[PATCH AUTOSEL 5.2 024/249] selftests/bpf: adjust verifier scale test

[PATCH AUTOSEL 5.2 024/249] selftests/bpf: adjust verifier scale test

[Sasha Levin]

From: Alexei Starovoitov <ast@kernel.org>

[ Upstream commit 7c0c6095d48dcd0e67c917aa73cdbb2715aafc36 ]

Adjust scale tests to check for new jmp sequence limit.

BPF_JGT had to be changed to BPF_JEQ because the verifier was
too smart. It tracked the known safe range of R0 values
and pruned the search earlier before hitting exact 8192 limit.
bpf_semi_rand_get() was too (un)?lucky.

k = 0; was missing in bpf_fill_scale2.
It was testing a bit shorter sequence of jumps than intended.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/test_verifier.c | 31 +++++++++++----------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 288cb740e005..6438d4dc8ae1 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -207,33 +207,35 @@ static void bpf_fill_rand_ld_dw(struct bpf_test *self)
 	self->retval = (uint32_t)res;
 }
 
-/* test the sequence of 1k jumps */
+#define MAX_JMP_SEQ 8192
+
+/* test the sequence of 8k jumps */
 static void bpf_fill_scale1(struct bpf_test *self)
 {
 	struct bpf_insn *insn = self->fill_insns;
 	int i = 0, k = 0;
 
 	insn[i++] = BPF_MOV64_REG(BPF_REG_6, BPF_REG_1);
-	/* test to check that the sequence of 1024 jumps is acceptable */
-	while (k++ < 1024) {
+	/* test to check that the long sequence of jumps is acceptable */
+	while (k++ < MAX_JMP_SEQ) {
 		insn[i++] = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
 					 BPF_FUNC_get_prandom_u32);
-		insn[i++] = BPF_JMP_IMM(BPF_JGT, BPF_REG_0, bpf_semi_rand_get(), 2);
+		insn[i++] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, bpf_semi_rand_get(), 2);
 		insn[i++] = BPF_MOV64_REG(BPF_REG_1, BPF_REG_10);
 		insn[i++] = BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6,
 					-8 * (k % 64 + 1));
 	}
-	/* every jump adds 1024 steps to insn_processed, so to stay exactly
-	 * within 1m limit add MAX_TEST_INSNS - 1025 MOVs and 1 EXIT
+	/* every jump adds 1 step to insn_processed, so to stay exactly
+	 * within 1m limit add MAX_TEST_INSNS - MAX_JMP_SEQ - 1 MOVs and 1 EXIT
 	 */
-	while (i < MAX_TEST_INSNS - 1025)
+	while (i < MAX_TEST_INSNS - MAX_JMP_SEQ - 1)
 		insn[i++] = BPF_ALU32_IMM(BPF_MOV, BPF_REG_0, 42);
 	insn[i] = BPF_EXIT_INSN();
 	self->prog_len = i + 1;
 	self->retval = 42;
 }
 
-/* test the sequence of 1k jumps in inner most function (function depth 8)*/
+/* test the sequence of 8k jumps in inner most function (function depth 8)*/
 static void bpf_fill_scale2(struct bpf_test *self)
 {
 	struct bpf_insn *insn = self->fill_insns;
@@ -245,19 +247,20 @@ static void bpf_fill_scale2(struct bpf_test *self)
 		insn[i++] = BPF_EXIT_INSN();
 	}
 	insn[i++] = BPF_MOV64_REG(BPF_REG_6, BPF_REG_1);
-	/* test to check that the sequence of 1024 jumps is acceptable */
-	while (k++ < 1024) {
+	/* test to check that the long sequence of jumps is acceptable */
+	k = 0;
+	while (k++ < MAX_JMP_SEQ) {
 		insn[i++] = BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
 					 BPF_FUNC_get_prandom_u32);
-		insn[i++] = BPF_JMP_IMM(BPF_JGT, BPF_REG_0, bpf_semi_rand_get(), 2);
+		insn[i++] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, bpf_semi_rand_get(), 2);
 		insn[i++] = BPF_MOV64_REG(BPF_REG_1, BPF_REG_10);
 		insn[i++] = BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6,
 					-8 * (k % (64 - 4 * FUNC_NEST) + 1));
 	}
-	/* every jump adds 1024 steps to insn_processed, so to stay exactly
-	 * within 1m limit add MAX_TEST_INSNS - 1025 MOVs and 1 EXIT
+	/* every jump adds 1 step to insn_processed, so to stay exactly
+	 * within 1m limit add MAX_TEST_INSNS - MAX_JMP_SEQ - 1 MOVs and 1 EXIT
 	 */
-	while (i < MAX_TEST_INSNS - 1025)
+	while (i < MAX_TEST_INSNS - MAX_JMP_SEQ - 1)
 		insn[i++] = BPF_ALU32_IMM(BPF_MOV, BPF_REG_0, 42);
 	insn[i] = BPF_EXIT_INSN();
 	self->prog_len = i + 1;
-- 
2.20.1

