kernel/linux.git/drivers/char, branch master

Merge tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-04-15T19:59:16+00:00

Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ...

hpet: replace deprecated mmap hook with mmap_prepare

2026-04-05T20:53:43+00:00

The f_op->mmap interface is deprecated, so update driver to use its successor, mmap_prepare. The driver previously used vm_iomap_memory(), so this change replaces it with its mmap_prepare equivalent, mmap_action_simple_ioremap(). Link: https://lkml.kernel.org/r/094c5fcfb2459a4f6d791b1fb852b01e252a44d4.1774045440.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) Reviewed-by: Suren Baghdasaryan Acked-by: Vlastimil Babka (SUSE) Cc: Alexander Shishkin Cc: Alexandre Torgue Cc: Al Viro Cc: Arnd Bergmann Cc: Bodo Stroesser Cc: Christian Brauner Cc: Clemens Ladisch Cc: David Hildenbrand Cc: David Howells Cc: Dexuan Cui Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Jan Kara Cc: Jann Horn Cc: Jonathan Corbet Cc: K. Y. Srinivasan Cc: Liam Howlett Cc: Long Li Cc: Marc Dionne Cc: "Martin K. Petersen" Cc: Maxime Coquelin Cc: Michal Hocko Cc: Mike Rapoport Cc: Miquel Raynal Cc: Pedro Falcato Cc: Richard Weinberger Cc: Ryan Roberts Cc: Vignesh Raghavendra Cc: Wei Liu Signed-off-by: Andrew Morton

mm: reintroduce vma_desc_test() as a singular flag test

2026-04-05T20:53:19+00:00

Similar to vma_flags_test(), we have previously renamed vma_desc_test() to vma_desc_test_any(). Now that is in place, we can reintroduce vma_desc_test() to explicitly check for a single VMA flag. As with vma_flags_test(), this is useful as often flag tests are against a single flag, and vma_desc_test_any(flags, VMA_READ_BIT) reads oddly and potentially causes confusion. As with vma_flags_test() a combination of sparse and vma_flags_t being a struct means that users cannot misuse this function without it getting flagged. Also update the VMA tests to reflect this change. Link: https://lkml.kernel.org/r/3a65ca23defb05060333f0586428fe279a484564.1772704455.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) Acked-by: David Hildenbrand (Arm) Reviewed-by: Pedro Falcato Cc: Arnd Bergmann Cc: Babu Moger Cc: Baolin Wang Cc: Chao Yu Cc: Chatre, Reinette Cc: Chunhai Guo Cc: Damien Le Maol Cc: Dan Williams Cc: Dave Jiang Cc: Dave Martin Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Hongbo Li Cc: Hugh Dickins Cc: James Morse Cc: Jan Kara Cc: Jann Horn Cc: Jason Gunthorpe Cc: Jeffle Xu Cc: Johannes Thumshirn Cc: Konstantin Komarov Cc: Liam Howlett Cc: "Luck, Tony" Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naohiro Aota Cc: Oscar Salvador Cc: Sandeep Dhavale Cc: Suren Baghdasaryan Cc: Vishal Verma Cc: Vlastimil Babka Cc: Yue Hu Signed-off-by: Andrew Morton

