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 "skas.h"
  18 #include "os.h"
  19 #include "user_util.h"
  20 #include "tlb.h"
  21 #include "kern.h"
  22 #include "mode.h"
  23 #include "proc_mm.h"
  24 #include "registers.h"
  25
  26 void switch_to_skas(void *prev, void *next)
  27 {
  28         struct task_struct *from, *to;
  29
  30         from = prev;
  31         to = next;
  32
  33         /* XXX need to check runqueues[cpu].idle */
  34         if(current->pid == 0)
  35                 switch_timers(0);
  36
  37         switch_threads(&from->thread.mode.skas.switch_buf,
  38                        to->thread.mode.skas.switch_buf);
  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         change_sig(SIGUSR1, 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         change_sig(SIGUSR1, 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         else {
 116                 init_thread_registers(&p->thread.regs.regs);
 117                 p->thread.request.u.thread = current->thread.request.u.thread;
 118                 handler = new_thread_handler;
 119         }
 120
 121         new_thread(p->thread_info, &p->thread.mode.skas.switch_buf,
 122                    &p->thread.mode.skas.fork_buf, handler);
 123         return(0);
 124 }
 125
 126 extern void map_stub_pages(int fd, unsigned long code,
 127                            unsigned long data, unsigned long stack);
 128 int new_mm(int from, unsigned long stack)
 129 {
 130         struct proc_mm_op copy;
 131         int n, fd;
 132
 133         fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
 134         if(fd < 0)
 135                 return(fd);
 136
 137         if(from != -1){
 138                 copy = ((struct proc_mm_op) { .op       = MM_COPY_SEGMENTS,
 139                                               .u        =
 140                                               { .copy_segments  = from } } );
 141                 n = os_write_file(fd, &copy, sizeof(copy));
 142                 if(n != sizeof(copy))
 143                         printk("new_mm : /proc/mm copy_segments failed, "
 144                                "err = %d\n", -n);
 145         }
 146
 147         if(skas_needs_stub)
 148                 map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
 149
 150         return(fd);
 151 }
 152
 153 void init_idle_skas(void)
 154 {
 155         cpu_tasks[current_thread->cpu].pid = os_getpid();
 156         default_idle();
 157 }
 158
 159 extern void start_kernel(void);
 160
 161 static int start_kernel_proc(void *unused)
 162 {
 163         int pid;
 164
 165         block_signals();
 166         pid = os_getpid();
 167
 168         cpu_tasks[0].pid = pid;
 169         cpu_tasks[0].task = current;
 170 #ifdef CONFIG_SMP
 171         cpu_online_map = cpumask_of_cpu(0);
 172 #endif
 173         start_kernel();
 174         return(0);
 175 }
 176
 177 extern int userspace_pid[];
 178
 179 int start_uml_skas(void)
 180 {
 181         if(proc_mm)
 182                 userspace_pid[0] = start_userspace(0);
 183
 184         init_new_thread_signals(1);
 185
 186         init_task.thread.request.u.thread.proc = start_kernel_proc;
 187         init_task.thread.request.u.thread.arg = NULL;
 188         return(start_idle_thread(init_task.thread_info,
 189                                  &init_task.thread.mode.skas.switch_buf,
 190                                  &init_task.thread.mode.skas.fork_buf));
 191 }
 192
 193 int external_pid_skas(struct task_struct *task)
 194 {
 195 #warning Need to look up userspace_pid by cpu
 196         return(userspace_pid[0]);
 197 }
 198
 199 int thread_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 void kill_off_processes_skas(void)
 206 {
 207         if(proc_mm)
 208 #warning need to loop over userspace_pids in kill_off_processes_skas
 209                 os_kill_ptraced_process(userspace_pid[0], 1);
 210         else {
 211                 struct task_struct *p;
 212                 int pid, me;
 213
 214                 me = os_getpid();
 215                 for_each_process(p){
 216                         if(p->mm == NULL)
 217                                 continue;
 218
 219                         pid = p->mm->context.skas.id.u.pid;
 220                         os_kill_ptraced_process(pid, 1);
 221                 }
 222         }
 223 }
 224
 225 unsigned long current_stub_stack(void)
 226 {
 227         if(current->mm == NULL)
 228                 return(0);
 229
 230         return(current->mm->context.skas.id.stack);
 231 }