From: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date: Wed, 7 Sep 2022 16:37:38 +0000 (+0100)
Subject: TODO(api): cheri: fix dl_iterate_phdr dlpi_addr
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ea99c81afe66b84460685114e79b95b97c7ba83;p=thirdparty%2Fglibc.git

TODO(api): cheri: fix dl_iterate_phdr dlpi_addr

The dlpi_addr field is a capability that has value l_addr, but we can
only do this for libraries (ET_DYN) where l_addr == l_map_start,
otherwise we return l_addr which is normally 0 then (ET_EXEC) so the
caller can detect and special case it.

For now l_addr != 0 and l_addr != l_map_start case is not supported.
Note: this api may be used by the unwinder to find and read .eh_frame
data.

TODO: dlpi_addr could be address only, but requires unwinder update
and agreement about the abi.
---

diff --git a/elf/dl-iteratephdr.c b/elf/dl-iteratephdr.c
index 4d12a8ed50e..146850b88a7 100644
--- a/elf/dl-iteratephdr.c
+++ b/elf/dl-iteratephdr.c
@@ -61,7 +61,13 @@ __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info,
 
   for (l = GL(dl_ns)[ns]._ns_loaded; l != NULL; l = l->l_next)
     {
+#ifdef __CHERI_PURE_CAPABILITY__
+      info.dlpi_addr = l->l_real->l_addr == l->l_real->l_map_start
+		       ? l->l_real->l_map_start
+		       : l->l_real->l_addr;
+#else
       info.dlpi_addr = l->l_real->l_addr;
+#endif
       info.dlpi_name = l->l_real->l_name;
       info.dlpi_phdr = l->l_real->l_phdr;
       info.dlpi_phnum = l->l_real->l_phnum;