[gcc r12-6857] libgcc: Fix _Unwind_Find_FDE for missing unwind data with glibc 2.35

[Florian Weimer]

https://gcc.gnu.org/g:ab2a2457780d224343ce05e7d8e2964c6a47fd83

commit r12-6857-gab2a2457780d224343ce05e7d8e2964c6a47fd83
Author: Florian Weimer <fweimer@redhat.com>
Date:   Tue Jan 25 12:09:56 2022 +0100

    libgcc: Fix _Unwind_Find_FDE for missing unwind data with glibc 2.35
    
    _dl_find_object returns success even if no unwind information has been
    found, and dlfo_eh_frame is NULL.
    
    libgcc/ChangeLog:
    
            PR libgcc/104207
            * unwind-dw2-fde-dip.c (_Unwind_Find_FDE): Add NULL check.

Diff:
---
 libgcc/unwind-dw2-fde-dip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libgcc/unwind-dw2-fde-dip.c b/libgcc/unwind-dw2-fde-dip.c
index 7de847cb120..3d6f39f5460 100644
--- a/libgcc/unwind-dw2-fde-dip.c
+++ b/libgcc/unwind-dw2-fde-dip.c
@@ -509,7 +509,7 @@ _Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
 #ifdef DLFO_STRUCT_HAS_EH_DBASE
   {
     struct dl_find_object dlfo;
-    if (_dl_find_object (pc, &dlfo) == 0)
+    if (_dl_find_object (pc, &dlfo) == 0 && dlfo.dlfo_eh_frame != NULL)
       return find_fde_tail ((_Unwind_Ptr) pc, dlfo.dlfo_eh_frame,
 # if DLFO_STRUCT_HAS_EH_DBASE
 			    (_Unwind_Ptr) dlfo.dlfo_eh_dbase,