[PATCH V2 net-next 0/6] test_bpf improvements

[PATCH V2 net-next 0/6] test_bpf improvements

[Nicolas Schichan]

Hello,

Please find below the patch series with my latest changes to test_bpf.

The first patch checks for unexpected NULL generated skbs before
running the filter.

The second patch adds the possibility for tests to generate fragmented
skbs.

The third patch tests LD_ABS and LD_IND on fragmented skbs.

The fourth patch adds the possibility to restrict the tests being run
by specifying the name/id/range of the test(s) to run via module
parameters.

The fifth patch tests LD_ABS and LD_IND on non fragmented skbs with
various sizes and alignments.

The sixth and final patch checks that the interpreter or JIT correctly
resets A and X to 0.

This serie is against today's net-next tree.

Changes in V2:

* move declaration of 'ptr' in if() block in patch 2/6.

* fix various typos in patch 4/6

* rework default init of test_range array and cleanup exclude_test()
  return condition in patch 4/6.

Regards,

Nicolas Schichan (6):
  test_bpf: avoid oopsing the kernel when generate_test_data() fails.
  test_bpf: allow tests to specify an skb fragment.
  test_bpf: test LD_ABS and LD_IND instructions on fragmented skbs.
  test_bpf: allow running of a single test specified as a module
    parameter.
  test_bpf: add more tests for LD_ABS and LD_IND.
  test_bpf: add tests checking that JIT/interpreter sets A and X to 0.

 lib/test_bpf.c | 645 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 644 insertions(+), 1 deletion(-)

-- 
1.9.1

[PATCH V2 net-next 1/6] test_bpf: avoid oopsing the kernel when generate_test_data() fails.

[Nicolas Schichan]

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
 lib/test_bpf.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 3afddf2..6843d0b 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4672,6 +4672,11 @@ static int run_one(const struct bpf_prog *fp, struct bpf_test *test)
 			break;
 
 		data = generate_test_data(test, i);
+		if (!data && !(test->aux & FLAG_NO_DATA)) {
+			pr_cont("data generation failed ");
+			err_cnt++;
+			break;
+		}
 		ret = __run_one(fp, data, runs, &duration);
 		release_test_data(test, data);
 
-- 
1.9.1

[PATCH V2 net-next 2/6] test_bpf: allow tests to specify an skb fragment.

[Nicolas Schichan]

This introduce a new test->aux flag (FLAG_SKB_FRAG) to tell the
populate_skb() function to add a fragment to the test skb containing
the data specified in test->frag_data).

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
 lib/test_bpf.c | 39 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 6843d0b..e261751 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -23,6 +23,7 @@
 #include <linux/netdevice.h>
 #include <linux/if_vlan.h>
 #include <linux/random.h>
+#include <linux/highmem.h>
 
 /* General test specific settings */
 #define MAX_SUBTESTS	3
@@ -56,6 +57,7 @@
 /* Flags that can be passed to test cases */
 #define FLAG_NO_DATA		BIT(0)
 #define FLAG_EXPECTED_FAIL	BIT(1)
+#define FLAG_SKB_FRAG		BIT(2)
 
 enum {
 	CLASSIC  = BIT(6),	/* Old BPF instructions only. */
@@ -81,6 +83,7 @@ struct bpf_test {
 		__u32 result;
 	} test[MAX_SUBTESTS];
 	int (*fill_helper)(struct bpf_test *self);
+	__u8 frag_data[MAX_DATA];
 };
 
 /* Large test cases need separate allocation and fill handler. */
@@ -4525,6 +4528,9 @@ static struct sk_buff *populate_skb(char *buf, int size)
 
 static void *generate_test_data(struct bpf_test *test, int sub)
 {
+	struct sk_buff *skb;
+	struct page *page;
+
 	if (test->aux & FLAG_NO_DATA)
 		return NULL;
 
