[PATCH 5/5] ARM: pgtable: provide RDONLY page table bit rather than WRITE bit
Russell King - ARM Linux
linux at arm.linux.org.uk
Wed Nov 17 12:29:55 EST 2010
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
arch/arm/include/asm/pgtable.h | 38 +++++++++++++++++++-------------------
arch/arm/mm/mmu.c | 19 +++++++++----------
arch/arm/mm/proc-macros.S | 16 ++++++++--------
arch/arm/mm/proc-v7.S | 6 +++---
arch/arm/mm/proc-xscale.S | 4 ++--
5 files changed, 41 insertions(+), 42 deletions(-)
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index a4eda5f..77b6634 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -170,7 +170,7 @@ extern void __pgd_error(const char *file, int line, pgd_t);
#define L_PTE_YOUNG (_AT(pteval_t, 1) << 1)
#define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */
#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
-#define L_PTE_WRITE (_AT(pteval_t, 1) << 7)
+#define L_PTE_RDONLY (_AT(pteval_t, 1) << 7)
#define L_PTE_USER (_AT(pteval_t, 1) << 8)
#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 _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_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY)
+#define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
+#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
+#define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
+#define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
#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)
+#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
+#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
+#define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
+#define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
+#define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
#endif /* __ASSEMBLY__ */
@@ -305,7 +305,7 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
* Undefined behaviour if not..
*/
#define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT)
-#define pte_write(pte) (pte_val(pte) & L_PTE_WRITE)
+#define pte_write(pte) (!(pte_val(pte) & L_PTE_RDONLY))
#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_XN))
@@ -318,8 +318,8 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
#define PTE_BIT_FUNC(fn,op) \
static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
-PTE_BIT_FUNC(wrprotect, &= ~L_PTE_WRITE);
-PTE_BIT_FUNC(mkwrite, |= L_PTE_WRITE);
+PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
+PTE_BIT_FUNC(mkwrite, &= ~L_PTE_RDONLY);
PTE_BIT_FUNC(mkclean, &= ~L_PTE_DIRTY);
PTE_BIT_FUNC(mkdirty, |= L_PTE_DIRTY);
PTE_BIT_FUNC(mkold, &= ~L_PTE_YOUNG);
@@ -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_XN | L_PTE_WRITE | L_PTE_USER;
+ const unsigned long mask = L_PTE_XN | L_PTE_RDONLY | 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 a7f56fc..3447c1b 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|L_PTE_XN
+#define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
#define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
static struct mem_type mem_types[] = {
@@ -234,19 +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,
+ .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
+ L_PTE_RDONLY,
.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_USER | L_PTE_RDONLY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_USER,
},
[MT_MEMORY] = {
- .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
- L_PTE_WRITE,
+ .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
@@ -257,21 +257,20 @@ 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_MT_BUFFERABLE,
+ 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_XN,
+ 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,
+ .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
.prot_l1 = PMD_TYPE_TABLE,
.domain = DOMAIN_KERNEL,
},
@@ -478,7 +477,7 @@ static void __init build_mem_type_table(void)
pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
- L_PTE_DIRTY | L_PTE_WRITE | kern_pgprot);
+ L_PTE_DIRTY | kern_pgprot);
mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
diff --git a/arch/arm/mm/proc-macros.S b/arch/arm/mm/proc-macros.S
index 4a7a9e1..f5ca6aa 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_XN+L_PTE_USER+L_PTE_WRITE+L_PTE_DIRTY+L_PTE_YOUNG+\
+#if (L_PTE_XN+L_PTE_USER+L_PTE_RDONLY+L_PTE_DIRTY+L_PTE_YOUNG+\
L_PTE_FILE+L_PTE_PRESENT) > L_PTE_SHARED
#error Invalid Linux PTE bit settings
#endif
@@ -132,9 +132,9 @@
and r2, r1, #L_PTE_MT_MASK
ldr r2, [ip, r2]
- tst r1, #L_PTE_WRITE
- tstne r1, #L_PTE_DIRTY
- orreq r3, r3, #PTE_EXT_APX
+ eor r1, r1, #L_PTE_DIRTY
+ tst r1, #L_PTE_DIRTY|L_PTE_RDONLY
+ orrne r3, r3, #PTE_EXT_APX
tst r1, #L_PTE_USER
orrne r3, r3, #PTE_EXT_AP1
@@ -172,7 +172,7 @@
.macro armv3_set_pte_ext wc_disable=1
str r1, [r0], #2048 @ linux version
- eor r3, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
+ eor r3, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY
bic r2, r1, #PTE_SMALL_AP_MASK @ keep C, B bits
bic r2, r2, #PTE_TYPE_MASK
@@ -181,7 +181,7 @@
tst r3, #L_PTE_USER @ user?
