mprotect system call exposed to the untrusted code.

src/untrusted/irt/irt.h

Index: src/untrusted/irt/irt.h
diff --git a/src/untrusted/irt/irt.h b/src/untrusted/irt/irt.h
index d417be8fe41ad4f9427beed790f6564a9f19bab8..583a87a392f6bf06416ff6cd72974576353a64bd 100644
--- a/src/untrusted/irt/irt.h
+++ b/src/untrusted/irt/irt.h
@@ -91,6 +91,7 @@ struct nacl_irt_memory {
   int (*sysbrk)(void **newbrk);
   int (*mmap)(void **addr, size_t len, int prot, int flags, int fd, off_t off);
   int (*munmap)(void *addr, size_t len);
+  int (*mprotect)(void *addr, size_t len, int prot);

[Mark Seaborn, 2012/10/14 00:47:16]

You can't just add to "struct nacl_irt_memory".  You need to either change the
version number (but keep the old interface version) or introduce a new
interface.

[Petr Hosek, 2012/10/14 00:53:21]

Which one of these two is the preferred way?

[Mark Seaborn, 2012/10/14 00:59:49]

There's no precedent here.  We haven't extended any interfaces so far.  My
preference would be for a new interface containing only mprotect(), since it
avoids compatibility and testing problems.  Roland might disagree.

 };
 
 #define NACL_IRT_DYNCODE_v0_1   "nacl-irt-dyncode-0.1"