In preparation for upcoming execute-only support, change the magic branch

instruction used by __canonicalize_funcptr_for_compare() from "bl" into "b".
This allows __canonicalize_funcptr_for_compare() to execute the branch
instead of decoding the instruction to find the address of _dl_bind().

This is the first step in the transition to a new ABI.  Once an updated
ld.so has been installed, we can change __canonicalize_funcptr_for_compare()
(which lives in libgcc) and rebuild everything with a new libgcc.  Only
then we can actually make ld.so executable-only.

ok deraadt@, miod@

diff --git a/libexec/ld.so/hppa/ldasm.S b/libexec/ld.so/hppa/ldasm.S
index 1362129..4d19f9b 100644 (file)
--- a/libexec/ld.so/hppa/ldasm.S
+++ b/libexec/ld.so/hppa/ldasm.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ldasm.S,v 1.24 2017/08/27 21:59:52 deraadt Exp $      */
+/*     $OpenBSD: ldasm.S,v 1.25 2023/01/09 13:45:55 kettenis Exp $     */
 
 /*
  * Copyright (c) 2004 Michael Shalayeff
@@ -113,7 +113,7 @@ EXIT(_hppa_dl_set_dp)
  * __canonicalize_funcptr_for_compare() function to fixup relocations
  * in order to do function pointer comparisons.
  */
-       bl      _dl_bind, rp
+       b       _dl_bind
 
 ENTRY(_dl_bind_start,32)
        copy    r3, r1