kernel/linux.git/arch/arm/include/asm/page.h, branch v7.1

mm: convert do_brk_flags() to use vma_flags_t

2026-04-05T20:53:40+00:00

In order to be able to do this, we need to change VM_DATA_DEFAULT_FLAGS and friends and update the architecture-specific definitions also. We then have to update some KSM logic to handle VMA flags, and introduce VMA_STACK_FLAGS to define the vma_flags_t equivalent of VM_STACK_FLAGS. We also introduce two helper functions for use during the time we are converting legacy flags to vma_flags_t values - vma_flags_to_legacy() and legacy_to_vma_flags(). This enables us to iteratively make changes to break these changes up into separate parts. We use these explicitly here to keep VM_STACK_FLAGS around for certain users which need to maintain the legacy vm_flags_t values for the time being. We are no longer able to rely on the simple VM_xxx being set to zero if the feature is not enabled, so in the case of VM_DROPPABLE we introduce VMA_DROPPABLE as the vma_flags_t equivalent, which is set to EMPTY_VMA_FLAGS if the droppable flag is not available. While we're here, we make the description of do_brk_flags() into a kdoc comment, as it almost was already. We use vma_flags_to_legacy() to not need to update the vm_get_page_prot() logic as this time. Note that in create_init_stack_vma() we have to replace the BUILD_BUG_ON() with a VM_WARN_ON_ONCE() as the tested values are no longer build time available. We also update mprotect_fixup() to use VMA flags where possible, though we have to live with a little duplication between vm_flags_t and vma_flags_t values for the time being until further conversions are made. While we're here, update VM_SPECIAL to be defined in terms of VMA_SPECIAL_FLAGS now we have vma_flags_to_legacy(). Finally, we update the VMA tests to reflect these changes. Link: https://lkml.kernel.org/r/d02e3e45d9a33d7904b149f5604904089fd640ae.1774034900.git.ljs@kernel.org Signed-off-by: Lorenzo Stoakes (Oracle) Acked-by: Paul Moore [SELinux] Acked-by: Vlastimil Babka (SUSE) Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Al Viro Cc: Anton Ivanov Cc: "Borislav Petkov (AMD)" Cc: Catalin Marinas Cc: Chengming Zhou Cc: Christian Borntraeger Cc: Christian Brauner Cc: David Hildenbrand Cc: Dinh Nguyen Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Jan Kara Cc: Jann Horn Cc: Johannes Berg Cc: Kees Cook Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Ondrej Mosnacek Cc: Palmer Dabbelt Cc: Pedro Falcato Cc: Richard Weinberger Cc: Russell King Cc: Stephen Smalley Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: xu xin Signed-off-by: Andrew Morton

vdso: Introduce vdso/page.h

2024-10-15T22:13:04+00:00

The VDSO implementation includes headers from outside of the vdso/ namespace. Introduce vdso/page.h to make sure that the generic library uses only the allowed namespace. Signed-off-by: Vincenzo Frascino Signed-off-by: Thomas Gleixner Reviewed-by: Arnd Bergmann Acked-by: Geert Uytterhoeven # m68k Link: https://lore.kernel.org/all/20241014151340.1639555-3-vincenzo.frascino@arm.com

arch: define CONFIG_PAGE_SIZE_*KB on all architectures

2024-03-06T18:29:09+00:00

Most architectures only support a single hardcoded page size. In order to ensure that each one of these sets the corresponding Kconfig symbols, change over the PAGE_SHIFT definition to the common one and allow only the hardware page size to be selected. Acked-by: Guo Ren Acked-by: Heiko Carstens Acked-by: Stafford Horne Acked-by: Johannes Berg Acked-by: Geert Uytterhoeven Reviewed-by: Thomas Gleixner Signed-off-by: Arnd Bergmann

Merge tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2023-07-06T17:06:04+00:00

Pull asm-generic updates from Arnd Bergmann: "These are cleanups for architecture specific header files: - the comments in include/linux/syscalls.h have gone out of sync and are really pointless, so these get removed - The asm/bitsperlong.h header no longer needs to be architecture specific on modern compilers, so use a generic version for newer architectures that use new enough userspace compilers - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking, forcing the use of pointers" * tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: syscalls: Remove file path comments from headers tools arch: Remove uapi bitsperlong.h of hexagon and microblaze asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch m68k/mm: Make pfn accessors static inlines arm64: memory: Make virt_to_pfn() a static inline ARM: mm: Make virt_to_pfn() a static inline asm-generic/page.h: Make pfn accessors static inlines xen/netback: Pass (void *) to virt_to_page() netfs: Pass a pointer to virt_to_page() cifs: Pass a pointer to virt_to_page() in cifsglob cifs: Pass a pointer to virt_to_page() riscv: mm: init: Pass a pointer to virt_to_page() ARC: init: Pass a pointer to virt_to_pfn() in init m68k: Pass a pointer to virt_to_pfn() virt_to_page() fs/proc/kcore.c: Pass a pointer to virt_addr_valid()

