[commit] r3594 - forth/wrapper

[repository service]

Author: wmb
Date: Wed Mar  6 20:53:52 2013
New Revision: 3594
URL: http://tracker.coreboot.org/trac/openfirmware/changeset/3594

Log:
wrapper.c - added commentary telling another way to accomplish
the same result as mprotect()ing the dictionary memory to make
it executable.

Modified:
   forth/wrapper/wrapper.c

Modified: forth/wrapper/wrapper.c
==============================================================================
--- forth/wrapper/wrapper.c	Wed Mar  6 19:55:27 2013	(r3593)
+++ forth/wrapper/wrapper.c	Wed Mar  6 20:53:52 2013	(r3594)
@@ -2201,6 +2201,13 @@
    return 0L;
 #endif
 #if defined(__linux__) && defined(ARM) 
+	/* There is another way to achieve the goal of making the */
+	/* dictionary executable.  You can add "-Wl,-z,execstack" */
+	/* to the cc command line or add "-z execstack" to the ld */
+	/* command line.  mprotect() is perhaps more precise, making */
+	/* only the dictionary executable while leaving the stack */
+	/* protected, although that is probably pointless since */
+	/* the whole point of this program is code injection. */
    mprotect(adr, len, PROT_READ | PROT_WRITE | PROT_EXEC);
    __clear_cache(adr, adr+len);
    return 0L;