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arm64: define __alloc_zeroed_user_highpage

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When running the kernel with init_on_alloc=1, calling the default
implementation of __alloc_zeroed_user_highpage() from include/linux/highmem.h
leads to double-initialization of the allocated page (first by the page
allocator, then by clear_user_page().
Calling alloc_page_vma() with __GFP_ZERO, similarly to e.g. x86, seems
to be enough to ensure the user page is zeroed only once.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
glider@google.com 2020-03-12 16:59:20 +01:00 committed by Catalin Marinas
parent d22b115cbf
commit c17a290f7e
1 changed files with 4 additions and 0 deletions
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arch/arm64/include/asm/page.h
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@ -21,6 +21,10 @@ extern void __cpu_copy_user_page(void *to, const void *from,
extern void copy_page(void *to, const void *from);
extern void clear_page(void *to);
#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \
alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr)
#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
#define clear_user_page(addr,vaddr,pg) __cpu_clear_user_page(addr, vaddr)
#define copy_user_page(to,from,vaddr,pg) __cpu_copy_user_page(to, from, vaddr)