[glibc/arm/morello/main] cheri: elf: make sure dlpi_phdr covers the load segments

[Szabolcs Nagy <nsz@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c0a839639b6a9baeaafe5dad8f7739e6176a2c62

commit c0a839639b6a9baeaafe5dad8f7739e6176a2c62
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
Date:   Wed Sep 14 14:04:18 2022 +0100

    cheri: elf: make sure dlpi_phdr covers the load segments
    
    In dl_iterate_phdr phdr is the only capability passed to the callback
    that may be used to derive pointers of the elf module, so ensure it
    has wide bounds.

Diff:
---
 elf/dl-iteratephdr.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/elf/dl-iteratephdr.c b/elf/dl-iteratephdr.c
index 146850b88a..bd2588fae8 100644
--- a/elf/dl-iteratephdr.c
+++ b/elf/dl-iteratephdr.c
@@ -69,7 +69,12 @@ __dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info,
       info.dlpi_addr = l->l_real->l_addr;
 #endif
       info.dlpi_name = l->l_real->l_name;
+#ifdef __CHERI_PURE_CAPABILITY__
+      ElfW(Addr) phdr = (ElfW(Addr)) l->l_real->l_phdr - l->l_real->l_addr;
+      info.dlpi_phdr = (const void *) dl_rx_ptr (l->l_real, phdr);
+#else
       info.dlpi_phdr = l->l_real->l_phdr;
+#endif
       info.dlpi_phnum = l->l_real->l_phnum;
       info.dlpi_adds = GL(dl_load_adds);
       info.dlpi_subs = GL(dl_load_adds) - nloaded;