From 1d18ad026844b60d933c25ae38360f86a8cf41eb Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Tue, 15 Nov 2016 17:56:15 +1100 Subject: [PATCH] powerpc/mm: Detect instruction fetch denied and report ISA 3 allows for prevention of instruction fetch and execution of user mode pages. If such an error occurs, SRR1 bit 35 reports the error. We catch and report the error in do_page_fault(). Signed-off-by: Balbir Singh Signed-off-by: Michael Ellerman --- arch/powerpc/mm/fault.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 73932f4a386e..a17029aaf939 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -390,6 +390,12 @@ good_area: #endif /* CONFIG_8xx */ if (is_exec) { + /* + * An execution fault + no execute ? + */ + if (regs->msr & SRR1_ISI_N_OR_G) + goto bad_area; + /* * Allow execution from readable areas if the MMU does not * provide separate controls over reading and executing. @@ -404,6 +410,7 @@ good_area: (cpu_has_feature(CPU_FTR_NOEXECUTE) || !(vma->vm_flags & (VM_READ | VM_WRITE)))) goto bad_area; + #ifdef CONFIG_PPC_STD_MMU /* * protfault should only happen due to us -- 2.20.1