@@ -4532,7 +4538,38 @@ static void *generate_test_data(struct bpf_test *test, int sub)
 	 * subtests generate skbs of different sizes based on
 	 * the same data.
 	 */
-	return populate_skb(test->data, test->test[sub].data_size);
+	skb = populate_skb(test->data, test->test[sub].data_size);
+	if (!skb)
+		return NULL;
+
+	if (test->aux & FLAG_SKB_FRAG) {
+		/*
+		 * when the test requires a fragmented skb, add a
+		 * single fragment to the skb, filled with
+		 * test->frag_data.
+		 */
+		void *ptr;
+
+		page = alloc_page(GFP_KERNEL);
+
+		if (!page)
+			goto err_kfree_skb;
+
+		ptr = kmap(page);
+		if (!ptr)
+			goto err_free_page;
+		memcpy(ptr, test->frag_data, MAX_DATA);
+		kunmap(page);
+		skb_add_rx_frag(skb, 0, page, 0, MAX_DATA, MAX_DATA);
+	}
+
+	return skb;
+
+err_free_page:
+	__free_page(page);
+err_kfree_skb:
+	kfree_skb(skb);
+	return NULL;
 }
 
 static void release_test_data(const struct bpf_test *test, void *data)
-- 
1.9.1

[PATCH V2 net-next 3/6] test_bpf: test LD_ABS and LD_IND instructions on fragmented skbs.

[Nicolas Schichan]

These new tests exercise various load sizes and offsets crossing the
head/fragment boundary.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
 lib/test_bpf.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index e261751..f18b7b8 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4493,6 +4493,148 @@ static struct bpf_test tests[] = {
 		{ { 1, 0xbef } },
 		.fill_helper = bpf_fill_ld_abs_vlan_push_pop,
 	},
+	/*
+	 * LD_IND / LD_ABS on fragmented SKBs
+	 */
+	{
+		"LD_IND byte frag",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x40),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_B, 0x0),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ },
+		{ {0x40, 0x42} },
+		.frag_data = {
+			0x42, 0x00, 0x00, 0x00,
+			0x43, 0x44, 0x00, 0x00,
+			0x21, 0x07, 0x19, 0x83,
+		},
+	},
+	{
+		"LD_IND halfword frag",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x40),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_H, 0x4),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ },
+		{ {0x40, 0x4344} },
+		.frag_data = {
+			0x42, 0x00, 0x00, 0x00,
+			0x43, 0x44, 0x00, 0x00,
+			0x21, 0x07, 0x19, 0x83,
+		},
+	},
+	{
+		"LD_IND word frag",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x40),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, 0x8),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ },
+		{ {0x40, 0x21071983} },
+		.frag_data = {
+			0x42, 0x00, 0x00, 0x00,
+			0x43, 0x44, 0x00, 0x00,
+			0x21, 0x07, 0x19, 0x83,
+		},
+	},
+	{
+		"LD_IND halfword mixed head/frag",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x40),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_H, -0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ [0x3e] = 0x25, [0x3f] = 0x05, },
+		{ {0x40, 0x0519} },
+		.frag_data = { 0x19, 0x82 },
+	},
+	{
+		"LD_IND word mixed head/frag",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x40),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, -0x2),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ [0x3e] = 0x25, [0x3f] = 0x05, },
+		{ {0x40, 0x25051982} },
+		.frag_data = { 0x19, 0x82 },
+	},
+	{
+		"LD_ABS byte frag",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_B, 0x40),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ },
+		{ {0x40, 0x42} },
+		.frag_data = {
+			0x42, 0x00, 0x00, 0x00,
+			0x43, 0x44, 0x00, 0x00,
+			0x21, 0x07, 0x19, 0x83,
+		},
+	},
+	{
+		"LD_ABS halfword frag",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_H, 0x44),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ },
+		{ {0x40, 0x4344} },
+		.frag_data = {
+			0x42, 0x00, 0x00, 0x00,
+			0x43, 0x44, 0x00, 0x00,
+			0x21, 0x07, 0x19, 0x83,
+		},
+	},
+	{
+		"LD_ABS word frag",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_W, 0x48),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ },
+		{ {0x40, 0x21071983} },
+		.frag_data = {
+			0x42, 0x00, 0x00, 0x00,
+			0x43, 0x44, 0x00, 0x00,
+			0x21, 0x07, 0x19, 0x83,
+		},
+	},
+	{
+		"LD_ABS halfword mixed head/frag",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_H, 0x3f),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ [0x3e] = 0x25, [0x3f] = 0x05, },
+		{ {0x40, 0x0519} },
+		.frag_data = { 0x19, 0x82 },
+	},
+	{
+		"LD_ABS word mixed head/frag",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_W, 0x3e),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_SKB_FRAG,
+		{ [0x3e] = 0x25, [0x3f] = 0x05, },
+		{ {0x40, 0x25051982} },
+		.frag_data = { 0x19, 0x82 },
+	},
 };
 
 static struct net_device dev;
-- 
1.9.1

[PATCH V2 net-next 4/6] test_bpf: add module parameters to filter the tests to run.

[Nicolas Schichan]

When developping on the interpreter or a particular JIT, it can be
interesting to restrict the tests list to a specific test or a
particular range of tests.

This patch adds the following module parameters to the test_bpf module:

* test_name=<string>: only the specified named test will be run.

* test_id=<number>: only the test with the specified id will be run
  (see the output of test_bpf without parameters to get the test id).

* test_range=<number>,<number>: only the tests within IDs in the
  specified id range are run (see the output of test_bpf without
  parameters to get the test ids).

Any invalid range, test id or test name will result in -EINVAL being
returned and no tests being run.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
 lib/test_bpf.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index f18b7b8..8200980 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4871,10 +4871,73 @@ static int run_one(const struct bpf_prog *fp, struct bpf_test *test)
 	return err_cnt;
 }
 
+static char test_name[64];
+module_param_string(test_name, test_name, sizeof(test_name), 0);
+
+static int test_id = -1;
+module_param(test_id, int, 0);
+
+static int test_range[2] = { 0, ARRAY_SIZE(tests) - 1 };
+module_param_array(test_range, int, NULL, 0);
+
+static __init int find_test_index(const char *test_name)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		if (!strcmp(tests[i].descr, test_name))
+			return i;
+	}
+	return -1;
+}
+
 static __init int prepare_bpf_tests(void)
 {
 	int i;
 
+	if (test_id >= 0) {
+		/*
+		 * if a test_id was specified, use test_range to
+		 * cover only that test.
+		 */
+		if (test_id >= ARRAY_SIZE(tests)) {
+			pr_err("test_bpf: invalid test_id specified.\n");
+			return -EINVAL;
+		}
+
+		test_range[0] = test_id;
+		test_range[1] = test_id;
+	} else if (*test_name) {
+		/*
+		 * if a test_name was specified, find it and setup
+		 * test_range to cover only that test.
+		 */
+		int idx = find_test_index(test_name);
+
+		if (idx < 0) {
+			pr_err("test_bpf: no test named '%s' found.\n",
+			       test_name);
+			return -EINVAL;
+		}
+		test_range[0] = idx;
+		test_range[1] = idx;
+	} else {
+		/*
+		 * check that the supplied test_range is valid.
+		 */
+		if (test_range[0] >= ARRAY_SIZE(tests) ||
+		    test_range[1] >= ARRAY_SIZE(tests) ||
+		    test_range[0] < 0 || test_range[1] < 0) {
+			pr_err("test_bpf: test_range is out of bound.\n");
+			return -EINVAL;
+		}
+
+		if (test_range[1] < test_range[0]) {
+			pr_err("test_bpf: test_range is ending before it starts.\n");
+			return -EINVAL;
+		}
+	}
+
 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
 		if (tests[i].fill_helper &&
 		    tests[i].fill_helper(&tests[i]) < 0)
@@ -4894,6 +4957,11 @@ static __init void destroy_bpf_tests(void)
 	}
 }
 
+static bool exclude_test(int test_id)
+{
+	return test_id < test_range[0] || test_id > test_range[1];
+}
+
 static __init int test_bpf(void)
 {
 	int i, err_cnt = 0, pass_cnt = 0;
@@ -4903,6 +4971,9 @@ static __init int test_bpf(void)
 		struct bpf_prog *fp;
 		int err;
 
+		if (exclude_test(i))
+			continue;
+
 		pr_info("#%d %s ", i, tests[i].descr);
 
 		fp = generate_filter(i, &err);
-- 
1.9.1

Re: [PATCH V2 net-next 4/6] test_bpf: add module parameters to filter the tests to run.

[Alexei Starovoitov]

On 8/4/15 6:19 AM, Nicolas Schichan wrote:
> When developping on the interpreter or a particular JIT, it can be
> interesting to restrict the tests list to a specific test or a
> particular range of tests.
>
> This patch adds the following module parameters to the test_bpf module:
>
> * test_name=<string>: only the specified named test will be run.
>
> * test_id=<number>: only the test with the specified id will be run
>    (see the output of test_bpf without parameters to get the test id).
>
> * test_range=<number>,<number>: only the tests within IDs in the
>    specified id range are run (see the output of test_bpf without
>    parameters to get the test ids).
>
> Any invalid range, test id or test name will result in -EINVAL being
> returned and no tests being run.
>
> Signed-off-by: Nicolas Schichan<nschichan@freebox.fr>
> Acked-by: Daniel Borkmann<daniel@iogearbox.net>

looks good. thank you for adding range feature :)
Acked-by: Alexei Starovoitov <ast@plumgrid.com>

[PATCH V2 net-next 5/6] test_bpf: add more tests for LD_ABS and LD_IND.

