ARM: mm: Define set_memory_* functions for ARM

Other architectures define various set_memory functions to allow
attributes to be changed (e.g. set_memory_x, set_memory_rw, etc.)
Currently, these functions are missing on ARM. Define these in an
appropriate manner for ARM.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 43 insertions, 0 deletions

diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index ee753f1749cd..e9a49fe0284e 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -481,4 +481,9 @@ static inline void __sync_cache_range_r(volatile void *p, size_t size)
         : : : "r0","r1","r2","r3","r4","r5","r6","r7", \
               "r9","r10","lr","memory" )
 
+int set_memory_ro(unsigned long addr, int numpages);
+int set_memory_rw(unsigned long addr, int numpages);
+int set_memory_x(unsigned long addr, int numpages);
+int set_memory_nx(unsigned long addr, int numpages);
+
 #endif
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 9ec715f12224..09033890c8b0 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -345,6 +345,44 @@ const struct mem_type *get_mem_type(unsigned int type)
 }
 EXPORT_SYMBOL(get_mem_type);
 
+#define PTE_SET_FN(_name, pteop) \
+static int pte_set_##_name(pte_t *ptep, pgtable_t token, unsigned long addr, \
+                        void *data) \
+{ \
+        pte_t pte = pteop(*ptep); \
+\
+        set_pte_ext(ptep, pte, 0); \
+        return 0; \
+} \
+
+#define SET_MEMORY_FN(_name, callback) \
+int set_memory_##_name(unsigned long addr, int numpages) \
+{ \
+        unsigned long start = addr; \
+        unsigned long size = PAGE_SIZE*numpages; \
+        unsigned end = start + size; \
+\
+        if (start < MODULES_VADDR || start >= MODULES_END) \
+                return -EINVAL;\
+\
+        if (end < MODULES_VADDR || end >= MODULES_END) \
+                return -EINVAL; \
+\
+        apply_to_page_range(&init_mm, start, size, callback, NULL); \
+        flush_tlb_kernel_range(start, end); \
+        return 0;\
+}
+
+PTE_SET_FN(ro, pte_wrprotect)
+PTE_SET_FN(rw, pte_mkwrite)
+PTE_SET_FN(x, pte_mkexec)
+PTE_SET_FN(nx, pte_mknexec)
+
+SET_MEMORY_FN(ro, pte_set_ro)
+SET_MEMORY_FN(rw, pte_set_rw)
+SET_MEMORY_FN(x, pte_set_x)
+SET_MEMORY_FN(nx, pte_set_nx)
+
 /*
  * Adjust the PMD section entries according to the CPU in use.
  */