shuffle and tweak for formatting.

pdf has very good page breaks now.
would be a good copy for fall 2009.

1 files changed, 4 insertions, 2 deletions

diff --git a/exec.c b/exec.c
index 3be3eed..bee960e 100644
--- a/exec.c
+++ b/exec.c
@@ -11,7 +11,7 @@ exec(char *path, char **argv)
 {
   char *mem, *s, *last;
   int i, argc, arglen, len, off;
-  uint sz, sp, argp;
+  uint sz, sp, argp, x;
   struct elfhdr elf;
   struct inode *ip;
   struct proghdr ph;
@@ -67,7 +67,9 @@ exec(char *path, char **argv)
       goto bad;
     if(ph.type != ELF_PROG_LOAD)
       continue;
-    if(ph.va + ph.memsz < ph.va || ph.va + ph.memsz > sz || ph.memsz < ph.filesz)
+    if(ph.va + ph.memsz < ph.va || ph.va + ph.memsz > sz)
+      goto bad;
+    if(ph.memsz < ph.filesz)
       goto bad;
     if(readi(ip, mem + ph.va, ph.offset, ph.filesz) != ph.filesz)
       goto bad;