[PATCH AUTOSEL 5.2 085/249] selftests/bpf : clean up feature/ when make clean

[Sasha Levin]

From: Hechao Li <hechaol@fb.com>

[ Upstream commit 89cceaa939171fafa153d4bf637b39e396bbd785 ]

An error "implicit declaration of function 'reallocarray'" can be thrown
with the following steps:

$ cd tools/testing/selftests/bpf
$ make clean && make CC=<Path to GCC 4.8.5>
$ make clean && make CC=<Path to GCC 7.x>

The cause is that the feature folder generated by GCC 4.8.5 is not
removed, leaving feature-reallocarray being 1, which causes reallocarray
not defined when re-compliing with GCC 7.x. This diff adds feature
folder to EXTRA_CLEAN to avoid this problem.

v2: Rephrase the commit message.

Signed-off-by: Hechao Li <hechaol@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/bpf/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index e36356e2377e..1c9511262947 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -275,4 +275,5 @@ $(OUTPUT)/verifier/tests.h: $(VERIFIER_TESTS_DIR) $(VERIFIER_TEST_FILES)
 		 ) > $(VERIFIER_TESTS_H))
 
 EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(ALU32_BUILD_DIR) \
-	$(VERIFIER_TESTS_H) $(PROG_TESTS_H) $(MAP_TESTS_H)
+	$(VERIFIER_TESTS_H) $(PROG_TESTS_H) $(MAP_TESTS_H) \
+	feature
-- 
2.20.1

[PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[Sasha Levin]

From: Jiri Benc <jbenc@redhat.com>

[ Upstream commit 11aca65ec4db09527d3e9b6b41a0615b7da4386b ]

Selftests are reporting this failure in test_lwt_seg6local.sh:

+ ip netns exec ns2 ip -6 route add fb00::6 encap bpf in obj test_lwt_seg6local.o sec encap_srh dev veth2
Error fetching program/map!
Failed to parse eBPF program: Operation not permitted

The problem is __attribute__((always_inline)) alone is not enough to prevent
clang from inserting those functions in .text. In that case, .text is not
marked as relocateable.

See the output of objdump -h test_lwt_seg6local.o:

Idx Name          Size      VMA               LMA               File off  Algn
  0 .text         00003530  0000000000000000  0000000000000000  00000040  2**3
                  CONTENTS, ALLOC, LOAD, READONLY, CODE

This causes the iproute bpf loader to fail in bpf_fetch_prog_sec:
bpf_has_call_data returns true but bpf_fetch_prog_relo fails as there's no
relocateable .text section in the file.

To fix this, convert to 'static __always_inline'.

v2: Use 'static __always_inline' instead of 'static inline
    __attribute__((always_inline))'

Fixes: c99a84eac026 ("selftests/bpf: test for seg6local End.BPF action")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../testing/selftests/bpf/progs/test_lwt_seg6local.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/test_lwt_seg6local.c b/tools/testing/selftests/bpf/progs/test_lwt_seg6local.c
index 0575751bc1bc..e2f6ed0a583d 100644
--- a/tools/testing/selftests/bpf/progs/test_lwt_seg6local.c
+++ b/tools/testing/selftests/bpf/progs/test_lwt_seg6local.c
@@ -61,7 +61,7 @@ struct sr6_tlv_t {
 	unsigned char value[0];
 } BPF_PACKET_HEADER;
 
-__attribute__((always_inline)) struct ip6_srh_t *get_srh(struct __sk_buff *skb)
+static __always_inline struct ip6_srh_t *get_srh(struct __sk_buff *skb)
 {
 	void *cursor, *data_end;
 	struct ip6_srh_t *srh;
@@ -95,7 +95,7 @@ __attribute__((always_inline)) struct ip6_srh_t *get_srh(struct __sk_buff *skb)
 	return srh;
 }
 
