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 <asm/page.h>
  21 #include "kern_util.h"
  22 #include "user.h"
  23 #include "signal_kern.h"
  24 #include "sysdep/ptrace.h"
  25 #include "sysdep/sigcontext.h"
  26 #include "irq_user.h"
  27 #include "ptrace_user.h"
  28 #include "init.h"
  29 #include "os.h"
  30 #include "uml-config.h"
  31 #include "choose-mode.h"
  32 #include "mode.h"
  33 #include "tempfile.h"
  34 #include "kern_constants.h"
  35
  36 int protect_memory(unsigned long addr, unsigned long len, int r, int w, int x,
  37                    int must_succeed)
  38 {
  39         int err;
  40
  41         err = os_protect_memory((void *) addr, len, r, w, x);
  42         if(err < 0){
  43                 if(must_succeed)
  44                         panic("protect failed, err = %d", -err);
  45                 else return(err);
  46         }
  47         return(0);
  48 }
  49
  50 void kill_child_dead(int pid)
  51 {
  52         kill(pid, SIGKILL);
  53         kill(pid, SIGCONT);
  54         do {
  55                 int n;
  56                 CATCH_EINTR(n = waitpid(pid, NULL, 0));
  57                 if (n > 0)
  58                         kill(pid, SIGCONT);
  59                 else
  60                         break;
  61         } while(1);
  62 }
  63
  64 void stop(void)
  65 {
  66         while(1) sleep(1000000);
  67 }
  68
  69 int wait_for_stop(int pid, int sig, int cont_type, void *relay)
  70 {
  71         sigset_t *relay_signals = relay;
  72         int status, ret;
  73
  74         while(1){
  75                 CATCH_EINTR(ret = waitpid(pid, &status, WUNTRACED));
  76                 if((ret < 0) ||
  77                    !WIFSTOPPED(status) || (WSTOPSIG(status) != sig)){
  78                         if(ret < 0){
  79                                 printk("wait failed, errno = %d\n",
  80                                        errno);
  81                         }
  82                         else if(WIFEXITED(status))
  83                                 printk("process %d exited with status %d\n",
  84                                        pid, WEXITSTATUS(status));
  85                         else if(WIFSIGNALED(status))
  86                                 printk("process %d exited with signal %d\n",
  87                                        pid, WTERMSIG(status));
  88                         else if((WSTOPSIG(status) == SIGVTALRM) ||
  89                                 (WSTOPSIG(status) == SIGALRM) ||
  90                                 (WSTOPSIG(status) == SIGIO) ||
  91                                 (WSTOPSIG(status) == SIGPROF) ||
  92                                 (WSTOPSIG(status) == SIGCHLD) ||
  93                                 (WSTOPSIG(status) == SIGWINCH) ||
  94                                 (WSTOPSIG(status) == SIGINT)){
  95                                 ptrace(cont_type, pid, 0, WSTOPSIG(status));
  96                                 continue;
  97                         }
  98                         else if((relay_signals != NULL) &&
  99                                 sigismember(relay_signals, WSTOPSIG(status))){
 100                                 ptrace(cont_type, pid, 0, WSTOPSIG(status));
 101                                 continue;
 102                         }
 103                         else printk("process %d stopped with signal %d\n",
 104                                     pid, WSTOPSIG(status));
 105                         panic("wait_for_stop failed to wait for %d to stop "
 106                               "with %d\n", pid, sig);
 107                 }
 108                 return(status);
 109         }
 110 }
 111
 112 void forward_ipi(int fd, int pid)
 113 {
 114         int err;
 115
 116         err = os_set_owner(fd, pid);
 117         if(err < 0)
 118                 printk("forward_ipi: set_owner failed, fd = %d, me = %d, "
 119                        "target = %d, err = %d\n", fd, os_getpid(), pid, -err);
 120 }
 121
 122 /*
 123  *-------------------------
 124  * only for tt mode (will be deleted in future...)
 125  *-------------------------
 126  */
 127
 128 struct tramp {
 129         int (*tramp)(void *);
 130         void *tramp_data;
 131         unsigned long temp_stack;
 132         int flags;
 133         int pid;
 134 };
 135
 136 /* See above for why sigkill is here */
 137
 138 int sigkill = SIGKILL;
 139
 140 int outer_tramp(void *arg)
 141 {
 142         struct tramp *t;
 143         int sig = sigkill;
 144
 145         t = arg;
 146         t->pid = clone(t->tramp, (void *) t->temp_stack + UM_KERN_PAGE_SIZE/2,
 147                        t->flags, t->tramp_data);
 148         if(t->pid > 0) wait_for_stop(t->pid, SIGSTOP, PTRACE_CONT, NULL);
 149         kill(os_getpid(), sig);
 150         _exit(0);
 151 }
 152
 153 int start_fork_tramp(void *thread_arg, unsigned long temp_stack,
 154                      int clone_flags, int (*tramp)(void *))
 155 {
 156         struct tramp arg;
 157         unsigned long sp;
 158         int new_pid, status, err;
 159
 160         /* The trampoline will run on the temporary stack */
 161         sp = stack_sp(temp_stack);
 162
 163         clone_flags |= CLONE_FILES | SIGCHLD;
 164
 165         arg.tramp = tramp;
 166         arg.tramp_data = thread_arg;
 167         arg.temp_stack = temp_stack;
 168         arg.flags = clone_flags;
 169
 170         /* Start the process and wait for it to kill itself */
 171         new_pid = clone(outer_tramp, (void *) sp, clone_flags, &arg);
 172         if(new_pid < 0)
 173                 return(new_pid);
 174
 175         CATCH_EINTR(err = waitpid(new_pid, &status, 0));
 176         if(err < 0)
 177                 panic("Waiting for outer trampoline failed - errno = %d",
 178                       errno);
 179
 180         if(!WIFSIGNALED(status) || (WTERMSIG(status) != SIGKILL))
 181                 panic("outer trampoline didn't exit with SIGKILL, "
 182                       "status = %d", status);
 183
 184         return(arg.pid);
 185 }
 186
 187 void forward_pending_sigio(int target)
 188 {
 189         sigset_t sigs;
 190
 191         if(sigpending(&sigs))
 192                 panic("forward_pending_sigio : sigpending failed");
 193         if(sigismember(&sigs, SIGIO))
 194                 kill(target, SIGIO);
 195 }
 196