diff options
| author | Puranjay Mohan <puranjay@kernel.org> | 2026-09-16 11:43:05 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2026-09-21 11:02:11 +0200 |
| commit | b229562c2f44cdec4ce4b8b78428514bccff9dc0 (patch) | |
| tree | b9ed3053c0424133a88b4eef4f81f482b8dc9148 /tools/objtool/tests | |
| parent | 913bf39ff461bc65cfc4e1e05c3d738ffc6ffc75 (diff) | |
objtool/klp: Add test for rejecting changed data
Livepatching replaces functions. Nothing can swap a variable which live
code already refers to, so a patch which changes one has to be refused
rather than applied with the old value left in place.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Assisted-by: Claude:claude-opus-5
Link: https://patch.msgid.link/20260916184351.2720310-13-song@kernel.org
Diffstat (limited to 'tools/objtool/tests')
| -rw-r--r-- | tools/objtool/tests/generic/fixtures/changed_data.c | 16 | ||||
| -rwxr-xr-x | tools/objtool/tests/generic/test-changed-data.sh | 18 |
2 files changed, 34 insertions, 0 deletions
diff --git a/tools/objtool/tests/generic/fixtures/changed_data.c b/tools/objtool/tests/generic/fixtures/changed_data.c new file mode 100644 index 000000000000..b52461835444 --- /dev/null +++ b/tools/objtool/tests/generic/fixtures/changed_data.c @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Data whose value differs between the two builds. */ + +static const char __modinfo[] + __attribute__((section(".modinfo"), used, aligned(1))) = "\0name=vmlinux"; + +#ifdef PATCHED +int klp_test_data = 2; +#else +int klp_test_data = 1; +#endif + +int target(int x) +{ + return x + klp_test_data; +} diff --git a/tools/objtool/tests/generic/test-changed-data.sh b/tools/objtool/tests/generic/test-changed-data.sh new file mode 100755 index 000000000000..c5c7381bb409 --- /dev/null +++ b/tools/objtool/tests/generic/test-changed-data.sh @@ -0,0 +1,18 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Livepatching replaces functions, not data. A changed data symbol must be +# rejected. + +. "$(dirname "$0")/../lib.sh" + +setup +build_pair changed_data.c +run_diff 255 + +diff_log | grep -q 'changed data: klp_test_data' || + fail "expected rejection, got: $(diff_log | tail -1)" +[ -e "$workdir/out.o" ] && + fail "output object produced for a rejected input" + +pass "changed data symbol rejected" |