[PATCH 23/58] objtool/klp: Add test for rejecting references to init code/data
COLD23d
From: Song Liu <song@kernel.org>
Date: 2026-09-11 18:45:32
Subsystem:
objtool, the rest · Maintainers:
Josh Poimboeuf, Peter Zijlstra, Linus Torvalds
Revision v1 of 5 in this series.
Revisions (5)
From: Puranjay Mohan <puranjay@kernel.org> Init code and data are freed once boot finishes, so a klp relocation against them can never resolve. Signed-off-by: Puranjay Mohan <puranjay@kernel.org> Assisted-by: Claude:claude-opus-5 Signed-off-by: Song Liu <song@kernel.org> --- .../tests/generic/fixtures/init_reference.c | 16 ++++++++++++++++ .../objtool/tests/generic/test-init-reference.sh | 16 ++++++++++++++++ 2 files changed, 32 insertions(+) create mode 100644 tools/objtool/tests/generic/fixtures/init_reference.c create mode 100755 tools/objtool/tests/generic/test-init-reference.sh
diff --git a/tools/objtool/tests/generic/fixtures/init_reference.c b/tools/objtool/tests/generic/fixtures/init_reference.c
new file mode 100644
index 000000000000..51b2a57dde14
--- /dev/null
+++ b/tools/objtool/tests/generic/fixtures/init_reference.c@@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Patched function referencing data in an .init section. */ + +static const char __modinfo[] + __attribute__((section(".modinfo"), used, aligned(1))) = "\0name=vmlinux"; + +static int init_only __attribute__((section(".init.data"), used)) = 5; + +int target(int x) +{ +#ifdef PATCHED + return x + init_only + 1; +#else + return x + init_only; +#endif +}
diff --git a/tools/objtool/tests/generic/test-init-reference.sh b/tools/objtool/tests/generic/test-init-reference.sh
new file mode 100755
index 000000000000..8bf4b98bf458
--- /dev/null
+++ b/tools/objtool/tests/generic/test-init-reference.sh@@ -0,0 +1,16 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Init code and data are freed after boot, so a klp relocation against them can +# never resolve. Such a patch must be rejected. + +. "$(dirname "$0")/../lib.sh" + +setup +build_pair init_reference.c +run_diff 255 + +diff_log | grep -q "can't patch or reference init code/data" || + fail "expected rejection, got: $(diff_log | tail -1)" + +pass "reference to init data rejected"
--
2.53.0-Meta