From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 2/2] ARM: memory: define TASK_UNMAPPED_BASE in terms of TASK_SIZE
Date: Thu, 31 Jan 2013 15:09:09 +0000 [thread overview]
Message-ID: <1359644949-18550-2-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1359644949-18550-1-git-send-email-will.deacon@arm.com>
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 <cdall@cs.columbia.edu>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
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 924320f..64c770d 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 ALIGN(TASK_SIZE / 3, SZ_16M)
/*
* The maximum size of a 26-bit user space task.
--
1.8.0
next prev parent reply other threads:[~2013-01-31 15:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-31 15:09 [PATCH v2 1/2] ARM: memory: use SZ_ constants for defining the virtual memory layout Will Deacon
2013-01-31 15:09 ` Will Deacon [this message]
2013-01-31 15:58 ` [PATCH v2 2/2] ARM: memory: define TASK_UNMAPPED_BASE in terms of TASK_SIZE Nicolas Pitre
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