ARM: 9305/1: add clear/copy_user_highpage declarations

2023-06-19T08:35:53+00:00

The CPU specific helpers have to be global functions when building a kernel for just one CPU, but are called through indirect function pointers in a multi-CPU kernel. This config currently lacks the declarations for the individual helpers, e.g.: arch/arm/mm/copypage-v4wb.c:47:6: error: no previous prototype for 'v4wb_copy_user_highpage' [-Werror=missing-prototypes] arch/arm/mm/copypage-v4wb.c:65:6: error: no previous prototype for 'v4wb_clear_user_highpage' [-Werror=missing-prototypes] Add the complete set of prototypes in asm/page.h to allow building iwth -Wmissing-prototypes. Reviewed-by: Kees Cook Signed-off-by: Arnd Bergmann Signed-off-by: Russell King (Oracle)

ARM: mm: Make virt_to_pfn() a static inline

2023-05-29T09:27:08+00:00

Making virt_to_pfn() a static inline taking a strongly typed (const void *) makes the contract of a passing a pointer of that type to the function explicit and exposes any misuse of the macro virt_to_pfn() acting polymorphic and accepting many types such as (void *), (unitptr_t) or (unsigned long) as arguments without warnings. Doing this is a bit intrusive: virt_to_pfn() requires PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in , so this must be included *before* . The use of macros were obscuring the unclear inclusion order here, as the macros would eventually be resolved, but a static inline like this cannot be compiled with unresolved macros. The naive solution to include at the top of does not work, because sometimes includes at the end of itself, which would create a confusing inclusion loop. So instead, take the approach to always unconditionally include at the end of arch/arm uses explicitly in a lot of places, however it turns out that if we just unconditionally include into and switch all inclusions of to instead, we enforce the right order and will always have access to the definitions. Put an inclusion guard in place making it impossible to include explicitly. Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/ Signed-off-by: Linus Walleij

arm: include asm-generic/memory_model.h from page.h rather than memory.h

2023-02-10T00:51:40+00:00

Patch series "mm, arch: add generic implementation of pfn_valid() for FLATMEM", v2. Every architecture that supports FLATMEM memory model defines its own version of pfn_valid() that essentially compares a pfn to max_mapnr. Use mips/powerpc version implemented as static inline as a generic implementation of pfn_valid() and drop its per-architecture definitions This patch (of 4): Makes it consistent with other architectures and allows for generic definition of pfn_valid() in asm-generic/memory_model.h with clear override in arch/arm/include/asm/page.h Link: https://lkml.kernel.org/r/20230129124235.209895-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20230129124235.209895-2-rppt@kernel.org Signed-off-by: Mike Rapoport (IBM) Reviewed-by: David Hildenbrand Cc: Arnd Bergmann Cc: Brian Cain Cc: "David S. Miller" Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Greg Ungerer Cc: Guo Ren Cc: Helge Deller Cc: Huacai Chen Cc: Huacai Chen Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Richard Weinberger Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Vineet Gupta Cc: WANG Xuerui Cc: Yoshinori Sato Signed-off-by: Andrew Morton

ARM: mm: make vmalloc_seq handling SMP safe

2022-01-25T08:53:52+00:00

Rework the vmalloc_seq handling so it can be used safely under SMP, as we started using it to ensure that vmap'ed stacks are guaranteed to be mapped by the active mm before switching to a task, and here we need to ensure that changes to the page tables are visible to other CPUs when they observe a change in the sequence count. Since LPAE needs none of this, fold a check against it into the vmalloc_seq counter check after breaking it out into a separate static inline helper. Given that vmap'ed stacks are now also supported on !SMP configurations, let's drop the WARN() that could potentially now fire spuriously. Signed-off-by: Ard Biesheuvel

ARM: implement support for vmap'ed stacks

2021-12-03T14:11:33+00:00

Wire up the generic support for managing task stack allocations via vmalloc, and implement the entry code that detects whether we faulted because of a stack overrun (or future stack overrun caused by pushing the pt_regs array) While this adds a fair amount of tricky entry asm code, it should be noted that it only adds a TST + branch to the svc_entry path. The code implementing the non-trivial handling of the overflow stack is emitted out-of-line into the .text section. Since on ARM, we rely on do_translation_fault() to keep PMD level page table entries that cover the vmalloc region up to date, we need to ensure that we don't hit such a stale PMD entry when accessing the stack. So we do a dummy read from the new stack while still running from the old one on the context switch path, and bump the vmalloc_seq counter when PMD level entries in the vmalloc range are modified, so that the MM switch fetches the latest version of the entries. Note that we need to increase the per-mode stack by 1 word, to gain some space to stash a GPR until we know it is safe to touch the stack. However, due to the cacheline alignment of the struct, this does not actually increase the memory footprint of the struct stack array at all. Signed-off-by: Ard Biesheuvel Tested-by: Keith Packard Tested-by: Marc Zyngier Tested-by: Vladimir Murzin # ARMv7M

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

2020-04-10T22:36:21+00:00

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros with standard VMA access flag combinations that are used frequently across many platforms. Apart from simplification, this reduces code duplication as well. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Acked-by: Geert Uytterhoeven Cc: Richard Henderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Guo Ren Cc: Yoshinori Sato Cc: Brian Cain Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Ley Foon Tan Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Michael Ellerman Cc: Paul Walmsley Cc: Heiko Carstens Cc: Rich Felker Cc: "David S. Miller" Cc: Guan Xuetao Cc: Thomas Gleixner Cc: Jeff Dike Cc: Chris Zankel Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds