diff mbox series

[bpf,v3,2/2] selftests/bpf: Add a test for using a cpumap from an freplace-to-XDP program

Message ID 20221213232441.652313-2-toke@redhat.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series [bpf,v3,1/2] bpf: Resolve fext program type when checking map compatibility | expand

Checks

Context Check Description
bpf/vmtest-bpf-VM_Test-4 success Logs for build for s390x with gcc
bpf/vmtest-bpf-VM_Test-9 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-10 success Logs for test_maps on aarch64 with llvm-16
bpf/vmtest-bpf-VM_Test-11 pending Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-VM_Test-12 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-13 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-14 fail Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-15 fail Logs for test_progs on aarch64 with llvm-16
bpf/vmtest-bpf-VM_Test-16 pending Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-VM_Test-17 fail Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-18 fail Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-19 fail Logs for test_progs_no_alu32 on aarch64 with gcc
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netdev/tree_selection success Clearly marked for bpf, async
netdev/fixes_present success Fixes tag present in non-next series
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netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
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netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
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Commit Message

Toke Høiland-Jørgensen Dec. 13, 2022, 11:24 p.m. UTC 
This adds a simple test for inserting an XDP program into a cpumap that is
"owned" by an XDP program that was loaded as PROG_TYPE_EXT (as libxdp
does). Prior to the kernel fix this would fail because the map type
ownership would be set to PROG_TYPE_EXT instead of being resolved to
PROG_TYPE_XDP.

v3:
- Update comment to better explain the cause
- Add Yonghong's ACK

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
 .../selftests/bpf/prog_tests/fexit_bpf2bpf.c  | 57 +++++++++++++++++++
 .../selftests/bpf/progs/freplace_progmap.c    | 24 ++++++++
 tools/testing/selftests/bpf/testing_helpers.c | 24 +++++++-
 tools/testing/selftests/bpf/testing_helpers.h |  2 +
 4 files changed, 105 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/freplace_progmap.c

Comments

Andrii Nakryiko Dec. 13, 2022, 11:26 p.m. UTC | #1 
On Tue, Dec 13, 2022 at 3:24 PM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> This adds a simple test for inserting an XDP program into a cpumap that is
> "owned" by an XDP program that was loaded as PROG_TYPE_EXT (as libxdp
> does). Prior to the kernel fix this would fail because the map type
> ownership would be set to PROG_TYPE_EXT instead of being resolved to
> PROG_TYPE_XDP.
>
> v3:
> - Update comment to better explain the cause
> - Add Yonghong's ACK
>
> Acked-by: Yonghong Song <yhs@fb.com>
> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
> ---

what a race, I just replied a few minutes ago on your v2. Let's use
modern BPF skeleton approach instead of adding legacy stuff to
testing_helpers

