: Fix CONFIG_GCC_PLUGIN_RANDSTRUCT build fail
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Borislav Petkov: - AMD Memory bandwidth counter width fix, by Babu Moger. - Use the proper length type in the 32-bit truncate() syscall variant, by Jiri Slaby. - Reinit IA32_FEAT_CTL during wakeup to fix the case where after resume, VMXON would #GP due to VMX not being properly enabled, by Sean Christopherson. - Fix a static checker warning in the resctrl code, by Dan Carpenter. - Add a CR4 pinning mask for bits which cannot change after boot, by Kees Cook. - Align the start of the loop of __clear_user() to 16 bytes, to improve performance on AMD zen1 and zen2 microarchitectures, by Matt Fleming. * tag 'x86_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/asm/64: Align start of __clear_user() loop to 16-bytes x86/cpu: Use pinning mask for CR4 bits needing to be 0 x86/resctrl: Fix a NULL vs IS_ERR() static checker warning in rdt_cdp_peer_get() x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup syscalls: Fix offset type of ksys_ftruncate() x86/resctrl: Fix memory bandwidth counter width for AMD
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull RCU-vs-KCSAN fixes from Borislav Petkov: "A single commit that uses "arch_" atomic operations to avoid the instrumentation that comes with the non-"arch_" versions. In preparation for that commit, it also has another commit that makes these "arch_" atomic operations available to generic code. Without these commits, KCSAN uses can see pointless errors" * tag 'rcu_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Fixup noinstr warnings locking/atomics: Provide the arch_atomic_ interface to generic code
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull objtool fixes from Borislav Petkov: "Three fixes from Peter Zijlstra suppressing KCOV instrumentation in noinstr sections. Peter Zijlstra says: "Address KCOV vs noinstr. There is no function attribute to selectively suppress KCOV instrumentation, instead teach objtool to NOP out the calls in noinstr functions" This cures a bunch of KCOV crashes (as used by syzcaller)" * tag 'objtool_urgent_for_5.8_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix noinstr vs KCOV objtool: Provide elf_write_{insn,reloc}() objtool: Clean up elf_write() condition -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 entry fixes from Borislav Petkov: "This is the x86/entry urgent pile which has accumulated since the merge window. It is not the smallest but considering the almost complete entry core rewrite, the amount of fixes to follow is somewhat higher than usual, which is to be expected. Peter Zijlstra says: 'These patches address a number of instrumentation issues that were found after the x86/entry overhaul. When combined with rcu/urgent and objtool/urgent, these patches make UBSAN/KASAN/KCSAN happy again. Part of making this all work is bumping the minimum GCC version for KASAN builds to gcc-8.3, the reason for this is that the __no_sanitize_address function attribute is broken in GCC releases before that. No known GCC version has a working __no_sanitize_undefined, however because the only noinstr violation that results from this happens when an UB is found, we treat it like WARN. That is, we allow it to violate the noinstr rules in order to get the warning out'" * tag 'x86_entry_for_5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/entry: Fix #UD vs WARN more x86/entry: Increase entry_stack size to a full page x86/entry: Fixup bad_iret vs noinstr objtool: Don't consider vmlinux a C-file kasan: Fix required compiler version compiler_attributes.h: Support no_sanitize_undefined check with GCC 4 x86/entry, bug: Comment the instrumentation_begin() usage for WARN() x86/entry, ubsan, objtool: Whitelist __ubsan_handle_*() x86/entry, cpumask: Provide non-instrumented variant of cpu_is_offline() compiler_types.h: Add __no_sanitize_{address,undefined} to noinstr kasan: Bump required compiler version x86, kcsan: Add __no_kcsan to noinstr kcsan: Remove __no_kcsan_or_inline x86, kcsan: Remove __no_kcsan_or_inline usage -
