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 "skas.h"
  17 #include "os.h"
  18 #include "user_util.h"
  19 #include "tlb.h"
  20 #include "kern.h"
  21 #include "mode.h"
  22 #include "registers.h"
  23
  24 void switch_to_skas(void *prev, void *next)
  25 {
  26         struct task_struct *from, *to;
  27
  28         from = prev;
  29         to = next;
  30
  31         /* XXX need to check runqueues[cpu].idle */
  32         if(current->pid == 0)
  33                 switch_timers(0);
  34
  35         switch_threads(&from->thread.mode.skas.switch_buf,
  36                        to->thread.mode.skas.switch_buf);
  37
  38         arch_switch_to_skas(current->thread.prev_sched, current);
  39
  40         if(current->pid == 0)
  41                 switch_timers(1);
  42 }
  43
  44 extern void schedule_tail(struct task_struct *prev);
  45
  46 void new_thread_handler(int sig)
  47 {
  48         int (*fn)(void *), n;
  49         void *arg;
  50
  51         fn = current->thread.request.u.thread.proc;
  52         arg = current->thread.request.u.thread.arg;
  53         os_usr1_signal(1);
  54         thread_wait(&current->thread.mode.skas.switch_buf,
  55                     current->thread.mode.skas.fork_buf);
  56
  57         if(current->thread.prev_sched != NULL)
  58                 schedule_tail(current->thread.prev_sched);
  59         current->thread.prev_sched = NULL;
  60
  61         /* The return value is 1 if the kernel thread execs a process,
  62          * 0 if it just exits
  63          */
  64         n = run_kernel_thread(fn, arg, &current->thread.exec_buf);
  65         if(n == 1){
  66                 /* Handle any immediate reschedules or signals */
  67                 interrupt_end();
  68                 userspace(&current->thread.regs.regs);
  69         }
  70         else do_exit(0);
  71 }
  72
  73 void new_thread_proc(void *stack, void (*handler)(int sig))
  74 {
  75         init_new_thread_stack(stack, handler);
  76         os_usr1_process(os_getpid());
  77 }
  78
  79 void release_thread_skas(struct task_struct *task)
  80 {
  81 }
  82
  83 void fork_handler(int sig)
  84 {
  85         os_usr1_signal(1);
  86         thread_wait(&current->thread.mode.skas.switch_buf,
  87                     current->thread.mode.skas.fork_buf);
  88
  89         force_flush_all();
  90         if(current->thread.prev_sched == NULL)
  91                 panic("blech");
  92
  93         schedule_tail(current->thread.prev_sched);
  94         current->thread.prev_sched = NULL;
  95
  96 /* Handle any immediate reschedules or signals */
  97         interrupt_end();
  98         userspace(&current->thread.regs.regs);
  99 }
 100
 101 int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 102                      unsigned long stack_top, struct task_struct * p,
 103                      struct pt_regs *regs)
 104 {
 105         void (*handler)(int);
 106
 107         if(current->thread.forking){
 108                 memcpy(&p->thread.regs.regs.skas, &regs->regs.skas,
 109                        sizeof(p->thread.regs.regs.skas));
 110                 REGS_SET_SYSCALL_RETURN(p->thread.regs.regs.skas.regs, 0);
 111                 if(sp != 0) REGS_SP(p->thread.regs.regs.skas.regs) = sp;
 112
 113                 handler = fork_handler;
 114
 115                 arch_copy_thread(&current->thread.arch, &p->thread.arch);
 116         }
 117         else {
 118                 init_thread_registers(&p->thread.regs.regs);
 119                 p->thread.request.u.thread = current->thread.request.u.thread;
 120                 handler = new_thread_handler;
 121         }
 122
 123         new_thread(task_stack_page(p), &p->thread.mode.skas.switch_buf,
 124                    &p->thread.mode.skas.fork_buf, handler);
 125         return(0);
 126 }
 127
 128 int new_mm(unsigned long stack)
 129 {
 130         int fd;
 131
 132         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 133         if(fd < 0)
 134                 return(fd);
 135
 136         if(skas_needs_stub)
 137                 map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 138
 139         return(fd);
 140 }
 141
 142 void init_idle_skas(void)
 143 {
 144         cpu_tasks[current_thread->cpu].pid = os_getpid();
 145         default_idle();
 146 }
 147
 148 extern void start_kernel(void);
 149
 150 static int start_kernel_proc(void *unused)
 151 {
 152         int pid;
 153
 154         block_signals();
 155         pid = os_getpid();
 156
 157         cpu_tasks[0].pid = pid;
 158         cpu_tasks[0].task = current;
 159 #ifdef CONFIG_SMP
 160         cpu_online_map = cpumask_of_cpu(0);
 161 #endif
 162         start_kernel();
 163         return(0);
 164 }
 165
 166 extern int userspace_pid[];
 167
 168 int start_uml_skas(void)
 169 {
 170         if(proc_mm)
 171                 userspace_pid[0] = start_userspace(0);
 172
 173         init_new_thread_signals(1);
 174
 175         init_task.thread.request.u.thread.proc = start_kernel_proc;
 176         init_task.thread.request.u.thread.arg = NULL;
 177         return(start_idle_thread(task_stack_page(&init_task),
 178                                  &init_task.thread.mode.skas.switch_buf,
 179                                  &init_task.thread.mode.skas.fork_buf));
 180 }
 181
 182 int external_pid_skas(struct task_struct *task)
 183 {
 184 #warning Need to look up userspace_pid by cpu
 185         return(userspace_pid[0]);
 186 }
 187
 188 int thread_pid_skas(struct task_struct *task)
 189 {
 190 #warning Need to look up userspace_pid by cpu
 191         return(userspace_pid[0]);
 192 }
 193
 194 void kill_off_processes_skas(void)
 195 {
 196         if(proc_mm)
 197 #warning need to loop over userspace_pids in kill_off_processes_skas
 198                 os_kill_ptraced_process(userspace_pid[0], 1);
 199         else {
 200                 struct task_struct *p;
 201                 int pid, me;
 202
 203                 me = os_getpid();
 204                 for_each_process(p){
 205                         if(p->mm == NULL)
 206                                 continue;
 207
 208                         pid = p->mm->context.skas.id.u.pid;
 209                         os_kill_ptraced_process(pid, 1);
 210                 }
 211         }
 212 }
 213
 214 unsigned long current_stub_stack(void)
 215 {
 216         if(current->mm == NULL)
 217                 return(0);
 218
 219         return(current->mm->context.skas.id.stack);
 220 }