-__attribute__((always_inline))
+static __always_inline
 int update_tlv_pad(struct __sk_buff *skb, uint32_t new_pad,
 		   uint32_t old_pad, uint32_t pad_off)
 {
@@ -125,7 +125,7 @@ int update_tlv_pad(struct __sk_buff *skb, uint32_t new_pad,
 	return 0;
 }
 
-__attribute__((always_inline))
+static __always_inline
 int is_valid_tlv_boundary(struct __sk_buff *skb, struct ip6_srh_t *srh,
 			  uint32_t *tlv_off, uint32_t *pad_size,
 			  uint32_t *pad_off)
@@ -184,7 +184,7 @@ int is_valid_tlv_boundary(struct __sk_buff *skb, struct ip6_srh_t *srh,
 	return 0;
 }
 
-__attribute__((always_inline))
+static __always_inline
 int add_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh, uint32_t tlv_off,
 	    struct sr6_tlv_t *itlv, uint8_t tlv_size)
 {
@@ -228,7 +228,7 @@ int add_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh, uint32_t tlv_off,
 	return update_tlv_pad(skb, new_pad, pad_size, pad_off);
 }
 
-__attribute__((always_inline))
+static __always_inline
 int delete_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh,
 	       uint32_t tlv_off)
 {
@@ -266,7 +266,7 @@ int delete_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh,
 	return update_tlv_pad(skb, new_pad, pad_size, pad_off);
 }
 
-__attribute__((always_inline))
+static __always_inline
 int has_egr_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh)
 {
 	int tlv_offset = sizeof(struct ip6_t) + sizeof(struct ip6_srh_t) +
-- 
2.20.1

Re: [PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[Jiri Benc]

On Mon, 15 Jul 2019 09:46:31 -0400, Sasha Levin wrote:
> From: Jiri Benc <jbenc@redhat.com>
> 
> [ Upstream commit 11aca65ec4db09527d3e9b6b41a0615b7da4386b ]
> 
> Selftests are reporting this failure in test_lwt_seg6local.sh:

I don't think this is critical in any way and I don't think this is a
stable material. How was this selected?

 Jiri

Re: [PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[Sasha Levin]

On Wed, Jul 17, 2019 at 11:43:34AM +0200, Jiri Benc wrote:
>On Mon, 15 Jul 2019 09:46:31 -0400, Sasha Levin wrote:
>> From: Jiri Benc <jbenc@redhat.com>
>>
>> [ Upstream commit 11aca65ec4db09527d3e9b6b41a0615b7da4386b ]
>>
>> Selftests are reporting this failure in test_lwt_seg6local.sh:
>
>I don't think this is critical in any way and I don't think this is a
>stable material. How was this selected?

It fixes a bug, right?

--
Thanks,
Sasha

Re: [PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[Jiri Benc]

On Wed, 17 Jul 2019 19:47:57 -0400, Sasha Levin wrote:
> It fixes a bug, right?

A bug in selftests. And quite likely, it probably happens only with
some compiler versions.

I don't think patches only touching tools/testing/selftests/ qualify
for stable in general. They don't affect the end users.

 Jiri

Re: [PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[David Miller]

From: Jiri Benc <jbenc@redhat.com>
Date: Thu, 18 Jul 2019 09:36:54 +0200

> On Wed, 17 Jul 2019 19:47:57 -0400, Sasha Levin wrote:
>> It fixes a bug, right?
> 
> A bug in selftests. And quite likely, it probably happens only with
> some compiler versions.
> 
> I don't think patches only touching tools/testing/selftests/ qualify
> for stable in general. They don't affect the end users.

It has a significant impact on automated testing which lots of
individuals and entities perform, therefore I think it very much is
-stable material.

Re: [PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[Sasha Levin]

On Thu, Jul 18, 2019 at 09:36:54AM +0200, Jiri Benc wrote:
>On Wed, 17 Jul 2019 19:47:57 -0400, Sasha Levin wrote:
>> It fixes a bug, right?
>
>A bug in selftests. And quite likely, it probably happens only with
>some compiler versions.
>
>I don't think patches only touching tools/testing/selftests/ qualify
>for stable in general. They don't affect the end users.

I'd argue that a bug in your tests is just as (if not even more) worse
than a bug in the code.

--
Thanks,
Sasha

Re: [PATCH AUTOSEL 5.2 226/249] selftests: bpf: fix inlines in test_lwt_seg6local

[Jiri Benc]

On Thu, 18 Jul 2019 11:55:34 -0700 (PDT), David Miller wrote:
> It has a significant impact on automated testing which lots of
> individuals and entities perform, therefore I think it very much is
> -stable material.

Okay.

Thanks,

 Jiri