Vincent Guittot authored
Some performance regression on reaim benchmark have been raised with commit 070f5e86 ("sched/fair: Take into account runnable_avg to classify group") The problem comes from the init value of runnable_avg which is initialized with max value. This can be a problem if the newly forked task is finally a short task because the group of CPUs is wrongly set to overloaded and tasks are pulled less agressively. Set initial value of runnable_avg equals to util_avg to reflect that there is no waiting time so far. Fixes: 070f5e86 ("sched/fair: Take into account runnable_avg to classify group") Reported-by:
kernel test robot <rong.a.chen@intel.com> Signed-off-by:
Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200624154422.29166-1-vincent.guittot@linaro.org
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Peter Zijlstra authored
Instead of relying on BUG_ON() to ensure the various data structures line up, use a bunch of horrible unions to make it all automatic. Much of the union magic is to ensure irq_work and smp_call_function do not (yet) see the members of their respective data structures change name. Suggested-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Ingo Molnar <mingo@kernel.org> Reviewed-by:
Frederic Weisbecker <frederic@kernel.org> Link: https://lkml.kernel.org/r/20200622100825.844455025@infradead.org
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Peter Zijlstra authored
Use a better name for this poorly named flag, to avoid confusion... Signed-off-by:
Mel Gorman <mgorman@suse.de> Link: https://lkml.kernel.org/r/20200622100825.785115830@infradead.org
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Peter Zijlstra authored
Paul reported rcutorture occasionally hitting a NULL deref: sched_ttwu_pending() ttwu_do_wakeup() check_preempt_curr() := check_preempt_wakeup() find_matching_se() is_same_group() if (se->cfs_rq == pse->cfs_rq) <-- *BOOM* Debugging showed that this only appears to happen when we take the new code-path from commit: 2ebb1771 ("sched/core: Offload wakee task activation if it the wakee is descheduling") and only when @cpu == smp_processor_id(). Something which should not be possible, because p->on_cpu can only be true for remote tasks. Similarly, without the new code-path from commit: c6e7bd7a ("sched/core: Optimize ttwu() spinning on p->on_cpu") this would've unconditionally hit: smp_cond_load_acquire(&p->on_cpu, !VAL); and if: 'cpu == smp_processor_id() && p->on_cpu' is possible, this would result in an instant live-lock (with IRQs disabled), something that hasn't been reported. The NULL deref can be explained however if the task_cpu(p) load at the beginning of try_to_wake_up() returns an old value, and this old value happens to be smp_processor_id(). Further assume that the p->on_cpu load accurately returns 1, it really is still running, just not here. Then, when we enqueue the task locally, we can crash in exactly the observed manner because p->se.cfs_rq != rq->cfs_rq, because p's cfs_rq is from the wrong CPU, therefore we'll iterate into the non-existant parents and NULL deref. The closest semi-plausible scenario I've managed to contrive is somewhat elaborate (then again, actual reproduction takes many CPU hours of rcutorture, so it can't be anything obvious): X->cpu = 1 rq(1)->curr = X CPU0 CPU1 CPU2 // switch away from X LOCK rq(1)->lock smp_mb__after_spinlock dequeue_task(X) X->on_rq = 9 switch_to(Z) X->on_cpu = 0 UNLOCK rq(1)->lock // migrate X to cpu 0 LOCK rq(1)->lock dequeue_task(X) set_task_cpu(X, 0) X->cpu = 0 UNLOCK rq(1)->lock LOCK rq(0)->lock enqueue_task(X) X->on_rq = 1 UNLOCK rq(0)->lock // switch to X LOCK rq(0)->lock smp_mb__after_spinlock switch_to(X) X->on_cpu = 1 UNLOCK rq(0)->lock // X goes sleep X->state = TASK_UNINTERRUPTIBLE smp_mb(); // wake X ttwu() LOCK X->pi_lock smp_mb__after_spinlock if (p->state) cpu = X->cpu; // =? 