[PATCH] arm64/mm: remove unnecessary boundary check

From	<miles.chen@mediatek.com>
Newsgroups	linux.kernel
Subject	[PATCH] arm64/mm: remove unnecessary boundary check
Date	2016-02-25 04:50 +0100
Message-ID	<r5V69-6mZ-1@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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From: Miles Chen <miles.chen@mediatek.com>

Remove the unnecessary boundary check since there is a huge
gap between user and kernel address that they would never overlap.
(arm64 does not have enough levels of page tables to cover 64-bit
virtual address)

See Documentation/arm64/memory.txt

Signed-off-by: Miles Chen <miles.chen@mediatek.com>
---
 arch/arm64/mm/init.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f3b061e..4579604 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -343,8 +343,6 @@ void __init mem_init(void)
 #ifdef CONFIG_COMPAT
 	BUILD_BUG_ON(TASK_SIZE_32			> TASK_SIZE_64);
 #endif
-	BUILD_BUG_ON(TASK_SIZE_64			> MODULES_VADDR);
-	BUG_ON(TASK_SIZE_64				> MODULES_VADDR);
 
 	if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 		extern int sysctl_overcommit_memory;
-- 
1.9.1

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[PATCH] arm64/mm: remove unnecessary boundary check <miles.chen@mediatek.com> - 2016-02-25 04:50 +0100
  Re: [PATCH] arm64/mm: remove unnecessary boundary check Will Deacon <will.deacon@arm.com> - 2016-02-26 10:50 +0100
  Re: [PATCH] arm64/mm: remove unnecessary boundary check Catalin Marinas <catalin.marinas@arm.com> - 2016-02-26 14:50 +0100

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