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79 lines
1.7 KiB
79 lines
1.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2015 Thomas Meyer ([email protected]) |
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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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