From b552406427ba636b5d12b184ca184ac3e086542a Mon Sep 17 00:00:00 2001
From: Zach Brown <zab@versity.com>
Date: Tue, 21 Nov 2023 12:03:39 -0800
Subject: [PATCH] Ignore spurious KASAN unwind warning

KASAN could raise a spurious warning if the unwinder started in code
without ORC metadata and tried to access in the KASAN stack frame
redzones.  This was fixed upstream but we can rarely see it in older
kernels.  We can ignore these messages.

Signed-off-by: Zach Brown <zab@versity.com>
---
 tests/funcs/filter.sh | 58 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/tests/funcs/filter.sh b/tests/funcs/filter.sh
index 90496554..64f1f7c9 100644
--- a/tests/funcs/filter.sh
+++ b/tests/funcs/filter.sh
@@ -6,6 +6,61 @@ t_filter_fs()
 	    -e 's@Device: [a-fA-F0-9]*h/[0-9]*d@Device: 0h/0d@g'
 }
 
+#
+# We can hit a spurious kasan warning that was fixed upstream:
+#
+#  e504e74cc3a2 x86/unwind/orc: Disable KASAN checking in the ORC unwinder, part 2
+#
+# KASAN can get mad when the unwinder doesn't find ORC metadata and
+# wanders up without using frames and hits the KASAN stack red zones.
+# We can ignore these messages.
+#
+# They're bracketed by:
+# [ 2687.690127] ==================================================================
+# [ 2687.691366] BUG: KASAN: stack-out-of-bounds in get_reg+0x1bc/0x230
+# ...
+# [ 2687.706220] ==================================================================
+# [ 2687.707284] Disabling lock debugging due to kernel taint
+#
+# That final lock debugging message may not be included.
+#
+ignore_harmless_unwind_kasan_stack_oob()
+{
+awk '
+        BEGIN {
+                in_soob = 0
+                soob_nr = 0
+        }
+        ( !in_soob && $0 ~ /==================================================================/ ) {
+                in_soob = 1
+                soob_nr = NR
+                saved = $0
+        }
+        ( in_soob == 1 && NR == (soob_nr + 1) ) {
+                if (match($0, /KASAN: stack-out-of-bounds in get_reg/) != 0) {
+                        in_soob = 2
+                } else {
+                        in_soob = 0
+                        print saved
+                }
+		saved=""
+        }
+        ( in_soob == 2 && $0 ~ /==================================================================/ ) {
+                in_soob = 3
+                soob_nr = NR
+        }
+        ( in_soob == 3 && NR > soob_nr && $0 !~ /Disabling lock debugging/ ) {
+                in_soob = 0
+        }
+        ( !in_soob ) { print $0 }
+        END {
+                if (saved) {
+                        print saved
+                }
+        }
+'
+}
+
 #
 # Filter out expected messages.  Putting messages here implies that
 # tests aren't relying on messages to discover failures.. they're
@@ -92,5 +147,6 @@ t_filter_dmesg()
 	# ignore systemd-journal rotating
 	re="$re|systemd-journald.*"
 
-	egrep -v "($re)" 
+	egrep -v "($re)" | \
+		ignore_harmless_unwind_kasan_stack_oob
 }