From 7f6d498ed3354740cfd100e4aa99e388f1a95be7 Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Thu, 29 Jun 2017 03:04:10 +1000 Subject: [PATCH] powerpc/mm/radix: Fix execute permissions for interrupt_vectors Commit 9abcc981de97 ("powerpc/mm/radix: Only add X for pages overlapping kernel text") changed the linear mapping on Radix to only mark the kernel text executable. However if the kernel is run relocated, for example as a kdump kernel, then the exception vectors are split from the kernel text, ie. they remain at real address 0. We tend to get away with it, because the kernel itself will usually be below 1G, which means the 1G page at 0-1G is marked executable and everything works OK. However if the kernel is loaded above 1G, or the system has less than 1G in total (meaning we can't use a 1G page), then the exception vectors will not be marked executable and the kernel will fail to boot. Fix it by also checking if the address range overlaps the exception vectors when deciding if we should add PAGE_KERNEL_X. Fixes: 9abcc981de97 ("powerpc/mm/radix: Only add X for pages overlapping kernel text") Cc: stable@vger.kernel.org # v4.7+ Signed-off-by: Balbir Singh [mpe: Combine with the existing check, rewrite change log] Signed-off-by: Michael Ellerman --- arch/powerpc/mm/pgtable-radix.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c index f6af90371b1e..1342859552b1 100644 --- a/arch/powerpc/mm/pgtable-radix.c +++ b/arch/powerpc/mm/pgtable-radix.c @@ -150,7 +150,8 @@ static int __meminit create_physical_mapping(unsigned long start, vaddr = (unsigned long)__va(addr); - if (overlaps_kernel_text(vaddr, vaddr + mapping_size)) + if (overlaps_kernel_text(vaddr, vaddr + mapping_size) || + overlaps_interrupt_vector_text(vaddr, vaddr + mapping_size)) prot = PAGE_KERNEL_X; else prot = PAGE_KERNEL; -- 2.20.1