[PATCH] readelf: Type DIE offset is from start of CU.

[Mark Wielaard]

While inspecting some type units I noticed the type offset seemed off.
We were printing the offset as is, but it should include the offset of
the unit. There was actually a testcase for this, run-readelf-types.sh
but that had the same bug in the expected output. Fixed both.

Signed-off-by: Mark Wielaard <m...@klomp.org>
---
 src/ChangeLog              | 4 ++++
 src/readelf.c              | 3 ++-
 tests/ChangeLog            | 4 ++++
 tests/run-readelf-types.sh | 2 +-
 4 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/ChangeLog b/src/ChangeLog
index e65620fd..552002b0 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2021-02-12  Mark Wielaard  <m...@klomp.org>
+
+       * readelf.c (print_debug_units): Type DIE offset is from start CU.
+
 2021-02-03 Timm Bäder <tbae...@redhat.com>
 
        * ar.c (do_oper_extract): Extract should_truncate_fname function
diff --git a/src/readelf.c b/src/readelf.c
index 11692bb5..ccd59e39 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -7792,7 +7792,8 @@ print_debug_units (Dwfl_Module *dwflmod,
        {
          Dwarf_Die typedie;
          Dwarf_Off dieoffset;
-         dieoffset = dwarf_dieoffset (dwarf_offdie_types (dbg, subdie_off,
+         dieoffset = dwarf_dieoffset (dwarf_offdie_types (dbg, cu->start
+                                                          + subdie_off,
                                                           &typedie));
          printf (_(" Type unit at offset %" PRIu64 ":\n"
                           " Version: %" PRIu16
diff --git a/tests/ChangeLog b/tests/ChangeLog
index e22fa455..27827ed3 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,7 @@
+2021-02-12  Mark Wielaard  <m...@klomp.org>
+
+       * run-readelf-types.sh: Add CU start to type offset reference.
+
 2021-02-08  Érico Nogueira  <eric...@disroot.org>
 
        * run-debuginfod-find.sh: Check for cpio availability.
diff --git a/tests/run-readelf-types.sh b/tests/run-readelf-types.sh
index a7af5734..4f312697 100755
--- a/tests/run-readelf-types.sh
+++ b/tests/run-readelf-types.sh
@@ -97,7 +97,7 @@ DWARF section [32] '.debug_types' at offset 0x1260:
              specification        (ref4) [    34]
  Type unit at offset 67:
  Version: 4, Abbreviation section offset: 0, Address size: 8, Offset size: 4
- Type signature: 0x18763953736e2de0, Type offset: 0x25 [25]
+ Type signature: 0x18763953736e2de0, Type offset: 0x25 [68]
  [    5a]  type_unit            abbrev: 1
            language             (data1) C_plus_plus (4)
            GNU_odr_signature    (data8) 16005269134005989797
-- 
2.20.1