[Nicolas Schichan]

This exerces the LD_ABS and LD_IND instructions for various sizes and
alignments. This also checks that X when used as an offset to a
BPF_IND instruction first in a filter is correctly set to 0.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
 lib/test_bpf.c | 296 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 296 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 8200980..e6ef56d 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4635,6 +4635,302 @@ static struct bpf_test tests[] = {
 		{ {0x40, 0x25051982} },
 		.frag_data = { 0x19, 0x82 },
 	},
+	/*
+	 * LD_IND / LD_ABS on non fragmented SKBs
+	 */
+	{
+		/*
+		 * this tests that the JIT/interpreter correctly resets X
+		 * before using it in an LD_IND instruction.
+		 */
+		"LD_IND byte default X",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_IND | BPF_B, 0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{ [0x1] = 0x42 },
+		{ {0x40, 0x42 } },
+	},
+	{
+		"LD_IND byte positive offset",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x3e),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_B, 0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{ [0x3c] = 0x25, [0x3d] = 0x05,  [0x3e] = 0x19, [0x3f] = 0x82 },
+		{ {0x40, 0x82 } },
+	},
+	{
+		"LD_IND byte negative offset",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x3e),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_B, -0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{ [0x3c] = 0x25, [0x3d] = 0x05,  [0x3e] = 0x19, [0x3f] = 0x82 },
+		{ {0x40, 0x05 } },
+	},
+	{
+		"LD_IND halfword positive offset",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_H, 0x2),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+		},
+		{ {0x40, 0xdd88 } },
+	},
+	{
+		"LD_IND halfword negative offset",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_H, -0x2),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+		},
+		{ {0x40, 0xbb66 } },
+	},
+	{
+		"LD_IND halfword unaligned",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_H, -0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+		},
+		{ {0x40, 0x66cc } },
+	},
+	{
+		"LD_IND word positive offset",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, 0x4),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xee99ffaa } },
+	},
+	{
+		"LD_IND word negative offset",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, -0x4),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xaa55bb66 } },
+	},
+	{
+		"LD_IND word unaligned (addr & 3 == 2)",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, -0x2),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xbb66cc77 } },
+	},
+	{
+		"LD_IND word unaligned (addr & 3 == 1)",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, -0x3),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0x55bb66cc } },
+	},
+	{
+		"LD_IND word unaligned (addr & 3 == 3)",
+		.u.insns = {
+			BPF_STMT(BPF_LDX | BPF_IMM, 0x20),
+			BPF_STMT(BPF_LD | BPF_IND | BPF_W, -0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0x66cc77dd } },
+	},
+	{
+		"LD_ABS byte",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_B, 0x20),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xcc } },
+	},
+	{
+		"LD_ABS halfword",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_H, 0x22),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xdd88 } },
+	},
+	{
+		"LD_ABS halfword unaligned",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_H, 0x25),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0x99ff } },
+	},
+	{
+		"LD_ABS word",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_W, 0x1c),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xaa55bb66 } },
+	},
+	{
+		"LD_ABS word unaligned (addr & 3 == 2)",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_W, 0x22),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0xdd88ee99 } },
+	},
+	{
+		"LD_ABS word unaligned (addr & 3 == 1)",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_W, 0x21),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0x77dd88ee } },
+	},
+	{
+		"LD_ABS word unaligned (addr & 3 == 3)",
+		.u.insns = {
+			BPF_STMT(BPF_LD | BPF_ABS | BPF_W, 0x23),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC,
+		{
+			[0x1c] = 0xaa, [0x1d] = 0x55,
+			[0x1e] = 0xbb, [0x1f] = 0x66,
+			[0x20] = 0xcc, [0x21] = 0x77,
+			[0x22] = 0xdd, [0x23] = 0x88,
+			[0x24] = 0xee, [0x25] = 0x99,
+			[0x26] = 0xff, [0x27] = 0xaa,
+		},
+		{ {0x40, 0x88ee99ff } },
+	},
 };
 
 static struct net_device dev;
-- 
1.9.1

[PATCH V2 net-next 6/6] test_bpf: add tests checking that JIT/interpreter sets A and X to 0.

