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2021-11-06mm/vmalloc: do not adjust the search size for alignment overheadUladzislau Rezki (Sony)1-9/+13
We used to include an alignment overhead into a search length, in that case we guarantee that a found area will definitely fit after applying a specific alignment that user specifies. From the other hand we do not guarantee that an area has the lowest address if an alignment is >= PAGE_SIZE. It means that, when a user specifies a special alignment together with a range that corresponds to an exact requested size then an allocation will fail. This is what happens to KASAN, it wants the free block that exactly matches a specified range during onlining memory banks: [root@vm-0 fedora]# echo online > /sys/devices/system/memory/memory82/state [root@vm-0 fedora]# echo online > /sys/devices/system/memory/memory83/state [root@vm-0 fedora]# echo online > /sys/devices/system/memory/memory85/state [root@vm-0 fedora]# echo online > /sys/devices/system/memory/memory84/state vmap allocation for size 16777216 failed: use vmalloc=<size> to increase size bash: vmalloc: allocation failure: 16777216 bytes, mode:0x6000c0(GFP_KERNEL), nodemask=(null),cpuset=/,mems_allowed=0 CPU: 4 PID: 1644 Comm: bash Kdump: loaded Not tainted 4.18.0-339.el8.x86_64+debug #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack+0x8e/0xd0 warn_alloc.cold.90+0x8a/0x1b2 ? zone_watermark_ok_safe+0x300/0x300 ? slab_free_freelist_hook+0x85/0x1a0 ? __get_vm_area_node+0x240/0x2c0 ? kfree+0xdd/0x570 ? kmem_cache_alloc_node_trace+0x157/0x230 ? notifier_call_chain+0x90/0x160 __vmalloc_node_range+0x465/0x840 ? mark_held_locks+0xb7/0x120 Fix it by making sure that find_vmap_lowest_match() returns lowest start address with any given alignment value, i.e. for alignments bigger then PAGE_SIZE the algorithm rolls back toward parent nodes checking right sub-trees if the most left free block did not fit due to alignment overhead. Link: https://lkml.kernel.org/r/[email protected] Fixes: 68ad4a330433 ("mm/vmalloc.c: keep track of free blocks for vmap allocation") Signed-off-by: Uladzislau Rezki (Sony) <[email protected]> Reported-by: Ping Fang <[email protected]> Tested-by: David Hildenbrand <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Hillf Danton <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Oleksiy Avramchenko <[email protected]> Cc: Steven Rostedt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/vmalloc: make sure to dump unpurged areas in /proc/vmallocinfoEric Dumazet1-1/+2
If last va found in vmap_area_list does not have a vm pointer, vmallocinfo.s_show() returns 0, and show_purge_info() is not called as it should. Link: https://lkml.kernel.org/r/[email protected] Fixes: dd3b8353bae7 ("mm/vmalloc: do not keep unpurged areas in the busy tree") Signed-off-by: Eric Dumazet <[email protected]> Cc: Uladzislau Rezki (Sony) <[email protected]> Cc: Pengfei Li <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/vmalloc: make show_numa_info() aware of hugepage mappingsEric Dumazet1-3/+3
show_numa_info() can be slightly faster, by skipping over hugepages directly. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Eric Dumazet <[email protected]> Cc: Uladzislau Rezki (Sony) <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/vmalloc: don't allow VM_NO_GUARD on vmap()Peter Zijlstra2-1/+8
The vmalloc guard pages are added on top of each allocation, thereby isolating any two allocations from one another. The top guard of the lower allocation is the bottom guard guard of the higher allocation etc. Therefore VM_NO_GUARD is dangerous; it breaks the basic premise of isolating separate allocations. There are only two in-tree users of this flag, neither of which use it through the exported interface. Ensure it stays this way. Link: https://lkml.kernel.org/r/YUMfdA36fuyZ+/[email protected] Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Acked-by: Will Deacon <[email protected]> Acked-by: Kees Cook <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Uladzislau Rezki <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/vmalloc: repair warn_alloc()s in __vmalloc_area_node()Vasily Averin1-3/+4
Commit f255935b9767 ("mm: cleanup the gfp_mask handling in __vmalloc_area_node") added __GFP_NOWARN to gfp_mask unconditionally however it disabled all output inside warn_alloc() call. This patch saves original gfp_mask and provides it to all warn_alloc() calls. Link: https://lkml.kernel.org/r/[email protected] Fixes: f255935b9767 ("mm: cleanup the gfp_mask handling in __vmalloc_area_node") Signed-off-by: Vasily Averin <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Muchun Song <[email protected]> Cc: Uladzislau Rezki (Sony) <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: mmap_lock: use DECLARE_EVENT_CLASS and DEFINE_EVENT_FNGang Li1-32/+12
By using DECLARE_EVENT_CLASS and TRACE_EVENT_FN, we can save a lot of space from duplicate code. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Gang Li <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Cc: Axel Rasmussen <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: mmap_lock: remove redundant newline in TP_printkGang Li1-3/+3
