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 <sys/time.h>
  14 #include <sys/ptrace.h>
  15 #include <linux/ptrace.h>
  16 #include <sys/wait.h>
  17 #include <sys/mman.h>
  18 #include <asm/ptrace.h>
  19 #include <asm/unistd.h>
  20 #include "kern_util.h"
  21 #include "user.h"
  22 #include "signal_kern.h"
  23 #include "sysdep/ptrace.h"
  24 #include "sysdep/sigcontext.h"
  25 #include "irq_user.h"
  26 #include "ptrace_user.h"
  27 #include "init.h"
  28 #include "os.h"
  29 #include "uml-config.h"
  30 #include "choose-mode.h"
  31 #include "mode.h"
  32 #include "tempfile.h"
  33 #include "kern_constants.h"
  34
  35 int protect_memory(unsigned long addr, unsigned long len, int r, int w, int x,
  36                    int must_succeed)
  37 {
  38         int err;
  39
  40         err = os_protect_memory((void *) addr, len, r, w, x);
  41         if(err < 0){
  42                 if(must_succeed)
  43                         panic("protect failed, err = %d", -err);
  44                 else return(err);
  45         }
  46         return(0);
  47 }
  48
  49 void kill_child_dead(int pid)
  50 {
  51         kill(pid, SIGKILL);
  52         kill(pid, SIGCONT);
  53         do {
  54                 int n;
  55                 CATCH_EINTR(n = waitpid(pid, NULL, 0));
  56                 if (n > 0)
  57                         kill(pid, SIGCONT);
  58                 else
  59                         break;
  60         } while(1);
  61 }
  62
  63 void stop(void)
  64 {
  65         while(1) sleep(1000000);
  66 }
  67
  68 int wait_for_stop(int pid, int sig, int cont_type, void *relay)
  69 {
  70         sigset_t *relay_signals = relay;
  71         int status, ret;
  72
  73         while(1){
  74                 CATCH_EINTR(ret = waitpid(pid, &status, WUNTRACED));
  75                 if((ret < 0) ||
  76                    !WIFSTOPPED(status) || (WSTOPSIG(status) != sig)){
  77                         if(ret < 0){
  78                                 printk("wait failed, errno = %d\n",
  79                                        errno);
  80                         }
  81                         else if(WIFEXITED(status))
  82                                 printk("process %d exited with status %d\n",
  83                                        pid, WEXITSTATUS(status));
  84                         else if(WIFSIGNALED(status))
  85                                 printk("process %d exited with signal %d\n",
  86                                        pid, WTERMSIG(status));
  87                         else if((WSTOPSIG(status) == SIGVTALRM) ||
  88                                 (WSTOPSIG(status) == SIGALRM) ||
  89                                 (WSTOPSIG(status) == SIGIO) ||
  90                                 (WSTOPSIG(status) == SIGPROF) ||
  91                                 (WSTOPSIG(status) == SIGCHLD) ||
  92                                 (WSTOPSIG(status) == SIGWINCH) ||
  93                                 (WSTOPSIG(status) == SIGINT)){
  94                                 ptrace(cont_type, pid, 0, WSTOPSIG(status));
  95                                 continue;
  96                         }
  97                         else if((relay_signals != NULL) &&
  98                                 sigismember(relay_signals, WSTOPSIG(status))){
  99                                 ptrace(cont_type, pid, 0, WSTOPSIG(status));
 100                                 continue;
 101                         }
 102                         else printk("process %d stopped with signal %d\n",
 103                                     pid, WSTOPSIG(status));
 104                         panic("wait_for_stop failed to wait for %d to stop "
 105                               "with %d\n", pid, sig);
 106                 }
 107                 return(status);
 108         }
 109 }
 110
 111 void forward_ipi(int fd, int pid)
 112 {
 113         int err;
 114
 115         err = os_set_owner(fd, pid);
 116         if(err < 0)
 117                 printk("forward_ipi: set_owner failed, fd = %d, me = %d, "
 118                        "target = %d, err = %d\n", fd, os_getpid(), pid, -err);
 119 }
 120
 121 /*
 122  *-------------------------
 123  * only for tt mode (will be deleted in future...)
 124  *-------------------------
 125  */
 126
 127 struct tramp {
 128         int (*tramp)(void *);
 129         void *tramp_data;
 130         unsigned long temp_stack;
 131         int flags;
 132         int pid;
 133 };
 134
 135 /* See above for why sigkill is here */
 136
 137 int sigkill = SIGKILL;
 138
 139 int outer_tramp(void *arg)
 140 {
 141         struct tramp *t;
 142         int sig = sigkill;
 143
 144         t = arg;
 145         t->pid = clone(t->tramp, (void *) t->temp_stack + UM_KERN_PAGE_SIZE/2,
 146                        t->flags, t->tramp_data);
 147         if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
 148         kill(os_getpid(), sig);
 149         _exit(0);
 150 }
 151
 152 int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
 153                      int clone_flags, int (*tramp)(void *))
 154 {
 155         struct tramp arg;
 156         unsigned long sp;
 157         int new_pid, status, err;
 158
 159         /* The trampoline will run on the temporary stack */
 160         sp = stack_sp(temp_stack);
 161
 162         clone_flags |= CLONE_FILES | SIGCHLD;
 163
 164         arg.tramp = tramp;
 165         arg.tramp_data = thread_arg;
 166         arg.temp_stack = temp_stack;
 167         arg.flags = clone_flags;
 168
 169         /* Start the process and wait for it to kill itself */
 170         new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
 171         if(new_pid < 0)
 172                 return(new_pid);
 173
 174         CATCH_EINTR(err = waitpid(new_pid, &status, 0));
 175         if(err < 0)
 176                 panic("Waiting for outer trampoline failed - errno = %d",
 177                       errno);
 178
 179         if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
 180                 panic("outer trampoline didn't exit with SIGKILL, "
 181                       "status = %d", status);
 182
 183         return(arg.pid);
 184 }
 185
 186 void forward_pending_sigio(int target)
 187 {
 188         sigset_t sigs;
 189
 190         if(sigpending(&sigs))
 191                 panic("forward_pending_sigio : sigpending failed");
 192         if(sigismember(&sigs, SIGIO))
 193                 kill(target, SIGIO);
 194 }
 195