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From: Benjamin Tissoires <benjamin.tissoires@redhat.com>
To: Greg KH <gregkh@linuxfoundation.org>,
	Jiri Kosina <jikos@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	Kumar Kartikeya Dwivedi <memxor@gmail.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>, Shuah Khan <shuah@kernel.org>,
	Dave Marchevsky <davemarchevsky@fb.com>,
	Joe Stringer <joe@cilium.io>, Jonathan Corbet <corbet@lwn.net>
Cc: Tero Kristo <tero.kristo@linux.intel.com>,
	linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org,
	Benjamin Tissoires <benjamin.tissoires@redhat.com>
Subject: [PATCH bpf-next v7 06/24] selftests/bpf: Add tests for kfunc returning a memory pointer
Date: Thu, 21 Jul 2022 17:36:07 +0200	[thread overview]
Message-ID: <20220721153625.1282007-7-benjamin.tissoires@redhat.com> (raw)
In-Reply-To: <20220721153625.1282007-1-benjamin.tissoires@redhat.com>

We add 2 new kfuncs that are following the RET_PTR_TO_MEM
capability from the previous commit.
Then we test them in selftests:
the first tests are testing valid case, and are not failing,
and the later ones are actually preventing the program to be loaded
because they are wrong.

To work around that, we mark the failing ones as not autoloaded
(with SEC("?tc")), and we manually enable them one by one, ensuring
the verifier rejects them.

To be able to use bpf_program__set_autoload() from libbpf, we need
to use a plain skeleton, not a light-skeleton, and this is why we
also change the Makefile to generate both for kfunc_call_test.c

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

changes in v7:
- removed stray include/linux/btf.h change

new in v6
---
 net/bpf/test_run.c                            | 22 +++++
 tools/testing/selftests/bpf/Makefile          |  5 +-
 .../selftests/bpf/prog_tests/kfunc_call.c     | 48 ++++++++++
 .../selftests/bpf/progs/kfunc_call_test.c     | 89 +++++++++++++++++++
 4 files changed, 162 insertions(+), 2 deletions(-)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 8ada09ab1b15..1fc36a235bcd 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -606,6 +606,24 @@ noinline void bpf_kfunc_call_memb1_release(struct prog_test_member1 *p)
 	WARN_ON_ONCE(1);
 }
 
+static int *__bpf_kfunc_call_test_get_mem(struct prog_test_ref_kfunc *p, const int size)
+{
+	if (size > 2 * sizeof(int))
+		return NULL;
+
+	return (int *)p;
+}
+
+noinline int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int rdwr_buf_size)
+{
+	return __bpf_kfunc_call_test_get_mem(p, rdwr_buf_size);
+}
+
+noinline int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size)
+{
+	return __bpf_kfunc_call_test_get_mem(p, rdonly_buf_size);
+}
+
 noinline struct prog_test_ref_kfunc *
 bpf_kfunc_call_test_kptr_get(struct prog_test_ref_kfunc **pp, int a, int b)
 {
@@ -704,6 +722,8 @@ BTF_ID(func, bpf_kfunc_call_memb_acquire)
 BTF_ID(func, bpf_kfunc_call_test_release)
 BTF_ID(func, bpf_kfunc_call_memb_release)
 BTF_ID(func, bpf_kfunc_call_memb1_release)
+BTF_ID(func, bpf_kfunc_call_test_get_rdwr_mem)
+BTF_ID(func, bpf_kfunc_call_test_get_rdonly_mem)
 BTF_ID(func, bpf_kfunc_call_test_kptr_get)
 BTF_ID(func, bpf_kfunc_call_test_pass_ctx)
 BTF_ID(func, bpf_kfunc_call_test_pass1)
@@ -731,6 +751,8 @@ BTF_SET_END(test_sk_release_kfunc_ids)
 BTF_SET_START(test_sk_ret_null_kfunc_ids)
 BTF_ID(func, bpf_kfunc_call_test_acquire)
 BTF_ID(func, bpf_kfunc_call_memb_acquire)
+BTF_ID(func, bpf_kfunc_call_test_get_rdwr_mem)
+BTF_ID(func, bpf_kfunc_call_test_get_rdonly_mem)
 BTF_ID(func, bpf_kfunc_call_test_kptr_get)
 BTF_SET_END(test_sk_ret_null_kfunc_ids)
 
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 8d59ec7f4c2d..0905315ff86d 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -350,11 +350,12 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h		\
 		test_subskeleton.skel.h test_subskeleton_lib.skel.h	\
 		test_usdt.skel.h
 
-LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \
+LSKELS := fentry_test.c fexit_test.c fexit_sleep.c \
 	test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c \
 	map_ptr_kern.c core_kern.c core_kern_overflow.c
 # Generate both light skeleton and libbpf skeleton for these
-LSKELS_EXTRA := test_ksyms_module.c test_ksyms_weak.c kfunc_call_test_subprog.c
+LSKELS_EXTRA := test_ksyms_module.c test_ksyms_weak.c kfunc_call_test.c	\
+		kfunc_call_test_subprog.c
 SKEL_BLACKLIST += $$(LSKELS)
 
 test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
index 7e4804cce6b9..0815aa89d505 100644
--- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c
@@ -2,6 +2,7 @@
 /* Copyright (c) 2021 Facebook */
 #include <test_progs.h>
 #include <network_helpers.h>
+#include "kfunc_call_test.skel.h"
 #include "kfunc_call_test.lskel.h"
 #include "kfunc_call_test_subprog.skel.h"
 #include "kfunc_call_test_subprog.lskel.h"
@@ -50,10 +51,12 @@ static void test_main(void)
 	prog_fd = skel->progs.kfunc_syscall_test.prog_fd;
 	err = bpf_prog_test_run_opts(prog_fd, &syscall_topts);
 	ASSERT_OK(err, "bpf_prog_test_run(syscall_test)");
+	ASSERT_EQ(syscall_topts.retval, 0, "syscall_test-retval");
 
 	prog_fd = skel->progs.kfunc_syscall_test_fail.prog_fd;
 	err = bpf_prog_test_run_opts(prog_fd, &syscall_topts);
 	ASSERT_ERR(err, "bpf_prog_test_run(syscall_test_fail)");
+	ASSERT_EQ(syscall_topts.retval, 0, "syscall_test_fail-retval");
 
 	syscall_topts.ctx_in = NULL;
 	syscall_topts.ctx_size_in = 0;
@@ -114,6 +117,48 @@ static void test_subprog_lskel(void)
 	kfunc_call_test_subprog_lskel__destroy(skel);
 }
 
+static void test_get_mem(void)
+{
+	struct kfunc_call_test *skel;
+	int prog_fd, err;
+	LIBBPF_OPTS(bpf_test_run_opts, topts,
+		.data_in = &pkt_v4,
+		.data_size_in = sizeof(pkt_v4),
+		.repeat = 1,
+	);
+
+	skel = kfunc_call_test__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel"))
+		return;
+
+	prog_fd = bpf_program__fd(skel->progs.kfunc_call_test_get_mem);
+	err = bpf_prog_test_run_opts(prog_fd, &topts);
+	ASSERT_OK(err, "bpf_prog_test_run(test_get_mem)");
+	ASSERT_EQ(topts.retval, 42, "test_get_mem-retval");
+
+	kfunc_call_test__destroy(skel);
+
+	/* start the various failing tests */
+	skel = kfunc_call_test__open();
+	if (!ASSERT_OK_PTR(skel, "skel"))
+		return;
+
+	bpf_program__set_autoload(skel->progs.kfunc_call_test_get_mem_fail1, true);
+	err = kfunc_call_test__load(skel);
+	ASSERT_ERR(err, "load(kfunc_call_test_get_mem_fail1)");
+	kfunc_call_test__destroy(skel);
+
+	skel = kfunc_call_test__open();
+	if (!ASSERT_OK_PTR(skel, "skel"))
+		return;
+
+	bpf_program__set_autoload(skel->progs.kfunc_call_test_get_mem_fail2, true);
+	err = kfunc_call_test__load(skel);
+	ASSERT_ERR(err, "load(kfunc_call_test_get_mem_fail2)");
+
+	kfunc_call_test__destroy(skel);
+}
+
 void test_kfunc_call(void)
 {
 	if (test__start_subtest("main"))
@@ -124,4 +169,7 @@ void test_kfunc_call(void)
 
