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-rw-r--r--arch/um/kernel/mem.c238
1 files changed, 238 insertions, 0 deletions
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
new file mode 100644
index 000000000..38d5a71a5
--- /dev/null
+++ b/arch/um/kernel/mem.c
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/stddef.h>
+#include <linux/module.h>
+#include <linux/memblock.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <asm/fixmap.h>
+#include <asm/page.h>
+#include <as-layout.h>
+#include <init.h>
+#include <kern.h>
+#include <kern_util.h>
+#include <mem_user.h>
+#include <os.h>
+#include <linux/sched/task.h>
+
+#ifdef CONFIG_KASAN
+int kasan_um_is_ready;
+void kasan_init(void)
+{
+ /*
+ * kasan_map_memory will map all of the required address space and
+ * the host machine will allocate physical memory as necessary.
+ */
+ kasan_map_memory((void *)KASAN_SHADOW_START, KASAN_SHADOW_SIZE);
+ init_task.kasan_depth = 0;
+ kasan_um_is_ready = true;
+}
+
+static void (*kasan_init_ptr)(void)
+__section(".kasan_init") __used
+= kasan_init;
+#endif
+
+/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
+unsigned long *empty_zero_page = NULL;
+EXPORT_SYMBOL(empty_zero_page);
+
+/*
+ * Initialized during boot, and readonly for initializing page tables
+ * afterwards
+ */
+pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* Initialized at boot time, and readonly after that */
+unsigned long long highmem;
+EXPORT_SYMBOL(highmem);
+int kmalloc_ok = 0;
+
+/* Used during early boot */
+static unsigned long brk_end;
+
+void __init mem_init(void)
+{
+ /* clear the zero-page */
+ memset(empty_zero_page, 0, PAGE_SIZE);
+
+ /* Map in the area just after the brk now that kmalloc is about
+ * to be turned on.
+ */
+ brk_end = (unsigned long) UML_ROUND_UP(sbrk(0));
+ map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
+ memblock_free((void *)brk_end, uml_reserved - brk_end);
+ uml_reserved = brk_end;
+
+ /* this will put all low memory onto the freelists */
+ memblock_free_all();
+ max_low_pfn = totalram_pages();
+ max_pfn = max_low_pfn;
+ kmalloc_ok = 1;
+}
+
+/*
+ * Create a page table and place a pointer to it in a middle page
+ * directory entry.
+ */
+static void __init one_page_table_init(pmd_t *pmd)
+{
+ if (pmd_none(*pmd)) {
+ pte_t *pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
+ PAGE_SIZE);
+ if (!pte)
+ panic("%s: Failed to allocate %lu bytes align=%lx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE);
+
+ set_pmd(pmd, __pmd(_KERNPG_TABLE +
+ (unsigned long) __pa(pte)));
+ BUG_ON(pte != pte_offset_kernel(pmd, 0));
+ }
+}
+
+static void __init one_md_table_init(pud_t *pud)
+{
+#ifdef CONFIG_3_LEVEL_PGTABLES
+ pmd_t *pmd_table = (pmd_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
+ if (!pmd_table)
+ panic("%s: Failed to allocate %lu bytes align=%lx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE);
+
+ set_pud(pud, __pud(_KERNPG_TABLE + (unsigned long) __pa(pmd_table)));
+ BUG_ON(pmd_table != pmd_offset(pud, 0));
+#endif
+}
+
+static void __init fixrange_init(unsigned long start, unsigned long end,
+ pgd_t *pgd_base)
+{
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ int i, j;
+ unsigned long vaddr;
+
+ vaddr = start;
+ i = pgd_index(vaddr);
+ j = pmd_index(vaddr);
+ pgd = pgd_base + i;
+
+ for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
+ p4d = p4d_offset(pgd, vaddr);
+ pud = pud_offset(p4d, vaddr);
+ if (pud_none(*pud))
+ one_md_table_init(pud);
+ pmd = pmd_offset(pud, vaddr);
+ for (; (j < PTRS_PER_PMD) && (vaddr < end); pmd++, j++) {
+ one_page_table_init(pmd);
+ vaddr += PMD_SIZE;
+ }
+ j = 0;
+ }
+}
+
+static void __init fixaddr_user_init( void)
+{
+#ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
+ long size = FIXADDR_USER_END - FIXADDR_USER_START;
+ pte_t *pte;
+ phys_t p;
+ unsigned long v, vaddr = FIXADDR_USER_START;
+
+ if (!size)
+ return;
+
+ fixrange_init( FIXADDR_USER_START, FIXADDR_USER_END, swapper_pg_dir);
+ v = (unsigned long) memblock_alloc_low(size, PAGE_SIZE);
+ if (!v)
+ panic("%s: Failed to allocate %lu bytes align=%lx\n",
+ __func__, size, PAGE_SIZE);
+
+ memcpy((void *) v , (void *) FIXADDR_USER_START, size);
+ p = __pa(v);
+ for ( ; size > 0; size -= PAGE_SIZE, vaddr += PAGE_SIZE,
+ p += PAGE_SIZE) {
+ pte = virt_to_kpte(vaddr);
+ pte_set_val(*pte, p, PAGE_READONLY);
+ }
+#endif
+}
+
+void __init paging_init(void)
+{
+ unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
+ unsigned long vaddr;
+
+ empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
+ PAGE_SIZE);
+ if (!empty_zero_page)
+ panic("%s: Failed to allocate %lu bytes align=%lx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE);
+
+ max_zone_pfn[ZONE_NORMAL] = end_iomem >> PAGE_SHIFT;
+ free_area_init(max_zone_pfn);
+
+ /*
+ * Fixed mappings, only the page table structure has to be
+ * created - mappings will be set by set_fixmap():
+ */
+ vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+ fixrange_init(vaddr, FIXADDR_TOP, swapper_pg_dir);
+
+ fixaddr_user_init();
+}
+
+/*
+ * This can't do anything because nothing in the kernel image can be freed
+ * since it's not in kernel physical memory.
+ */
+
+void free_initmem(void)
+{
+}
+
+/* Allocate and free page tables. */
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
+
+ if (pgd) {
+ memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
+ memcpy(pgd + USER_PTRS_PER_PGD,
+ swapper_pg_dir + USER_PTRS_PER_PGD,
+ (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+ }
+ return pgd;
+}
+
+void *uml_kmalloc(int size, int flags)
+{
+ return kmalloc(size, flags);
+}
+
+static const pgprot_t protection_map[16] = {
+ [VM_NONE] = PAGE_NONE,
+ [VM_READ] = PAGE_READONLY,
+ [VM_WRITE] = PAGE_COPY,
+ [VM_WRITE | VM_READ] = PAGE_COPY,
+ [VM_EXEC] = PAGE_READONLY,
+ [VM_EXEC | VM_READ] = PAGE_READONLY,
+ [VM_EXEC | VM_WRITE] = PAGE_COPY,
+ [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY,
+ [VM_SHARED] = PAGE_NONE,
+ [VM_SHARED | VM_READ] = PAGE_READONLY,
+ [VM_SHARED | VM_WRITE] = PAGE_SHARED,
+ [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
+ [VM_SHARED | VM_EXEC] = PAGE_READONLY,
+ [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY,
+ [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
+ [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED
+};
+DECLARE_VM_GET_PAGE_PROT