[PATCH] DWZ aborted "write_types: Assertion `ref && ref->die_dup == NULL'"

["Sharma, Alok Kumar" <AlokKumar.Sharma@amd.com>]

[-- Attachment #1: Type: text/plain, Size: 831 bytes --]

Hi all,

Would you please review the attached patch containing modification of assert condition.
It was required to fix an abort which seem to be incorrect.

There is an assert condition as "ref && ref->die_dup == NULL".
As per definition of "struct dw_die", the structure fields starting
from 'die_dup' are present only if 'die_toplevel' is 1. In line with
this at multiple places in code, full/paritial memory is allocated for
pointer of type dw_die.
Ex.  die = pool_alloc (dw_die, offsetof (struct dw_die, die_dup));
Due to this, since memory is not allocated for field die_dup onwards,
it may contain junk values. Macro 'die_safe_dupe' must be used in place
of directly accessing 'die_dup' field whenever required.

      * dwz.c (write_types): Use 'die_safe_dup' to access field 'die_dup'.


Regards,
Alok

[-- Attachment #2: 0001-DWZ-aborted-write_types-Assertion-ref-ref-die_dup-NU.patch --]
[-- Type: application/octet-stream, Size: 1454 bytes --]

From a3274a19e5b73b7e41e74f6ddfcdd2073f83ab63 Mon Sep 17 00:00:00 2001
From: Alok Kumar Sharma <AlokKumar.Sharma@amd.com>
Date: Mon, 1 Feb 2021 23:57:51 +0530
Subject: [PATCH] DWZ aborted "write_types: Assertion `ref && ref->die_dup ==
 NULL'"

There is an assert condition as "ref && ref->die_dup == NULL".
As per definition of "struct dw_die", the structure fields starting
from 'die_dup' are present only if 'die_toplevel' is 1. In line with
this at multiple places in code, full/paritial memory is allocated for
pointer of type dw_die.
Ex.  die = pool_alloc (dw_die, offsetof (struct dw_die, die_dup));
Due to this, since memory is not allocated for field die_dup onwards,
it may contain junk values. Macro 'die_safe_dupe' must be used in place
of directly accessing 'die_dup' in assert condition here.

      * dwz.c (write_types): Use 'die_safe_dup' to access field 'die_dup'.
---
 dwz.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dwz.c b/dwz.c
index 1db93dd..920a9b8 100644
--- a/dwz.c
+++ b/dwz.c
@@ -12868,7 +12868,7 @@ write_types (void)
       memcpy (ptr, inptr - 8, 8);
       ptr += 8;
       ref = off_htab_lookup (cu, cu->cu_offset + read_32 (inptr));
-      assert (ref && ref->die_dup == NULL);
+      assert (ref && die_safe_dup(ref) == NULL);
       write_32 (ptr, ref->u.p2.die_new_offset);
       ptr = write_die (ptr, cu, cu->cu_die, NULL, NULL, NULL);
       assert (types + next_off == ptr);
-- 
2.17.1