536788fe2d
Calculate TASK_SIZE at run-time by figuring out the host's VMSPLIT - this is needed on i386 if UML is to run on hosts with varying VMSPLITs without recompilation. TASK_SIZE is now defined in terms of a variable, task_size. This gets rid of an include of pgtable.h from processor.h, which can cause include loops. On i386, task_size is calculated early in boot by probing the address space in a binary search to figure out where the boundary between usable and non-usable memory is. This tries to make sure that a page that is considered to be in userspace is, or can be made, read-write. I'm concerned about a system-global VDSO page in kernel memory being hit and considered to be a userspace page. On x86_64, task_size is just the old value of CONFIG_TOP_ADDR. A bunch of config variable are gone now. CONFIG_TOP_ADDR is directly replaced by TASK_SIZE. NEST_LEVEL is gone since the relocation of the stubs makes it irrelevant. All the HOST_VMSPLIT stuff is gone. All references to these in arch/um/Makefile are also gone. I noticed and fixed a missing extern in os.h when adding os_get_task_size. Note: This has been revised to fix the 32-bit UML on 64-bit host bug that Miklos ran into. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
100 lines
2.1 KiB
C
100 lines
2.1 KiB
C
/*
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* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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* Licensed under the GPL
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*/
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#include "linux/stddef.h"
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#include "linux/fs.h"
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#include "linux/smp_lock.h"
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#include "linux/ptrace.h"
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#include "linux/sched.h"
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#include "asm/current.h"
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#include "asm/processor.h"
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#include "asm/uaccess.h"
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#include "as-layout.h"
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#include "mem_user.h"
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#include "skas.h"
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#include "os.h"
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void flush_thread(void)
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{
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void *data = NULL;
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int ret;
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arch_flush_thread(¤t->thread.arch);
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ret = unmap(¤t->mm->context.id, 0, STUB_START, 0, &data);
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ret = ret || unmap(¤t->mm->context.id, STUB_END,
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host_task_size - STUB_END, 1, &data);
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if (ret) {
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printk(KERN_ERR "flush_thread - clearing address space failed, "
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"err = %d\n", ret);
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force_sig(SIGKILL, current);
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}
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__switch_mm(¤t->mm->context.id);
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}
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void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
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{
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set_fs(USER_DS);
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PT_REGS_IP(regs) = eip;
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PT_REGS_SP(regs) = esp;
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}
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#ifdef CONFIG_TTY_LOG
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extern void log_exec(char **argv, void *tty);
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#endif
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static long execve1(char *file, char __user * __user *argv,
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char __user *__user *env)
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{
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long error;
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#ifdef CONFIG_TTY_LOG
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struct tty_struct *tty;
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mutex_lock(&tty_mutex);
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tty = get_current_tty();
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if (tty)
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log_exec(argv, tty);
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mutex_unlock(&tty_mutex);
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#endif
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error = do_execve(file, argv, env, ¤t->thread.regs);
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if (error == 0) {
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task_lock(current);
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current->ptrace &= ~PT_DTRACE;
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#ifdef SUBARCH_EXECVE1
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SUBARCH_EXECVE1(¤t->thread.regs.regs);
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#endif
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task_unlock(current);
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}
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return error;
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}
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long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
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{
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long err;
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err = execve1(file, argv, env);
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if (!err)
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UML_LONGJMP(current->thread.exec_buf, 1);
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return err;
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}
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long sys_execve(char __user *file, char __user *__user *argv,
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char __user *__user *env)
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{
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long error;
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char *filename;
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lock_kernel();
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filename = getname(file);
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error = PTR_ERR(filename);
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if (IS_ERR(filename)) goto out;
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error = execve1(filename, argv, env);
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putname(filename);
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out:
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unlock_kernel();
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return error;
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}
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