kernel/linux.git/include/linux, branch v6.11.8

block: rework bio splitting

2024-11-14T12:21:15+00:00

[ Upstream commit b35243a447b9fe6457fa8e1352152b818436ba5a ] The current setup with bio_may_exceed_limit and __bio_split_to_limits is a bit of a mess. Change it so that __bio_split_to_limits does all the work and is just a variant of bio_split_to_limits that returns nr_segs. This is done by inlining it and instead have the various bio_split_* helpers directly submit the potentially split bios. To support btrfs, the rw version has a lower level helper split out that just returns the offset to split. This turns out to nicely clean up the btrfs flow as well. Signed-off-by: Christoph Hellwig Acked-by: David Sterba Reviewed-by: Damien Le Moal Tested-by: Hans Holmberg Reviewed-by: Hans Holmberg Link: https://lore.kernel.org/r/20240826173820.1690925-2-hch@lst.de Signed-off-by: Jens Axboe Stable-dep-of: be0e822bb3f5 ("block: fix queue limits checks in blk_rq_map_user_bvec for real") Signed-off-by: Sasha Levin

signal: restore the override_rlimit logic

2024-11-14T12:21:11+00:00

commit 9e05e5c7ee8758141d2db7e8fea2cab34500c6ed upstream. Prior to commit d64696905554 ("Reimplement RLIMIT_SIGPENDING on top of ucounts") UCOUNT_RLIMIT_SIGPENDING rlimit was not enforced for a class of signals. However now it's enforced unconditionally, even if override_rlimit is set. This behavior change caused production issues. For example, if the limit is reached and a process receives a SIGSEGV signal, sigqueue_alloc fails to allocate the necessary resources for the signal delivery, preventing the signal from being delivered with siginfo. This prevents the process from correctly identifying the fault address and handling the error. From the user-space perspective, applications are unaware that the limit has been reached and that the siginfo is effectively 'corrupted'. This can lead to unpredictable behavior and crashes, as we observed with java applications. Fix this by passing override_rlimit into inc_rlimit_get_ucounts() and skip the comparison to max there if override_rlimit is set. This effectively restores the old behavior. Link: https://lkml.kernel.org/r/20241104195419.3962584-1-roman.gushchin@linux.dev Fixes: d64696905554 ("Reimplement RLIMIT_SIGPENDING on top of ucounts") Signed-off-by: Roman Gushchin Co-developed-by: Andrei Vagin Signed-off-by: Andrei Vagin Acked-by: Oleg Nesterov Acked-by: Alexey Gladkov Cc: Kees Cook Cc: "Eric W. Biederman" Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

arm64: smccc: Remove broken support for SMCCCv1.3 SVE discard hint

2024-11-14T12:21:09+00:00

commit 8c462d56487e3abdbf8a61cedfe7c795a54f4a78 upstream. SMCCCv1.3 added a hint bit which callers can set in an SMCCC function ID (AKA "FID") to indicate that it is acceptable for the SMCCC implementation to discard SVE and/or SME state over a specific SMCCC call. The kernel support for using this hint is broken and SMCCC calls may clobber the SVE and/or SME state of arbitrary tasks, though FPSIMD state is unaffected. The kernel support is intended to use the hint when there is no SVE or SME state to save, and to do this it checks whether TIF_FOREIGN_FPSTATE is set or TIF_SVE is clear in assembly code: | ldr , [, #TSK_TI_FLAGS] | tbnz , #TIF_FOREIGN_FPSTATE, 1f // Any live FP state? | tbnz , #TIF_SVE, 2f // Does that state include SVE? | | 1: orr , , ARM_SMCCC_1_3_SVE_HINT | 2: | << SMCCC call using FID >> This is not safe as-is: (1) SMCCC calls can be made in a preemptible context and preemption can result in TIF_FOREIGN_FPSTATE being set or cleared at arbitrary points in time. Thus checking for TIF_FOREIGN_FPSTATE provides no guarantee. (2) TIF_FOREIGN_FPSTATE only indicates that the live FP/SVE/SME state in the CPU does not belong to the current task, and does not indicate that clobbering this state is acceptable. When the live CPU state is clobbered it is necessary to update fpsimd_last_state.st to ensure that a subsequent context switch will reload FP/SVE/SME state from memory rather than consuming the clobbered state. This and the SMCCC call itself must happen in a critical section with preemption disabled to avoid races. (3) Live SVE/SME state can exist with TIF_SVE clear (e.g. with only TIF_SME set), and checking TIF_SVE alone is insufficient. Remove the broken support for the SMCCCv1.3 SVE saving hint. This is effectively a revert of commits: * cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint") * a7c3acca5380 ("arm64: smccc: Save lr before calling __arm_smccc_sve_check()") ... leaving behind the ARM_SMCCC_VERSION_1_3 and ARM_SMCCC_1_3_SVE_HINT definitions, since these are simply definitions from the SMCCC specification, and the latter is used in KVM via ARM_SMCCC_CALL_HINTS. If we want to bring this back in future, we'll probably want to handle this logic in C where we can use all the usual FPSIMD/SVE/SME helper functions, and that'll likely require some rework of the SMCCC code and/or its callers. Fixes: cfa7ff959a78 ("arm64: smccc: Support SMCCC v1.3 SVE register saving hint") Signed-off-by: Mark Rutland Cc: Ard Biesheuvel Cc: Catalin Marinas Cc: Marc Zyngier Cc: Mark Brown Cc: Will Deacon Cc: stable@vger.kernel.org Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20241106160448.2712997-1-mark.rutland@arm.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

