* [PATCHv3 bpf-next 1/5] bpf: Allow trampoline re-attach for tracing and lsm programs
2021-04-11 13:00 [PATCHv3 bpf-next 0/5] bpf: Tracing and lsm programs re-attach Jiri Olsa
@ 2021-04-11 13:00 ` Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 2/5] selftests/bpf: Add re-attach test to fentry_test Jiri Olsa
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Jiri Olsa @ 2021-04-11 13:00 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: Toke Høiland-Jørgensen, netdev, bpf, Martin KaFai Lau,
Song Liu, Yonghong Song, John Fastabend, KP Singh
Currently we don't allow re-attaching of trampolines. Once
it's detached, it can't be re-attach even when the program
is still loaded.
Adding the possibility to re-attach the loaded tracing and
lsm programs.
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/bpf/syscall.c | 23 +++++++++++++++++------
kernel/bpf/trampoline.c | 2 +-
2 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6428634da57e..f416735b20b3 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2645,14 +2645,25 @@ 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_put_prog;
+ }
+ 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 1f3a4be4b175..48b8b9916aa2 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -437,7 +437,7 @@ 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:
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCHv3 bpf-next 2/5] selftests/bpf: Add re-attach test to fentry_test
2021-04-11 13:00 [PATCHv3 bpf-next 0/5] bpf: Tracing and lsm programs re-attach Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 1/5] bpf: Allow trampoline re-attach for tracing and lsm programs Jiri Olsa
@ 2021-04-11 13:00 ` Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 3/5] selftests/bpf: Add re-attach test to fexit_test Jiri Olsa
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Jiri Olsa @ 2021-04-11 13:00 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: netdev, bpf, Martin KaFai Lau, Song Liu, Yonghong Song,
John Fastabend, KP Singh, Toke Høiland-Jørgensen
Adding the test to re-attach (detach/attach again) tracing
fentry programs, plus check that already linked program can't
be attached again.
Also switching to ASSERT* macros and adding missing ';' in
ASSERT_ERR_PTR macro.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../selftests/bpf/prog_tests/fentry_test.c | 51 +++++++++++++------
tools/testing/selftests/bpf/test_progs.h | 2 +-
2 files changed, 37 insertions(+), 16 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/fentry_test.c b/tools/testing/selftests/bpf/prog_tests/fentry_test.c
index 04ebbf1cb390..f440c74f5367 100644
--- a/tools/testing/selftests/bpf/prog_tests/fentry_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/fentry_test.c
@@ -3,35 +3,56 @@
#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 || retval, "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/test_progs.h b/tools/testing/selftests/bpf/test_progs.h
index e87c8546230e..ee7e3b45182a 100644
--- a/tools/testing/selftests/bpf/test_progs.h
+++ b/tools/testing/selftests/bpf/test_progs.h
@@ -210,7 +210,7 @@ extern int test__join_cgroup(const char *path);
#define ASSERT_ERR_PTR(ptr, name) ({ \
static int duration = 0; \
const void *___res = (ptr); \
- bool ___ok = IS_ERR(___res) \
+ bool ___ok = IS_ERR(___res); \
CHECK(!___ok, (name), "unexpected pointer: %p\n", ___res); \
___ok; \
})
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCHv3 bpf-next 3/5] selftests/bpf: Add re-attach test to fexit_test
2021-04-11 13:00 [PATCHv3 bpf-next 0/5] bpf: Tracing and lsm programs re-attach Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 1/5] bpf: Allow trampoline re-attach for tracing and lsm programs Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 2/5] selftests/bpf: Add re-attach test to fentry_test Jiri Olsa
@ 2021-04-11 13:00 ` Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 4/5] selftests/bpf: Add re-attach test to lsm test Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 5/5] selftests/bpf: Test that module can't be unloaded with attached trampoline Jiri Olsa
4 siblings, 0 replies; 6+ messages in thread
From: Jiri Olsa @ 2021-04-11 13:00 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: netdev, bpf, Martin KaFai Lau, Song Liu, Yonghong Song,
John Fastabend, KP Singh, Toke Høiland-Jørgensen
Adding the test to re-attach (detach/attach again) tracing
fexit programs, plus check that already linked program can't
be attached again.
Also switching to ASSERT* macros.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../selftests/bpf/prog_tests/fexit_test.c | 51 +++++++++++++------
1 file changed, 36 insertions(+), 15 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_test.c b/tools/testing/selftests/bpf/prog_tests/fexit_test.c
index 78d7a2765c27..c48e10c138bc 100644
--- a/tools/testing/selftests/bpf/prog_tests/fexit_test.c
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_test.c
@@ -3,35 +3,56 @@
#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 || retval, "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);
}
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCHv3 bpf-next 4/5] selftests/bpf: Add re-attach test to lsm test
2021-04-11 13:00 [PATCHv3 bpf-next 0/5] bpf: Tracing and lsm programs re-attach Jiri Olsa
` (2 preceding siblings ...)
2021-04-11 13:00 ` [PATCHv3 bpf-next 3/5] selftests/bpf: Add re-attach test to fexit_test Jiri Olsa
@ 2021-04-11 13:00 ` Jiri Olsa
2021-04-11 13:00 ` [PATCHv3 bpf-next 5/5] selftests/bpf: Test that module can't be unloaded with attached trampoline Jiri Olsa
4 siblings, 0 replies; 6+ messages in thread
From: Jiri Olsa @ 2021-04-11 13:00 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: netdev, bpf, Martin KaFai Lau, Song Liu, Yonghong Song,
John Fastabend, KP Singh, Toke Høiland-Jørgensen
Adding the test to re-attach (detach/attach again) lsm programs,
plus check that already linked program can't be attached again.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../selftests/bpf/prog_tests/test_lsm.c | 48 +++++++++++++++----
1 file changed, 38 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/test_lsm.c b/tools/testing/selftests/bpf/prog_tests/test_lsm.c
index 2755e4f81499..d492e76e01cf 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_lsm.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_lsm.c
@@ -18,6 +18,8 @@ char *CMD_ARGS[] = {"true", NULL};
#define GET_PAGE_ADDR(ADDR, PAGE_SIZE) \
(char *)(((unsigned long) (ADDR + PAGE_SIZE)) & ~(PAGE_SIZE-1))
+static int duration = 0;
+
int stack_mprotect(void)
{
void *buf;
@@ -51,23 +53,25 @@ 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;
+ return err;
+
+ /* Check that already linked program can't be attached again. */
+ link = bpf_program__attach(skel->progs.test_int_hook);
+ if (CHECK(!IS_ERR(link), "attach_link",
+ "re-attach without detach should not succeed"))
+ 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;
+ return err;
CHECK(skel->bss->bprm_count != 1, "bprm_count", "bprm_count = %d\n",
skel->bss->bprm_count);
@@ -77,7 +81,7 @@ void test_test_lsm(void)
err = stack_mprotect();
if (CHECK(errno != EPERM, "stack_mprotect", "want err=EPERM, got %d\n",
errno))
- goto close_prog;
+ return err;
CHECK(skel->bss->mprotect_count != 1, "mprotect_count",
"mprotect_count = %d\n", skel->bss->mprotect_count);
@@ -89,6 +93,30 @@ void test_test_lsm(void)
CHECK(skel->bss->copy_test != 3, "copy_test",
"copy_test = %d\n", skel->bss->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 (CHECK(!skel, "lsm_skel_load", "lsm skeleton failed\n"))
+ goto close_prog;
+
+ err = test_lsm(skel);
+ if (CHECK(err, "test_lsm", "first attach failed\n"))
+ goto close_prog;
+
+ err = test_lsm(skel);
+ CHECK(err, "test_lsm", "second attach failed\n");
+
close_prog:
lsm__destroy(skel);
}
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCHv3 bpf-next 5/5] selftests/bpf: Test that module can't be unloaded with attached trampoline
2021-04-11 13:00 [PATCHv3 bpf-next 0/5] bpf: Tracing and lsm programs re-attach Jiri Olsa
` (3 preceding siblings ...)
2021-04-11 13:00 ` [PATCHv3 bpf-next 4/5] selftests/bpf: Add re-attach test to lsm test Jiri Olsa
@ 2021-04-11 13:00 ` Jiri Olsa
4 siblings, 0 replies; 6+ messages in thread
From: Jiri Olsa @ 2021-04-11 13:00 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: Andrii Nakryiko, netdev, bpf, Martin KaFai Lau, Song Liu,
Yonghong Song, John Fastabend, KP Singh,
Toke Høiland-Jørgensen
Adding test to verify that once we attach module's trampoline,
the module can't be unloaded.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
.../selftests/bpf/prog_tests/module_attach.c | 23 +++++++++++++++++++
1 file changed, 23 insertions(+)
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);
}
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread