ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/arch/um/kernel/skas/mmu.c b/marvell/linux/arch/um/kernel/skas/mmu.c
new file mode 100644
index 0000000..b5e3d91
--- /dev/null
+++ b/marvell/linux/arch/um/kernel/skas/mmu.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm/sections.h>
+#include <as-layout.h>
+#include <os.h>
+#include <skas.h>
+
+static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
+ unsigned long kernel)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = pgd_offset(mm, proc);
+ pud = pud_alloc(mm, pgd, proc);
+ if (!pud)
+ goto out;
+
+ pmd = pmd_alloc(mm, pud, proc);
+ if (!pmd)
+ goto out_pmd;
+
+ pte = pte_alloc_map(mm, pmd, proc);
+ if (!pte)
+ goto out_pte;
+
+ *pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
+ *pte = pte_mkread(*pte);
+ return 0;
+
+ out_pte:
+ pmd_free(mm, pmd);
+ out_pmd:
+ pud_free(mm, pud);
+ out:
+ return -ENOMEM;
+}
+
+int init_new_context(struct task_struct *task, struct mm_struct *mm)
+{
+ struct mm_context *from_mm = NULL;
+ struct mm_context *to_mm = &mm->context;
+ unsigned long stack = 0;
+ int ret = -ENOMEM;
+
+ stack = get_zeroed_page(GFP_KERNEL);
+ if (stack == 0)
+ goto out;
+
+ to_mm->id.stack = stack;
+ if (current->mm != NULL && current->mm != &init_mm)
+ from_mm = ¤t->mm->context;
+
+ block_signals_trace();
+ if (from_mm)
+ to_mm->id.u.pid = copy_context_skas0(stack,
+ from_mm->id.u.pid);
+ else to_mm->id.u.pid = start_userspace(stack);
+ unblock_signals_trace();
+
+ if (to_mm->id.u.pid < 0) {
+ ret = to_mm->id.u.pid;
+ goto out_free;
+ }
+
+ ret = init_new_ldt(to_mm, from_mm);
+ if (ret < 0) {
+ printk(KERN_ERR "init_new_context_skas - init_ldt"
+ " failed, errno = %d\n", ret);
+ goto out_free;
+ }
+
+ return 0;
+
+ out_free:
+ if (to_mm->id.stack != 0)
+ free_page(to_mm->id.stack);
+ out:
+ return ret;
+}
+
+void uml_setup_stubs(struct mm_struct *mm)
+{
+ int err, ret;
+
+ ret = init_stub_pte(mm, STUB_CODE,
+ (unsigned long) __syscall_stub_start);
+ if (ret)
+ goto out;
+
+ ret = init_stub_pte(mm, STUB_DATA, mm->context.id.stack);
+ if (ret)
+ goto out;
+
+ mm->context.stub_pages[0] = virt_to_page(__syscall_stub_start);
+ mm->context.stub_pages[1] = virt_to_page(mm->context.id.stack);
+
+ /* dup_mmap already holds mmap_sem */
+ err = install_special_mapping(mm, STUB_START, STUB_END - STUB_START,
+ VM_READ | VM_MAYREAD | VM_EXEC |
+ VM_MAYEXEC | VM_DONTCOPY | VM_PFNMAP,
+ mm->context.stub_pages);
+ if (err) {
+ printk(KERN_ERR "install_special_mapping returned %d\n", err);
+ goto out;
+ }
+ return;
+
+out:
+ force_sigsegv(SIGSEGV);
+}
+
+void arch_exit_mmap(struct mm_struct *mm)
+{
+ pte_t *pte;
+
+ pte = virt_to_pte(mm, STUB_CODE);
+ if (pte != NULL)
+ pte_clear(mm, STUB_CODE, pte);
+
+ pte = virt_to_pte(mm, STUB_DATA);
+ if (pte == NULL)
+ return;
+
+ pte_clear(mm, STUB_DATA, pte);
+}
+
+void destroy_context(struct mm_struct *mm)
+{
+ struct mm_context *mmu = &mm->context;
+
+ /*
+ * If init_new_context wasn't called, this will be
+ * zero, resulting in a kill(0), which will result in the
+ * whole UML suddenly dying. Also, cover negative and
+ * 1 cases, since they shouldn't happen either.
+ */
+ if (mmu->id.u.pid < 2) {
+ printk(KERN_ERR "corrupt mm_context - pid = %d\n",
+ mmu->id.u.pid);
+ return;
+ }
+ os_kill_ptraced_process(mmu->id.u.pid, 1);
+
+ free_page(mmu->id.stack);
+ free_ldt(mmu);
+}