EDAC/qcom: Make irq configuration optional

2024-11-14T12:20:54+00:00

[ Upstream commit 0a97195d2181caced187acd7454464b8e37021d7 ] On most modern qualcomm SoCs, the configuration necessary to enable the Tag/Data RAM related irqs being propagated to the SoC irq controller is already done in firmware (in DSF or 'DDR System Firmware') On some like the x1e80100, these registers aren't even accesible to the kernel causing a crash when edac device is probed. Hence, make the irq configuration optional in the driver and mark x1e80100 as the SoC on which this should be avoided. Fixes: af16b00578a7 ("arm64: dts: qcom: Add base X1E80100 dtsi and the QCP dts") Reported-by: Bjorn Andersson Signed-off-by: Rajendra Nayak Reviewed-by: Manivannan Sadhasivam Reviewed-by: Abel Vesa Link: https://lore.kernel.org/r/20240903101510.3452734-1-quic_rjendra@quicinc.com Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin

rcu/kvfree: Add kvfree_rcu_barrier() API

2024-11-08T15:31:04+00:00

commit 2b55d6a42d14c8675e38d6d9adca3014fdf01951 upstream. Add a kvfree_rcu_barrier() function. It waits until all in-flight pointers are freed over RCU machinery. It does not wait any GP completion and it is within its right to return immediately if there are no outstanding pointers. This function is useful when there is a need to guarantee that a memory is fully freed before destroying memory caches. For example, during unloading a kernel module. Signed-off-by: Uladzislau Rezki (Sony) Signed-off-by: Vlastimil Babka Signed-off-by: Suren Baghdasaryan Signed-off-by: Greg Kroah-Hartman

mm: multi-gen LRU: use {ptep,pmdp}_clear_young_notify()

2024-11-08T15:31:01+00:00

[ Upstream commit 1d4832becdc2cdb2cffe2a6050c9d9fd8ff1c58c ] When the MM_WALK capability is enabled, memory that is mostly accessed by a VM appears younger than it really is, therefore this memory will be less likely to be evicted. Therefore, the presence of a running VM can significantly increase swap-outs for non-VM memory, regressing the performance for the rest of the system. Fix this regression by always calling {ptep,pmdp}_clear_young_notify() whenever we clear the young bits on PMDs/PTEs. [jthoughton@google.com: fix link-time error] Link: https://lkml.kernel.org/r/20241019012940.3656292-3-jthoughton@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao Signed-off-by: James Houghton Reported-by: David Stevens Cc: Axel Rasmussen Cc: David Matlack Cc: David Rientjes Cc: Oliver Upton Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Wei Xu Cc: Cc: kernel test robot Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

mm: multi-gen LRU: remove MM_LEAF_OLD and MM_NONLEAF_TOTAL stats

2024-11-08T15:31:01+00:00

[ Upstream commit ddd6d8e975b171ea3f63a011a75820883ff0d479 ] Patch series "mm: multi-gen LRU: Have secondary MMUs participate in MM_WALK". Today, the MM_WALK capability causes MGLRU to clear the young bit from PMDs and PTEs during the page table walk before eviction, but MGLRU does not call the clear_young() MMU notifier in this case. By not calling this notifier, the MM walk takes less time/CPU, but it causes pages that are accessed mostly through KVM / secondary MMUs to appear younger than they should be. We do call the clear_young() notifier today, but only when attempting to evict the page, so we end up clearing young/accessed information less frequently for secondary MMUs than for mm PTEs, and therefore they appear younger and are less likely to be evicted. Therefore, memory that is *not* being accessed mostly by KVM will be evicted *more* frequently, worsening performance. ChromeOS observed a tab-open latency regression when enabling MGLRU with a setup that involved running a VM: Tab-open latency histogram (ms) Version p50 mean p95 p99 max base 1315 1198 2347 3454 10319 mglru 2559 1311 7399 12060 43758 fix 1119 926 2470 4211 6947 This series replaces the final non-selftest patchs from this series[1], which introduced a similar change (and a new MMU notifier) with KVM optimizations. I'll send a separate series (to Sean and Paolo) for the KVM optimizations. This series also makes proactive reclaim with MGLRU possible for KVM memory. I have verified that this functions correctly with the selftest from [1], but given that that test is a KVM selftest, I'll send it with the rest of the KVM optimizations later. Andrew, let me know if you'd like to take the test now anyway. [1]: https://lore.kernel.org/linux-mm/20240926013506.860253-18-jthoughton@google.com/ This patch (of 2): The removed stats, MM_LEAF_OLD and MM_NONLEAF_TOTAL, are not very helpful and become more complicated to properly compute when adding test/clear_young() notifiers in MGLRU's mm walk. Link: https://lkml.kernel.org/r/20241019012940.3656292-1-jthoughton@google.com Link: https://lkml.kernel.org/r/20241019012940.3656292-2-jthoughton@google.com Fixes: bd74fdaea146 ("mm: multi-gen LRU: support page table walks") Signed-off-by: Yu Zhao Signed-off-by: James Houghton Cc: Axel Rasmussen Cc: David Matlack Cc: David Rientjes Cc: David Stevens Cc: Oliver Upton Cc: Paolo Bonzini Cc: Sean Christopherson Cc: Wei Xu Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

