From a02d8dfd54cdf3b1b0464ccc2c1c4afe2c003a35 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 21 Aug 2015 09:38:31 +0100 Subject: ARM: domains: keep vectors in separate domain Keep the machine vectors in its own domain to avoid software based user access control from making the vector code inaccessible, and thereby deadlocking the machine. Signed-off-by: Russell King --- arch/arm/mm/mmu.c | 4 ++-- arch/arm/mm/pgd.c | 10 ++++++++++ 2 files changed, 12 insertions(+), 2 deletions(-) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 6ca7d9aa896f..a016de248034 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -291,13 +291,13 @@ static struct mem_type mem_types[] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_RDONLY, .prot_l1 = PMD_TYPE_TABLE, - .domain = DOMAIN_USER, + .domain = DOMAIN_VECTORS, }, [MT_HIGH_VECTORS] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY | L_PTE_USER | L_PTE_RDONLY, .prot_l1 = PMD_TYPE_TABLE, - .domain = DOMAIN_USER, + .domain = DOMAIN_VECTORS, }, [MT_MEMORY_RWX] = { .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY, diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c index a3681f11dd9f..e683db1b90a3 100644 --- a/arch/arm/mm/pgd.c +++ b/arch/arm/mm/pgd.c @@ -84,6 +84,16 @@ pgd_t *pgd_alloc(struct mm_struct *mm) if (!new_pte) goto no_pte; +#ifndef CONFIG_ARM_LPAE + /* + * Modify the PTE pointer to have the correct domain. This + * needs to be the vectors domain to avoid the low vectors + * being unmapped. + */ + pmd_val(*new_pmd) &= ~PMD_DOMAIN_MASK; + pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS); +#endif + init_pud = pud_offset(init_pgd, 0); init_pmd = pmd_offset(init_pud, 0); init_pte = pte_offset_map(init_pmd, 0); -- cgit v1.2.3-59-g8ed1b