>Number:         1392
>Category:       kern
>Synopsis:       linux waitpid & wait4 fail if status == NULL
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 21 11:05:02 1995
>Last-Modified:
>Originator:     Thomas Eberhardt
>Organization:
CeVis, University of Bremen, Germany
>Release:        NetBSD-current 950819
>Environment:
	
System: NetBSD ed209 1.0A NetBSD 1.0A (ED209) #4: Mon Aug 21 16:10:21 MET DST 1995     thomas@ed209:/usr/src/sys/arch/i386/compile/ED209 i386

Machine: i386
>Description:
	The linux compat code for waitpid & wait4 fails if the status
	argument is a NULL pointer.
>How-To-Repeat:
	Call the linux ldd binary (version 1.7.3 in my case) with a
	dynamically linked linux binary as an argument and watch it hang.
>Fix:
*** sys/compat/linux/linux_misc.c-	Mon Aug 21 09:00:14 1995
--- sys/compat/linux/linux_misc.c	Mon Aug 21 16:00:41 1995
***************
*** 112,134 ****
  	int error, *status, tstat;
  	caddr_t sg;
  
! 	sg = stackgap_init(p->p_emul);
! 	status = (int *) stackgap_alloc(&sg, sizeof status);
  
! 	SCARG(&w4a, pid) = SCARG(uap, pid);
! 	SCARG(&w4a, status) = status;
! 	SCARG(&w4a, options) = SCARG(uap, options);
! 	SCARG(&w4a, rusage) = NULL;
! 
! 	if ((error = wait4(p, &w4a, retval)))
! 		return error;
! 
! 	if ((error = copyin(status, &tstat, sizeof tstat)))
! 		return error;
! 
! 	bsd_to_linux_wstat(&tstat);
! 
! 	return copyout(&tstat, SCARG(uap, status), sizeof tstat);
  }
  
  /*
--- 112,143 ----
  	int error, *status, tstat;
  	caddr_t sg;
  
! 	if (SCARG(uap, status) != NULL) {
! 		sg = stackgap_init(p->p_emul);
! 		status = (int *) stackgap_alloc(&sg, sizeof status);
! 
! 		SCARG(&w4a, pid) = SCARG(uap, pid);
! 		SCARG(&w4a, status) = status;
! 		SCARG(&w4a, options) = SCARG(uap, options);
! 		SCARG(&w4a, rusage) = NULL;
! 
! 		if ((error = wait4(p, &w4a, retval)))
! 			return error;
! 
! 		if ((error = copyin(status, &tstat, sizeof tstat)))
! 			return error;
! 
! 		bsd_to_linux_wstat(&tstat);
! 
! 		return copyout(&tstat, SCARG(uap, status), sizeof tstat);
! 	} else {
! 		SCARG(&w4a, pid) = SCARG(uap, pid);
! 		SCARG(&w4a, status) = NULL;
! 		SCARG(&w4a, options) = SCARG(uap, options);
! 		SCARG(&w4a, rusage) = NULL;
  
! 		return wait4(p, &w4a, retval);
! 	}
  }
  
  /*
***************
*** 149,171 ****
  	int error, *status, tstat;
  	caddr_t sg;
  
! 	sg = stackgap_init(p->p_emul);
! 	status = (int *) stackgap_alloc(&sg, sizeof status);
! 
! 	SCARG(&w4a, pid) = SCARG(uap, pid);
! 	SCARG(&w4a, status) = status;
! 	SCARG(&w4a, options) = SCARG(uap, options);
! 	SCARG(&w4a, rusage) = SCARG(uap, rusage);
! 
! 	if ((error = wait4(p, &w4a, retval)))
! 		return error;
! 
! 	if ((error = copyin(status, &tstat, sizeof tstat)))
! 		return error;
! 
! 	bsd_to_linux_wstat(&tstat);
  
! 	return copyout(&tstat, SCARG(uap, status), sizeof tstat);
  }
  
  /*
--- 158,189 ----
  	int error, *status, tstat;
  	caddr_t sg;
  
! 	if (SCARG(uap, status) != NULL) {
! 		sg = stackgap_init(p->p_emul);
! 		status = (int *) stackgap_alloc(&sg, sizeof status);
! 
! 		SCARG(&w4a, pid) = SCARG(uap, pid);
! 		SCARG(&w4a, status) = status;
! 		SCARG(&w4a, options) = SCARG(uap, options);
! 		SCARG(&w4a, rusage) = SCARG(uap, rusage);
! 
! 		if ((error = wait4(p, &w4a, retval)))
! 			return error;
! 
! 		if ((error = copyin(status, &tstat, sizeof tstat)))
! 			return error;
! 
! 		bsd_to_linux_wstat(&tstat);
! 
! 		return copyout(&tstat, SCARG(uap, status), sizeof tstat);
! 	} else {
! 		SCARG(&w4a, pid) = SCARG(uap, pid);
! 		SCARG(&w4a, status) = NULL;
! 		SCARG(&w4a, options) = SCARG(uap, options);
! 		SCARG(&w4a, rusage) = NULL;
  
! 		return wait4(p, &w4a, retval);
! 	}
  }
  
  /*
>Audit-Trail:
>Unformatted: