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| author | Will Deacon <will.deacon@arm.com> | 2013-02-08 12:52:29 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-02-08 12:21:07 +0000 |
| commit | 79d1f5c9acf9fc8d06e5537083b19114ce87159f (patch) | |
| tree | f19d70755c5b4ce98e097d43830c969e267f91aa | |
| parent | 633dc92a28fc3fea6f08ef34de0b353ff5f9bf08 (diff) | |
| download | linux-79d1f5c9acf9fc8d06e5537083b19114ce87159f.tar.gz linux-79d1f5c9acf9fc8d06e5537083b19114ce87159f.tar.bz2 linux-79d1f5c9acf9fc8d06e5537083b19114ce87159f.zip | |
ARM: 7641/1: memory: fix broken mmap by ensuring TASK_UNMAPPED_BASE is aligned
We have received multiple reports of mmap failures when running with a
2:2 vm split. These manifest as either -EINVAL with a non page-aligned
address (ending 0xaaa) or a SEGV, depending on the application. The
issue is commonly observed in children of make, which appears to use
bottom-up mmap (assumedly because it changes the stack rlimit).
Further investigation reveals that this regression was triggered 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 addressed.
This patch fixes the problem by defining TASK_UNMAPPED_BASE in terms of
TASK_SIZE and explicitly aligns the result to 16M, matching the other
end of the heap.
Acked-by: Nicolas Pitre <nico@linaro.org>
Reported-by: Steve Capper <steve.capper@arm.com>
Reported-by: Jean-Francois Moine <moinejf@free.fr>
Reported-by: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/include/asm/memory.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 73cf03aa981e..1c4df27f9332 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(0x01000000)) -#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. |