From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Wed, 30 Jan 2013 14:08:32 +0000 Subject: [PATCH 2/2] ARM: memory: define TASK_UNMAPPED_BASE in terms of TASK_SIZE In-Reply-To: <1359554912-26872-1-git-send-email-will.deacon@arm.com> References: <1359554912-26872-1-git-send-email-will.deacon@arm.com> Message-ID: <1359554912-26872-2-git-send-email-will.deacon@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org TASK_UNMAPPED_BASE is defined directly in terms of PAGE_OFFSET, which is confusing given that the modules area sits between here and TASK_SIZE and is not available for user allocations. This patch defines TASK_UNMAPPED_BASE in terms of TASK_SIZE instead and fixes a bug introduced by 394ef6403abc ("mm: use vm_unmapped_area() on arm architecture") whereby TASK_UNMAPPED_BASE is no longer page-aligned for bottom-up mmap, causing get_unmapped_area to choke on misaligned addresses. Reported-by: Christoffer Dall Signed-off-by: Will Deacon --- arch/arm/include/asm/memory.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index a0fd518..255a01b 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -37,7 +37,7 @@ */ #define PAGE_OFFSET UL(CONFIG_PAGE_OFFSET) #define TASK_SIZE (UL(CONFIG_PAGE_OFFSET) - UL(SZ_16M)) -#define TASK_UNMAPPED_BASE (UL(CONFIG_PAGE_OFFSET) / 3) +#define TASK_UNMAPPED_BASE ((TASK_SIZE / 3) & ~UL(SZ_16M - 1)) /* * The maximum size of a 26-bit user space task. -- 1.8.0