From 23c8ef5a2f592acf1afc3ce84373301fead3f761 Mon Sep 17 00:00:00 2001 From: "glider@google.com" Date: Thu, 12 Mar 2020 16:59:20 +0100 Subject: [PATCH] FROMLIST: arm64: define __alloc_zeroed_user_highpage 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 Signed-off-by: Catalin Marinas Bug: 149975351 Link: https://lore.kernel.org/linux-arm-kernel/20200312155920.50067-1-glider@google.com/ Change-Id: I3ff7c3fb082b420491313e0fdd841ce340989d72 Signed-off-by: Alexander Potapenko --- arch/arm64/include/asm/page.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index 60d02c81a3a2..6b9c3025c817 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -32,6 +32,10 @@ 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)