[patch] somebody please fix this outstanding mmap(2) bug

[Alexander Best]

oops. forgot the patch. ;)

-- 
Alexander Best
-------------- next part --------------
Index: sys/vm/vm_mmap.c
===================================================================
--- sys/vm/vm_mmap.c	(revision 205390)
+++ sys/vm/vm_mmap.c	(working copy)
@@ -241,19 +241,23 @@
 		    ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
 			return (EINVAL);
 		flags |= MAP_ANON;
-		pos = 0;
 	}
 
-	/*
-	 * Align the file position to a page boundary,
-	 * and save its page offset component.
-	 */
-	pageoff = (pos & PAGE_MASK);
-	pos -= pageoff;
+	/* If MAP_ANON has been set the offset argument is being discarded. */
+	if (flags & MAP_ANON) {
+		pageoff = pos = 0;
+	} else {
+		/*
+		 * Align the file position to a page boundary,
+		 * and save its page offset component.
+		 */
+		pageoff = (pos & PAGE_MASK);
+		pos -= pageoff;
 
-	/* Adjust size for rounding (on both ends). */
-	size += pageoff;			/* low end... */
-	size = (vm_size_t) round_page(size);	/* hi end */
+		/* Adjust size for rounding (on both ends). */
+		size += pageoff;			/* low end... */
+		size = (vm_size_t) round_page(size);	/* hi end */
+	}
 
 	/*
 	 * Check for illegal addresses.  Watch out for address wrap... Note
@@ -300,7 +304,6 @@
 		handle = NULL;
 		handle_type = OBJT_DEFAULT;
 		maxprot = VM_PROT_ALL;
-		pos = 0;
 	} else {
 		/*
 		 * Mapping file, get fp for validation and