ARM: 9016/2: Initialize the mapping of KASan shadow memory
mainline inclusion from mainline-5.11-rc1 commit 5615f69b category: feature feature: ARM KASAN support bugzilla: 46872 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5615f69bc2097452ecc954f5264d784e158d6801 ------------------------------------------------- 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 <liuwenliang@huawei.com> - 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 <f.fainelli@gmail.com> Linus Walleij <linus.walleij@linaro.org>: - 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 <ardb@kernel.org>: - Necessary underlying fixes. - Crucial bug fixes to the memory set-up code. Co-developed-by: NAndrey Ryabinin <aryabinin@virtuozzo.com> Co-developed-by: NAbbott Liu <liuwenliang@huawei.com> Co-developed-by: NArd Biesheuvel <ardb@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: kasan-dev@googlegroups.com Cc: Mike Rapoport <rppt@linux.ibm.com> Acked-by: NMike Rapoport <rppt@linux.ibm.com> Reviewed-by: NArd Biesheuvel <ardb@kernel.org> Tested-by: Ard Biesheuvel <ardb@kernel.org> # QEMU/KVM/mach-virt/LPAE/8G Tested-by: Florian Fainelli <f.fainelli@gmail.com> # Brahma SoCs Tested-by: Ahmad Fatoum <a.fatoum@pengutronix.de> # i.MX6Q Reported-by: NRussell King - ARM Linux <rmk+kernel@armlinux.org.uk> Reported-by: NFlorian Fainelli <f.fainelli@gmail.com> Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: NAbbott Liu <liuwenliang@huawei.com> Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com> Signed-off-by: NArd Biesheuvel <ardb@kernel.org> Signed-off-by: NLinus Walleij <linus.walleij@linaro.org> Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk> (cherry picked from commit 5615f69b) Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com> Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
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arch/arm/include/asm/kasan.h
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arch/arm/mm/kasan_init.c
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