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 "sysdep/ptrace.h"
  27 #include "sysdep/sigcontext.h"
  28 #include "irq_user.h"
  29 #include "ptrace_user.h"
  30 #include "init.h"
  31 #include "os.h"
  32 #include "uml-config.h"
  33 #include "choose-mode.h"
  34 #include "mode.h"
  35 #include "tempfile.h"
  36
  37 int protect_memory(unsigned long addr, unsigned long len, int r, int w, int x,
  38                    int must_succeed)
  39 {
  40         int err;
  41
  42         err = os_protect_memory((void *) addr, len, r, w, x);
  43         if(err < 0){
  44                 if(must_succeed)
  45                         panic("protect failed, err = %d", -err);
  46                 else return(err);
  47         }
  48         return(0);
  49 }
  50
  51 void kill_child_dead(int pid)
  52 {
  53         kill(pid, SIGKILL);
  54         kill(pid, SIGCONT);
  55         do {
  56                 int n;
  57                 CATCH_EINTR(n = waitpid(pid, NULL, 0));
  58                 if (n > 0)
  59                         kill(pid, SIGCONT);
  60                 else
  61                         break;
  62         } while(1);
  63 }
  64
  65 void stop(void)
  66 {
  67         while(1) sleep(1000000);
  68 }
  69
  70 int wait_for_stop(int pid, int sig, int cont_type, void *relay)
  71 {
  72         sigset_t *relay_signals = relay;
  73         int status, ret;
  74
  75         while(1){
  76                 CATCH_EINTR(ret = waitpid(pid, &status, WUNTRACED));
  77                 if((ret < 0) ||
  78                    !WIFSTOPPED(status) || (WSTOPSIG(status) != sig)){
  79                         if(ret < 0){
  80                                 printk("wait failed, errno = %d\n",
  81                                        errno);
  82                         }
  83                         else if(WIFEXITED(status))
  84                                 printk("process %d exited with status %d\n",
  85                                        pid, WEXITSTATUS(status));
  86                         else if(WIFSIGNALED(status))
  87                                 printk("process %d exited with signal %d\n",
  88                                        pid, WTERMSIG(status));
  89                         else if((WSTOPSIG(status) == SIGVTALRM) ||
  90                                 (WSTOPSIG(status) == SIGALRM) ||
  91                                 (WSTOPSIG(status) == SIGIO) ||
  92                                 (WSTOPSIG(status) == SIGPROF) ||
  93                                 (WSTOPSIG(status) == SIGCHLD) ||
  94                                 (WSTOPSIG(status) == SIGWINCH) ||
  95                                 (WSTOPSIG(status) == SIGINT)){
  96                                 ptrace(cont_type, pid, 0, WSTOPSIG(status));
  97                                 continue;
  98                         }
  99                         else if((relay_signals != NULL) &&
 100                                 sigismember(relay_signals, WSTOPSIG(status))){
 101                                 ptrace(cont_type, pid, 0, WSTOPSIG(status));
 102                                 continue;
 103                         }
 104                         else printk("process %d stopped with signal %d\n",
 105                                     pid, WSTOPSIG(status));
 106                         panic("wait_for_stop failed to wait for %d to stop "
 107                               "with %d\n", pid, sig);
 108                 }
 109                 return(status);
 110         }
 111 }
 112
 113 /*
 114  *-------------------------
 115  * only for tt mode (will be deleted in future...)
 116  *-------------------------
 117  */
 118
 119 struct tramp {
 120         int (*tramp)(void *);
 121         void *tramp_data;
 122         unsigned long temp_stack;
 123         int flags;
 124         int pid;
 125 };
 126
 127 /* See above for why sigkill is here */
 128
 129 int sigkill = SIGKILL;
 130
 131 int outer_tramp(void *arg)
 132 {
 133         struct tramp *t;
 134         int sig = sigkill;
 135
 136         t = arg;
 137         t->pid = clone(t->tramp, (void *) t->temp_stack + page_size()/2,
 138                        t->flags, t->tramp_data);
 139         if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
 140         kill(os_getpid(), sig);
 141         _exit(0);
 142 }
 143
 144 int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
 145                      int clone_flags, int (*tramp)(void *))
 146 {
 147         struct tramp arg;
 148         unsigned long sp;
 149         int new_pid, status, err;
 150
 151         /* The trampoline will run on the temporary stack */
 152         sp = stack_sp(temp_stack);
 153
 154         clone_flags |= CLONE_FILES | SIGCHLD;
 155
 156         arg.tramp = tramp;
 157         arg.tramp_data = thread_arg;
 158         arg.temp_stack = temp_stack;
 159         arg.flags = clone_flags;
 160
 161         /* Start the process and wait for it to kill itself */
 162         new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
 163         if(new_pid < 0)
 164                 return(new_pid);
 165
 166         CATCH_EINTR(err = waitpid(new_pid, &status, 0));
 167         if(err < 0)
 168                 panic("Waiting for outer trampoline failed - errno = %d",
 169                       errno);
 170
 171         if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
 172                 panic("outer trampoline didn't exit with SIGKILL, "
 173                       "status = %d", status);
 174
 175         return(arg.pid);
 176 }
 177
 178 void forward_pending_sigio(int target)
 179 {
 180         sigset_t sigs;
 181
 182         if(sigpending(&sigs))
 183                 panic("forward_pending_sigio : sigpending failed");
 184         if(sigismember(&sigs, SIGIO))
 185                 kill(target, SIGIO);
 186 }
 187