kernel/linux.git/include/asm-generic, branch v5.15.88

mm/khugepaged: fix GUP-fast interaction by sending IPI

2022-12-14T10:37:17+00:00

commit 2ba99c5e08812494bc57f319fb562f527d9bacd8 upstream. Since commit 70cbc3cc78a99 ("mm: gup: fix the fast GUP race against THP collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to ensure that the page table was not removed by khugepaged in between. However, lockless_pages_from_mm() still requires that the page table is not concurrently freed. Fix it by sending IPIs (if the architecture uses semi-RCU-style page table freeing) before freeing/reusing page tables. Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Jann Horn Reviewed-by: Yang Shi Acked-by: David Hildenbrand Cc: John Hubbard Cc: Peter Xu Cc: Signed-off-by: Andrew Morton [manual backport: two of the three places in khugepaged that can free ptes were refactored into a common helper between 5.15 and 6.0] Signed-off-by: Jann Horn Signed-off-by: Sasha Levin

vmlinux.lds.h: Fix placement of '.data..decrypted' section

2022-11-16T08:58:26+00:00

commit 000f8870a47bdc36730357883b6aef42bced91ee upstream. Commit d4c639990036 ("vmlinux.lds.h: Avoid orphan section with !SMP") fixed an orphan section warning by adding the '.data..decrypted' section to the linker script under the PERCPU_DECRYPTED_SECTION define but that placement introduced a panic with !SMP, as the percpu sections are not instantiated with that configuration so attempting to access variables defined with DEFINE_PER_CPU_DECRYPTED() will result in a page fault. Move the '.data..decrypted' section to the DATA_MAIN define so that the variables in it are properly instantiated at boot time with CONFIG_SMP=n. Cc: stable@vger.kernel.org Fixes: d4c639990036 ("vmlinux.lds.h: Avoid orphan section with !SMP") Link: https://lore.kernel.org/cbbd3548-880c-d2ca-1b67-5bb93b291d5f@huawei.com/ Debugged-by: Ard Biesheuvel Reported-by: Zhao Wenhui Tested-by: xiafukun Signed-off-by: Nathan Chancellor Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20221108174934.3384275-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman

vmlinux.lds.h: CFI: Reduce alignment of jump-table to function alignment

2022-09-28T09:11:45+00:00

commit 13b0566962914e167cb3238fbe29ced618f07a27 upstream. Due to undocumented, hysterical raisins on x86, the CFI jump-table sections in .text are needlessly aligned to PMD_SIZE in the vmlinux linker script. When compiling a CFI-enabled arm64 kernel with a 64KiB page-size, a PMD maps 512MiB of virtual memory and so the .text section increases to a whopping 940MiB and blows the final Image up to 960MiB. Others report a link failure. Since the CFI jump-table requires only instruction alignment, reduce the alignment directives to function alignment for parity with other parts of the .text section. This reduces the size of the .text section for the aforementioned 64KiB page size arm64 kernel to 19MiB for a much more reasonable total Image size of 39MiB. Cc: Sami Tolvanen Cc: Mark Rutland Cc: "Mohan Rao .vanimina" Cc: Kees Cook Cc: Nathan Chancellor Cc: Link: https://lore.kernel.org/all/CAL_GTzigiNOMYkOPX1KDnagPhJtFNqSK=1USNbS0wUL4PW6-Uw@mail.gmail.com/ Fixes: cf68fffb66d6 ("add support for Clang CFI") Reviewed-by: Mark Rutland Tested-by: Mark Rutland Reviewed-by: Sami Tolvanen Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20220922215715.13345-1-will@kernel.org Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

