diff options
author | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
---|---|---|
committer | Max Krummenacher <max.krummenacher@toradex.com> | 2018-03-13 11:32:58 +0100 |
commit | 6fb9f3c8a4992f67dcb3ce413df2e22e96b2d400 (patch) | |
tree | 6e3071b2f179a62b027669ac2a238383293bf941 /arch/x86/kernel/tboot.c | |
parent | a126a5e5dc2fcc5cb36af14c89b440cc8e3bab30 (diff) | |
parent | 8b5ab55d254f36e89b1b53aeac7223d2d102483e (diff) |
Merge tag 'v4.4.121' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b2.97-20180331
This is the 4.4.121 stable release
Diffstat (limited to 'arch/x86/kernel/tboot.c')
-rw-r--r-- | arch/x86/kernel/tboot.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c index 91a4496db434..c77ab1f51fbe 100644 --- a/arch/x86/kernel/tboot.c +++ b/arch/x86/kernel/tboot.c @@ -140,6 +140,16 @@ static int map_tboot_page(unsigned long vaddr, unsigned long pfn, return -1; set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); pte_unmap(pte); + + /* + * PTI poisons low addresses in the kernel page tables in the + * name of making them unusable for userspace. To execute + * code at such a low address, the poison must be cleared. + * + * Note: 'pgd' actually gets set in pud_alloc(). + */ + pgd->pgd &= ~_PAGE_NX; + return 0; } |