Input: fix regression when re-registering input handlers

2024-11-08T15:31:01+00:00

[ Upstream commit 071b24b54d2d05fbf39ddbb27dee08abd1d713f3 ] Commit d469647bafd9 ("Input: simplify event handling logic") introduced code that would set handler->events() method to either input_handler_events_filter() or input_handler_events_default() or input_handler_events_null(), depending on the kind of input handler (a filter or a regular one) we are dealing with. Unfortunately this breaks cases when we try to re-register the same filter (as is the case with sysrq handler): after initial registration the handler will have 2 event handling methods defined, and will run afoul of the check in input_handler_check_methods(): input: input_handler_check_methods: only one event processing method can be defined (sysrq) sysrq: Failed to register input handler, error -22 Fix this by adding handle_events() method to input_handle structure and setting it up when registering a new input handle according to event handling methods defined in associated input_handler structure, thus avoiding modifying the input_handler structure. Reported-by: "Ned T. Crigler" Reported-by: Christian Heusel Tested-by: "Ned T. Crigler" Tested-by: Peter Seiderer Fixes: d469647bafd9 ("Input: simplify event handling logic") Link: https://lore.kernel.org/r/Zx2iQp6csn42PJA7@xavtug Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov Signed-off-by: Sasha Levin

x86/traps: Enable UBSAN traps on x86

2024-11-08T15:30:58+00:00

[ Upstream commit 7424fc6b86c8980a87169e005f5cd4438d18efe6 ] Currently ARM64 extracts which specific sanitizer has caused a trap via encoded data in the trap instruction. Clang on x86 currently encodes the same data in the UD1 instruction but x86 handle_bug() and is_valid_bugaddr() currently only look at UD2. Bring x86 to parity with ARM64, similar to commit 25b84002afb9 ("arm64: Support Clang UBSAN trap codes for better reporting"). See the llvm links for information about the code generation. Enable the reporting of UBSAN sanitizer details on x86 compiled with clang when CONFIG_UBSAN_TRAP=y by analysing UD1 and retrieving the type immediate which is encoded by the compiler after the UD1. [ tglx: Simplified it by moving the printk() into handle_bug() ] Signed-off-by: Gatlin Newhouse Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: Kees Cook Link: https://lore.kernel.org/all/20240724000206.451425-1-gatlin.newhouse@gmail.com Link: https://github.com/llvm/llvm-project/commit/c5978f42ec8e9#diff-bb68d7cd885f41cfc35843998b0f9f534adb60b415f647109e597ce448e92d9f Link: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/X86/X86InstrSystem.td#L27 Stable-dep-of: 1db272864ff2 ("x86/traps: move kmsan check after instrumentation_begin") Signed-off-by: Sasha Levin

fork: only invoke khugepaged, ksm hooks if no error

2024-11-08T15:30:58+00:00

[ Upstream commit 985da552a98e27096444508ce5d853244019111f ] There is no reason to invoke these hooks early against an mm that is in an incomplete state. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. Their placement early in dup_mmap() only appears to have been meaningful for early error checking, and since functionally it'd require a very small allocation to fail (in practice 'too small to fail') that'd only occur in the most dire circumstances, meaning the fork would fail or be OOM'd in any case. Since both khugepaged and KSM tracking are there to provide optimisations to memory performance rather than critical functionality, it doesn't really matter all that much if, under such dire memory pressure, we fail to register an mm with these. As a result, we follow the example of commit d2081b2bf819 ("mm: khugepaged: make khugepaged_enter() void function") and make ksm_fork() a void function also. We only expose the mm to these functions once we are done with them and only if no error occurred in the fork operation. Link: https://lkml.kernel.org/r/e0cb8b840c9d1d5a6e84d4f8eff5f3f2022aa10c.1729014377.git.lorenzo.stoakes@oracle.com Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") Signed-off-by: Lorenzo Stoakes Reported-by: Jann Horn Reviewed-by: Liam R. Howlett Reviewed-by: Vlastimil Babka Reviewed-by: Jann Horn Cc: Alexander Viro Cc: Christian Brauner Cc: Jan Kara Cc: Linus Torvalds Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin