Add set_memory_ro/rw/x/nx architecture hooks to change the page
attribution.
Use own set_memory.h rather than generic set_memory.h (i.e.
include/asm-generic/set_memory.h), because we want to add other function
prototypes here.
Note: We can only set attributes for KVRANGE/XKVRANGE kernel addresses.
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/set_memory.h | 17 +++
arch/loongarch/mm/Makefile | 3 +-
arch/loongarch/mm/pageattr.c | 159 ++++++++++++++++++++++++
4 files changed, 179 insertions(+), 1 deletion(-)
create mode 100644 arch/loongarch/include/asm/set_memory.h
create mode 100644 arch/loongarch/mm/pageattr.c
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 0e3abf7b0bd3..49efa0470e16 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -25,6 +25,7 @@ config LOONGARCH
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PTE_DEVMAP
select ARCH_HAS_PTE_SPECIAL
+ select ARCH_HAS_SET_MEMORY
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_INLINE_READ_LOCK if !PREEMPTION
select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
diff --git a/arch/loongarch/include/asm/set_memory.h b/arch/loongarch/include/asm/set_memory.h
new file mode 100644
index 000000000000..64c7f942e8ec
--- /dev/null
+++ b/arch/loongarch/include/asm/set_memory.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#ifndef _ASM_LOONGARCH_SET_MEMORY_H
+#define _ASM_LOONGARCH_SET_MEMORY_H
+
+/*
+ * Functions to change memory attributes.
+ */
+int set_memory_x(unsigned long addr, int numpages);
+int set_memory_nx(unsigned long addr, int numpages);
+int set_memory_ro(unsigned long addr, int numpages);
+int set_memory_rw(unsigned long addr, int numpages);
+
+#endif /* _ASM_LOONGARCH_SET_MEMORY_H */
diff --git a/arch/loongarch/mm/Makefile b/arch/loongarch/mm/Makefile
index e4d1e581dbae..278be2c8fc36 100644
--- a/arch/loongarch/mm/Makefile
+++ b/arch/loongarch/mm/Makefile
@@ -4,7 +4,8 @@
#
obj-y += init.o cache.o tlb.o tlbex.o extable.o \
- fault.o ioremap.o maccess.o mmap.o pgtable.o page.o
+ fault.o ioremap.o maccess.o mmap.o pgtable.o \
+ page.o pageattr.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_KASAN) += kasan_init.o
diff --git a/arch/loongarch/mm/pageattr.c b/arch/loongarch/mm/pageattr.c
new file mode 100644
index 000000000000..d11c8f4b8248
--- /dev/null
+++ b/arch/loongarch/mm/pageattr.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 Loongson Technology Corporation Limited
+ */
+
+#include <linux/pagewalk.h>
+#include <linux/pgtable.h>
+#include <linux/vmalloc.h>
+#include <asm/set_memory.h>
+#include <asm/tlbflush.h>
+
+struct pageattr_masks {
+ pgprot_t set_mask;
+ pgprot_t clear_mask;
+};
+
+static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
+{
+ unsigned long new_val = val;
+ struct pageattr_masks *masks = walk->private;
+
+ new_val &= ~(pgprot_val(masks->clear_mask));
+ new_val |= (pgprot_val(masks->set_mask));
+
+ return new_val;
+}
+
+static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pgd_t val = pgdp_get(pgd);
+
+ if (pgd_leaf(val)) {
+ val = __pgd(set_pageattr_masks(pgd_val(val), walk));
+ set_pgd(pgd, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ p4d_t val = p4dp_get(p4d);
+
+ if (p4d_leaf(val)) {
+ val = __p4d(set_pageattr_masks(p4d_val(val), walk));
+ set_p4d(p4d, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pud_t val = pudp_get(pud);
+
+ if (pud_leaf(val)) {
+ val = __pud(set_pageattr_masks(pud_val(val), walk));
+ set_pud(pud, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pmd_t val = pmdp_get(pmd);
+
+ if (pmd_leaf(val)) {
+ val = __pmd(set_pageattr_masks(pmd_val(val), walk));
+ set_pmd(pmd, val);
+ }
+
+ return 0;
+}
+
+static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ pte_t val = ptep_get(pte);
+
+ val = __pte(set_pageattr_masks(pte_val(val), walk));
+ set_pte(pte, val);
+
+ return 0;
+}
+
+static int pageattr_pte_hole(unsigned long addr, unsigned long next,
+ int depth, struct mm_walk *walk)
+{
+ return 0;
+}
+
+static const struct mm_walk_ops pageattr_ops = {
+ .pgd_entry = pageattr_pgd_entry,
+ .p4d_entry = pageattr_p4d_entry,
+ .pud_entry = pageattr_pud_entry,
+ .pmd_entry = pageattr_pmd_entry,
+ .pte_entry = pageattr_pte_entry,
+ .pte_hole = pageattr_pte_hole,
+ .walk_lock = PGWALK_RDLOCK,
+};
+
+static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask, pgprot_t clear_mask)
+{
+ int ret;
+ unsigned long start = addr;
+ unsigned long end = start + PAGE_SIZE * numpages;
+ struct pageattr_masks masks = {
+ .set_mask = set_mask,
+ .clear_mask = clear_mask
+ };
+
+ if (!numpages)
+ return 0;
+
+ mmap_write_lock(&init_mm);
+ ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL, &masks);
+ mmap_write_unlock(&init_mm);
+
+ flush_tlb_kernel_range(start, end);
+
+ return ret;
+}
+
+int set_memory_x(unsigned long addr, int numpages)
+{
+ if (addr < vm_map_base)
+ return 0;
+
+ return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_NO_EXEC));
+}
+
+int set_memory_nx(unsigned long addr, int numpages)
+{
+ if (addr < vm_map_base)
+ return 0;
+
+ return __set_memory(addr, numpages, __pgprot(_PAGE_NO_EXEC), __pgprot(0));
+}
+
+int set_memory_ro(unsigned long addr, int numpages)
+{
+ if (addr < vm_map_base)
+ return 0;
+
+ return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_WRITE | _PAGE_DIRTY));
+}
+
+int set_memory_rw(unsigned long addr, int numpages)
+{
+ if (addr < vm_map_base)
+ return 0;
+
+ return __set_memory(addr, numpages, __pgprot(_PAGE_WRITE | _PAGE_DIRTY), __pgprot(0));
+}
--
2.43.5
