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 "kern.h"
  23 #include "mode.h"
  24 #include "proc_mm.h"
  25 #include "registers.h"
  26
  27 void *switch_to_skas(void *prev, void *next)
  28 {
  29         struct task_struct *from, *to;
  30
  31         from = prev;
  32         to = next;
  33
  34         /* XXX need to check runqueues[cpu].idle */
  35         if(current->pid == 0)
  36                 switch_timers(0);
  37
  38         to->thread.prev_sched = from;
  39         set_current(to);
  40
  41         switch_threads(&from->thread.mode.skas.switch_buf,
  42                        to->thread.mode.skas.switch_buf);
  43
  44         if(current->pid == 0)
  45                 switch_timers(1);
  46
  47         return(current->thread.prev_sched);
  48 }
  49
  50 extern void schedule_tail(struct task_struct *prev);
  51
  52 void new_thread_handler(int sig)
  53 {
  54         int (*fn)(void *), n;
  55         void *arg;
  56
  57         fn = current->thread.request.u.thread.proc;
  58         arg = current->thread.request.u.thread.arg;
  59         change_sig(SIGUSR1, 1);
  60         thread_wait(&current->thread.mode.skas.switch_buf,
  61                     current->thread.mode.skas.fork_buf);
  62
  63         if(current->thread.prev_sched != NULL)
  64                 schedule_tail(current->thread.prev_sched);
  65         current->thread.prev_sched = NULL;
  66
  67         /* The return value is 1 if the kernel thread execs a process,
  68          * 0 if it just exits
  69          */
  70         n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
  71         if(n == 1)
  72                 userspace(&current->thread.regs.regs);
  73         else do_exit(0);
  74 }
  75
  76 void new_thread_proc(void *stack, void (*handler)(int sig))
  77 {
  78         init_new_thread_stack(stack, handler);
  79         os_usr1_process(os_getpid());
  80 }
  81
  82 void release_thread_skas(struct task_struct *task)
  83 {
  84 }
  85
  86 void exit_thread_skas(void)
  87 {
  88 }
  89
  90 void fork_handler(int sig)
  91 {
  92         change_sig(SIGUSR1, 1);
  93         thread_wait(&current->thread.mode.skas.switch_buf,
  94                     current->thread.mode.skas.fork_buf);
  95
  96         force_flush_all();
  97         if(current->thread.prev_sched == NULL)
  98                 panic("blech");
  99
 100         schedule_tail(current->thread.prev_sched);
 101         current->thread.prev_sched = NULL;
 102
 103         userspace(&current->thread.regs.regs);
 104 }
 105
 106 int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 107                      unsigned long stack_top, struct task_struct * p,
 108                      struct pt_regs *regs)
 109 {
 110         void (*handler)(int);
 111
 112         if(current->thread.forking){
 113                 memcpy(&p->thread.regs.regs.skas,
 114                        &current->thread.regs.regs.skas,
 115                        sizeof(p->thread.regs.regs.skas));
 116                 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
 117                 if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
 118
 119                 handler = fork_handler;
 120         }
 121         else {
 122                 init_thread_registers(&p->thread.regs.regs);
 123                 p->thread.request.u.thread = current->thread.request.u.thread;
 124                 handler = new_thread_handler;
 125         }
 126
 127         new_thread(p->thread_info, &p->thread.mode.skas.switch_buf,
 128                    &p->thread.mode.skas.fork_buf, handler);
 129         return(0);
 130 }
 131
 132 int new_mm(int from)
 133 {
 134         struct proc_mm_op copy;
 135         int n, fd;
 136
 137         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 138         if(fd < 0)
 139                 return(fd);
 140
 141         if(from != -1){
 142                 copy = ((struct proc_mm_op) { .op       = MM_COPY_SEGMENTS,
 143                                               .u        =
 144                                               { .copy_segments  = from } } );
 145                 n = os_write_file(fd, &copy, sizeof(copy));
 146                 if(n != sizeof(copy))
 147                         printk("new_mm : /proc/mm copy_segments failed, "
 148                                "err = %d\n", -n);
 149         }
 150
 151         return(fd);
 152 }
 153
 154 void init_idle_skas(void)
 155 {
 156         cpu_tasks[current_thread->cpu].pid = os_getpid();
 157         default_idle();
 158 }
 159
 160 extern void start_kernel(void);
 161
 162 static int start_kernel_proc(void *unused)
 163 {
 164         int pid;
 165
 166         block_signals();
 167         pid = os_getpid();
 168
 169         cpu_tasks[0].pid = pid;
 170         cpu_tasks[0].task = current;
 171 #ifdef CONFIG_SMP
 172         cpu_online_map = cpumask_of_cpu(0);
 173 #endif
 174         start_kernel();
 175         return(0);
 176 }
 177
 178 int start_uml_skas(void)
 179 {
 180         start_userspace(0);
 181
 182         init_new_thread_signals(1);
 183         uml_idle_timer();
 184
 185         init_task.thread.request.u.thread.proc = start_kernel_proc;
 186         init_task.thread.request.u.thread.arg = NULL;
 187         return(start_idle_thread(init_task.thread_info,
 188                                  &init_task.thread.mode.skas.switch_buf,
 189                                  &init_task.thread.mode.skas.fork_buf));
 190 }
 191
 192 int external_pid_skas(struct task_struct *task)
 193 {
 194 #warning Need to look up userspace_pid by cpu
 195         return(userspace_pid[0]);
 196 }
 197
 198 int thread_pid_skas(struct task_struct *task)
 199 {
 200 #warning Need to look up userspace_pid by cpu
 201         return(userspace_pid[0]);
 202 }
 203
 204 /*
 205  * Overrides for Emacs so that we follow Linus's tabbing style.
 206  * Emacs will notice this stuff at the end of the file and automatically
 207  * adjust the settings for this buffer only.  This must remain at the end
 208  * of the file.
 209  * ---------------------------------------------------------------------------
 210  * Local variables:
 211  * c-file-style: "linux"
 212  * End:
 213  */