asm-generic: sections: refactor memory_intersects

2022-08-31T15:16:47+00:00

commit 0c7d7cc2b4fe2e74ef8728f030f0f1674f9f6aee upstream. There are two problems with the current code of memory_intersects: First, it doesn't check whether the region (begin, end) falls inside the region (virt, vend), that is (virt < begin && vend > end). The second problem is if vend is equal to begin, it will return true but this is wrong since vend (virt + size) is not the last address of the memory region but (virt + size -1) is. The wrong determination will trigger the misreporting when the function check_for_illegal_area calls memory_intersects to check if the dma region intersects with stext region. The misreporting is as below (stext is at 0x80100000): WARNING: CPU: 0 PID: 77 at kernel/dma/debug.c:1073 check_for_illegal_area+0x130/0x168 DMA-API: chipidea-usb2 e0002000.usb: device driver maps memory from kernel text or rodata [addr=800f0000] [len=65536] Modules linked in: CPU: 1 PID: 77 Comm: usb-storage Not tainted 5.19.0-yocto-standard #5 Hardware name: Xilinx Zynq Platform unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x58/0x70 dump_stack_lvl from __warn+0xb0/0x198 __warn from warn_slowpath_fmt+0x80/0xb4 warn_slowpath_fmt from check_for_illegal_area+0x130/0x168 check_for_illegal_area from debug_dma_map_sg+0x94/0x368 debug_dma_map_sg from __dma_map_sg_attrs+0x114/0x128 __dma_map_sg_attrs from dma_map_sg_attrs+0x18/0x24 dma_map_sg_attrs from usb_hcd_map_urb_for_dma+0x250/0x3b4 usb_hcd_map_urb_for_dma from usb_hcd_submit_urb+0x194/0x214 usb_hcd_submit_urb from usb_sg_wait+0xa4/0x118 usb_sg_wait from usb_stor_bulk_transfer_sglist+0xa0/0xec usb_stor_bulk_transfer_sglist from usb_stor_bulk_srb+0x38/0x70 usb_stor_bulk_srb from usb_stor_Bulk_transport+0x150/0x360 usb_stor_Bulk_transport from usb_stor_invoke_transport+0x38/0x440 usb_stor_invoke_transport from usb_stor_control_thread+0x1e0/0x238 usb_stor_control_thread from kthread+0xf8/0x104 kthread from ret_from_fork+0x14/0x2c Refactor memory_intersects to fix the two problems above. Before the 1d7db834a027e ("dma-debug: use memory_intersects() directly"), memory_intersects is called only by printk_late_init: printk_late_init -> init_section_intersects ->memory_intersects. There were few places where memory_intersects was called. When commit 1d7db834a027e ("dma-debug: use memory_intersects() directly") was merged and CONFIG_DMA_API_DEBUG is enabled, the DMA subsystem uses it to check for an illegal area and the calltrace above is triggered. [akpm@linux-foundation.org: fix nearby comment typo] Link: https://lkml.kernel.org/r/20220819081145.948016-1-quanyang.wang@windriver.com Fixes: 979559362516 ("asm/sections: add helpers to check for section data") Signed-off-by: Quanyang Wang Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Thierry Reding Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

locking/atomic: Make test_and_*_bit() ordered on failure

2022-08-25T09:39:54+00:00

commit 415d832497098030241605c52ea83d4e2cfa7879 upstream. These operations are documented as always ordered in include/asm-generic/bitops/instrumented-atomic.h, and producer-consumer type use cases where one side needs to ensure a flag is left pending after some shared data was updated rely on this ordering, even in the failure case. This is the case with the workqueue code, which currently suffers from a reproducible ordering violation on Apple M1 platforms (which are notoriously out-of-order) that ends up causing the TTY layer to fail to deliver data to userspace properly under the right conditions. This change fixes that bug. Change the documentation to restrict the "no order on failure" story to the _lock() variant (for which it makes sense), and remove the early-exit from the generic implementation, which is what causes the missing barrier semantics in that case. Without this, the remaining atomic op is fully ordered (including on ARM64 LSE, as of recent versions of the architecture spec). Suggested-by: Linus Torvalds Cc: stable@vger.kernel.org Fixes: e986a0d6cb36 ("locking/atomics, asm-generic/bitops/atomic.h: Rewrite using atomic_*() APIs") Fixes: 61e02392d3c7 ("locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()") Signed-off-by: Hector Martin Acked-by: Will Deacon Reviewed-by: Arnd Bergmann Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

