fix corner cases in exec of ELF

put an invalid page below the stack
have fork() handle invalid pages

1 files changed, 2 insertions, 1 deletions

diff --git a/defs.h b/defs.h
index 4a63154..b691099 100644
--- a/defs.h
+++ b/defs.h
@@ -163,7 +163,8 @@ void            freevm(pde_t*);
 void            inituvm(pde_t*, char*, char*, uint);
 int             loaduvm(pde_t*, char*, struct inode *ip, uint, uint);
 pde_t*          copyuvm(pde_t*,uint);
-void            loadvm(struct proc*);
+void            switchuvm(struct proc*);
+void            switchkvm();
 
 // number of elements in fixed-size array
 #define NELEM(x) (sizeof(x)/sizeof((x)[0]))