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-rw-r--r--arch/arm/mm/pageattr.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/arch/arm/mm/pageattr.c b/arch/arm/mm/pageattr.c
new file mode 100644
index 0000000000..064ad508c1
--- /dev/null
+++ b/arch/arm/mm/pageattr.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ */
+#include <linux/mm.h>
+#include <linux/module.h>
+
+#include <asm/tlbflush.h>
+#include <asm/set_memory.h>
+
+struct page_change_data {
+ pgprot_t set_mask;
+ pgprot_t clear_mask;
+};
+
+static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
+{
+ struct page_change_data *cdata = data;
+ pte_t pte = *ptep;
+
+ pte = clear_pte_bit(pte, cdata->clear_mask);
+ pte = set_pte_bit(pte, cdata->set_mask);
+
+ set_pte_ext(ptep, pte, 0);
+ return 0;
+}
+
+static bool range_in_range(unsigned long start, unsigned long size,
+ unsigned long range_start, unsigned long range_end)
+{
+ return start >= range_start && start < range_end &&
+ size <= range_end - start;
+}
+
+/*
+ * This function assumes that the range is mapped with PAGE_SIZE pages.
+ */
+static int __change_memory_common(unsigned long start, unsigned long size,
+ pgprot_t set_mask, pgprot_t clear_mask)
+{
+ struct page_change_data data;
+ int ret;
+
+ data.set_mask = set_mask;
+ data.clear_mask = clear_mask;
+
+ ret = apply_to_page_range(&init_mm, start, size, change_page_range,
+ &data);
+
+ flush_tlb_kernel_range(start, start + size);
+ return ret;
+}
+
+static int change_memory_common(unsigned long addr, int numpages,
+ pgprot_t set_mask, pgprot_t clear_mask)
+{
+ unsigned long start = addr & PAGE_MASK;
+ unsigned long end = PAGE_ALIGN(addr) + numpages * PAGE_SIZE;
+ unsigned long size = end - start;
+
+ WARN_ON_ONCE(start != addr);
+
+ if (!size)
+ return 0;
+
+ if (!range_in_range(start, size, MODULES_VADDR, MODULES_END) &&
+ !range_in_range(start, size, VMALLOC_START, VMALLOC_END))
+ return -EINVAL;
+
+ return __change_memory_common(start, size, set_mask, clear_mask);
+}
+
+int set_memory_ro(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(L_PTE_RDONLY),
+ __pgprot(0));
+}
+
+int set_memory_rw(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(0),
+ __pgprot(L_PTE_RDONLY));
+}
+
+int set_memory_nx(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(L_PTE_XN),
+ __pgprot(0));
+}
+
+int set_memory_x(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(0),
+ __pgprot(L_PTE_XN));
+}
+
+int set_memory_valid(unsigned long addr, int numpages, int enable)
+{
+ if (enable)
+ return __change_memory_common(addr, PAGE_SIZE * numpages,
+ __pgprot(L_PTE_VALID),
+ __pgprot(0));
+ else
+ return __change_memory_common(addr, PAGE_SIZE * numpages,
+ __pgprot(0),
+ __pgprot(L_PTE_VALID));
+}