From: Paul Floyd <pjfloyd@wanadoo.fr>
Date: Tue, 5 Jul 2022 10:53:34 +0000 (+0200)
Subject: Fix reading dwarf info for arrays with lower bound and count
X-Git-Tag: VALGRIND_3_20_0~22
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=498b5c4286ec631bec43b8c359e3ff00c00b90e7;p=valgrind.git

Fix reading dwarf info for arrays with lower bound and count

There was an out-by-one error, the upper bound was being set to
count whereas it should be count - 1.

This was causing drd/tests/atomic_var to fail because the g_dummy
array seemed to overlap the following s_y variable.

This seems only to have been caused by clang, not GCC, which
presumably supplies lower and upper bound rather than lower
bound and count.
---

diff --git a/coregrind/m_debuginfo/readdwarf3.c b/coregrind/m_debuginfo/readdwarf3.c
index 96bd21f7f7..b1a709e6a0 100644
--- a/coregrind/m_debuginfo/readdwarf3.c
+++ b/coregrind/m_debuginfo/readdwarf3.c
@@ -4571,7 +4571,7 @@ static void parse_type_DIE ( /*MOD*/XArray* /* of TyEnt */ tyents,
          boundE.Te.Bound.knownL = True;
          boundE.Te.Bound.knownU = True;
          boundE.Te.Bound.boundL = lower;
-         boundE.Te.Bound.boundU = lower + count;
+         boundE.Te.Bound.boundU = lower + count - 1;
       } else {
          /* FIXME: handle more cases */
          goto_bad_DIE;