Attaching fexit probes to functions marked with __noreturn may lead to unpredictable behavior. To avoid this, we will reject attaching probes to such functions. Currently, there is no ideal solution, so we will hardcode a check for all __noreturn functions. Since objtool already handles this, we will leverage its implementation. Once a more robust solution is found, this workaround can be removed. v1->v2: - keep tools/objtool/noreturns.h as is (Josh) - Add noreturns.h to objtool/sync-check.sh (Josh) - Add verbose for the reject and simplify the test case (Song) v1: https://lore.kernel.org/bpf/20250211023359.1570-1-laoar.shao@xxxxxxxxx/ Yafang Shao (3): objtool: Copy noreturns.h to include/linux bpf: Reject attaching fexit to functions annotated with __noreturn selftests/bpf: Add selftest for attaching fexit to __noreturn functions include/linux/noreturns.h | 52 +++++++++++++++++++ kernel/bpf/verifier.c | 11 ++++ tools/objtool/Documentation/objtool.txt | 3 +- tools/objtool/sync-check.sh | 2 + .../bpf/prog_tests/fexit_noreturns.c | 9 ++++ .../selftests/bpf/progs/fexit_noreturns.c | 15 ++++++ 6 files changed, 91 insertions(+), 1 deletion(-) create mode 100644 include/linux/noreturns.h create mode 100644 tools/testing/selftests/bpf/prog_tests/fexit_noreturns.c create mode 100644 tools/testing/selftests/bpf/progs/fexit_noreturns.c -- 2.43.5
