From d94b827e89dc3f92cd871d10f4992a6bd3c861e5 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 27 Nov 2020 10:14:10 +0530 Subject: powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation This patch updates kernel hash page table entries to use storage key 3 for its mapping. This implies all kernel access will now use key 3 to control READ/WRITE. The patch also prevents the allocation of key 3 from userspace and UAMOR value is updated such that userspace cannot modify key 3. Signed-off-by: Aneesh Kumar K.V Reviewed-by: Sandipan Das Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201127044424.40686-9-aneesh.kumar@linux.ibm.com --- arch/powerpc/mm/book3s64/hash_utils.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'arch/powerpc/mm/book3s64/hash_utils.c') diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index d2dcb7757c68..e0fe1a43e7b8 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -186,7 +186,7 @@ static struct mmu_psize_def mmu_psize_defaults_gp[] = { * - We make sure R is always set and never lost * - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping */ -unsigned long htab_convert_pte_flags(unsigned long pteflags) +unsigned long htab_convert_pte_flags(unsigned long pteflags, unsigned long flags) { unsigned long rflags = 0; @@ -240,7 +240,7 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags) */ rflags |= HPTE_R_M; - rflags |= pte_to_hpte_pkey_bits(pteflags); + rflags |= pte_to_hpte_pkey_bits(pteflags, flags); return rflags; } @@ -255,7 +255,7 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend, shift = mmu_psize_defs[psize].shift; step = 1 << shift; - prot = htab_convert_pte_flags(prot); + prot = htab_convert_pte_flags(prot, HPTE_USE_KERNEL_KEY); DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n", vstart, vend, pstart, prot, psize, ssize); @@ -1316,12 +1316,14 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea, vsid = get_kernel_vsid(ea, mmu_kernel_ssize); psize = mmu_vmalloc_psize; ssize = mmu_kernel_ssize; + flags |= HPTE_USE_KERNEL_KEY; break; case IO_REGION_ID: vsid = get_kernel_vsid(ea, mmu_kernel_ssize); psize = mmu_io_psize; ssize = mmu_kernel_ssize; + flags |= HPTE_USE_KERNEL_KEY; break; default: /* @@ -1900,7 +1902,7 @@ static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi) unsigned long hash; unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize); - unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL)); + unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL), HPTE_USE_KERNEL_KEY); long ret; hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize); -- cgit