From d71f290b4e98a39f49f2595a13be3b4d5ce8e1f1 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 13 May 2014 23:58:24 +0100 Subject: metag: Reduce maximum stack size to 256MB Specify the maximum stack size for arches where the stack grows upward (parisc and metag) in asm/processor.h rather than hard coding in fs/exec.c so that metag can specify a smaller value of 256MB rather than 1GB. This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased beyond a safe value by root. E.g. when starting a process after running "ulimit -H -s unlimited" it will then attempt to use a stack size of the maximum 1GB which is far too big for metag's limited user virtual address space (stack_top is usually 0x3ffff000): BUG: failure at fs/exec.c:589/shift_arg_pages()! Signed-off-by: James Hogan Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: linux-parisc@vger.kernel.org Cc: linux-metag@vger.kernel.org Cc: John David Anglin Cc: stable@vger.kernel.org # only needed for >= v3.9 (arch/metag) --- arch/metag/include/asm/processor.h | 2 ++ arch/parisc/include/asm/processor.h | 2 ++ 2 files changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/metag/include/asm/processor.h b/arch/metag/include/asm/processor.h index f16477d1f571..3be8581af495 100644 --- a/arch/metag/include/asm/processor.h +++ b/arch/metag/include/asm/processor.h @@ -22,6 +22,8 @@ /* Add an extra page of padding at the top of the stack for the guard page. */ #define STACK_TOP (TASK_SIZE - PAGE_SIZE) #define STACK_TOP_MAX STACK_TOP +/* Maximum virtual space for stack */ +#define STACK_SIZE_MAX (1 << 28) /* 256 MB */ /* This decides where the kernel will search for a free chunk of vm * space during mmap's. diff --git a/arch/parisc/include/asm/processor.h b/arch/parisc/include/asm/processor.h index 198a86feb574..86522ef09d52 100644 --- a/arch/parisc/include/asm/processor.h +++ b/arch/parisc/include/asm/processor.h @@ -55,6 +55,8 @@ #define STACK_TOP TASK_SIZE #define STACK_TOP_MAX DEFAULT_TASK_SIZE +#define STACK_SIZE_MAX (1 << 30) /* 1 GB */ + #endif #ifndef __ASSEMBLY__ -- cgit v1.2.3