 	if (test__start_subtest("subprog_lskel"))
 		test_subprog_lskel();
+
+	if (test__start_subtest("get_mem"))
+		test_get_mem();
 }
diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
index da7ae0ef9100..b4a98d17c2b6 100644
--- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c
+++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c
@@ -14,6 +14,8 @@ extern void bpf_kfunc_call_test_pass1(struct prog_test_pass1 *p) __ksym;
 extern void bpf_kfunc_call_test_pass2(struct prog_test_pass2 *p) __ksym;
 extern void bpf_kfunc_call_test_mem_len_pass1(void *mem, int len) __ksym;
 extern void bpf_kfunc_call_test_mem_len_fail2(__u64 *mem, int len) __ksym;
+extern int *bpf_kfunc_call_test_get_rdwr_mem(struct prog_test_ref_kfunc *p, const int rdwr_buf_size) __ksym;
+extern int *bpf_kfunc_call_test_get_rdonly_mem(struct prog_test_ref_kfunc *p, const int rdonly_buf_size) __ksym;
 
 SEC("tc")
 int kfunc_call_test2(struct __sk_buff *skb)
@@ -128,4 +130,91 @@ int kfunc_syscall_test_fail(struct syscall_test_args *args)
 	return 0;
 }
 
+SEC("tc")
+int kfunc_call_test_get_mem(struct __sk_buff *skb)
+{
+	struct prog_test_ref_kfunc *pt;
+	unsigned long s = 0;
+	int *p = NULL;
+	int ret = 0;
+
+	pt = bpf_kfunc_call_test_acquire(&s);
+	if (pt) {
+		if (pt->a != 42 || pt->b != 108)
+			ret = -1;
+
+		p = bpf_kfunc_call_test_get_rdwr_mem(pt, 2 * sizeof(int));
+		if (p) {
+			p[0] = 42;
+			ret = p[1]; /* 108 */
+		} else {
+			ret = -1;
+		}
+
+		if (ret >= 0) {
+			p = bpf_kfunc_call_test_get_rdonly_mem(pt, 2 * sizeof(int));
+			if (p)
+				ret = p[0]; /* 42 */
+			else
+				ret = -1;
+		}
+
+		bpf_kfunc_call_test_release(pt);
+	}
+	return ret;
+}
+
+SEC("?tc")
+int kfunc_call_test_get_mem_fail1(struct __sk_buff *skb)
+{
+	struct prog_test_ref_kfunc *pt;
+	unsigned long s = 0;
+	int *p = NULL;
+	int ret = 0;
+
+	pt = bpf_kfunc_call_test_acquire(&s);
+	if (pt) {
+		if (pt->a != 42 || pt->b != 108)
+			ret = -1;
+
+		p = bpf_kfunc_call_test_get_rdonly_mem(pt, 2 * sizeof(int));
+		if (p)
+			p[0] = 42; /* this is a read-only buffer, so -EACCES */
+		else
+			ret = -1;
+
+		bpf_kfunc_call_test_release(pt);
+	}
+	return ret;
+}
+
+SEC("?tc")
+int kfunc_call_test_get_mem_fail2(struct __sk_buff *skb)
+{
+	struct prog_test_ref_kfunc *pt;
+	unsigned long s = 0;
+	int *p = NULL;
+	int ret = 0;
+
+	pt = bpf_kfunc_call_test_acquire(&s);
+	if (pt) {
+		if (pt->a != 42 || pt->b != 108)
+			ret = -1;
+
+		p = bpf_kfunc_call_test_get_rdwr_mem(pt, 2 * sizeof(int));
+		if (p) {
+			p[0] = 42;
+			ret = p[1]; /* 108 */
+		} else {
+			ret = -1;
+		}
+
+		bpf_kfunc_call_test_release(pt);
+	}
+	if (p)
+		ret = p[0]; /* p is not valid anymore */
+
+	return ret;
+}
+
 char _license[] SEC("license") = "GPL";
-- 
2.36.1


