svn commit: r270444 - in head/sys: kern sys

[Mateusz Guzik]

Author: mjg
Date: Sun Aug 24 09:04:09 2014
New Revision: 270444
URL: http://svnweb.freebsd.org/changeset/base/270444

Log:
  Fix getppid for traced processes.
  
  Traced processes always have the tracer set as the parent.
  Utilize proc_realparent to obtain the right process when needed.
  
  Reviewed by:	kib
  MFC after:	1 week

Modified:
  head/sys/kern/kern_prot.c
  head/sys/sys/syscallsubr.h

Modified: head/sys/kern/kern_prot.c
==============================================================================
--- head/sys/kern/kern_prot.c	Sun Aug 24 09:02:16 2014	(r270443)
+++ head/sys/kern/kern_prot.c	Sun Aug 24 09:04:09 2014	(r270444)
@@ -105,9 +105,7 @@ sys_getpid(struct thread *td, struct get
 
 	td->td_retval[0] = p->p_pid;
 #if defined(COMPAT_43)
-	PROC_LOCK(p);
-	td->td_retval[1] = p->p_pptr->p_pid;
-	PROC_UNLOCK(p);
+	td->td_retval[1] = kern_getppid(td);
 #endif
 	return (0);
 }
@@ -121,12 +119,31 @@ struct getppid_args {
 int
 sys_getppid(struct thread *td, struct getppid_args *uap)
 {
+
+	td->td_retval[0] = kern_getppid(td);
+	return (0);
+}
+
+int
+kern_getppid(struct thread *td)
+{
 	struct proc *p = td->td_proc;
+	struct proc *pp;
+	int ppid;
 
 	PROC_LOCK(p);
-	td->td_retval[0] = p->p_pptr->p_pid;
-	PROC_UNLOCK(p);
-	return (0);
+	if (!(p->p_flag & P_TRACED)) {
+		ppid = p->p_pptr->p_pid;
+		PROC_UNLOCK(p);
+	} else {
+		PROC_UNLOCK(p);
+		sx_slock(&proctree_lock);
+		pp = proc_realparent(p);
+		ppid = pp->p_pid;
+		sx_sunlock(&proctree_lock);
+	}
+
+	return (ppid);
 }
 
 /*

Modified: head/sys/sys/syscallsubr.h
==============================================================================
--- head/sys/sys/syscallsubr.h	Sun Aug 24 09:02:16 2014	(r270443)
+++ head/sys/sys/syscallsubr.h	Sun Aug 24 09:04:09 2014	(r270444)
@@ -110,6 +110,7 @@ int	kern_getfsstat(struct thread *td, st
 	    enum uio_seg bufseg, int flags);
 int	kern_getgroups(struct thread *td, u_int *ngrp, gid_t *groups);
 int	kern_getitimer(struct thread *, u_int, struct itimerval *);
+int	kern_getppid(struct thread *);
 int	kern_getpeername(struct thread *td, int fd, struct sockaddr **sa,
 	    socklen_t *alen);
 int	kern_getrusage(struct thread *td, int who, struct rusage *rup);