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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-08-21 08:38:31 (GMT)
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-08-21 12:55:53 (GMT)
commita02d8dfd54cdf3b1b0464ccc2c1c4afe2c003a35 (patch)
treeb760333143b1fa4e3de0b6c22c854c67a1e47c4a /arch/arm
parent3c2aed5b28819564e1a07b4686bd89802bcc4d6b (diff)
downloadlinux-a02d8dfd54cdf3b1b0464ccc2c1c4afe2c003a35.tar.xz
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 <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/domain.h4
-rw-r--r--arch/arm/include/asm/pgtable-2level-hwdef.h1
-rw-r--r--arch/arm/mm/mmu.c4
-rw-r--r--arch/arm/mm/pgd.c10
4 files changed, 16 insertions, 3 deletions
diff --git a/arch/arm/include/asm/domain.h b/arch/arm/include/asm/domain.h
index 08b601e..396a12e 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 5e68278..d0131ee 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 6ca7d9a..a016de2 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 a3681f1..e683db1 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);