RFC: [PATCH] trans/fakeroot.c

[Svante Signell]

Hello,

The attached test case gnat-4.9-test.tar.gz is a stripped-down version
of the gnat-4.9 build with a custom fakeroot-hurd script.  With the
current version of fakeroot-hurd, the build fails. The attached patch
trans_fakeroot.patch fixes this.

The idea is to limit the openmodes according to the values defined in
struct netnode and to change the test for overlapping sets. Packages
built with the patched fakeroot are: gnumach, hurd, glibc and gnat-4.9.
Currently gcc-5 is building. The patch is verbose, the redundant
comments will be removed when the patch is commented on and hopefully
approved.

Thanks!

gnat-4.9-test.tar.gz
Description: application/compressed-tar

Index: hurd-0.6/trans/fakeroot.c
===================================================================
--- hurd-0.6.orig/trans/fakeroot.c
+++ hurd-0.6/trans/fakeroot.c
@@ -59,6 +59,8 @@ struct netnode
   unsigned int faked;
 };
 
+#define O_ALLOWED (O_READ | O_WRITE | O_EXEC)
+
 #define FAKE_UID	(1 << 0)
 #define FAKE_GID	(1 << 1)
 #define FAKE_AUTHOR	(1 << 2)
@@ -79,6 +81,11 @@ new_node (file_t file, mach_port_t idpor
 {
   error_t err;
   struct netnode *nn;
+
+  /* XXX: Limit openmodes */
+  if (openmodes > O_ALLOWED)
+    openmodes &= O_ALLOWED; /* works */
+
   *np = netfs_make_node_alloc (sizeof *nn);
   if (*np == 0)
     {
@@ -91,7 +98,12 @@ new_node (file_t file, mach_port_t idpor
     }
   nn = netfs_node_netnode (*np);
   nn->file = file;
-  nn->openmodes = openmodes;
+
+  /* FIXME: Forbid nn->openmodes == 0 and openmodes == 0? */
+  /* XXX: Change nn->openmodes selectively */
+  if (openmodes != nn->openmodes)  /* works */
+    nn->openmodes = openmodes;
+
   if (idport != MACH_PORT_NULL)
     nn->idport = idport;
   else
@@ -207,11 +219,14 @@ check_openmodes (struct netnode *nn, int
 {
   error_t err = 0;
 
-  if (newmodes &~ nn->openmodes)
+  /* XXX: Limit modes */
+  newmodes &= O_ALLOWED;
+  nn->openmodes &= O_ALLOWED;
+  if (~nn->openmodes & newmodes)
     {
       /* The user wants openmodes we haven't tried before.  */
 
-      if (file != MACH_PORT_NULL && (nn->openmodes & ~newmodes))
+      if (file != MACH_PORT_NULL && (nn->openmodes & newmodes )) /* works */
 	{
 	  /* Intersecting sets.
 	     We need yet another new peropen on this node.  */
@@ -237,7 +252,9 @@ check_openmodes (struct netnode *nn, int
 	     the old one.  We can just use it now.  */
 	  mach_port_deallocate (mach_task_self (), nn->file);
 	  nn->file = file;
-	  nn->openmodes = newmodes;
+	  /* XXX: Change nn->openmodes selectively */
+	  //if (newmodes > nn->openmodes)
+	    nn->openmodes = newmodes;
 	}
     }
   else if (file != MACH_PORT_NULL)
@@ -394,7 +411,8 @@ netfs_S_dir_lookup (struct protid *dirus
   else
     {
       pthread_spin_unlock (&netfs_node_refcnt_lock);
-      err = new_node (file, idport, 1, flags, &np);
+      /* XXX: Don't limit flags */
+      err = new_node (file, idport, 1, flags, &np); /* works with limit */
       pthread_mutex_unlock (&dnp->lock);
       if (!err)
 	{