[Nicolas Schichan]

It is mandatory for the JIT or interpreter to reset the A and X
registers to 0 before running the filter. Check that it is the case on
various ALU and JMP instructions.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
 lib/test_bpf.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index e6ef56d..d137739 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -4931,6 +4931,164 @@ static struct bpf_test tests[] = {
 		},
 		{ {0x40, 0x88ee99ff } },
 	},
+	/*
+	 * verify that the interpreter or JIT correctly sets A and X
+	 * to 0.
+	 */
+	{
+		"ADD default X",
+		.u.insns = {
+			/*
+			 * A = 0x42
+			 * A = A + X
+			 * ret A
+			 */
+			BPF_STMT(BPF_LD | BPF_IMM, 0x42),
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x42 } },
+	},
+	{
+		"ADD default A",
+		.u.insns = {
+			/*
+			 * A = A + 0x42
+			 * ret A
+			 */
+			BPF_STMT(BPF_ALU | BPF_ADD | BPF_K, 0x42),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x42 } },
+	},
+	{
+		"SUB default X",
+		.u.insns = {
+			/*
+			 * A = 0x66
+			 * A = A - X
+			 * ret A
+			 */
+			BPF_STMT(BPF_LD | BPF_IMM, 0x66),
+			BPF_STMT(BPF_ALU | BPF_SUB | BPF_X, 0),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x66 } },
+	},
+	{
+		"SUB default A",
+		.u.insns = {
+			/*
+			 * A = A - -0x66
+			 * ret A
+			 */
+			BPF_STMT(BPF_ALU | BPF_SUB | BPF_K, -0x66),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x66 } },
+	},
+	{
+		"MUL default X",
+		.u.insns = {
+			/*
+			 * A = 0x42
+			 * A = A * X
+			 * ret A
+			 */
+			BPF_STMT(BPF_LD | BPF_IMM, 0x42),
+			BPF_STMT(BPF_ALU | BPF_MUL | BPF_X, 0),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x0 } },
+	},
+	{
+		"MUL default A",
+		.u.insns = {
+			/*
+			 * A = A * 0x66
+			 * ret A
+			 */
+			BPF_STMT(BPF_ALU | BPF_MUL | BPF_K, 0x66),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x0 } },
+	},
+	{
+		"DIV default X",
+		.u.insns = {
+			/*
+			 * A = 0x42
+			 * A = A / X ; this halt the filter execution if X is 0
+			 * ret 0x42
+			 */
+			BPF_STMT(BPF_LD | BPF_IMM, 0x42),
+			BPF_STMT(BPF_ALU | BPF_DIV | BPF_X, 0),
+			BPF_STMT(BPF_RET | BPF_K, 0x42),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x0 } },
+	},
+	{
+		"DIV default A",
+		.u.insns = {
+			/*
+			 * A = A / 1
+			 * ret A
+			 */
+			BPF_STMT(BPF_ALU | BPF_DIV | BPF_K, 0x1),
+			BPF_STMT(BPF_RET | BPF_A, 0x0),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x0 } },
+	},
+	{
+		"JMP EQ default A",
+		.u.insns = {
+			/*
+			 * cmp A, 0x0, 0, 1
+			 * ret 0x42
+			 * ret 0x66
+			 */
+			BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x0, 0, 1),
+			BPF_STMT(BPF_RET | BPF_K, 0x42),
+			BPF_STMT(BPF_RET | BPF_K, 0x66),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x42 } },
+	},
+	{
+		"JMP EQ default X",
+		.u.insns = {
+			/*
+			 * A = 0x0
+			 * cmp A, X, 0, 1
+			 * ret 0x42
+			 * ret 0x66
+			 */
+			BPF_STMT(BPF_LD | BPF_IMM, 0x0),
+			BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_X, 0x0, 0, 1),
+			BPF_STMT(BPF_RET | BPF_K, 0x42),
+			BPF_STMT(BPF_RET | BPF_K, 0x66),
+		},
+		CLASSIC | FLAG_NO_DATA,
+		{},
+		{ {0x1, 0x42 } },
+	},
 };
 
 static struct net_device dev;
-- 
1.9.1

Re: [PATCH V2 net-next 0/6] test_bpf improvements

[David Miller]

From: Nicolas Schichan <nschichan@freebox.fr>
Date: Tue,  4 Aug 2015 15:19:06 +0200

> Please find below the patch series with my latest changes to test_bpf.

Series applied, thank you.