Ftrace core will add newline automatically on printing, so using it in TP_printkcreates a blank line. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Gang Li <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Reviewed-by: Steven Rostedt (VMware) <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Axel Rasmussen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06include/linux/io-mapping.h: remove fallback for writecombineLucas De Marchi1-6/+0
The fallback was introduced in commit 80c33624e472 ("io-mapping: Fixup for different names of writecombine") to fix the build on microblaze. 5 years later, it seems all archs now provide a pgprot_writecombine(), so just remove the other possible fallbacks. For microblaze, pgprot_writecombine() is available since commit 97ccedd793ac ("microblaze: Provide pgprot_device/writecombine macros for nommu"). This is build-tested on microblaze with a hack to always build mm/io-mapping.o and without DIYing on an x86-only macro (_PAGE_CACHE_MASK) Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Lucas De Marchi <[email protected]> Cc: Chris Wilson <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Joonas Lahtinen <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/mremap: don't account pages in vma_to_resize()Dmitry Safonov1-28/+22
All this vm_unacct_memory(charged) dance seems to complicate the life without a good reason. Furthermore, it seems not always done right on error-pathes in mremap_to(). And worse than that: this `charged' difference is sometimes double-accounted for growing MREMAP_DONTUNMAP mremap()s in move_vma(): if (security_vm_enough_memory_mm(mm, new_len >> PAGE_SHIFT)) Let's not do this. Account memory in mremap() fast-path for growing VMAs or in move_vma() for actually moving things. The same simpler way as it's done by vm_stat_account(), but with a difference to call security_vm_enough_memory_mm() before copying/adjusting VMA. Originally noticed by Chen Wandun: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: e346b3813067 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()") Signed-off-by: Dmitry Safonov <[email protected]> Acked-by: Brian Geffon <[email protected]> Cc: Alexander Viro <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Chen Wandun <[email protected]> Cc: Dan Carpenter <[email protected]> Cc: Dan Williams <[email protected]> Cc: Dave Jiang <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: John Hubbard <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Minchan Kim <[email protected]> Cc: Ralph Campbell <[email protected]> Cc: Russell King <[email protected]> Cc: Thomas Bogendoerfer <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vishal Verma <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Wei Yongjun <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/mprotect.c: avoid repeated assignment in do_mprotect_pkey()Liu Song1-1/+4
After adjustment, the repeated assignment of "prev" is avoided, and the readability of the code is improved. Link: https://lkml.kernel.org/r/[email protected] Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Liu Song <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06memory: remove unused CONFIG_MEM_BLOCK_SIZELukas Bulwahn1-1/+0
Commit 3947be1969a9 ("[PATCH] memory hotplug: sysfs and add/remove functions") defines CONFIG_MEM_BLOCK_SIZE, but this has never been utilized anywhere. It is a good practice to keep the CONFIG_* defines exclusively for the Kbuild system. So, drop this unused definition. This issue was noticed due to running ./scripts/checkkconfigsymbols.py. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Lukas Bulwahn <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Dave Hansen <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06Documentation: update pagemap with shmem exceptionsTiberiu A Georgescu1-0/+22
This patch follows the discussions on previous documentation patch threads [1][2]. It presents the exception case of shared memory management from the pagemap's point of view. It briefly describes what is missing, why it is missing and alternatives to the pagemap for page info retrieval in user space. In short, the kernel does not keep track of PTEs for swapped out shared pages within the processes that references them. Thus, the proc/pid/pagemap tool cannot print the swap destination of the shared memory pages, instead setting the pagemap entry to zero for both non-allocated and swapped out pages. This can create confusion for users who need information on swapped out pages. The reasons why maintaining the PTEs of all swapped out shared pages among all processes while maintaining similar performance is not a trivial task, or a desirable change, have been discussed extensively [1][3][4][5]. There are also arguments for why this arguably missing information should eventually be exposed to the user in either a future pagemap patch, or by an alternative tool. [1]: https://marc.info/?m=162878395426774 [2]: https://lore.kernel.org/lkml/[email protected]/ [3]: https://lore.kernel.org/lkml/[email protected]/ [4]: https://lore.kernel.org/lkml/[email protected]/ [5]: https://lore.kernel.org/lkml/[email protected]/ Mention the current missing information in the pagemap and alternatives on how to retrieve it, in case someone stumbles upon unexpected behaviour. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Tiberiu A Georgescu <[email protected]> Reviewed-by: Ivan Teterevkov <[email protected]> Reviewed-by: Florian Schmidt <[email protected]> Reviewed-by: Carl Waldspurger <[email protected]> Reviewed-by: Jonathan Davies <[email protected]> Reviewed-by: Peter Xu <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Cc: Jonathan Corbet <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: remove redundant smp_wmb()Qi Zheng2-30/+24