mm: rename VMA flag helpers to be more readable

2026-04-05T20:53:18+00:00

Patch series "mm: vma flag tweaks". The ongoing work around introducing non-system word VMA flags has introduced a number of helper functions and macros to make life easier when working with these flags and to make conversions from the legacy use of VM_xxx flags more straightforward. This series improves these to reduce confusion as to what they do and to improve consistency and readability. Firstly the series renames vma_flags_test() to vma_flags_test_any() to make it abundantly clear that this function tests whether any of the flags are set (as opposed to vma_flags_test_all()). It then renames vma_desc_test_flags() to vma_desc_test_any() for the same reason. Note that we drop the 'flags' suffix here, as vma_desc_test_any_flags() would be cumbersome and 'test' implies a flag test. Similarly, we rename vma_test_all_flags() to vma_test_all() for consistency. Next, we have a couple of instances (erofs, zonefs) where we are now testing for vma_desc_test_any(desc, VMA_SHARED_BIT) && vma_desc_test_any(desc, VMA_MAYWRITE_BIT). This is silly, so this series introduces vma_desc_test_all() so these callers can instead invoke vma_desc_test_all(desc, VMA_SHARED_BIT, VMA_MAYWRITE_BIT). We then observe that quite a few instances of vma_flags_test_any() and vma_desc_test_any() are in fact only testing against a single flag. Using the _any() variant here is just confusing - 'any' of single item reads strangely and is liable to cause confusion. So in these instances the series reintroduces vma_flags_test() and vma_desc_test() as helpers which test against a single flag. The fact that vma_flags_t is a struct and that vma_flag_t utilises sparse to avoid confusion with vm_flags_t makes it impossible for a user to misuse these helpers without it getting flagged somewhere. The series also updates __mk_vma_flags() and functions invoked by it to explicitly mark them always inline to match expectation and to be consistent with other VMA flag helpers. It also renames vma_flag_set() to vma_flags_set_flag() (a function only used by __mk_vma_flags()) to be consistent with other VMA flag helpers. Finally it updates the VMA tests for each of these changes, and introduces explicit tests for vma_flags_test() and vma_desc_test() to assert that they behave as expected. This patch (of 6): On reflection, it's confusing to have vma_flags_test() and vma_desc_test_flags() test whether any comma-separated VMA flag bit is set, while also having vma_flags_test_all() and vma_test_all_flags() separately test whether all flags are set. Firstly, rename vma_flags_test() to vma_flags_test_any() to eliminate this confusion. Secondly, since the VMA descriptor flag functions are becoming rather cumbersome, prefer vma_desc_test*() to vma_desc_test_flags*(), and also rename vma_desc_test_flags() to vma_desc_test_any(). Finally, rename vma_test_all_flags() to vma_test_all() to keep the VMA-specific helper consistent with the VMA descriptor naming convention and to help avoid confusion vs. vma_flags_test_all(). While we're here, also update whitespace to be consistent in helper functions. Link: https://lkml.kernel.org/r/cover.1772704455.git.ljs@kernel.org Link: https://lkml.kernel.org/r/0f9cb3c511c478344fac0b3b3b0300bb95be95e9.1772704455.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) Suggested-by: Pedro Falcato Acked-by: David Hildenbrand (Arm) Reviewed-by: Pedro Falcato Cc: Arnd Bergmann Cc: Babu Moger Cc: Baolin Wang Cc: Chao Yu Cc: Chatre, Reinette Cc: Chunhai Guo Cc: Damien Le Maol Cc: Dan Williams Cc: Dave Jiang Cc: Dave Martin Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Hongbo Li Cc: Hugh Dickins Cc: James Morse Cc: Jan Kara Cc: Jann Horn Cc: Jason Gunthorpe Cc: Jeffle Xu Cc: Johannes Thumshirn Cc: Konstantin Komarov Cc: Liam Howlett Cc: "Luck, Tony" Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naohiro Aota Cc: Oscar Salvador Cc: Sandeep Dhavale Cc: Suren Baghdasaryan Cc: Vishal Verma Cc: Vlastimil Babka Cc: Yue Hu Signed-off-by: Andrew Morton

random: vDSO: Remove ifdeffery

2026-03-11T14:22:49+00:00

Recent cleanups of the vDSO headers allow the unconditional inclusion of vdso/datapage.h and the declarations it provides. This also means that the declaration of vdso_k_rng_data is always visible and its usage does not need to be guarded by ifdefs anymore. Instead use IS_ENABLED(). Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Jason A. Donenfeld Link: https://patch.msgid.link/20260227-vdso-header-cleanups-v2-15-35d60acf7410@linutronix.de

random: vDSO: Trim vDSO includes

2026-03-11T14:22:43+00:00

These includes are not used, remove them. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Jason A. Donenfeld Link: https://patch.msgid.link/20260227-vdso-header-cleanups-v2-14-35d60acf7410@linutronix.de