  parent reply	other threads:[~2022-07-21 15:38 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-21 15:36 [PATCH bpf-next v7 00/24] Introduce eBPF support for HID devices Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 01/24] selftests/bpf: fix config for CLS_BPF Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 02/24] bpf/verifier: allow kfunc to read user provided context Benjamin Tissoires
2022-07-21 20:15   ` Kumar Kartikeya Dwivedi
2022-07-22  8:43     ` Benjamin Tissoires
2022-07-22  8:45   ` [PATCH bpf-next v8 " Benjamin Tissoires
2022-07-22 16:16     ` Alexei Starovoitov
2022-07-25 16:36       ` Benjamin Tissoires
2022-08-24  9:57         ` Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 03/24] bpf/verifier: do not clear meta in check_mem_size Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 04/24] selftests/bpf: add test for accessing ctx from syscall program type Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 05/24] bpf/verifier: allow kfunc to return an allocated mem Benjamin Tissoires
2022-07-21 21:05   ` Kumar Kartikeya Dwivedi
2022-07-21 15:36 ` Benjamin Tissoires [this message]
2022-07-21 15:36 ` [PATCH bpf-next v7 07/24] bpf: prepare for more bpf syscall to be used from kernel and user space Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 08/24] libbpf: add map_get_fd_by_id and map_delete_elem in light skeleton Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 09/24] HID: core: store the unique system identifier in hid_device Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 10/24] HID: export hid_report_type to uapi Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 11/24] HID: convert defines of HID class requests into a proper enum Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 12/24] HID: Kconfig: split HID support and hid-core compilation Benjamin Tissoires
2022-07-28 14:14   ` Greg KH
2022-07-21 15:36 ` [PATCH bpf-next v7 13/24] HID: initial BPF implementation Benjamin Tissoires
2022-07-28 14:15   ` Greg KH
2022-08-24  9:41     ` Benjamin Tissoires
2022-07-28 14:19   ` Greg KH
2022-08-24  9:48     ` Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 14/24] selftests/bpf: add tests for the HID-bpf initial implementation Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 15/24] HID: bpf: allocate data memory for device_event BPF programs Benjamin Tissoires
2022-07-28 15:10   ` Greg KH
2022-07-21 15:36 ` [PATCH bpf-next v7 16/24] selftests/bpf/hid: add test to change the report size Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 17/24] HID: bpf: introduce hid_hw_request() Benjamin Tissoires
2022-07-28 15:10   ` Greg KH
2022-07-21 15:36 ` [PATCH bpf-next v7 18/24] selftests/bpf: add tests for bpf_hid_hw_request Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 19/24] HID: bpf: allow to change the report descriptor Benjamin Tissoires
2022-07-28 15:10   ` Greg KH
2022-07-21 15:36 ` [PATCH bpf-next v7 20/24] selftests/bpf: add report descriptor fixup tests Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 21/24] selftests/bpf: Add a test for BPF_F_INSERT_HEAD Benjamin Tissoires
2022-07-21 15:36 ` [PATCH bpf-next v7 22/24] samples/bpf: add new hid_mouse example Benjamin Tissoires
2022-07-28 15:13   ` Greg KH
2022-07-21 15:36 ` [PATCH bpf-next v7 23/24] HID: bpf: add Surface Dial example Benjamin Tissoires
2022-07-28 15:12   ` Greg KH
2022-07-21 15:36 ` [PATCH bpf-next v7 24/24] Documentation: add HID-BPF docs Benjamin Tissoires
2022-08-25  2:52   ` Bagas Sanjaya
2022-08-30 13:30     ` Benjamin Tissoires
2022-08-03  7:41 ` [PATCH bpf-next v7 00/24] Introduce eBPF support for HID devices Tero Kristo

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