From 960c3e352bac749c35041d683f32bdde467a2960 Mon Sep 17 00:00:00 2001 From: Puranjay Mohan Date: Wed, 16 Sep 2026 11:43:07 -0700 Subject: objtool/klp: Add test for newly introduced functions A function added by the patch has no original to correlate against, and still has to be carried into the livepatch or the changed caller ends up referencing something which does not exist. The helper is noinline so the case survives the optimiser; otherwise the compiler folds it into its only caller and the test covers nothing. Signed-off-by: Puranjay Mohan Signed-off-by: Song Liu Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Assisted-by: Claude:claude-opus-5 Link: https://patch.msgid.link/20260916184351.2720310-15-song@kernel.org --- tools/objtool/tests/generic/fixtures/new_function.c | 21 +++++++++++++++++++++ tools/objtool/tests/generic/test-new-function.sh | 16 ++++++++++++++++ 2 files changed, 37 insertions(+) create mode 100644 tools/objtool/tests/generic/fixtures/new_function.c create mode 100755 tools/objtool/tests/generic/test-new-function.sh diff --git a/tools/objtool/tests/generic/fixtures/new_function.c b/tools/objtool/tests/generic/fixtures/new_function.c new file mode 100644 index 000000000000..e7886eaaff3e --- /dev/null +++ b/tools/objtool/tests/generic/fixtures/new_function.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Function introduced by the patch. noinline keeps it from being folded. */ + +static const char __modinfo[] + __attribute__((section(".modinfo"), used, aligned(1))) = "\0name=vmlinux"; + +#ifdef PATCHED +static __attribute__((noinline)) int klp_new_helper(int x) +{ + return x * 7; +} +#endif + +int target(int x) +{ +#ifdef PATCHED + return klp_new_helper(x); +#else + return x; +#endif +} diff --git a/tools/objtool/tests/generic/test-new-function.sh b/tools/objtool/tests/generic/test-new-function.sh new file mode 100755 index 000000000000..b0b7f6443110 --- /dev/null +++ b/tools/objtool/tests/generic/test-new-function.sh @@ -0,0 +1,16 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# A function added by the patch has no original to correlate against and must +# still be carried into the livepatch. + +. "$(dirname "$0")/../lib.sh" + +setup +build_pair new_function.c +run_diff + +assert_patched target +assert_symbol klp_new_helper + +pass "new function carried into the patch with its caller" -- cgit v1.2.3