[PATCH] arm64/mm: fix virtual address boundary check
From: miles.chen at mediatek.com <hidden>
Date: 2016-02-24 16:02:35
Also in:
linux-mediatek, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
From: Miles Chen <redacted> The MODULES_VADDR is not the lowest possible kernel virtual address. TASK_SIZE_64 may be larger than MODULES_VADDR, FIXADDR_TOP, and PCI_IO_START. Fix this by comparing TASK_SIZE_64 (highest user virtual address) with VA_START (lowest kernel virtual address). #define VA_BITS (CONFIG_ARM64_VA_BITS) #define VA_START (UL(0xffffffffffffffff) << VA_BITS) #define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1)) #define MODULES_END (PAGE_OFFSET) #define MODULES_VADDR (MODULES_END - SZ_64M) #define PCI_IO_END (MODULES_VADDR - SZ_2M) #define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE) #define FIXADDR_TOP (PCI_IO_START - SZ_2M) #define TASK_SIZE_64 (UL(1) << VA_BITS) Signed-off-by: Miles Chen <redacted> --- arch/arm64/mm/init.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f3b061e..7d75697 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c@@ -343,8 +343,8 @@ 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); + BUILD_BUG_ON(TASK_SIZE_64 > VA_START); + BUG_ON(TASK_SIZE_64 > VA_START); if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { extern int sysctl_overcommit_memory;
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1.9.1