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                 /* Handle any immediate reschedules or signals */
  73                 interrupt_end();
  74                 userspace(&current->thread.regs.regs);
  75         }
  76         else do_exit(0);
  77 }
  78
  79 void new_thread_proc(void *stack, void (*handler)(int sig))
  80 {
  81         init_new_thread_stack(stack, handler);
  82         os_usr1_process(os_getpid());
  83 }
  84
  85 void release_thread_skas(struct task_struct *task)
  86 {
  87 }
  88
  89 void fork_handler(int sig)
  90 {
  91         change_sig(SIGUSR1, 1);
  92         thread_wait(&current->thread.mode.skas.switch_buf,
  93                     current->thread.mode.skas.fork_buf);
  94
  95         force_flush_all();
  96         if(current->thread.prev_sched == NULL)
  97                 panic("blech");
  98
  99         schedule_tail(current->thread.prev_sched);
 100         current->thread.prev_sched = NULL;
 101
 102         /* Handle any immediate reschedules or signals */
 103         interrupt_end();
 104         userspace(&current->thread.regs.regs);
 105 }
 106
 107 int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp,
 108                      unsigned long stack_top, struct task_struct * p,
 109                      struct pt_regs *regs)
 110 {
 111         void (*handler)(int);
 112
 113         if(current->thread.forking){
 114                 memcpy(&p->thread.regs.regs.skas, &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 extern void map_stub_pages(int fd, unsigned long code,
 133                            unsigned long data, unsigned long stack);
 134 int new_mm(int from, unsigned long stack)
 135 {
 136         struct proc_mm_op copy;
 137         int n, fd;
 138
 139         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 140         if(fd < 0)
 141                 return(fd);
 142
 143         if(from != -1){
 144                 copy = ((struct proc_mm_op) { .op       = MM_COPY_SEGMENTS,
 145                                               .u        =
 146                                               { .copy_segments  = from } } );
 147                 n = os_write_file(fd, &copy, sizeof(copy));
 148                 if(n != sizeof(copy))
 149                         printk("new_mm : /proc/mm copy_segments failed, "
 150                                "err = %d\n", -n);
 151         }
 152
 153         if(!ptrace_faultinfo)
 154                 map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 155
 156         return(fd);
 157 }
 158
 159 void init_idle_skas(void)
 160 {
 161         cpu_tasks[current_thread->cpu].pid = os_getpid();
 162         default_idle();
 163 }
 164
 165 extern void start_kernel(void);
 166
 167 static int start_kernel_proc(void *unused)
 168 {
 169         int pid;
 170
 171         block_signals();
 172         pid = os_getpid();
 173
 174         cpu_tasks[0].pid = pid;
 175         cpu_tasks[0].task = current;
 176 #ifdef CONFIG_SMP
 177         cpu_online_map = cpumask_of_cpu(0);
 178 #endif
 179         start_kernel();
 180         return(0);
 181 }
 182
 183 extern int userspace_pid[];
 184
 185 int start_uml_skas(void)
 186 {
 187         if(proc_mm)
 188                 userspace_pid[0] = start_userspace(0);
 189
 190         init_new_thread_signals(1);
 191
 192         init_task.thread.request.u.thread.proc = start_kernel_proc;
 193         init_task.thread.request.u.thread.arg = NULL;
 194         return(start_idle_thread(init_task.thread_info,
 195                                  &init_task.thread.mode.skas.switch_buf,
 196                                  &init_task.thread.mode.skas.fork_buf));
 197 }
 198
 199 int external_pid_skas(struct task_struct *task)
 200 {
 201 #warning Need to look up userspace_pid by cpu
 202         return(userspace_pid[0]);
 203 }
 204
 205 int thread_pid_skas(struct task_struct *task)
 206 {
 207 #warning Need to look up userspace_pid by cpu
 208         return(userspace_pid[0]);
 209 }
 210
 211 void kill_off_processes_skas(void)
 212 {
 213         if(proc_mm)
 214 #warning need to loop over userspace_pids in kill_off_processes_skas
 215                 os_kill_ptraced_process(userspace_pid[0], 1);
 216         else {
 217                 struct task_struct *p;
 218                 int pid, me;
 219
 220                 me = os_getpid();
 221                 for_each_process(p){
 222                         if(p->mm == NULL)
 223                                 continue;
 224
 225                         pid = p->mm->context.skas.id.u.pid;
 226                         os_kill_ptraced_process(pid, 1);
 227                 }
 228         }
 229 }
 230
 231 unsigned long current_stub_stack(void)
 232 {
 233         if(current->mm == NULL)
 234                 return(0);
 235
 236         return(current->mm->context.skas.id.stack);
 237 }