Merge tag 'for-linus-7.0-1' of https://github.com/cminyard/linux-ipmi

2026-02-26T22:34:21+00:00

Pull IPMI driver fixes from Corey Minyard: "This mostly revolves around getting the driver to behave when the IPMI device misbehaves. Past attempts have not worked very well because I didn't have hardware I could make do this, and AI was fairly useless for help on this. So I modified qemu and my test suite so I could reproduce a misbehaving IPMI device, and with that I was able to fix the issues" * tag 'for-linus-7.0-1' of https://github.com/cminyard/linux-ipmi: ipmi:si: Fix check for a misbehaving BMC ipmi:msghandler: Handle error returns from the SMI sender ipmi:si: Don't block module unload if the BMC is messed up ipmi:si: Use a long timeout when the BMC is misbehaving ipmi:si: Handle waiting messages when BMC failure detected ipmi:ls2k: Make ipmi_ls2k_platform_driver static ipmi: ipmb: initialise event handler read bytes ipmi: Consolidate the run to completion checking for xmit msgs lock ipmi: Fix use-after-free and list corruption on sender error

Remove WARN_ALL_UNSEEDED_RANDOM kernel config option

2026-02-23T19:18:48+00:00

This config option goes way back - it used to be an internal debug option to random.c (at that point called DEBUG_RANDOM_BOOT), then was renamed and exposed as a config option as CONFIG_WARN_UNSEEDED_RANDOM, and then further renamed to the current CONFIG_WARN_ALL_UNSEEDED_RANDOM. It was all done with the best of intentions: the more limited rate-limited reports were reporting some cases, but if you wanted to see all the gory details, you'd enable this "ALL" option. However, it turns out - perhaps not surprisingly - that when people don't care about and fix the first rate-limited cases, they most certainly don't care about any others either, and so warning about all of them isn't actually helping anything. And the non-ratelimited reporting causes problems, where well-meaning people enable debug options, but the excessive flood of messages that nobody cares about will hide actual real information when things go wrong. I just got a kernel bug report (which had nothing to do with randomness) where two thirds of the the truncated dmesg was just variations of random: get_random_u32 called from __get_random_u32_below+0x10/0x70 with crng_init=0 and in the process early boot messages had been lost (in addition to making the messages that _hadn't_ been lost harder to read). The proper way to find these things for the hypothetical developer that cares - if such a person exists - is almost certainly with boot time tracing. That gives you the option to get call graphs etc too, which is likely a requirement for fixing any problems anyway. See Documentation/trace/boottime-trace.rst for that option. And if we for some reason do want to re-introduce actual printing of these things, it will need to have some uniqueness filtering rather than this "just print it all" model. Fixes: cc1e127bfa95 ("random: remove ratelimiting for in-kernel unseeded randomness") Acked-by: Jason Donenfeld Signed-off-by: Linus Torvalds

ipmi:si: Fix check for a misbehaving BMC

2026-02-23T15:00:48+00:00

There is a race on checking the state in the sender, it needs to be checked under a lock. But you also need a check to avoid issues with a misbehaving BMC for run to completion mode. So leave the check at the beginning for run to completion, and add a check under the lock to avoid the race. Reported-by: Rafael J. Wysocki Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard Reviewed-by: Rafael J. Wysocki (Intel)

ipmi:msghandler: Handle error returns from the SMI sender

2026-02-23T15:00:48+00:00

It used to be, until recently, that the sender operation on the low level interfaces would not fail. That's not the case any more with recent changes. So check the return value from the sender operation, and propagate it back up from there and handle the errors in all places. Reported-by: Rafael J. Wysocki Fixes: bc3a9d217755 ("ipmi:si: Gracefully handle if the BMC is non-functional") Cc: stable@vger.kernel.org # 4.18 Signed-off-by: Corey Minyard Reviewed-by: Rafael J. Wysocki (Intel)