From dff8ac7b1feb81ed74cea24d78fa9f24d1325a46 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Fri, 5 Dec 2008 03:25:47 +0100 Subject: [PATCH] [ARM] 5340/1: fix stack placement after noexecstack changes Commit 93aa7c5d34e4da315fce781f857e96d639f99a7b ("[ARM] Improve non-executable support") added support for detecting non-executable stack binaries. One of the things it does is to make READ_IMPLIES_EXEC be set in ->personality if we are running on a CPU that doesn't support the XN ("Execute Never") page table bit or if we are running a binary that needs an executable stack. This exposed a latent bug in ARM's asm/processor.h due to which we'll end up placing the stack at a very low address, where it will bump into the heap on any application that uses significant amount of stack or heap or both, causing many interesting crashes. Fix this by testing the ADDR_LIMIT_32BIT bit in ->personality instead of testing for equality against PER_LINUX_32BIT. Reviewed-by: Nicolas Pitre Signed-off-by: Lennert Buytenhek Signed-off-by: Russell King --- arch/arm/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index 517a4d6ffc74b..6ff33790f47b1 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -23,7 +23,7 @@ #include #ifdef __KERNEL__ -#define STACK_TOP ((current->personality == PER_LINUX_32BIT) ? \ +#define STACK_TOP ((current->personality & ADDR_LIMIT_32BIT) ? \ TASK_SIZE : TASK_SIZE_26) #define STACK_TOP_MAX TASK_SIZE #endif -- 2.39.5