Commit-ID: 434a6c9f90f7ab5ade619455df01ef5ebea533ee Gitweb: http://git.kernel.org/tip/434a6c9f90f7ab5ade619455df01ef5ebea533ee Author: Kees Cook <keesc...@chromium.org> AuthorDate: Mon, 9 May 2016 13:22:04 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 10 May 2016 10:12:02 +0200
x86/KASLR: Initialize mapping_info every time As it turns out, mapping_info DOES need to be initialized every time, because pgt_data address could be changed during kernel relocation. So it can not be build time assigned. Without this, page tables were not being corrected updated, which could cause reboots when a physical address beyond 2G was chosen. Signed-off-by: Kees Cook <keesc...@chromium.org> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Andy Lutomirski <l...@kernel.org> Cc: Baoquan He <b...@redhat.com> Cc: Borislav Petkov <b...@alien8.de> Cc: Borislav Petkov <b...@suse.de> Cc: Brian Gerst <brge...@gmail.com> Cc: Dave Young <dyo...@redhat.com> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Vivek Goyal <vgo...@redhat.com> Cc: Yinghai Lu <ying...@kernel.org> Cc: kernel-harden...@lists.openwall.com Cc: lasse.col...@tukaani.org Link: http://lkml.kernel.org/r/1462825332-10505-2-git-send-email-keesc...@chromium.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/boot/compressed/pagetable.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/arch/x86/boot/compressed/pagetable.c b/arch/x86/boot/compressed/pagetable.c index 3c99051..34b95df 100644 --- a/arch/x86/boot/compressed/pagetable.c +++ b/arch/x86/boot/compressed/pagetable.c @@ -90,23 +90,17 @@ static void prepare_level4(void) } /* - * Mapping information structure passed to kernel_ident_mapping_init(). - * Since this never changes, there's no reason to repeatedly fill it - * in on the stack when calling add_identity_map(). - */ -static struct x86_mapping_info mapping_info = { - .alloc_pgt_page = alloc_pgt_page, - .context = &pgt_data, - .pmd_flag = __PAGE_KERNEL_LARGE_EXEC, -}; - -/* * Adds the specified range to what will become the new identity mappings. * Once all ranges have been added, the new mapping is activated by calling * finalize_identity_maps() below. */ void add_identity_map(unsigned long start, unsigned long size) { + struct x86_mapping_info mapping_info = { + .alloc_pgt_page = alloc_pgt_page, + .context = &pgt_data, + .pmd_flag = __PAGE_KERNEL_LARGE_EXEC, + }; unsigned long end = start + size; /* Make sure we have a top level page table ready to use. */
