arch/um/kernel/skas/process_kern.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/sched.h"
   7 #include "linux/slab.h"
   8 #include "linux/ptrace.h"
   9 #include "linux/proc_fs.h"
  10 #include "linux/file.h"
  11 #include "linux/errno.h"
  12 #include "linux/init.h"
  13 #include "asm/uaccess.h"
  14 #include "asm/atomic.h"
  15 #include "kern_util.h"
  16 #include "time_user.h"
  17 #include "signal_user.h"
  18 #include "skas.h"
  19 #include "os.h"
  20 #include "user_util.h"
  21 #include "tlb.h"
  22 #include "frame.h"
  23 #include "kern.h"
  24 #include "mode.h"
  25
  26 #ifdef PTRACE_SYSEMU
  27 static atomic_t using_sysemu;
  28 #endif
  29
  30 void set_using_sysemu(int value)
  31 {
  32         atomic_set(&using_sysemu, value);
  33 }
  34
  35 int get_using_sysemu(void)
  36 {
  37         return atomic_read(&using_sysemu);
  38 }
  39
  40 int proc_read_sysemu(char *buf, char **start, off_t offset, int size,int *eof, void *data)
  41 {
  42         if (snprintf(buf, size, "%d\n", get_using_sysemu()) < size) /*No overflow*/
  43                 *eof = 1;
  44
  45         return strlen(buf);
  46 }
  47
  48 int proc_write_sysemu(struct file *file,const char *buf, unsigned long count,void *data)
  49 {
  50         char tmp[2];
  51
  52         if (copy_from_user(tmp, buf, 1))
  53                 return -EFAULT;
  54
  55         if (tmp[0] == '0' || tmp[0] == '1')
  56                 set_using_sysemu(tmp[0] - '0');
  57         return count; /*We use the first char, but pretend to write everything*/
  58 }
  59
  60 int __init make_proc_sysemu(void)
  61 {
  62         struct proc_dir_entry *ent;
  63
  64         ent = create_proc_entry("sysemu", 00600, &proc_root);
  65         ent->read_proc  = proc_read_sysemu;
  66         ent->write_proc = proc_write_sysemu;
  67
  68         if (ent == NULL)
  69         {
  70                 printk("Failed to register /proc/sysemu\n");
  71                 return(0);
  72         }
  73
  74         return 0;
  75 }
  76
  77 late_initcall(make_proc_sysemu);
  78
  79 int singlestepping_skas(void)
  80 {
  81         int ret = current->ptrace & PT_DTRACE;
  82
  83         current->ptrace &= ~PT_DTRACE;
  84         return(ret);
  85 }
  86
  87 void *switch_to_skas(void *prev, void *next)
  88 {
  89         struct task_struct *from, *to;
  90
  91         from = prev;
  92         to = next;
  93
  94         /* XXX need to check runqueues[cpu].idle */
  95         if(current->pid == 0)
  96                 switch_timers(0);
  97
  98         to->thread.prev_sched = from;
  99         set_current(to);
 100
 101         switch_threads(&from->thread.mode.skas.switch_buf,
 102                        to->thread.mode.skas.switch_buf);
 103
 104         if(current->pid == 0)
 105                 switch_timers(1);
 106
 107         return(current->thread.prev_sched);
 108 }
 109
 110 extern void schedule_tail(struct task_struct *prev);
 111
 112 void new_thread_handler(int sig)
 113 {
 114         int (*fn)(void *), n;
 115         void *arg;
 116
 117         fn = current->thread.request.u.thread.proc;
 118         arg = current->thread.request.u.thread.arg;
 119         change_sig(SIGUSR1, 1);
 120         thread_wait(&current->thread.mode.skas.switch_buf,
 121                     current->thread.mode.skas.fork_buf);
 122
 123         if(current->thread.prev_sched != NULL)
 124                 schedule_tail(current->thread.prev_sched);
 125         current->thread.prev_sched = NULL;
 126
 127         /* The return value is 1 if the kernel thread execs a process,
 128          * 0 if it just exits
 129          */
 130         n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
 131         if(n == 1)
 132                 userspace(&current->thread.regs.regs);
 133         else do_exit(0);
 134 }
 135
 136 void new_thread_proc(void *stack, void (*handler)(int sig))
 137 {
 138         init_new_thread_stack(stack, handler);
 139         os_usr1_process(os_getpid());