>  .../selftests/bpf/prog_tests/fexit_bpf2bpf.c  | 57 +++++++++++++++++++
>  .../selftests/bpf/progs/freplace_progmap.c    | 24 ++++++++
>  tools/testing/selftests/bpf/testing_helpers.c | 24 +++++++-
>  tools/testing/selftests/bpf/testing_helpers.h |  2 +
>  4 files changed, 105 insertions(+), 2 deletions(-)
>  create mode 100644 tools/testing/selftests/bpf/progs/freplace_progmap.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
> index d1e32e792536..fa8e129d1a71 100644
> --- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
> +++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
> @@ -500,6 +500,61 @@ static void test_fentry_to_cgroup_bpf(void)
>         bind4_prog__destroy(skel);
>  }
>
> +static void test_func_replace_progmap(void)
> +{
> +       struct bpf_cpumap_val value = { .qsize = 1 };
> +       struct bpf_object *obj, *tgt_obj = NULL;
> +       struct bpf_program *drop, *redirect;
> +       struct bpf_map *cpumap;
> +       int err, tgt_fd;
> +       __u32 key = 0;
> +
> +       err = bpf_prog_test_open("freplace_progmap.bpf.o", BPF_PROG_TYPE_UNSPEC, &obj);
> +       if (!ASSERT_OK(err, "prog_open"))
> +               return;
> +
> +       err = bpf_prog_test_load("xdp_dummy.bpf.o", BPF_PROG_TYPE_UNSPEC, &tgt_obj, &tgt_fd);
> +       if (!ASSERT_OK(err, "tgt_prog_load"))
> +               goto out;
> +
> +       drop = bpf_object__find_program_by_name(obj, "xdp_drop_prog");
> +       redirect = bpf_object__find_program_by_name(obj, "xdp_cpumap_prog");
> +       cpumap = bpf_object__find_map_by_name(obj, "cpu_map");
> +
> +       if (!ASSERT_OK_PTR(drop, "drop") || !ASSERT_OK_PTR(redirect, "redirect") ||
> +           !ASSERT_OK_PTR(cpumap, "cpumap"))
> +               goto out;
> +
> +       /* Change the 'redirect' program type to be a PROG_TYPE_EXT
> +        * with an XDP target
> +        */
> +       bpf_program__set_type(redirect, BPF_PROG_TYPE_EXT);
> +       bpf_program__set_expected_attach_type(redirect, 0);
> +       err = bpf_program__set_attach_target(redirect, tgt_fd, "xdp_dummy_prog");
> +       if (!ASSERT_OK(err, "set_attach_target"))
> +               goto out;
> +
> +       err = bpf_object__load(obj);
> +       if (!ASSERT_OK(err, "obj_load"))
> +               goto out;
> +
> +       /* Prior to fixing the kernel, loading the PROG_TYPE_EXT 'redirect'
> +        * program above will cause the map owner type of 'cpumap' to be set to
> +        * PROG_TYPE_EXT. This in turn will cause the bpf_map_update_elem()
> +        * below to fail, because the program we are inserting into the map is
> +        * of PROG_TYPE_XDP. After fixing the kernel, the initial ownership will
> +        * be correctly resolved to the *target* of the PROG_TYPE_EXT program
> +        * (i.e., PROG_TYPE_XDP) and the map update will succeed.
> +        */
> +       value.bpf_prog.fd = bpf_program__fd(drop);
> +       err = bpf_map_update_elem(bpf_map__fd(cpumap), &key, &value, 0);
> +       ASSERT_OK(err, "map_update");
> +
> +out:
> +       bpf_object__close(tgt_obj);
> +       bpf_object__close(obj);
> +}
> +
>  /* NOTE: affect other tests, must run in serial mode */
>  void serial_test_fexit_bpf2bpf(void)
>  {
> @@ -525,4 +580,6 @@ void serial_test_fexit_bpf2bpf(void)
>                 test_func_replace_global_func();
>         if (test__start_subtest("fentry_to_cgroup_bpf"))