1 smp_rmb() // X calls schedule() LOCK rq(0)->lock smp_mb__after_spinlock dequeue_task(X) X->on_rq = 0 if (p->on_rq) smp_rmb(); if (p->on_cpu && ttwu_queue_wakelist(..)) [*] smp_cond_load_acquire(&p->on_cpu, !VAL) cpu = select_task_rq(X, X->wake_cpu, ...) if (X->cpu != cpu) switch_to(Y) X->on_cpu = 0 UNLOCK rq(0)->lock However I'm having trouble convincing myself that's actually possible on x86_64 -- after all, every LOCK implies an smp_mb() there, so if ttwu observes ->state != RUNNING, it must also observe ->cpu != 1. (Most of the previous ttwu() races were found on very large PowerPC) Nevertheless, this fully explains the observed failure case. Fix it by ordering the task_cpu(p) load after the p->on_cpu load, which is easy since nothing actually uses @cpu before this. Fixes: c6e7bd7a ("sched/core: Optimize ttwu() spinning on p->on_cpu") Reported-by:Paul E. McKenney <paulmck@kernel.org> Tested-by:
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Juri Lelli authored
syzbot reported the following warning: WARNING: CPU: 1 PID: 6351 at kernel/sched/deadline.c:628 enqueue_task_dl+0x22da/0x38a0 kernel/sched/deadline.c:1504 At deadline.c:628 we have: 623 static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se) 624 { 625 struct dl_rq *dl_rq = dl_rq_of_se(dl_se); 626 struct rq *rq = rq_of_dl_rq(dl_rq); 627 628 WARN_ON(dl_se->dl_boosted); 629 WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline)); [...] } Which means that setup_new_dl_entity() has been called on a task currently boosted. This shouldn't happen though, as setup_new_dl_entity() is only called when the 'dynamic' deadline of the new entity is in the past w.r.t. rq_clock and boosted tasks shouldn't verify this condition. Digging through the PI code I noticed that what above might in fact happen if an RT tasks blocks on an rt_mutex hold by a DEADLINE task. In the first branch of boosting conditions we check only if a pi_task 'dynamic' deadline is earlier than mutex holder's and in this case we set mutex holder to be dl_boosted. However, since RT 'dynamic' deadlines are only initialized if such tasks get boosted at some point (or if they become DEADLINE of course), in general RT 'dynamic' deadlines are usually equal to 0 and this verifies the aforementioned condition. Fix it by checking that the potential donor task is actually (even if temporary because in turn boosted) running at DEADLINE priority before using its 'dynamic' deadline value. Fixes: 2d3d891d ("sched/deadline: Add SCHED_DEADLINE inheritance logic") Reported-by: syzbot+119ba87189432ead09b4@syzkaller.appspotmail.com Signed-off-by:Juri Lelli <juri.lelli@redhat.com> Signed-off-by:
Daniel Bristot de Oliveira <bristot@redhat.com> Tested-by:
Daniel Wagner <dwagner@suse.de> Link: https://lkml.kernel.org/r/20181119153201.GB2119@localhost.localdomain
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Juri Lelli authored
syzbot reported the following warning triggered via SYSC_sched_setattr(): WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 setup_new_dl_entity /kernel/sched/deadline.c:594 [inline] WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_dl_entity /kernel/sched/deadline.c:1370 [inline] WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_task_dl+0x1c17/0x2ba0 /kernel/sched/deadline.c:1441 This happens because the ->dl_boosted flag is currently not initialized by __dl_clear_params() (unlike the other flags) and setup_new_dl_entity() rightfully complains about it. Initialize dl_boosted to 0. Fixes: 2d3d891d ("sched/deadline: Add SCHED_DEADLINE inheritance logic") Reported-by: syzbot+5ac8bac25f95e8b221e7@syzkaller.appspotmail.com Signed-off-by:
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Scott Wood authored
This function is concerned with the long-term CPU mask, not the transitory mask the task might have while migrate disabled. Before this patch, if a task was migrate-disabled at the time __set_cpus_allowed_ptr() was called, and the new mask happened to be equal to the CPU that the task was running on, then the mask update would be lost. Signed-off-by:
Scott Wood <swood@redhat.com> Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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