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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-08-21 09:38:31 +0100
committerJeff Vander Stoep <jeffv@google.com>2016-01-25 09:26:15 -0800
commit9a1f6e83b6a0197f0c4cdc6e289865a8ab6ed4eb (patch)
treedcab2e39506f40af9c6841ccf33af5837df04d05
parentb2cfef831e74fe04838e29c6d254b6d99a3dc614 (diff)
downloadhikey-linaro-9a1f6e83b6a0197f0c4cdc6e289865a8ab6ed4eb.tar.gz
UPSTREAM: 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> Bug: 25672827 Patchset: PAN emulation (cherry picked from commit a02d8dfd54cdf3b1b0464ccc2c1c4afe2c003a35) Signed-off-by: Kees Cook <keescook@google.com> Change-Id: I2f912a55c606a08b9e123de2819bc77f8dac955b
-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 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 7186382672b5..ddb5a7b38b56 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);