 140 }
 141
 142 void release_thread_skas(struct task_struct *task)
 143 {
 144 }
 145
 146 void exit_thread_skas(void)
 147 {
 148 }
 149
 150 void fork_handler(int sig)
 151 {
 152         change_sig(SIGUSR1, 1);
 153         thread_wait(&current->thread.mode.skas.switch_buf,
 154                     current->thread.mode.skas.fork_buf);
 155
 156         force_flush_all();
 157         if(current->thread.prev_sched == NULL)
 158                 panic("blech");
 159
 160         schedule_tail(current->thread.prev_sched);
 161         current->thread.prev_sched = NULL;
 162
 163         userspace(&current->thread.regs.regs);
 164 }
 165
 166 int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 167                      unsigned long stack_top, struct task_struct * p,
 168                      struct pt_regs *regs)
 169 {
 170         void (*handler)(int);
 171
 172         if(current->thread.forking){
 173                 memcpy(&p->thread.regs.regs.skas,
 174                        &current->thread.regs.regs.skas,
 175                        sizeof(p->thread.regs.regs.skas));
 176                 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
 177                 if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
 178
 179                 handler = fork_handler;
 180         }
 181         else {
 182                 memcpy(p->thread.regs.regs.skas.regs, exec_regs,
 183                        sizeof(p->thread.regs.regs.skas.regs));
 184                 memcpy(p->thread.regs.regs.skas.fp, exec_fp_regs,
 185                        sizeof(p->thread.regs.regs.skas.fp));
 186                 memcpy(p->thread.regs.regs.skas.xfp, exec_fpx_regs,
 187                        sizeof(p->thread.regs.regs.skas.xfp));
 188                 p->thread.request.u.thread = current->thread.request.u.thread;
 189                 handler = new_thread_handler;
 190         }
 191
 192         new_thread((void *) p->thread.kernel_stack,
 193                    &p->thread.mode.skas.switch_buf,
 194                    &p->thread.mode.skas.fork_buf, handler);
 195         return(0);
 196 }
 197
 198 void init_idle_skas(void)
 199 {
 200         cpu_tasks[current_thread->cpu].pid = os_getpid();
 201         default_idle();
 202 }
 203
 204 extern void start_kernel(void);
 205
 206 static int start_kernel_proc(void *unused)
 207 {
 208         int pid;
 209
 210         block_signals();
 211         pid = os_getpid();
 212
 213         cpu_tasks[0].pid = pid;
 214         cpu_tasks[0].task = current;
 215 #ifdef CONFIG_SMP
 216         cpu_online_map = cpumask_of_cpu(0);
 217 #endif
 218         start_kernel();
 219         return(0);
 220 }
 221
 222 int start_uml_skas(void)
 223 {
 224         start_userspace(0);
 225         capture_signal_stack();
 226         uml_idle_timer();
 227
 228         init_new_thread_signals(1);
 229
 230         init_task.thread.request.u.thread.proc = start_kernel_proc;
 231         init_task.thread.request.u.thread.arg = NULL;
 232         return(start_idle_thread((void *) init_task.thread.kernel_stack,
 233                                  &init_task.thread.mode.skas.switch_buf,
 234                                  &init_task.thread.mode.skas.fork_buf));
 235 }
 236
 237 int external_pid_skas(struct task_struct *task)
 238 {
 239 #warning Need to look up userspace_pid by cpu
 240         return(userspace_pid[0]);
 241 }
 242
 243 int thread_pid_skas(struct task_struct *task)
 244 {
 245 #warning Need to look up userspace_pid by cpu
 246         return(userspace_pid[0]);
 247 }
 248
 249 /*
 250  * Overrides for Emacs so that we follow Linus's tabbing style.
 251  * Emacs will notice this stuff at the end of the file and automatically
 252  * adjust the settings for this buffer only.  This must remain at the end
 253  * of the file.
 254  * ---------------------------------------------------------------------------
 255  * Local variables:
 256  * c-file-style: "linux"
 257  * End:
 258  */