>                 test_fentry_to_cgroup_bpf();
> +       if (test__start_subtest("func_replace_progmap"))
> +               test_func_replace_progmap();
>  }
> diff --git a/tools/testing/selftests/bpf/progs/freplace_progmap.c b/tools/testing/selftests/bpf/progs/freplace_progmap.c
> new file mode 100644
> index 000000000000..68174c3d7b37
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/freplace_progmap.c
> @@ -0,0 +1,24 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +
> +struct {
> +       __uint(type, BPF_MAP_TYPE_CPUMAP);
> +       __uint(key_size, sizeof(__u32));
> +       __uint(value_size, sizeof(struct bpf_cpumap_val));
> +       __uint(max_entries, 1);
> +} cpu_map SEC(".maps");
> +
> +SEC("xdp/cpumap")
> +int xdp_drop_prog(struct xdp_md *ctx)
> +{
> +       return XDP_DROP;
> +}
> +
> +SEC("xdp")
> +int xdp_cpumap_prog(struct xdp_md *ctx)
> +{
> +       return bpf_redirect_map(&cpu_map, 0, XDP_PASS);
> +}
> +
> +char _license[] SEC("license") = "GPL";
> diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
> index 9695318e8132..2050244e6f24 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.c
> +++ b/tools/testing/selftests/bpf/testing_helpers.c
> @@ -174,8 +174,8 @@ __u32 link_info_prog_id(const struct bpf_link *link, struct bpf_link_info *info)
>
>  int extra_prog_load_log_flags = 0;
>
> -int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
> -                      struct bpf_object **pobj, int *prog_fd)
> +int bpf_prog_test_open(const char *file, enum bpf_prog_type type,
> +                      struct bpf_object **pobj)
>  {
>         LIBBPF_OPTS(bpf_object_open_opts, opts,
>                 .kernel_log_level = extra_prog_load_log_flags,
> @@ -201,6 +201,26 @@ int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
>         flags = bpf_program__flags(prog) | BPF_F_TEST_RND_HI32;
>         bpf_program__set_flags(prog, flags);
>
> +       *pobj = obj;
> +       return 0;
> +err_out:
> +       bpf_object__close(obj);
> +       return err;
> +}
> +
> +int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
> +                      struct bpf_object **pobj, int *prog_fd)
> +{
> +       struct bpf_program *prog;
> +       struct bpf_object *obj;
> +       int err;
> +
> +       err = bpf_prog_test_open(file, type, &obj);
> +       if (err)
> +               return err;
> +
> +       prog = bpf_object__next_program(obj, NULL);
> +
>         err = bpf_object__load(obj);
>         if (err)
>                 goto err_out;
> diff --git a/tools/testing/selftests/bpf/testing_helpers.h b/tools/testing/selftests/bpf/testing_helpers.h
> index 6ec00bf79cb5..977eb520d119 100644
> --- a/tools/testing/selftests/bpf/testing_helpers.h
> +++ b/tools/testing/selftests/bpf/testing_helpers.h
> @@ -6,6 +6,8 @@
>
>  int parse_num_list(const char *s, bool **set, int *set_len);
>  __u32 link_info_prog_id(const struct bpf_link *link, struct bpf_link_info *info);
> +int bpf_prog_test_open(const char *file, enum bpf_prog_type type,
> +                      struct bpf_object **pobj);
>  int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
>                        struct bpf_object **pobj, int *prog_fd);
>  int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
> --
> 2.38.1
>
Toke Høiland-Jørgensen Dec. 14, 2022, 12:30 a.m. UTC | #2 
Andrii Nakryiko <andrii.nakryiko@gmail.com> writes:

> On Tue, Dec 13, 2022 at 3:24 PM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>>
>> This adds a simple test for inserting an XDP program into a cpumap that is
>> "owned" by an XDP program that was loaded as PROG_TYPE_EXT (as libxdp
>> does). Prior to the kernel fix this would fail because the map type
>> ownership would be set to PROG_TYPE_EXT instead of being resolved to
>> PROG_TYPE_XDP.
>>
>> v3:
>> - Update comment to better explain the cause
>> - Add Yonghong's ACK
>>
>> Acked-by: Yonghong Song <yhs@fb.com>
>> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
>> ---
>
> what a race, I just replied a few minutes ago on your v2. Let's use
> modern BPF skeleton approach instead of adding legacy stuff to
> testing_helpers

Sure, will respin...

-Toke
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
index d1e32e792536..fa8e129d1a71 100644
--- a/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
+++ b/tools/testing/selftests/bpf/prog_tests/fexit_bpf2bpf.c
@@ -500,6 +500,61 @@  static void test_fentry_to_cgroup_bpf(void)
 	bind4_prog__destroy(skel);
 }
 
+static void test_func_replace_progmap(void)
+{
+	struct bpf_cpumap_val value = { .qsize = 1 };
+	struct bpf_object *obj, *tgt_obj = NULL;
+	struct bpf_program *drop, *redirect;
+	struct bpf_map *cpumap;
+	int err, tgt_fd;
+	__u32 key = 0;
+
+	err = bpf_prog_test_open("freplace_progmap.bpf.o", BPF_PROG_TYPE_UNSPEC, &obj);
+	if (!ASSERT_OK(err, "prog_open"))
+		return;
+
+	err = bpf_prog_test_load("xdp_dummy.bpf.o", BPF_PROG_TYPE_UNSPEC, &tgt_obj, &tgt_fd);
+	if (!ASSERT_OK(err, "tgt_prog_load"))
+		goto out;
+
+	drop = bpf_object__find_program_by_name(obj, "xdp_drop_prog");
+	redirect = bpf_object__find_program_by_name(obj, "xdp_cpumap_prog");
+	cpumap = bpf_object__find_map_by_name(obj, "cpu_map");
+
+	if (!ASSERT_OK_PTR(drop, "drop") || !ASSERT_OK_PTR(redirect, "redirect") ||
+	    !ASSERT_OK_PTR(cpumap, "cpumap"))
+		goto out;
+
+	/* Change the 'redirect' program type to be a PROG_TYPE_EXT
+	 * with an XDP target
+	 */
+	bpf_program__set_type(redirect, BPF_PROG_TYPE_EXT);
+	bpf_program__set_expected_attach_type(redirect, 0);
+	err = bpf_program__set_attach_target(redirect, tgt_fd, "xdp_dummy_prog");
+	if (!ASSERT_OK(err, "set_attach_target"))
+		goto out;
+
+	err = bpf_object__load(obj);
+	if (!ASSERT_OK(err, "obj_load"))
+		goto out;
+
+	/* Prior to fixing the kernel, loading the PROG_TYPE_EXT 'redirect'
+	 * program above will cause the map owner type of 'cpumap' to be set to
+	 * PROG_TYPE_EXT. This in turn will cause the bpf_map_update_elem()
+	 * below to fail, because the program we are inserting into the map is
+	 * of PROG_TYPE_XDP. After fixing the kernel, the initial ownership will
+	 * be correctly resolved to the *target* of the PROG_TYPE_EXT program
+	 * (i.e., PROG_TYPE_XDP) and the map update will succeed.
+	 */
+	value.bpf_prog.fd = bpf_program__fd(drop);
+	err = bpf_map_update_elem(bpf_map__fd(cpumap), &key, &value, 0);
+	ASSERT_OK(err, "map_update");
+
+out:
+	bpf_object__close(tgt_obj);
+	bpf_object__close(obj);
+}
+
 /* NOTE: affect other tests, must run in serial mode */
 void serial_test_fexit_bpf2bpf(void)
 {
@@ -525,4 +580,6 @@  void serial_test_fexit_bpf2bpf(void)
 		test_func_replace_global_func();
 	if (test__start_subtest("fentry_to_cgroup_bpf"))
 		test_fentry_to_cgroup_bpf();
+	if (test__start_subtest("func_replace_progmap"))
+		test_func_replace_progmap();
 }
diff --git a/tools/testing/selftests/bpf/progs/freplace_progmap.c b/tools/testing/selftests/bpf/progs/freplace_progmap.c
new file mode 100644
index 000000000000..68174c3d7b37
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/freplace_progmap.c
@@ -0,0 +1,24 @@ 
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_CPUMAP);
+	__uint(key_size, sizeof(__u32));
+	__uint(value_size, sizeof(struct bpf_cpumap_val));
+	__uint(max_entries, 1);
+} cpu_map SEC(".maps");
+
+SEC("xdp/cpumap")
+int xdp_drop_prog(struct xdp_md *ctx)
+{
+	return XDP_DROP;
+}
+
+SEC("xdp")
+int xdp_cpumap_prog(struct xdp_md *ctx)
+{
+	return bpf_redirect_map(&cpu_map, 0, XDP_PASS);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/testing_helpers.c b/tools/testing/selftests/bpf/testing_helpers.c
index 9695318e8132..2050244e6f24 100644
--- a/tools/testing/selftests/bpf/testing_helpers.c
+++ b/tools/testing/selftests/bpf/testing_helpers.c
@@ -174,8 +174,8 @@  __u32 link_info_prog_id(const struct bpf_link *link, struct bpf_link_info *info)
 
 int extra_prog_load_log_flags = 0;
 
-int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
-		       struct bpf_object **pobj, int *prog_fd)
+int bpf_prog_test_open(const char *file, enum bpf_prog_type type,
+		       struct bpf_object **pobj)
 {
 	LIBBPF_OPTS(bpf_object_open_opts, opts,
 		.kernel_log_level = extra_prog_load_log_flags,
@@ -201,6 +201,26 @@  int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
 	flags = bpf_program__flags(prog) | BPF_F_TEST_RND_HI32;
 	bpf_program__set_flags(prog, flags);
 
+	*pobj = obj;
+	return 0;
+err_out:
+	bpf_object__close(obj);
+	return err;
+}
+
+int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
+		       struct bpf_object **pobj, int *prog_fd)
+{
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int err;
+
+	err = bpf_prog_test_open(file, type, &obj);
+	if (err)
+		return err;
+
+	prog = bpf_object__next_program(obj, NULL);
+
 	err = bpf_object__load(obj);
 	if (err)
 		goto err_out;
diff --git a/tools/testing/selftests/bpf/testing_helpers.h b/tools/testing/selftests/bpf/testing_helpers.h
index 6ec00bf79cb5..977eb520d119 100644
--- a/tools/testing/selftests/bpf/testing_helpers.h
+++ b/tools/testing/selftests/bpf/testing_helpers.h
@@ -6,6 +6,8 @@ 
 
 int parse_num_list(const char *s, bool **set, int *set_len);
 __u32 link_info_prog_id(const struct bpf_link *link, struct bpf_link_info *info);
+int bpf_prog_test_open(const char *file, enum bpf_prog_type type,
+		       struct bpf_object **pobj);
 int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
 		       struct bpf_object **pobj, int *prog_fd);
 int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,