orrne r2, r2, #PTE_SMALL_AP_URO_SRW
- tst r3, #L_PTE_WRITE | L_PTE_DIRTY @ write and dirty?
+ tst r3, #L_PTE_RDONLY | L_PTE_DIRTY @ write and dirty?
orreq r2, r2, #PTE_SMALL_AP_UNO_SRW
tst r3, #L_PTE_PRESENT | L_PTE_YOUNG @ present and young?
@@ -215,7 +215,7 @@
.macro xscale_set_pte_ext_prologue
str r1, [r0] @ linux version
- eor r3, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY
+ eor r3, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY
bic r2, r1, #PTE_SMALL_AP_MASK @ keep C, B bits
orr r2, r2, #PTE_TYPE_EXT @ extended page
@@ -223,7 +223,7 @@
tst r3, #L_PTE_USER @ user?
orrne r2, r2, #PTE_EXT_AP_URO_SRW @ yes -> user r/o, system r/w
- tst r3, #L_PTE_WRITE | L_PTE_DIRTY @ write and dirty?
+ tst r3, #L_PTE_RDONLY | L_PTE_DIRTY @ write and dirty?
orreq r2, r2, #PTE_EXT_AP_UNO_SRW @ yes -> user n/a, system r/w
@ combined with user -> user r/w
.endm
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 4f5a594..210d051 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -140,9 +140,9 @@ ENTRY(cpu_v7_set_pte_ext)
tst r1, #1 << 4
orrne r3, r3, #PTE_EXT_TEX(1)
- tst r1, #L_PTE_WRITE
- tstne r1, #L_PTE_DIRTY
- orreq r3, r3, #PTE_EXT_APX
+ eor r1, r1, #L_PTE_DIRTY
+ tst r1, #L_PTE_RDONLY | L_PTE_DIRTY
+ orrne r3, r3, #PTE_EXT_APX
tst r1, #L_PTE_USER
orrne r3, r3, #PTE_EXT_AP1
diff --git a/arch/arm/mm/proc-xscale.S b/arch/arm/mm/proc-xscale.S
index 523408c..5a37c5e 100644
--- a/arch/arm/mm/proc-xscale.S
+++ b/arch/arm/mm/proc-xscale.S
@@ -500,8 +500,8 @@ ENTRY(cpu_xscale_set_pte_ext)
@
@ Erratum 40: must set memory to write-through for user read-only pages
@
- and ip, r1, #(L_PTE_MT_MASK | L_PTE_USER | L_PTE_WRITE) & ~(4 << 2)
- teq ip, #L_PTE_MT_WRITEBACK | L_PTE_USER
+ and ip, r1, #(L_PTE_MT_MASK | L_PTE_USER | L_PTE_RDONLY) & ~(4 << 2)
+ teq ip, #L_PTE_MT_WRITEBACK | L_PTE_USER | L_PTE_RDONLY
moveq r1, #L_PTE_MT_WRITETHROUGH
and r1, r1, #L_PTE_MT_MASK
--
1.6.2.5
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