Allow users to attach a 64-bits cookie to a bpf_link of fentry, fexit, or fmod_ret. This patchset includes several major changes. - Define struct bpf_tramp_links to replace bpf_tramp_prog. struct bpf_tramp_links collects bpf_links of a trampoline - Generate a trampoline to call bpf_progs of given bpf_links. - Trampolines always set/reset bpf_run_ctx before/after calling/leaving a tracing program. - Attach a cookie to a bpf_link of fentry/fexit/fmod_ret/lsm. The value will be available when running the associated bpf_prog. Th major differences from v6: - bpf_link_create() can create links of BPF_LSM_MAC attach type. - Add a test for lsm. - Add function proto of bpf_get_attach_cookie() for lsm. - Check BPF_LSM_MAC in bpf_prog_has_trampoline(). - Adapt to the changes of LINK_CREATE made by Andrii. v1: https://lore.kernel.org/all/20220126214809.3868787-1-kuifeng@xxxxxx/ v2: https://lore.kernel.org/bpf/20220316004231.1103318-1-kuifeng@xxxxxx/ v3: https://lore.kernel.org/bpf/20220407192552.2343076-1-kuifeng@xxxxxx/ v4: https://lore.kernel.org/bpf/20220411173429.4139609-1-kuifeng@xxxxxx/ v5: https://lore.kernel.org/bpf/20220412165555.4146407-1-kuifeng@xxxxxx/ v6: https://lore.kernel.org/bpf/20220416042940.656344-1-kuifeng@xxxxxx/ Kui-Feng Lee (5): bpf, x86: Generate trampolines from bpf_tramp_links bpf, x86: Create bpf_tramp_run_ctx on the caller thread's stack bpf, x86: Attach a cookie to fentry/fexit/fmod_ret/lsm. libbpf: Assign cookies to links in libbpf. selftest/bpf: The test cses of BPF cookie for fentry/fexit/fmod_ret/lsm. arch/x86/net/bpf_jit_comp.c | 82 +++++++++++--- include/linux/bpf.h | 54 +++++++--- include/linux/bpf_types.h | 1 + include/uapi/linux/bpf.h | 10 ++ kernel/bpf/bpf_lsm.c | 17 +++ kernel/bpf/bpf_struct_ops.c | 69 ++++++++---- kernel/bpf/syscall.c | 42 ++++---- kernel/bpf/trampoline.c | 100 +++++++++++------- kernel/trace/bpf_trace.c | 17 +++ net/bpf/bpf_dummy_struct_ops.c | 36 ++++++- tools/bpf/bpftool/link.c | 1 + tools/include/uapi/linux/bpf.h | 10 ++ tools/lib/bpf/bpf.c | 8 ++ tools/lib/bpf/bpf.h | 3 + tools/lib/bpf/libbpf.c | 32 ++++++ tools/lib/bpf/libbpf.h | 12 +++ tools/lib/bpf/libbpf.map | 1 + .../selftests/bpf/prog_tests/bpf_cookie.c | 89 ++++++++++++++++ .../selftests/bpf/progs/test_bpf_cookie.c | 52 +++++++-- 19 files changed, 509 insertions(+), 127 deletions(-) -- 2.30.2
