[PATCH] avr32: fix integer overflow in ELF_ET_DYN_BASE

From: Andrey Ryabinin
Date: Tue Mar 24 2015 - 11:31:58 EST


Almost all arches define ELF_ET_DYN_BASE as 2/3 of TASK_SIZE.
Though it seems that some architectures do this in a wrong way.
The problem is that 2*TASK_SIZE may overflow 32-bits so
the real ELF_ET_DYN_BASE becomes wrong.
Fix this overflow by dividing TASK_SIZE prior to multiplying:
(TASK_SIZE / 3 * 2)

Signed-off-by: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
---
arch/avr32/include/asm/elf.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/avr32/include/asm/elf.h b/arch/avr32/include/asm/elf.h
index d232888..0388ece 100644
--- a/arch/avr32/include/asm/elf.h
+++ b/arch/avr32/include/asm/elf.h
@@ -84,7 +84,7 @@ typedef struct user_fpu_struct elf_fpregset_t;
the loader. We need to make sure that it is out of the way of the program
that it will "exec", and that there is sufficient room for the brk. */

-#define ELF_ET_DYN_BASE (2 * TASK_SIZE / 3)
+#define ELF_ET_DYN_BASE (TASK_SIZE / 3 * 2)


/* This yields a mask that user programs can use to figure out what
--
2.3.3

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