80 lines
1.7 KiB
C
80 lines
1.7 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
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* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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*/
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#include <linux/mm.h>
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#include <linux/sched/signal.h>
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#include <linux/slab.h>
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#include <asm/pgalloc.h>
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#include <asm/sections.h>
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#include <as-layout.h>
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#include <os.h>
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#include <skas.h>
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int init_new_context(struct task_struct *task, struct mm_struct *mm)
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{
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struct mm_context *from_mm = NULL;
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struct mm_context *to_mm = &mm->context;
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unsigned long stack = 0;
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int ret = -ENOMEM;
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stack = get_zeroed_page(GFP_KERNEL);
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if (stack == 0)
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goto out;
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to_mm->id.stack = stack;
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if (current->mm != NULL && current->mm != &init_mm)
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from_mm = ¤t->mm->context;
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block_signals_trace();
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if (from_mm)
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to_mm->id.u.pid = copy_context_skas0(stack,
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from_mm->id.u.pid);
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else to_mm->id.u.pid = start_userspace(stack);
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unblock_signals_trace();
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if (to_mm->id.u.pid < 0) {
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ret = to_mm->id.u.pid;
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goto out_free;
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}
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ret = init_new_ldt(to_mm, from_mm);
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if (ret < 0) {
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printk(KERN_ERR "init_new_context_skas - init_ldt"
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" failed, errno = %d\n", ret);
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goto out_free;
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}
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return 0;
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out_free:
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if (to_mm->id.stack != 0)
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free_page(to_mm->id.stack);
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out:
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return ret;
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}
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void destroy_context(struct mm_struct *mm)
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{
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struct mm_context *mmu = &mm->context;
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/*
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* If init_new_context wasn't called, this will be
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* zero, resulting in a kill(0), which will result in the
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* whole UML suddenly dying. Also, cover negative and
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* 1 cases, since they shouldn't happen either.
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*/
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if (mmu->id.u.pid < 2) {
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printk(KERN_ERR "corrupt mm_context - pid = %d\n",
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mmu->id.u.pid);
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return;
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}
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os_kill_ptraced_process(mmu->id.u.pid, 1);
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free_page(mmu->id.stack);
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free_ldt(mmu);
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}
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