diff --git a/tools/objtool/tests/generic/fixtures/checksum_skip.c b/tools/objtool/tests/generic/fixtures/checksum_skip.c
new file mode 100644
index 000000000000..973bdc10295d
--- /dev/null
+++ b/tools/objtool/tests/generic/fixtures/checksum_skip.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Symbols calculate_checksums() must not give an entry of their own.
+ *
+ * Three kinds are skipped, for two different reasons:
+ *
+ *   zero-length   there is nothing to hash, and an entry keyed on the
+ *                 symbol's address would collide with whatever really lives
+ *                 there.
+ *   alias         a second name for an address already checksummed.
+ *   cold part     hashed as part of its parent, which func_for_each_insn()
+ *                 walks into, so a separate entry would double-count it.
+ *
+ * An entry per address is the invariant: .discard.sym_checksum is looked up by
+ * the address a relocation points at, so two entries for one address make the
+ * lookup ambiguous and one of the two checksums unreachable.
+ */
+
+static const char __modinfo[]
+	__attribute__((section(".modinfo"), used, aligned(1))) = "\0name=vmlinux";
+
+/* Zero-length: an object symbol of size 0, in a section of its own. */
+extern char empty_marker[];
+__asm__(".pushsection .data.empty_marker,\"aw\",@progbits\n"
+	".globl empty_marker\n"
+	".type empty_marker, @object\n"
+	"empty_marker:\n"
+	".size empty_marker, 0\n"
+	".popsection\n");
+
+int real_function(int x);
+int real_function(int x)
+{
+#ifdef PATCHED
+	return x + 2;
+#else
+	return x + 1;
+#endif
+}
+
+/* Alias: a second name for real_function's address. */
+int alias_function(int x) __attribute__((alias("real_function")));
+
+int target(int x)
+{
+	return real_function(x) + alias_function(x) + (int)(long)empty_marker;
+}
diff --git a/tools/objtool/tests/generic/test-checksum-skip.sh b/tools/objtool/tests/generic/test-checksum-skip.sh
new file mode 100755
index 000000000000..f245535a0f36
--- /dev/null
+++ b/tools/objtool/tests/generic/test-checksum-skip.sh
@@ -0,0 +1,81 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Symbols which must not get a checksum entry of their own.
+#
+# .discard.sym_checksum is an array of { address, checksum } looked up by the
+# address a relocation points at, so the invariant is one entry per address.
+# calculate_checksums() skips three kinds of symbol to keep it:
+#
+#   zero-length   nothing to hash, and its address belongs to whatever really
+#                 lives there
+#   alias         a second name for an address already covered
+#   cold part     hashed into its parent, which func_for_each_insn() walks
+#                 into, so its own entry would double-count
+#
+# A duplicate entry is not a build failure.  It makes the lookup ambiguous, and
+# whichever checksum loses is simply never consulted again -- so a function
+# whose code changed can be read as unchanged and dropped from the patch.
+#
+# Of the three, only the alias skip is isolated here: removing it makes this
+# test fail.  A zero-length symbol is excluded by more than one of the guards
+# at once -- its section has no data either -- so no single change makes that
+# assertion fail, and it stands as a check on the behaviour rather than on the
+# line which produces it.  Nothing here reaches the cold-part skip, which
+# wants a compiler that splits functions; test-cold-function covers that
+# symbol surviving into the patch, not its checksum.
+#
+# Covers the same ground as corpus/x86_64/checksum-zero-len-sym,
+# checksum-alias-skip and checksum-cold-skip in Joe Lawrence's klp-build unit
+# test corpus.
+
+. "$(dirname "$0")/../lib.sh"
+
+setup
+build_pair checksum_skip.c
+
+assert_input_symbol empty_marker
+assert_input_symbol alias_function
+run_checksum
+
+# entries_for <object> [-t]
+#
+# The symbol names .discard.sym_checksum has an entry for, one per line.  With
+# -t, what each entry points at instead: the name and its addend, which is the
+# address the kernel looks the entry up by.  A name alone is not that address,
+# since a relocation against a section symbol names the section and puts the
+# offset in the addend, and several entries can then share a name honestly.
+entries_for()
+{
+	in_relocs "$1" | awk -v target="${2:-}" '/rela\.discard\.sym_checksum/,/^$/ {
+		if ($1 !~ /^[0-9a-f]{8,}/)
+			next
+		if (target == "-t")
+			print $5, $6, $7
+		else
+			print $5
+	}'
+}
+
+entries="$(entries_for orig.o)"
+
+# The control: something real did get an entry, so an empty listing cannot
+# make the rest of this pass by default.
+echo "$entries" | grep -qx target ||
+	fail "no checksum entry for target"
+
+echo "$entries" | grep -qx empty_marker &&
+	fail "zero-length symbol got a checksum entry"
+
+# One of the two names for that address is kept and the other skipped; which
+# one falls out of symbol table order and is not the point.  Two would be.
+n="$(echo "$entries" | grep -cxE 'real_function|alias_function')"
+[ "$n" = 1 ] ||
+	fail "expected 1 checksum entry across real_function and its alias, found $n"
+
+# One entry per address, which is what the skipping is for.
+dupes="$(entries_for orig.o -t | sort | uniq -d)"
+[ -z "$dupes" ] ||
+	fail "two checksum entries for one address: $dupes"
+
+pass "zero-length symbols and aliases get no checksum entry of their own"