Untangle ifdef forest in sys_mmap64. No code changes
After careful analysis, it looks like !LINUX and ALPHA
pass all seven parameters in registers; and in all other cases
parameters are on stack (pointed to by tcp->u_arg[0]).
In light of this, reorganize ifdefs, making them simpler,
without changing any logic.
After this, it's apparent we use tcp->u_arg[4,5,6] and possibly
[7] without checking that it's valid to do so.
So far, just add a comment about this.
* mem.c (sys_mmap64): Rewrite ifdefs in a much simpler way.
Add comments about apparent bugs.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
diff --git a/mem.c b/mem.c
index f0ccfc7..de9b6bb 100644
--- a/mem.c
+++ b/mem.c
@@ -334,25 +334,15 @@
int
sys_mmap64(struct tcb *tcp)
{
-#ifdef linux
-#ifdef ALPHA
- long *u_arg = tcp->u_arg;
-#else /* !ALPHA */
- long u_arg[7];
-#endif /* !ALPHA */
-#else /* !linux */
- long *u_arg = tcp->u_arg;
-#endif /* !linux */
-
if (entering(tcp)) {
-#ifdef linux
-#ifndef ALPHA
+#if !defined(LINUX) || defined(ALPHA)
+ long *u_arg = tcp->u_arg;
+#else
+ long u_arg[7];
if (umoven(tcp, tcp->u_arg[0], sizeof u_arg,
(char *) u_arg) == -1)
return 0;
-#endif /* ALPHA */
-#endif /* linux */
-
+#endif
/* addr */
tprintf("%#lx, ", u_arg[0]);
/* len */
@@ -369,13 +359,16 @@
#endif
/* fd */
tprintf(", ");
+ /* BUG?! should be u_arg[4] (without tcp->)? */
printfd(tcp, tcp->u_arg[4]);
/* offset */
+ /* BUG?! on non-ALPHA linux, offset will be not in tcp->u_arg,
+ * but in local u_arg, but printllval prints tcp->u_arg! */
printllval(tcp, ", %#llx", 5);
}
return RVAL_HEX;
}
-#endif
+#endif /* _LFS64_LARGEFILE || HAVE_LONG_LONG_OFF_T */
int