From: Joerg Roedel <jroedel@xxxxxxx> Mapping the kernel text area to user-space makes only sense if it has the same permissions as in the kernel page-table. If permissions are different this will cause a TLB reload when using the kernel page-table, which is as good as not mapping it at all. On 64-bit kernels this patch makes no difference, as the whole range cloned by pti_clone_kernel_text() is mapped RO anyway. On 32 bit there are writeable mappings in the range, so just keep the permissions as they are. Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> --- arch/x86/mm/pti.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 4f6e933..fc77054 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -482,7 +482,7 @@ void pti_clone_kernel_text(void) * pti_set_kernel_image_nonglobal() did to clear the * global bit. */ - pti_clone_pmds(start, end, _PAGE_RW); + pti_clone_pmds(start, end, 0); } /* -- 2.7.4
