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linux/include/asm-um/processor-generic.h
Paolo 'Blaisorblade' Giarrusso acef2e55d2 [PATCH] uml: commentary about forking flag
Add some commentary about UML internals, for a strange trick.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:56 -07:00

159 lines
3.3 KiB
C

/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#ifndef __UM_PROCESSOR_GENERIC_H
#define __UM_PROCESSOR_GENERIC_H
struct pt_regs;
struct task_struct;
#include "linux/config.h"
#include "asm/ptrace.h"
#include "choose-mode.h"
struct mm_struct;
struct thread_struct {
/* This flag is set to 1 before calling do_fork (and analyzed in
* copy_thread) to mark that we are begin called from userspace (fork /
* vfork / clone), and reset to 0 after. It is left to 0 when called
* from kernelspace (i.e. kernel_thread() or fork_idle(), as of 2.6.11). */
int forking;
int nsyscalls;
struct pt_regs regs;
unsigned long cr2;
int err;
unsigned long trap_no;
int singlestep_syscall;
void *fault_addr;
void *fault_catcher;
struct task_struct *prev_sched;
unsigned long temp_stack;
void *exec_buf;
struct arch_thread arch;
union {
#ifdef CONFIG_MODE_TT
struct {
int extern_pid;
int tracing;
int switch_pipe[2];
int vm_seq;
} tt;
#endif
#ifdef CONFIG_MODE_SKAS
struct {
void *switch_buf;
void *fork_buf;
int mm_count;
} skas;
#endif
} mode;
struct {
int op;
union {
struct {
int pid;
} fork, exec;
struct {
int (*proc)(void *);
void *arg;
} thread;
struct {
void (*proc)(void *);
void *arg;
} cb;
} u;
} request;
};
#define INIT_THREAD \
{ \
.forking = 0, \
.nsyscalls = 0, \
.regs = EMPTY_REGS, \
.cr2 = 0, \
.err = 0, \
.fault_addr = NULL, \
.prev_sched = NULL, \
.temp_stack = 0, \
.exec_buf = NULL, \
.arch = INIT_ARCH_THREAD, \
.request = { 0 } \
}
typedef struct {
unsigned long seg;
} mm_segment_t;
extern struct task_struct *alloc_task_struct(void);
extern void release_thread(struct task_struct *);
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
extern void dump_thread(struct pt_regs *regs, struct user *u);
static inline void prepare_to_copy(struct task_struct *tsk)
{
}
extern unsigned long thread_saved_pc(struct task_struct *t);
static inline void mm_copy_segments(struct mm_struct *from_mm,
struct mm_struct *new_mm)
{
}
#define init_stack (init_thread_union.stack)
/*
* User space process size: 3GB (default).
*/
extern unsigned long task_size;
#define TASK_SIZE (task_size)
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE (0x40000000)
extern void start_thread(struct pt_regs *regs, unsigned long entry,
unsigned long stack);
struct cpuinfo_um {
unsigned long loops_per_jiffy;
int ipi_pipe[2];
};
extern struct cpuinfo_um boot_cpu_data;
#define my_cpu_data cpu_data[smp_processor_id()]
#ifdef CONFIG_SMP
extern struct cpuinfo_um cpu_data[];
#define current_cpu_data cpu_data[smp_processor_id()]
#else
#define cpu_data (&boot_cpu_data)
#define current_cpu_data boot_cpu_data
#endif
#define KSTK_EIP(tsk) (PT_REGS_IP(&tsk->thread.regs))
#define KSTK_ESP(tsk) (PT_REGS_SP(&tsk->thread.regs))
#define get_wchan(p) (0)
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/