kernel/linux.git/arch/arm/mm/pgd.c, branch linux-7.0.y

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

asm-generic: pgalloc: provide generic __pgd_{alloc,free}

2025-01-26T04:22:24+00:00

We already have a generic implementation of alloc/free up to P4D level, as well as pgd_free(). Let's finish the work and add a generic PGD-level alloc helper as well. Unlike at lower levels, almost all architectures need some specific magic at PGD level (typically initialising PGD entries), so introducing a generic pgd_alloc() isn't worth it. Instead we introduce two new helpers, __pgd_alloc() and __pgd_free(), and make use of them in the arch-specific pgd_alloc() and pgd_free() wherever possible. To accommodate as many arch as possible, __pgd_alloc() takes a page allocation order. Because pagetable_alloc() allocates zeroed pages, explicit zeroing in pgd_alloc() becomes redundant and we can get rid of it. Some trivial implementations of pgd_free() also become unnecessary once __pgd_alloc() is used; remove them. Another small improvement is consistent accounting of PGD pages by using GFP_PGTABLE_{USER,KERNEL} as appropriate. Not all PGD allocations can be handled by the generic helpers. In particular, multiple architectures allocate PGDs from a kmem_cache, and those PGDs may not be page-sized. Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Acked-by: Dave Hansen Acked-by: Qi Zheng Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Ingo Molnar Cc: Linus Walleij Cc: Matthew Wilcox (Oracle) Cc: Mike Rapoport (Microsoft) Cc: Peter Zijlstra Cc: Ryan Roberts Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton

ARM: mm: rename PGD helpers

2025-01-26T04:22:24+00:00

Generic implementations of __pgd_alloc and __pgd_free are about to be introduced. Rename the macros in arch/arm/mm/pgd.c to avoid clashes. While we're at it, also pass down the mm as argument to those helpers, as it will be needed to call the generic __pgd_{alloc,free}. Link: https://lkml.kernel.org/r/20250103184415.2744423-5-kevin.brodsky@arm.com Signed-off-by: Kevin Brodsky Acked-by: Dave Hansen Acked-by: Qi Zheng Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Ingo Molnar Cc: Linus Walleij Cc: Matthew Wilcox (Oracle) Cc: Mike Rapoport (Microsoft) Cc: Peter Zijlstra Cc: Ryan Roberts Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton

ARM: 9016/2: Initialize the mapping of KASan shadow memory

2020-10-27T12:11:10+00:00

This patch initializes KASan shadow region's page table and memory. There are two stage for KASan initializing: 1. At early boot stage the whole shadow region is mapped to just one physical page (kasan_zero_page). It is finished by the function kasan_early_init which is called by __mmap_switched(arch/arm/kernel/ head-common.S) 2. After the calling of paging_init, we use kasan_zero_page as zero shadow for some memory that KASan does not need to track, and we allocate a new shadow space for the other memory that KASan need to track. These issues are finished by the function kasan_init which is call by setup_arch. When using KASan we also need to increase the THREAD_SIZE_ORDER from 1 to 2 as the extra calls for shadow memory uses quite a bit of stack. As we need to make a temporary copy of the PGD when setting up shadow memory we create a helpful PGD_SIZE definition for both LPAE and non-LPAE setups. The KASan core code unconditionally calls pud_populate() so this needs to be changed from BUG() to do {} while (0) when building with KASan enabled. After the initial development by Andre Ryabinin several modifications have been made to this code: Abbott Liu - Add support ARM LPAE: If LPAE is enabled, KASan shadow region's mapping table need be copied in the pgd_alloc() function. - Change kasan_pte_populate,kasan_pmd_populate,kasan_pud_populate, kasan_pgd_populate from .meminit.text section to .init.text section. Reported by Florian Fainelli Linus Walleij : - Drop the custom mainpulation of TTBR0 and just use cpu_switch_mm() to switch the pgd table. - Adopt to handle 4th level page tabel folding. - Rewrite the entire page directory and page entry initialization sequence to be recursive based on ARM64:s kasan_init.c. Ard Biesheuvel : - Necessary underlying fixes. - Crucial bug fixes to the memory set-up code. Co-developed-by: Andrey Ryabinin Co-developed-by: Abbott Liu Co-developed-by: Ard Biesheuvel Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport Acked-by: Mike Rapoport Reviewed-by: Ard Biesheuvel Tested-by: Ard Biesheuvel # QEMU/KVM/mach-virt/LPAE/8G Tested-by: Florian Fainelli # Brahma SoCs Tested-by: Ahmad Fatoum # i.MX6Q Reported-by: Russell King - ARM Linux Reported-by: Florian Fainelli Signed-off-by: Andrey Ryabinin Signed-off-by: Abbott Liu Signed-off-by: Florian Fainelli Signed-off-by: Ard Biesheuvel Signed-off-by: Linus Walleij Signed-off-by: Russell King

arm: add support for folded p4d page tables

2020-06-05T02:06:21+00:00

Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate, and remove __ARCH_USE_5LEVEL_HACK. [rppt@linux.ibm.com: fix kexec] Link: http://lkml.kernel.org/r/20200508174232.GA759899@linux.ibm.com Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Tested-by: Marek Szyprowski Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Fenghua Yu Cc: Geert Uytterhoeven Cc: Guan Xuetao Cc: James Morse Cc: Jonas Bonn Cc: Julien Thierry Cc: Ley Foon Tan Cc: Marc Zyngier Cc: Michael Ellerman Cc: Paul Mackerras Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Stefan Kristiansson Cc: Suzuki K Poulose Cc: Tony Luck Cc: Will Deacon Cc: Yoshinori Sato Link: http://lkml.kernel.org/r/20200414153455.21744-3-rppt@kernel.org Signed-off-by: Linus Torvalds

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Enrico Weigelt Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman

treewide: kmalloc() -> kmalloc_array()

2018-06-12T23:19:22+00:00

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook

mm: introduce wrappers to access mm->nr_ptes

2017-11-16T02:21:04+00:00

Let's add wrappers for ->nr_ptes with the same interface as for nr_pmd and nr_pud. The patch also makes nr_ptes accounting dependent onto CONFIG_MMU. Page table accounting doesn't make sense if you don't have page tables. It's preparation for consolidation of page-table counters in mm_struct. Link: http://lkml.kernel.org/r/20171006100651.44742-1-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arm: get rid of superfluous __GFP_REPEAT

2016-07-26T23:19:19+00:00

__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. PGALLOC_GFP uses __GFP_REPEAT but none of the allocation which uses this flag is for more than order-2. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-5-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: cleanup pte_alloc interfaces

2016-03-17T22:09:34+00:00

There are few things about *pte_alloc*() helpers worth cleaning up: - 'vma' argument is unused, let's drop it; - most __pte_alloc() callers do speculative check for pmd_none(), before taking ptl: let's introduce pte_alloc() macro which does the check. The only direct user of __pte_alloc left is userfaultfd, which has different expectation about atomicity wrt pmd. - pte_alloc_map() and pte_alloc_map_lock() are redefined using pte_alloc(). [sudeep.holla@arm.com: fix build for arm64 hugetlbpage] [sfr@canb.auug.org.au: fix arch/arm/mm/mmu.c some more] Signed-off-by: Kirill A. Shutemov Cc: Dave Hansen Signed-off-by: Sudeep Holla Acked-by: Kirill A. Shutemov Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds