[PATCH 4/5] ARM: pgtable: invert L_PTE_EXEC to L_PTE_XN
Russell King - ARM Linux
linux at arm.linux.org.uk
Wed Nov 17 12:29:35 EST 2010
The hardware page tables use an XN bit 'execute never'. Historically,
we've had a Linux 'execute allow' bit, in the positive sense. Get rid
of this artifact as future hardware will continue to have the XN sense.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
arch/arm/include/asm/pgtable.h | 44 ++++++++++++++++++++--------------------
arch/arm/mm/mmu.c | 15 ++++++-------
arch/arm/mm/proc-macros.S | 6 ++--
arch/arm/mm/proc-v7.S | 4 +-
4 files changed, 34 insertions(+), 35 deletions(-)
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 59e0ea2..a4eda5f 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -172,7 +172,7 @@ extern void __pgd_error(const char *file, int line, pgd_t);
#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
#define L_PTE_WRITE (_AT(pteval_t, 1) << 7)
#define L_PTE_USER (_AT(pteval_t, 1) << 8)
-#define L_PTE_EXEC (_AT(pteval_t, 1) << 9)
+#define L_PTE_XN (_AT(pteval_t, 1) << 9)
#define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */
/*
@@ -206,23 +206,23 @@ extern pgprot_t pgprot_kernel;
#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
-#define PAGE_NONE pgprot_user
-#define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_WRITE)
-#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_WRITE | L_PTE_EXEC)
-#define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER)
-#define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_EXEC)
-#define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER)
-#define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_EXEC)
-#define PAGE_KERNEL pgprot_kernel
-#define PAGE_KERNEL_EXEC _MOD_PROT(pgprot_kernel, L_PTE_EXEC)
-
-#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT)
-#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_WRITE)
-#define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_WRITE | L_PTE_EXEC)
-#define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
-#define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_EXEC)
-#define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
-#define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_EXEC)
+#define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN)
+#define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_WRITE | L_PTE_XN)
+#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_WRITE)
+#define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
+#define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
+#define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
+#define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
+#define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
+#define PAGE_KERNEL_EXEC pgprot_kernel
+
+#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_XN)
+#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_WRITE | L_PTE_XN)
+#define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_WRITE)
+#define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
+#define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
+#define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
+#define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
#endif /* __ASSEMBLY__ */
@@ -308,7 +308,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
#define pte_write(pte) (pte_val(pte) & L_PTE_WRITE)
#define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY)
#define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG)
-#define pte_exec(pte) (pte_val(pte) & L_PTE_EXEC)
+#define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN))
#define pte_special(pte) (0)
#define pte_present_user(pte) \
@@ -339,14 +339,14 @@ static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
__pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
#define pgprot_dmacoherent(prot) \
- __pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_BUFFERABLE)
+ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE|L_PTE_XN)
#define __HAVE_PHYS_MEM_ACCESS_PROT
struct file;
extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot);
#else
#define pgprot_dmacoherent(prot) \
- __pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_UNCACHED)
+ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED|L_PTE_XN)
#endif
#define pmd_none(pmd) (!pmd_val(pmd))
@@ -408,7 +408,7 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd)
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
- const unsigned long mask = L_PTE_EXEC | L_PTE_WRITE | L_PTE_USER;
+ const unsigned long mask = L_PTE_XN | L_PTE_WRITE | L_PTE_USER;
pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
return pte;
}
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 9963189..a7f56fc 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -190,7 +190,7 @@ void adjust_cr(unsigned long mask, unsigned long set)
}
#endif
-#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_WRITE
+#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_WRITE|L_PTE_XN
#define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
static struct mem_type mem_types[] = {
@@ -234,20 +234,19 @@ static struct mem_type mem_types[] = {
.domain = DOMAIN_KERNEL,
},
[MT_LOW_VECTORS] = {
- .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_EXEC,
+ .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
},
[MT_HIGH_VECTORS] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_USER | L_PTE_EXEC,
+ L_PTE_USER,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
},
[MT_MEMORY] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_WRITE | L_PTE_EXEC,
+ L_PTE_WRITE,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
@@ -258,21 +257,21 @@ static struct mem_type mem_types[] = {
},
[MT_MEMORY_NONCACHED] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_WRITE | L_PTE_EXEC | L_PTE_MT_BUFFERABLE,
+ L_PTE_WRITE| L_PTE_MT_BUFFERABLE,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_DTCM] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_WRITE,
+ L_PTE_WRITE | L_PTE_XN,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_ITCM] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_WRITE | L_PTE_EXEC,
+ L_PTE_WRITE,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_KERNEL,
},
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index cbedf9c..4a7a9e1 100644
--- a/arch/arm/mm/proc-macros.S
+++ b/arch/arm/mm/proc-macros.S
@@ -81,7 +81,7 @@
#if L_PTE_SHARED != PTE_EXT_SHARED
#error PTE shared bit mismatch
#endif
-#if (L_PTE_EXEC+L_PTE_USER+L_PTE_WRITE+L_PTE_DIRTY+L_PTE_YOUNG+\
+#if (L_PTE_XN+L_PTE_USER+L_PTE_WRITE+L_PTE_DIRTY+L_PTE_YOUNG+\
L_PTE_FILE+L_PTE_PRESENT) > L_PTE_SHARED
#error Invalid Linux PTE bit settings
#endif
@@ -141,8 +141,8 @@
tstne r3, #PTE_EXT_APX
bicne r3, r3, #PTE_EXT_APX | PTE_EXT_AP0
- tst r1, #L_PTE_EXEC
- orreq r3, r3, #PTE_EXT_XN
+ tst r1, #L_PTE_XN
+ orrne r3, r3, #PTE_EXT_XN
orr r3, r3, r2
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 89c31a6..4f5a594 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -149,8 +149,8 @@ ENTRY(cpu_v7_set_pte_ext)
tstne r3, #PTE_EXT_APX
bicne r3, r3, #PTE_EXT_APX | PTE_EXT_AP0
- tst r1, #L_PTE_EXEC
- orreq r3, r3, #PTE_EXT_XN
+ tst r1, #L_PTE_XN
+ orrne r3, r3, #PTE_EXT_XN
tst r1, #L_PTE_YOUNG
tstne r1, #L_PTE_PRESENT
--
1.6.2.5
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