The smp_wmb() which is in the __pte_alloc() is used to ensure all ptes setup is visible before the pte is made visible to other CPUs by being put into page tables. We only need this when the pte is actually populated, so move it to pmd_install(). __pte_alloc_kernel(), __p4d_alloc(), __pud_alloc() and __pmd_alloc() are similar to this case. We can also defer smp_wmb() to the place where the pmd entry is really populated by preallocated pte. There are two kinds of user of preallocated pte, one is filemap & finish_fault(), another is THP. The former does not need another smp_wmb() because the smp_wmb() has been done by pmd_install(). Fortunately, the latter also does not need another smp_wmb() because there is already a smp_wmb() before populating the new pte when the THP uses a preallocated pte to split a huge pmd. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Qi Zheng <[email protected]> Reviewed-by: Muchun Song <[email protected]> Acked-by: David Hildenbrand <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Mika Penttila <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: introduce pmd_install() helperQi Zheng3-27/+19
Patch series "Do some code cleanups related to mm", v3. This patch (of 2): Currently we have three times the same few lines repeated in the code. Deduplicate them by newly introduced pmd_install() helper. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Qi Zheng <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Muchun Song <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Mika Penttila <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: add zap_skip_check_mapping() helperPeter Xu2-24/+21
Use the helper for the checks. Rename "check_mapping" into "zap_mapping" because "check_mapping" looks like a bool but in fact it stores the mapping itself. When it's set, we check the mapping (it must be non-NULL). When it's cleared we skip the check, which works like the old way. Move the duplicated comments to the helper too. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peter Xu <[email protected]> Reviewed-by: Alistair Popple <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Axel Rasmussen <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: "Kirill A . Shutemov" <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: drop first_index/last_index in zap_detailsPeter Xu2-15/+18
The first_index/last_index parameters in zap_details are actually only used in unmap_mapping_range_tree(). At the meantime, this function is only called by unmap_mapping_pages() once. Instead of passing these two variables through the whole stack of page zapping code, remove them from zap_details and let them simply be parameters of unmap_mapping_range_tree(), which is inlined. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peter Xu <[email protected]> Reviewed-by: Alistair Popple <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Liam Howlett <[email protected]> Acked-by: Hugh Dickins <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Axel Rasmussen <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: "Kirill A . Shutemov" <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: clear vmf->pte after pte_unmap_same() returnsPeter Xu1-6/+6
pte_unmap_same() will always unmap the pte pointer. After the unmap, vmf->pte will not be valid any more, we should clear it. It was safe only because no one is accessing vmf->pte after pte_unmap_same() returns, since the only caller of pte_unmap_same() (so far) is do_swap_page(), where vmf->pte will in most cases be overwritten very soon. Directly pass in vmf into pte_unmap_same() and then we can also avoid the long parameter list too, which should be a nice cleanup. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peter Xu <[email protected]> Reviewed-by: Miaohe Lin <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Reviewed-by: Liam Howlett <[email protected]> Acked-by: Hugh Dickins <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Axel Rasmussen <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: "Kirill A . Shutemov" <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/shmem: unconditionally set pte dirty in mfill_atomic_install_ptePeter Xu2-3/+1
Patch series "mm: A few cleanup patches around zap, shmem and uffd", v4. IMHO all of them are very nice cleanups to existing code already, they're all small and self-contained. They'll be needed by uffd-wp coming series. This patch (of 4): It was conditionally done previously, as there's one shmem special case that we use SetPageDirty() instead. However that's not necessary and it should be easier and cleaner to do it unconditionally in mfill_atomic_install_pte(). The most recent discussion about this is here, where Hugh explained the history of SetPageDirty() and why it's possible that it's not required at all: https://lore.kernel.org/lkml/[email protected]/ Currently mfill_atomic_install_pte() has three callers: 1. shmem_mfill_atomic_pte 2. mcopy_atomic_pte 3. mcontinue_atomic_pte After the change: case (1) should have its SetPageDirty replaced by the dirty bit on pte (so we unify them together, finally), case (2) should have no functional change at all as it has page_in_cache==false, case (3) may add a dirty bit to the pte. However since case (3) is UFFDIO_CONTINUE for shmem, it's merely 100% sure the page is dirty after all because UFFDIO_CONTINUE normally requires another process to modify the page cache and kick the faulted thread, so should not make a real difference either. This should make it much easier to follow on which case will set dirty for uffd, as we'll simply set it all now for all uffd related ioctls. Meanwhile, no special handling of SetPageDirty() if there's no need. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peter Xu <[email protected]> Reviewed-by: Axel Rasmussen <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Liam Howlett <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Yang Shi <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: "Kirill A . Shutemov" <[email protected]> Cc: Jerome Glisse <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Matthew Wilcox <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/memory.c: avoid unnecessary kernel/user pointer conversionAmit Daniel Kachhap1-3/+1
Annotating a pointer from __user to kernel and then back again might confuse sparse. In copy_huge_page_from_user() it can be avoided by removing the intermediate variable since it is never used. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Amit Daniel Kachhap <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Vincenzo Frascino <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: use __pfn_to_section() instead of open coding itRolf Eike Beer1-2/+2
It is defined in the same file just a few lines above. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Rolf Eike Beer <[email protected]> Reviewed-by: Andrew Morton <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/mmap.c: fix a data race of mm->total_vmPeng Liu2-2/+2
The variable mm->total_vm could be accessed concurrently during mmaping and system accounting as noticed by KCSAN, BUG: KCSAN: data-race in __acct_update_integrals / mmap_region read-write to 0xffffa40267bd14c8 of 8 bytes by task 15609 on cpu 3: mmap_region+0x6dc/0x1400 do_mmap+0x794/0xca0 vm_mmap_pgoff+0xdf/0x150 ksys_mmap_pgoff+0xe1/0x380 do_syscall_64+0x37/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffffa40267bd14c8 of 8 bytes by interrupt on cpu 2: __acct_update_integrals+0x187/0x1d0 acct_account_cputime+0x3c/0x40 update_process_times+0x5c/0x150 tick_sched_timer+0x184/0x210 __run_hrtimer+0x119/0x3b0 hrtimer_interrupt+0x350/0xaa0 __sysvec_apic_timer_interrupt+0x7b/0x220 asm_call_irq_on_stack+0x12/0x20 sysvec_apic_timer_interrupt+0x4d/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20 smp_call_function_single+0x192/0x2b0 perf_install_in_context+0x29b/0x4a0 __se_sys_perf_event_open+0x1a98/0x2550 __x64_sys_perf_event_open+0x63/0x70 do_syscall_64+0x37/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 2 PID: 15610 Comm: syz-executor.3 Not tainted 5.10.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 In vm_stat_account which called by mmap_region, increase total_vm, and __acct_update_integrals may read total_vm at the same time. This will cause a data race which lead to undefined behaviour. To avoid potential bad read/write, volatile property and barrier are both used to avoid undefined behaviour. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peng Liu <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06memcg: prohibit unconditional exceeding the limit of dying tasksVasily Averin1-19/+8
Memory cgroup charging allows killed or exiting tasks to exceed the hard limit. It is assumed that the amount of the memory charged by those tasks is bound and most of the memory will get released while the task is exiting. This is resembling a heuristic for the global OOM situation when tasks get access to memory reserves. There is no global memory shortage at the memcg level so the memcg heuristic is more relieved. The above assumption is overly optimistic though. E.g. vmalloc can scale to really large requests and the heuristic would allow that. We used to have an early break in the vmalloc allocator for killed tasks but this has been reverted by commit b8c8a338f75e ("Revert "vmalloc: back off when the current task is killed""). There are likely other similar code paths which do not check for fatal signals in an allocation&charge loop. Also there are some kernel objects charged to a memcg which are not bound to a process life time. It has been observed that it is not really hard to trigger these bypasses and cause global OOM situation. One potential way to address these runaways would be to limit the amount of excess (similar to the global OOM with limited oom reserves). This is certainly possible but it is not really clear how much of an excess is desirable and still protects from global OOMs as that would have to consider the overall memcg configuration. This patch is addressing the problem by removing the heuristic altogether. Bypass is only allowed for requests which either cannot fail or where the failure is not desirable while excess should be still limited (e.g. atomic requests). Implementation wise a killed or dying task fails to charge if it has passed the OOM killer stage. That should give all forms of reclaim chance to restore the limit before the failure (ENOMEM) and tell the caller to back off. In addition, this patch renames should_force_charge() helper to task_is_dying() because now its use is not associated witch forced charging. This patch depends on pagefault_out_of_memory() to not trigger out_of_memory(), because then a memcg failure can unwind to VM_FAULT_OOM and cause a global OOM killer. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Vasily Averin <[email protected]> Suggested-by: Michal Hocko <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Uladzislau Rezki <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm, oom: do not trigger out_of_memory from the #PFMichal Hocko1-14/+8
