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![Jeff Dike](/assets/img/avatar_default.png)
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>
136 lines
2.8 KiB
C
136 lines
2.8 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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#ifndef __UM_PROCESSOR_GENERIC_H
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#define __UM_PROCESSOR_GENERIC_H
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struct pt_regs;
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struct task_struct;
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#include "asm/ptrace.h"
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#include "registers.h"
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#include "sysdep/archsetjmp.h"
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struct mm_struct;
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struct thread_struct {
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struct task_struct *saved_task;
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/*
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* This flag is set to 1 before calling do_fork (and analyzed in
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* copy_thread) to mark that we are begin called from userspace (fork /
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* vfork / clone), and reset to 0 after. It is left to 0 when called
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* from kernelspace (i.e. kernel_thread() or fork_idle(),
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* as of 2.6.11).
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*/
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int forking;
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struct pt_regs regs;
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int singlestep_syscall;
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void *fault_addr;
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jmp_buf *fault_catcher;
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struct task_struct *prev_sched;
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unsigned long temp_stack;
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jmp_buf *exec_buf;
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struct arch_thread arch;
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jmp_buf switch_buf;
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int mm_count;
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struct {
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int op;
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union {
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struct {
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int pid;
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} fork, exec;
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struct {
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int (*proc)(void *);
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void *arg;
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} thread;
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struct {
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void (*proc)(void *);
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void *arg;
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} cb;
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} u;
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} request;
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};
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#define INIT_THREAD \
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{ \
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.forking = 0, \
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.regs = EMPTY_REGS, \
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.fault_addr = NULL, \
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.prev_sched = NULL, \
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.temp_stack = 0, \
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.exec_buf = NULL, \
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.arch = INIT_ARCH_THREAD, \
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.request = { 0 } \
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}
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extern struct task_struct *alloc_task_struct(void);
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static inline void release_thread(struct task_struct *task)
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{
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}
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extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
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static inline void prepare_to_copy(struct task_struct *tsk)
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{
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}
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extern unsigned long thread_saved_pc(struct task_struct *t);
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static inline void mm_copy_segments(struct mm_struct *from_mm,
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struct mm_struct *new_mm)
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{
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}
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#define init_stack (init_thread_union.stack)
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/*
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* User space process size: 3GB (default).
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*/
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extern unsigned long task_size;
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#define TASK_SIZE (task_size)
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#undef STACK_TOP
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#undef STACK_TOP_MAX
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extern unsigned long stacksizelim;
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#define STACK_ROOM (stacksizelim)
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#define STACK_TOP (TASK_SIZE - 2 * PAGE_SIZE)
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#define STACK_TOP_MAX STACK_TOP
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/* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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*/
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#define TASK_UNMAPPED_BASE (0x40000000)
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extern void start_thread(struct pt_regs *regs, unsigned long entry,
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unsigned long stack);
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struct cpuinfo_um {
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unsigned long loops_per_jiffy;
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int ipi_pipe[2];
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};
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extern struct cpuinfo_um boot_cpu_data;
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#define my_cpu_data cpu_data[smp_processor_id()]
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#ifdef CONFIG_SMP
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extern struct cpuinfo_um cpu_data[];
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#define current_cpu_data cpu_data[smp_processor_id()]
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#else
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#define cpu_data (&boot_cpu_data)
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#define current_cpu_data boot_cpu_data
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#endif
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#define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf)
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extern unsigned long get_wchan(struct task_struct *p);
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#endif
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