asm-generic: remove a broken and needless ifdef conditional

2022-08-03T10:03:42+00:00

commit e2a619ca0b38f2114347b7078b8a67d72d457a3d upstream. Commit 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") introduces the config symbol GENERIC_LIB_DEVMEM_IS_ALLOWED, but then falsely refers to CONFIG_GENERIC_DEVMEM_IS_ALLOWED (note the missing LIB in the reference) in ./include/asm-generic/io.h. Luckily, ./scripts/checkkconfigsymbols.py warns on non-existing configs: GENERIC_DEVMEM_IS_ALLOWED Referencing files: include/asm-generic/io.h The actual fix, though, is simply to not to make this function declaration dependent on any kernel config. For architectures that intend to use the generic version, the arch's 'select GENERIC_LIB_DEVMEM_IS_ALLOWED' will lead to picking the function definition, and for other architectures, this function is simply defined elsewhere. The wrong '#ifndef' on a non-existing config symbol also always had the same effect (although more by mistake than by intent). So, there is no functional change. Remove this broken and needless ifdef conditional. Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") Signed-off-by: Lukas Bulwahn Signed-off-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry

2022-04-20T07:34:16+00:00

[ Upstream commit 697a1d44af8ba0477ee729e632f4ade37999249a ] tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when updating the mmu_gather structure. Unfortunately on arm64 there are two additional huge page sizes that need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced due to the fact that the tlb structure hasn't been correctly updated by the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry. This patch adds inequality logic to the generic implementation of tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are effectively covered on arm64. Also, as well as ptes, pmds and puds; p4ds are now considered too. Reported-by: David Hildenbrand Suggested-by: Peter Zijlstra (Intel) Cc: Anshuman Khandual Cc: Catalin Marinas Cc: Will Deacon Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/ Signed-off-by: Steve Capper Acked-by: David Hildenbrand Reviewed-by: Anshuman Khandual Reviewed-by: Catalin Marinas Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220330112543.863-1-steve.capper@arm.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

bitops: protect find_first_{,zero}_bit properly

2022-01-27T10:05:34+00:00

commit b7ec62d7ee0f0b8af6ba190501dff7f9ee6545ca upstream. find_first_bit() and find_first_zero_bit() are not protected with ifdefs as other functions in find.h. It causes build errors on some platforms if CONFIG_GENERIC_FIND_FIRST_BIT is enabled. Signed-off-by: Yury Norov Fixes: 2cc7b6a44ac2 ("lib: add fast path for find_first_*_bit() and find_last_bit()") Reported-by: kernel test robot Tested-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

Merge tag 'asm-generic-fixes-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2021-10-08T18:57:54+00:00

Pull asm-generic fixes from Arnd Bergmann: "There is one build fix for Arm platforms that ended up impacting most architectures because of the way the drivers/firmware Kconfig file is wired up: The CONFIG_QCOM_SCM dependency have caused a number of randconfig regressions over time, and some still remain in v5.15-rc4. The fix we agreed on in the end is to make this symbol selected by any driver using it, and then building it even for non-Arm platforms with CONFIG_COMPILE_TEST. To make this work on all architectures, the drivers/firmware/Kconfig file needs to be included for all architectures to make the symbol itself visible. In a separate discussion, we found that a sound driver patch that is pending for v5.16 needs the same change to include this Kconfig file, so the easiest solution seems to have my Kconfig rework included in v5.15. Finally, the branch also includes a small unrelated build fix for NOMMU architectures" Link: https://lore.kernel.org/all/20210928153508.101208f8@canb.auug.org.au/ Link: https://lore.kernel.org/all/20210928075216.4193128-1-arnd@kernel.org/ Link: https://lore.kernel.org/all/20211007151010.333516-1-arnd@kernel.org/ * tag 'asm-generic-fixes-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic/io.h: give stub iounmap() on !MMU same prototype as elsewhere qcom_scm: hide Kconfig symbol firmware: include drivers/firmware/Kconfig unconditionally

asm-generic/io.h: give stub iounmap() on !MMU same prototype as elsewhere

2021-10-08T13:39:33+00:00

It made -Werror sad. Signed-off-by: Adam Borowski Signed-off-by: Arnd Bergmann