[glibc/arm/morello/main] TODO(api): cheri: fix dl_iterate_phdr dlpi_addr

[Szabolcs Nagy <nsz@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=40ede395252b8dfedabd2cf3bcff1ee87d94e2ee

commit 40ede395252b8dfedabd2cf3bcff1ee87d94e2ee
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Sep 7 17:37:38 2022 +0100

    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:
---
 elf/dl-iteratephdr.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/elf/dl-iteratephdr.c b/elf/dl-iteratephdr.c
index 4d12a8ed50..146850b88a 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;