PERFORCE change 113546 for review

[Jung-uk Kim]

http://perforce.freebsd.org/chv.cgi?CH=113546

Change 113546 by jkim at jkim_hammer on 2007/01/26 05:00:44

	Stop mimicking Linux mmap behavior and use Linux/ia64 wisdom.
	Many Linux/i386 distros have shown different mmap behaviors.

Affected files ...

.. //depot/projects/linuxolator/src/sys/amd64/linux32/linux32_machdep.c#29 edit
.. //depot/projects/linuxolator/src/sys/i386/linux/linux_machdep.c#23 edit

Differences ...

==== //depot/projects/linuxolator/src/sys/amd64/linux32/linux32_machdep.c#29 (text+ko) ====

@@ -852,12 +852,14 @@
 		bsd_args.flags |= MAP_STACK;
 
 	/*
-	 * Linux has added READ_IMPLIES_EXEC personality but we do not support
-	 * the feature yet. We just assume READ_IMPLIES_EXEC is always on.
+	 * PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC
+	 * on Linux/i386. We do this to ensure maximum compatibility.
+	 * Linux/ia64 does the same in i386 emulation mode.
 	 */
 	bsd_args.prot = linux_args->prot;
-	if (bsd_args.prot & PROT_READ)
-		bsd_args.prot |= PROT_EXEC;
+	if ((bsd_args.prot & PROT_WRITE) ||
+	    (bsd_args.prot & (PROT_READ | PROT_EXEC)))
+		bsd_args.prot |= PROT_READ | PROT_EXEC;
 
 	if (linux_args->fd != -1) {
 		/*
@@ -977,9 +979,9 @@
 	bsd_args.addr = uap->addr;
 	bsd_args.len = uap->len;
 	bsd_args.prot = uap->prot;
-	/* XXX PROT_READ implies PROT_EXEC; see linux_mmap_common(). */
-	if (bsd_args.prot & PROT_READ)
-		bsd_args.prot |= PROT_EXEC;
+	if ((bsd_args.prot & PROT_WRITE) ||
+	    (bsd_args.prot & (PROT_READ | PROT_EXEC)))
+		bsd_args.prot |= PROT_READ | PROT_EXEC;
 	return (mprotect(td, &bsd_args));
 }
 

==== //depot/projects/linuxolator/src/sys/i386/linux/linux_machdep.c#23 (text+ko) ====

@@ -653,12 +653,14 @@
 		bsd_args.flags |= MAP_STACK;
 
 	/*
-	 * Linux has added READ_IMPLIES_EXEC personality but we do not support
-	 * the feature yet. We just assume READ_IMPLIES_EXEC is always on.
+	 * PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC
+	 * on Linux/i386. We do this to ensure maximum compatibility.
+	 * Linux/ia64 does the same in i386 emulation mode.
 	 */
 	bsd_args.prot = linux_args->prot;
-	if (bsd_args.prot & PROT_READ)
-		bsd_args.prot |= PROT_EXEC;
+	if ((bsd_args.prot & PROT_WRITE) ||
+	    (bsd_args.prot & (PROT_READ | PROT_EXEC)))
+		bsd_args.prot |= PROT_READ | PROT_EXEC;
 
 	if (linux_args->fd != -1) {
 		/*
@@ -778,9 +780,9 @@
 	bsd_args.addr = uap->addr;
 	bsd_args.len = uap->len;
 	bsd_args.prot = uap->prot;
-	/* XXX PROT_READ implies PROT_EXEC; see linux_mmap_common(). */
-	if (bsd_args.prot & PROT_READ)
-		bsd_args.prot |= PROT_EXEC;
+	if ((bsd_args.prot & PROT_WRITE) ||
+	    (bsd_args.prot & (PROT_READ | PROT_EXEC)))
+		bsd_args.prot |= PROT_READ | PROT_EXEC;
 	return (mprotect(td, &bsd_args));
 }