[PATCH v2 05/10] ARM: domains: keep vectors in separate domain
From: Russell King <hidden>
Date: 2015-08-25 15:41:42
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
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 <redacted> --- arch/arm/include/asm/domain.h | 4 +++- arch/arm/include/asm/pgtable-2level-hwdef.h | 1 + arch/arm/mm/mmu.c | 4 ++-- arch/arm/mm/pgd.c | 10 ++++++++++ 4 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h
index 08b601e69ddc..396a12e486fe 100644
--- a/arch/arm/include/asm/domain.h
+++ b/arch/arm/include/asm/domain.h@@ -43,6 +43,7 @@ #define DOMAIN_USER 1 #define DOMAIN_IO 0 #endif +#define DOMAIN_VECTORS 3 /* * Domain types
@@ -62,7 +63,8 @@ (domain_val(DOMAIN_USER, DOMAIN_CLIENT) | \ domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) | \ domain_val(DOMAIN_TABLE, DOMAIN_MANAGER) | \ - domain_val(DOMAIN_IO, DOMAIN_CLIENT)) + domain_val(DOMAIN_IO, DOMAIN_CLIENT) | \ + domain_val(DOMAIN_VECTORS, DOMAIN_CLIENT)) #ifndef __ASSEMBLY__
diff --git a/arch/arm/include/asm/pgtable-2level-hwdef.h b/arch/arm/include/asm/pgtable-2level-hwdef.h
index 5e68278e953e..d0131ee6f6af 100644
--- a/arch/arm/include/asm/pgtable-2level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-2level-hwdef.h@@ -23,6 +23,7 @@ #define PMD_PXNTABLE (_AT(pmdval_t, 1) << 2) /* v7 */ #define PMD_BIT4 (_AT(pmdval_t, 1) << 4) #define PMD_DOMAIN(x) (_AT(pmdval_t, (x)) << 5) +#define PMD_DOMAIN_MASK PMD_DOMAIN(0x0f) #define PMD_PROTECTION (_AT(pmdval_t, 1) << 9) /* v5 */ /* * - section
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);
--
2.1.0