Any allocation failure during the #PF path will return with VM_FAULT_OOM which in turn results in pagefault_out_of_memory. This can happen for 2 different reasons. a) Memcg is out of memory and we rely on mem_cgroup_oom_synchronize to perform the memcg OOM handling or b) normal allocation fails. The latter is quite problematic because allocation paths already trigger out_of_memory and the page allocator tries really hard to not fail allocations. Anyway, if the OOM killer has been already invoked there is no reason to invoke it again from the #PF path. Especially when the OOM condition might be gone by that time and we have no way to find out other than allocate. Moreover if the allocation failed and the OOM killer hasn't been invoked then we are unlikely to do the right thing from the #PF context because we have already lost the allocation context and restictions and therefore might oom kill a task from a different NUMA domain. This all suggests that there is no legitimate reason to trigger out_of_memory from pagefault_out_of_memory so drop it. Just to be sure that no #PF path returns with VM_FAULT_OOM without allocation print a warning that this is happening before we restart the #PF. [VvS: #PF allocation can hit into limit of cgroup v1 kmem controller. This is a local problem related to memcg, however, it causes unnecessary global OOM kills that are repeated over and over again and escalate into a real disaster. This has been broken since kmem accounting has been introduced for cgroup v1 (3.8). There was no kmem specific reclaim for the separate limit so the only way to handle kmem hard limit was to return with ENOMEM. In upstream the problem will be fixed by removing the outdated kmem limit, however stable and LTS kernels cannot do it and are still affected. This patch fixes the problem and should be backported into stable/LTS.] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Michal Hocko <[email protected]> Signed-off-by: Vasily Averin <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Uladzislau Rezki <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm, oom: pagefault_out_of_memory: don't force global OOM for dying tasksVasily Averin1-0/+3
Patch series "memcg: prohibit unconditional exceeding the limit of dying tasks", v3. Memory cgroup charging allows killed or exiting tasks to exceed the hard limit. It can be misused and allowed to trigger global OOM from inside a memcg-limited container. On the other hand if memcg fails allocation, called from inside #PF handler it triggers global OOM from inside pagefault_out_of_memory(). To prevent these problems this patchset: (a) removes execution of out_of_memory() from pagefault_out_of_memory(), becasue nobody can explain why it is necessary. (b) allow memcg to fail allocation of dying/killed tasks. This patch (of 3): Any allocation failure during the #PF path will return with VM_FAULT_OOM which in turn results in pagefault_out_of_memory which in turn executes out_out_memory() and can kill a random task. An allocation might fail when the current task is the oom victim and there are no memory reserves left. The OOM killer is already handled at the page allocator level for the global OOM and at the charging level for the memcg one. Both have much more information about the scope of allocation/charge request. This means that either the OOM killer has been invoked properly and didn't lead to the allocation success or it has been skipped because it couldn't have been invoked. In both cases triggering it from here is pointless and even harmful. It makes much more sense to let the killed task die rather than to wake up an eternally hungry oom-killer and send him to choose a fatter victim for breakfast. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Vasily Averin <[email protected]> Suggested-by: Michal Hocko <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Uladzislau Rezki <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: list_lru: only add memcg-aware lrus to the global lru listMuchun Song1-19/+16
The non-memcg-aware lru is always skiped when traversing the global lru list, which is not efficient. We can only add the memcg-aware lru to the global lru list instead to make traversing more efficient. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Muchun Song <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Shakeel Butt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: memcontrol: remove the kmem statesMuchun Song2-12/+2
Now the kmem states is only used to indicate whether the kmem is offline. However, we can set ->kmemcg_id to -1 to indicate whether the kmem is offline. Finally, we can remove the kmem states to simplify the code. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Muchun Song <[email protected]> Acked-by: Roman Gushchin <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Shakeel Butt <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Johannes Weiner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: memcontrol: remove kmemcg_id reparentingMuchun Song1-15/+4
