arch/um/os-Linux/tt.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <unistd.h>
   8 #include <signal.h>
   9 #include <sched.h>
  10 #include <errno.h>
  11 #include <stdarg.h>
  12 #include <stdlib.h>
  13 #include <setjmp.h>
  14 #include <sys/time.h>
  15 #include <sys/ptrace.h>
  16 #include <linux/ptrace.h>
  17 #include <sys/wait.h>
  18 #include <sys/mman.h>
  19 #include <asm/ptrace.h>
  20 #include <asm/unistd.h>
  21 #include <asm/page.h>
  22 #include "user_util.h"
  23 #include "kern_util.h"
  24 #include "user.h"
  25 #include "signal_kern.h"
  26 #include "signal_user.h"
  27 #include "sysdep/ptrace.h"
  28 #include "sysdep/sigcontext.h"
  29 #include "irq_user.h"
  30 #include "ptrace_user.h"
  31 #include "time_user.h"
  32 #include "init.h"
  33 #include "os.h"
  34 #include "uml-config.h"
  35 #include "choose-mode.h"
  36 #include "mode.h"
  37 #include "tempfile.h"
  38
  39 /*
  40  *-------------------------
  41  * only for tt mode (will be deleted in future...)
  42  *-------------------------
  43  */
  44
  45 struct tramp {
  46         int (*tramp)(void *);
  47         void *tramp_data;
  48         unsigned long temp_stack;
  49         int flags;
  50         int pid;
  51 };
  52
  53 /* See above for why sigkill is here */
  54
  55 int sigkill = SIGKILL;
  56
  57 int outer_tramp(void *arg)
  58 {
  59         struct tramp *t;
  60         int sig = sigkill;
  61
  62         t = arg;
  63         t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2,
  64                        t->flags, t->tramp_data);
  65         if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
  66         kill(os_getpid(), sig);
  67         _exit(0);
  68 }
  69
  70 int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
  71                      int clone_flags, int (*tramp)(void *))
  72 {
  73         struct tramp arg;
  74         unsigned long sp;
  75         int new_pid, status, err;
  76
  77         /* The trampoline will run on the temporary stack */
  78         sp = stack_sp(temp_stack);
  79
  80         clone_flags |= CLONE_FILES | SIGCHLD;
  81
  82         arg.tramp = tramp;
  83         arg.tramp_data = thread_arg;
  84         arg.temp_stack = temp_stack;
  85         arg.flags = clone_flags;
  86
  87         /* Start the process and wait for it to kill itself */
  88         new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
  89         if(new_pid < 0)
  90                 return(new_pid);
  91
  92         CATCH_EINTR(err = waitpid(new_pid, &status, 0));
  93         if(err < 0)
  94                 panic("Waiting for outer trampoline failed - errno = %d",
  95                       errno);
  96
  97         if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
  98                 panic("outer trampoline didn't exit with SIGKILL, "
  99                       "status = %d", status);
 100
 101         return(arg.pid);
 102 }
 103
 104 void forward_pending_sigio(int target)
 105 {
 106         sigset_t sigs;
 107
 108         if(sigpending(&sigs))
 109                 panic("forward_pending_sigio : sigpending failed");
 110         if(sigismember(&sigs, SIGIO))
 111                 kill(target, SIGIO);
 112 }
 113