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author | Alexei Starovoitov <ast@kernel.org> | 2021-04-26 07:09:03 +0300 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2021-04-26 07:09:03 +0300 |
commit | 87bd9e602e39585c5280556a2b6a6363bb334257 (patch) | |
tree | 472342bc1d5691d102a741505e46de688651fa40 | |
parent | 0ea1041bfa3aa2971f858edd9e05477c2d3d54a0 (diff) | |
parent | 7bb2cc19aee8f7150851bb8668c9ff655a5e7678 (diff) | |
download | linux-87bd9e602e39585c5280556a2b6a6363bb334257.tar.xz |
Merge branch 'bpf: Tracing and lsm programs re-attach'
Jiri Olsa says:
====================
hi,
while adding test for pinning the module while there's
trampoline attach to it, I noticed that we don't allow
link detach and following re-attach for trampolines.
Adding that for tracing and lsm programs.
You need to have patch [1] from bpf tree for test module
attach test to pass.
v5 changes:
- fixed missing hlist_del_init change
- fixed several ASSERT calls
- added extra patch for missing ';'
- added ASSERT macros to lsm test
- added acks
thanks,
jirka
[1] https://lore.kernel.org/bpf/20210326105900.151466-1-jolsa@kernel.org/
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r-- | kernel/bpf/syscall.c | 23 | ||||
-rw-r--r-- | kernel/bpf/trampoline.c | 4 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/fentry_test.c | 52 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/fexit_test.c | 52 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/module_attach.c | 23 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/test_lsm.c | 61 |
6 files changed, 157 insertions, 58 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index fd495190115e..941ca06d9dfa 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2648,14 +2648,25 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, * target_btf_id using the link_create API. * * - if tgt_prog == NULL when this function was called using the old - * raw_tracepoint_open API, and we need a target from prog->aux - * - * The combination of no saved target in prog->aux, and no target - * specified on load is illegal, and we reject that here. + * raw_tracepoint_open API, and we need a target from prog->aux + * + * - if prog->aux->dst_trampoline and tgt_prog is NULL, the program + * was detached and is going for re-attachment. */ if (!prog->aux->dst_trampoline && !tgt_prog) { - err = -ENOENT; - goto out_unlock; + /* + * Allow re-attach for TRACING and LSM programs. If it's + * currently linked, bpf_trampoline_link_prog will fail. + * EXT programs need to specify tgt_prog_fd, so they + * re-attach in separate code path. + */ + if (prog->type != BPF_PROG_TYPE_TRACING && + prog->type != BPF_PROG_TYPE_LSM) { + err = -EINVAL; + goto out_unlock; + } + btf_id = prog->aux->attach_btf_id; + key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id); } if (!prog->aux->dst_trampoline || diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 4aa8b52adf25..2d44b5aa0057 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -444,7 +444,7 @@ int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) tr->progs_cnt[kind]++; err = bpf_trampoline_update(tr); if (err) { - hlist_del(&prog->aux->tramp_hlist); + hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; } out: @@ -467,7 +467,7 @@ int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) tr->extension_prog = NULL; goto out; } - hlist_del(&prog->aux->tramp_hlist); + hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; err = bpf_trampoline_update(tr); out: diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_test.c b/tools/testing/selftests/bpf/prog_tests/fentry_test.c index 04ebbf1cb390..7cb111b11995 100644 --- a/tools/testing/selftests/bpf/prog_tests/fentry_test.c +++ b/tools/testing/selftests/bpf/prog_tests/fentry_test.c @@ -3,35 +3,57 @@ #include <test_progs.h> #include "fentry_test.skel.h" -void test_fentry_test(void) +static int fentry_test(struct fentry_test *fentry_skel) { - struct fentry_test *fentry_skel = NULL; int err, prog_fd, i; __u32 duration = 0, retval; + struct bpf_link *link; __u64 *result; - fentry_skel = fentry_test__open_and_load(); - if (CHECK(!fentry_skel, "fentry_skel_load", "fentry skeleton failed\n")) - goto cleanup; - err = fentry_test__attach(fentry_skel); - if (CHECK(err, "fentry_attach", "fentry attach failed: %d\n", err)) - goto cleanup; + if (!ASSERT_OK(err, "fentry_attach")) + return err; + + /* Check that already linked program can't be attached again. */ + link = bpf_program__attach(fentry_skel->progs.test1); + if (!ASSERT_ERR_PTR(link, "fentry_attach_link")) + return -1; prog_fd = bpf_program__fd(fentry_skel->progs.test1); err = bpf_prog_test_run(prog_fd, 1, NULL, 0, NULL, NULL, &retval, &duration); - CHECK(err || retval, "test_run", - "err %d errno %d retval %d duration %d\n", - err, errno, retval, duration); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(retval, 0, "test_run"); result = (__u64 *)fentry_skel->bss; - for (i = 0; i < 6; i++) { - if (CHECK(result[i] != 1, "result", - "fentry_test%d failed err %lld\n", i + 1, result[i])) - goto cleanup; + for (i = 0; i < sizeof(*fentry_skel->bss) / sizeof(__u64); i++) { + if (!ASSERT_EQ(result[i], 1, "fentry_result")) + return -1; } + fentry_test__detach(fentry_skel); + + /* zero results for re-attach test */ + memset(fentry_skel->bss, 0, sizeof(*fentry_skel->bss)); + return 0; +} + +void test_fentry_test(void) +{ + struct fentry_test *fentry_skel = NULL; + int err; + + fentry_skel = fentry_test__open_and_load(); + if (!ASSERT_OK_PTR(fentry_skel, "fentry_skel_load")) + goto cleanup; + + err = fentry_test(fentry_skel); + if (!ASSERT_OK(err, "fentry_first_attach")) + goto cleanup; + + err = fentry_test(fentry_skel); + ASSERT_OK(err, "fentry_second_attach"); + cleanup: fentry_test__destroy(fentry_skel); } diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_test.c b/tools/testing/selftests/bpf/prog_tests/fexit_test.c index 78d7a2765c27..6792e41f7f69 100644 --- a/tools/testing/selftests/bpf/prog_tests/fexit_test.c +++ b/tools/testing/selftests/bpf/prog_tests/fexit_test.c @@ -3,35 +3,57 @@ #include <test_progs.h> #include "fexit_test.skel.h" -void test_fexit_test(void) +static int fexit_test(struct fexit_test *fexit_skel) { - struct fexit_test *fexit_skel = NULL; int err, prog_fd, i; __u32 duration = 0, retval; + struct bpf_link *link; __u64 *result; - fexit_skel = fexit_test__open_and_load(); - if (CHECK(!fexit_skel, "fexit_skel_load", "fexit skeleton failed\n")) - goto cleanup; - err = fexit_test__attach(fexit_skel); - if (CHECK(err, "fexit_attach", "fexit attach failed: %d\n", err)) - goto cleanup; + if (!ASSERT_OK(err, "fexit_attach")) + return err; + + /* Check that already linked program can't be attached again. */ + link = bpf_program__attach(fexit_skel->progs.test1); + if (!ASSERT_ERR_PTR(link, "fexit_attach_link")) + return -1; prog_fd = bpf_program__fd(fexit_skel->progs.test1); err = bpf_prog_test_run(prog_fd, 1, NULL, 0, NULL, NULL, &retval, &duration); - CHECK(err || retval, "test_run", - "err %d errno %d retval %d duration %d\n", - err, errno, retval, duration); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(retval, 0, "test_run"); result = (__u64 *)fexit_skel->bss; - for (i = 0; i < 6; i++) { - if (CHECK(result[i] != 1, "result", - "fexit_test%d failed err %lld\n", i + 1, result[i])) - goto cleanup; + for (i = 0; i < sizeof(*fexit_skel->bss) / sizeof(__u64); i++) { + if (!ASSERT_EQ(result[i], 1, "fexit_result")) + return -1; } + fexit_test__detach(fexit_skel); + + /* zero results for re-attach test */ + memset(fexit_skel->bss, 0, sizeof(*fexit_skel->bss)); + return 0; +} + +void test_fexit_test(void) +{ + struct fexit_test *fexit_skel = NULL; + int err; + + fexit_skel = fexit_test__open_and_load(); + if (!ASSERT_OK_PTR(fexit_skel, "fexit_skel_load")) + goto cleanup; + + err = fexit_test(fexit_skel); + if (!ASSERT_OK(err, "fexit_first_attach")) + goto cleanup; + + err = fexit_test(fexit_skel); + ASSERT_OK(err, "fexit_second_attach"); + cleanup: fexit_test__destroy(fexit_skel); } diff --git a/tools/testing/selftests/bpf/prog_tests/module_attach.c b/tools/testing/selftests/bpf/prog_tests/module_attach.c index 5bc53d53d86e..d85a69b7ce44 100644 --- a/tools/testing/selftests/bpf/prog_tests/module_attach.c +++ b/tools/testing/selftests/bpf/prog_tests/module_attach.c @@ -45,12 +45,18 @@ static int trigger_module_test_write(int write_sz) return 0; } +static int delete_module(const char *name, int flags) +{ + return syscall(__NR_delete_module, name, flags); +} + void test_module_attach(void) { const int READ_SZ = 456; const int WRITE_SZ = 457; struct test_module_attach* skel; struct test_module_attach__bss *bss; + struct bpf_link *link; int err; skel = test_module_attach__open(); @@ -84,6 +90,23 @@ void test_module_attach(void) ASSERT_EQ(bss->fexit_ret, -EIO, "fexit_tet"); ASSERT_EQ(bss->fmod_ret_read_sz, READ_SZ, "fmod_ret"); + test_module_attach__detach(skel); + + /* attach fentry/fexit and make sure it get's module reference */ + link = bpf_program__attach(skel->progs.handle_fentry); + if (!ASSERT_OK_PTR(link, "attach_fentry")) + goto cleanup; + + ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module"); + bpf_link__destroy(link); + + link = bpf_program__attach(skel->progs.handle_fexit); + if (!ASSERT_OK_PTR(link, "attach_fexit")) + goto cleanup; + + ASSERT_ERR(delete_module("bpf_testmod", 0), "delete_module"); + bpf_link__destroy(link); + cleanup: test_module_attach__destroy(skel); } diff --git a/tools/testing/selftests/bpf/prog_tests/test_lsm.c b/tools/testing/selftests/bpf/prog_tests/test_lsm.c index 2755e4f81499..244c01125126 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_lsm.c +++ b/tools/testing/selftests/bpf/prog_tests/test_lsm.c @@ -51,43 +51,64 @@ int exec_cmd(int *monitored_pid) return -EINVAL; } -void test_test_lsm(void) +static int test_lsm(struct lsm *skel) { - struct lsm *skel = NULL; - int err, duration = 0; + struct bpf_link *link; int buf = 1234; - - skel = lsm__open_and_load(); - if (CHECK(!skel, "skel_load", "lsm skeleton failed\n")) - goto close_prog; + int err; err = lsm__attach(skel); - if (CHECK(err, "attach", "lsm attach failed: %d\n", err)) - goto close_prog; + if (!ASSERT_OK(err, "attach")) + return err; + + /* Check that already linked program can't be attached again. */ + link = bpf_program__attach(skel->progs.test_int_hook); + if (!ASSERT_ERR_PTR(link, "attach_link")) + return -1; err = exec_cmd(&skel->bss->monitored_pid); - if (CHECK(err < 0, "exec_cmd", "err %d errno %d\n", err, errno)) - goto close_prog; + if (!ASSERT_OK(err, "exec_cmd")) + return err; - CHECK(skel->bss->bprm_count != 1, "bprm_count", "bprm_count = %d\n", - skel->bss->bprm_count); + ASSERT_EQ(skel->bss->bprm_count, 1, "bprm_count"); skel->bss->monitored_pid = getpid(); err = stack_mprotect(); - if (CHECK(errno != EPERM, "stack_mprotect", "want err=EPERM, got %d\n", - errno)) - goto close_prog; + if (!ASSERT_EQ(errno, EPERM, "stack_mprotect")) + return err; - CHECK(skel->bss->mprotect_count != 1, "mprotect_count", - "mprotect_count = %d\n", skel->bss->mprotect_count); + ASSERT_EQ(skel->bss->mprotect_count, 1, "mprotect_count"); syscall(__NR_setdomainname, &buf, -2L); syscall(__NR_setdomainname, 0, -3L); syscall(__NR_setdomainname, ~0L, -4L); - CHECK(skel->bss->copy_test != 3, "copy_test", - "copy_test = %d\n", skel->bss->copy_test); + ASSERT_EQ(skel->bss->copy_test, 3, "copy_test"); + + lsm__detach(skel); + + skel->bss->copy_test = 0; + skel->bss->bprm_count = 0; + skel->bss->mprotect_count = 0; + return 0; +} + +void test_test_lsm(void) +{ + struct lsm *skel = NULL; + int err; + + skel = lsm__open_and_load(); + if (!ASSERT_OK_PTR(skel, "lsm_skel_load")) + goto close_prog; + + err = test_lsm(skel); + if (!ASSERT_OK(err, "test_lsm_first_attach")) + goto close_prog; + + err = test_lsm(skel); + ASSERT_OK(err, "test_lsm_second_attach"); close_prog: lsm__destroy(skel); |