Since slab objects and kmem pages are charged to object cgroup instead of memory cgroup, memcg_reparent_objcgs() will reparent this cgroup and all its descendants to its parent cgroup. This already makes further list_lru_add()'s add elements to the parent's list. So it is unnecessary to change kmemcg_id of an offline cgroup to its parent's id. It just wastes CPU cycles. Just remove the redundant code. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Muchun Song <[email protected]> Acked-by: Roman Gushchin <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Shakeel Butt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: list_lru: fix the return value of list_lru_count_one()Muchun Song1-1/+4
Since commit 2788cf0c401c ("memcg: reparent list_lrus and free kmemcg_id on css offline"), ->nr_items can be negative during memory cgroup reparenting. In this case, list_lru_count_one() will return an unusual and huge value, which can surprise users. At least for now it hasn't affected any users. But it is better to let list_lru_count_ont() returns zero when ->nr_items is negative. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Muchun Song <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Shakeel Butt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: list_lru: remove holding lru lockMuchun Song1-11/+0
Since commit e5bc3af7734f ("rcu: Consolidate PREEMPT and !PREEMPT synchronize_rcu()"), the critical section of spin lock can serve as an RCU read-side critical section which already allows readers that hold nlru->lock to avoid taking rcu lock. So just remove holding lock. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Muchun Song <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Shakeel Butt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06memcg, kmem: further deprecate kmem.limit_in_bytesShakeel Butt2-43/+7
The deprecation process of kmem.limit_in_bytes started with the commit 0158115f702 ("memcg, kmem: deprecate kmem.limit_in_bytes") which also explains in detail the motivation behind the deprecation. To summarize, it is the unexpected behavior on hitting the kmem limit. This patch moves the deprecation process to the next stage by disallowing to set the kmem limit. In future we might just remove the kmem.limit_in_bytes file completely. [[email protected]: s/ENOTSUPP/EOPNOTSUPP/] [[email protected]: mark cancel_charge() inline] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Shakeel Butt <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Acked-by: Roman Gushchin <[email protected]> Acked-by: Michal Hocko <[email protected]> Reviewed-by: Muchun Song <[email protected]> Cc: Vasily Averin <[email protected]> Cc: Johannes Weiner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/list_lru.c: prefer struct_size over open coded arithmeticLen Baker1-4/+3
As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kvmalloc() functions. Also, take the opportunity to refactor the memcpy() call to use the flex_array_size() helper. This code was detected with the help of Coccinelle and audited and fixed manually. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Len Baker <[email protected]> Cc: Kees Cook <[email protected]> Cc: "Gustavo A. R. Silva" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/memcg: remove obsolete memcg_free_kmem()Waiman Long1-11/+3
Since commit d648bcc7fe65 ("mm: kmem: make memcg_kmem_enabled() irreversible"), the only thing memcg_free_kmem() does is to call memcg_offline_kmem() when the memcg is still online which can happen when online_css() fails due to -ENOMEM. However, the name memcg_free_kmem() is confusing and it is more clear and straight forward to call memcg_offline_kmem() directly from mem_cgroup_css_free(). Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Waiman Long <[email protected]> Suggested-by: Roman Gushchin <[email protected]> Reviewed-by: Aaron Tomlin <[email protected]> Reviewed-by: Shakeel Butt <[email protected]> Reviewed-by: Roman Gushchin <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Vladimir Davydov <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Muchun Song <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06memcg: unify memcg stat flushingShakeel Butt1-9/+10
The memcg stats can be flushed in multiple context and potentially in parallel too. For example multiple parallel user space readers for memcg stats will contend on the rstat locks with each other. There is no need for that. We just need one flusher and everyone else can benefit. In addition after aa48e47e3906 ("memcg: infrastructure to flush memcg stats") the kernel periodically flush the memcg stats from the root, so, the other flushers will potentially have much less work to do. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Shakeel Butt <[email protected]> Acked-by: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: "Michal Koutný" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06memcg: flush stats only if updatedShakeel Butt1-23/+55
