From b18db0b80867931f4e3a844400a3c22a4fd2ff57 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Tue, 29 Apr 2014 12:17:26 +0200 Subject: KVM guest: Make pv trampoline code executable Our PV guest patching code assembles chunks of instructions on the fly when it encounters more complicated instructions to hijack. These instructions need to live in a section that we don't mark as non-executable, as otherwise we fault when jumping there. Right now we put it into the .bss section where it automatically gets marked as non-executable. Add a check to the NX setting function to ensure that we leave these particular pages executable. Signed-off-by: Alexander Graf --- arch/powerpc/include/asm/sections.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h index d0e784e0ff4..52179033067 100644 --- a/arch/powerpc/include/asm/sections.h +++ b/arch/powerpc/include/asm/sections.h @@ -39,6 +39,17 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end) (unsigned long)_stext < end; } +static inline int overlaps_kvm_tmp(unsigned long start, unsigned long end) +{ +#ifdef CONFIG_KVM_GUEST + extern char kvm_tmp[]; + return start < (unsigned long)kvm_tmp && + (unsigned long)&kvm_tmp[1024 * 1024] < end; +#else + return 0; +#endif +} + #undef dereference_function_descriptor static inline void *dereference_function_descriptor(void *ptr) { -- cgit v1.2.3-70-g09d2