From 19accfd373847ac3d10623c5d20f948846299741 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 4 Jul 2013 11:40:32 +0100 Subject: ARM: move vector stubs Move the machine vector stubs into the page above the vector page, which we can prevent from being visible to userspace. Also move the reset stub, and place the swi vector at a location that the 'ldr' can get to it. This hides pointers into the kernel which could give valuable information to attackers, and reduces the number of exploitable instructions at a fixed address. Cc: Acked-by: Nicolas Pitre Signed-off-by: Russell King --- arch/arm/kernel/traps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/kernel/traps.c') diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 9433e8a12b5e..2c8c7fa78b8c 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -837,7 +837,7 @@ void __init early_trap_init(void *vectors_base) * are visible to the instruction stream. */ memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start); - memcpy((void *)vectors + 0x200, __stubs_start, __stubs_end - __stubs_start); + memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start); memcpy((void *)vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz); /* @@ -852,7 +852,7 @@ void __init early_trap_init(void *vectors_base) memcpy((void *)(vectors + KERN_SIGRETURN_CODE - CONFIG_VECTORS_BASE), sigreturn_codes, sizeof(sigreturn_codes)); - flush_icache_range(vectors, vectors + PAGE_SIZE); + flush_icache_range(vectors, vectors + PAGE_SIZE * 2); modify_domain(DOMAIN_USER, DOMAIN_CLIENT); #else /* ifndef CONFIG_CPU_V7M */ /* -- cgit v1.2.3