At the moment, the kernel flushes the memcg stats on every refault and also on every reclaim iteration. Although rstat maintains per-cpu update tree but on the flush the kernel still has to go through all the cpu rstat update tree to check if there is anything to flush. This patch adds the tracking on the stats update side to make flush side more clever by skipping the flush if there is no update. The stats update codepath is very sensitive performance wise for many workloads and benchmarks. So, we can not follow what the commit aa48e47e3906 ("memcg: infrastructure to flush memcg stats") did which was triggering async flush through queue_work() and caused a lot performance regression reports. That got reverted by the commit 1f828223b799 ("memcg: flush lruvec stats in the refault"). In this patch we kept the stats update codepath very minimal and let the stats reader side to flush the stats only when the updates are over a specific threshold. For now the threshold is (nr_cpus * CHARGE_BATCH). To evaluate the impact of this patch, an 8 GiB tmpfs file is created on a system with swap-on-zram and the file was pushed to swap through memory.force_empty interface. On reading the whole file, the memcg stat flush in the refault code path is triggered. With this patch, we observed 63% reduction in the read time of 8 GiB file. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Shakeel Butt <[email protected]> Acked-by: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Reviewed-by: "Michal Koutný" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/memcg: drop swp_entry_t* in mc_handle_file_pte()Peter Xu1-2/+2
It is unused after the rework of commit f5df8635c5a3 ("mm: use find_get_incore_page in memcontrol"). Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Peter Xu <[email protected]> Reviewed-by: Muchun Song <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Matthew Wilcox <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: optimise put_pages_list()Matthew Wilcox (Oracle)1-7/+16
Instead of calling put_page() one page at a time, pop pages off the list if their refcount was too high and pass the remainder to put_unref_page_list(). This should be a speed improvement, but I have no measurements to support that. Current callers do not care about performance, but I hope to add some which do. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Reviewed-by: Anthony Yznaga <[email protected]> Cc: Mel Gorman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/swapfile: fix an integer overflow in swap_show()Rafael Aquini1-2/+2
This one is just a minor nuisance for people going through /proc/swaps if any of their swapareas is bigger than, or equal to 1073741824 pages (4TB). seq_printf() format string casts as uint the conversion from pages to KB, and that will overflow in the aforementioned case. Albeit being almost unthinkable that someone would actually set up such big of a single swaparea, there is a ticket recently filed against RHEL: https://bugzilla.redhat.com/show_bug.cgi?id=2008812 Given that all other codesites that use format strings for the same swap pages-to-KB conversion do cast it as ulong, this patch just follows suit. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Rafael Aquini <[email protected]> Cc: Hugh Dickins <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/swapfile: remove needless request_queue NULL pointer checkXu Wang1-1/+1
The request_queue pointer returned from bdev_get_queue() shall never be NULL, so the null check is unnecessary, just remove it. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Xu Wang <[email protected]> Acked-by: David Hildenbrand <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/gup: further simplify __gup_device_huge()John Hubbard1-4/+1
Commit 6401c4eb57f9 ("mm: gup: fix potential pgmap refcnt leak in __gup_device_huge()") simplified the return paths, but didn't go quite far enough, as discussed in [1]. Remove the "ret" variable entirely, because there is enough information already available to provide the return value. [1] https://lore.kernel.org/r/CAHk-=wgQTRX=5SkCmS+zfmpqubGHGJvXX_HgnPG8JSpHKHBMeg@mail.gmail.com Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: John Hubbard <[email protected]> Suggested-by: Linus Torvalds <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Miaohe Lin <[email protected]> Cc: Claudio Imbrenda <[email protected]> Cc: Kirill A. Shutemov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: move more expensive part of XA setup out of mapping checkJens Axboe1-18/+25
The fast path here is not needing any writeback, yet we spend time setting up the xarray lookup data upfront. Move the part that actually needs to iterate the address space mapping into a separate helper, saving ~30% of the time here. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Cc: Matthew Wilcox <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/filemap.c: remove bogus VM_BUG_ONMatthew Wilcox (Oracle)1-1/+0
It is not safe to check page->index without holding the page lock. It can be changed if the page is moved between the swap cache and the page cache for a shmem file, for example. There is a VM_BUG_ON below which checks page->index is correct after taking the page lock. Link: https://lkml.kernel.org/r/[email protected] Fixes: 5c211ba29deb ("mm: add and use find_lock_entries") Signed-off-by: Matthew Wilcox (Oracle) <[email protected]> Reported-by: <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: don't read i_size of inode unless we need itJens Axboe1-4/+3
We always go through i_size_read(), and we rarely end up needing it. Push the read to down where we need to check it, which avoids it for most cases. It looks like we can even remove this check entirely, which might be worth pursuing. But at least this takes it out of the hot path. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Acked-by: Chris Mason <[email protected]> Cc: Josef Bacik <[email protected]> Cc: Dave Chinner <[email protected]> Cc: Pavel Begunkov <[email protected]> Cc: Jan Kara <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: simplify bdi refcountingChristoph Hellwig2-8/+8
Move grabbing and releasing the bdi refcount out of the common wb_init/wb_exit helpers into code that is only used for the non-default memcg driven bdi_writeback structures. [[email protected]: add comment] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: fix typo] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Miquel Raynal <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Vignesh Raghavendra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: don't automatically unregister bdisChristoph Hellwig1-2/+1
All BDI users now unregister explicitly. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Miquel Raynal <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Vignesh Raghavendra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06fs: explicitly unregister per-superblock BDIsChristoph Hellwig2-0/+4
Add a new SB_I_ flag to mark superblocks that have an ephemeral bdi associated with them, and unregister it when the superblock is shut down. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Miquel Raynal <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Vignesh Raghavendra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mtd: call bdi_unregister explicitlyChristoph Hellwig1-0/+1
Call bdi_unregister explicitly instead of relying on the automatic unregistration. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Miquel Raynal <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Vignesh Raghavendra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: export bdi_unregisterChristoph Hellwig1-0/+1
Patch series "simplify bdi unregistation". This series simplifies the BDI code to get rid of the magic auto-unregister feature that hid a recent block layer refcounting bug. This patch (of 5): To wind down the magic auto-unregister semantics we'll need to push this into modular code. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Christoph Hellwig <[email protected]> Reviewed-by: Jan Kara <[email protected]> Cc: Miquel Raynal <[email protected]> Cc: Richard Weinberger <[email protected]> Cc: Vignesh Raghavendra <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm: stop filemap_read() from grabbing a superfluous pageDavid Howells1-0/+3
Under some circumstances, filemap_read() will allocate sufficient pages to read to the end of the file, call readahead/readpages on them and copy the data over - and then it will allocate another page at the EOF and call readpage on that and then ignore it. This is unnecessary and a waste of time and resources. filemap_read() *does* check for this, but only after it has already done the allocation and I/O. Fix this by checking before calling filemap_get_pages() also. Link: https://lkml.kernel.org/r/163472463105.3126792.7056099385135786492.stgit@warthog.procyon.org.uk Link: https://lore.kernel.org/r/160588481358.3465195.16552616179674485179.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163456863216.2614702.6384850026368833133.stgit@warthog.procyon.org.uk/ Signed-off-by: David Howells <[email protected]> Acked-by: Jeff Layton <[email protected]> Reviewed-by: Matthew Wilcox (Oracle) <[email protected]> Cc: Kent Overstreet <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06mm/page_ext.c: fix a commentYinan Zhang1-1/+1
I have noticed that the previous macro is #ifndef CONFIG_SPARSEMEM. I think the comment of #else should be CONFIG_SPARSEMEM. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Yinan Zhang <[email protected]> Acked-by: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2021-11-06percpu: add __alloc_size attributes for better bounds checkingKees Cook1-3/+3
As already done in GrapheneOS, add the __alloc_size attribute for appropriate percpu allocator interfaces, to provide additional hinting for better bounds checking, assisting CONFIG_FORTIFY_SOURCE and other compiler optimizations. Note that due to the implementation of the percpu API, this is unlikely to ever actually provide compile-time checking beyond very simple non-SMP builds. But, since they are technically allocators, mark them as such. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Kees Cook <[email protected]> Co-developed-by: Daniel Micay <[email protected]> Signed-off-by: Daniel Micay <[email protected]> Acked-by: Dennis Zhou <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Andy Whitcroft <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dwaipayan Ray <[email protected]> Cc: Joe Perches <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Lukas Bulwahn <[email protected]> Cc: Miguel Ojeda <[email protected]> Cc: Nathan Chancellor <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Vlastimil Babka <[email protected]> Cc: Alexandre Bounine <[email protected]> Cc: Gustavo A. R. Silva <[email protected]> Cc: Ira Weiny <[email protected]> Cc: Jing Xiangfeng <[email protected]> Cc: John Hubbard <[email protected]> Cc: kernel test robot <[email protected]> Cc: Matt Porter <[email protected]> Cc: Randy Dunlap <[email protected]> Cc: Souptick Joarder <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>