diff mbox series

[bpf-next,v4,4/5] selftests/bpf: BPF test_verifier selftests for bpf_loop inlining

Message ID 20220608192630.3710333-5-eddyz87@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series bpf_loop inlining | expand

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bpf/vmtest-bpf-next-VM_Test-3 success Logs for Kernel LATEST on z15 with gcc
bpf/vmtest-bpf-next-PR success PR summary
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
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
netdev/cc_maintainers warning 8 maintainers not CCed: netdev@vger.kernel.org songliubraving@fb.com linux-kselftest@vger.kernel.org yhs@fb.com john.fastabend@gmail.com kafai@fb.com shuah@kernel.org kpsingh@kernel.org
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

Eduard Zingerman June 8, 2022, 7:26 p.m. UTC 
A number of test cases for BPF selftests test_verifier to check how
bpf_loop inline transformation rewrites the BPF program. The following
cases are covered:
 - happy path
 - no-rewrite when flags is non-zero
 - no-rewrite when callback is non-constant
 - subprogno in insn_aux is updated correctly when dead sub-programs
   are removed
 - check that correct stack offsets are assigned for spilling of R6-R8
   registers

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
---
 .../selftests/bpf/verifier/bpf_loop_inline.c  | 244 ++++++++++++++++++
 1 file changed, 244 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/verifier/bpf_loop_inline.c

Comments

Song Liu June 10, 2022, 6:14 p.m. UTC | #1 
On Wed, Jun 8, 2022 at 12:27 PM Eduard Zingerman <eddyz87@gmail.com> wrote:
>
> A number of test cases for BPF selftests test_verifier to check how
> bpf_loop inline transformation rewrites the BPF program. The following
> cases are covered:
>  - happy path
>  - no-rewrite when flags is non-zero
>  - no-rewrite when callback is non-constant
>  - subprogno in insn_aux is updated correctly when dead sub-programs
>    are removed
>  - check that correct stack offsets are assigned for spilling of R6-R8
>    registers
>
> Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>

Acked-by: Song Liu <songliubraving@fb.com>

PS: I already acked v3, so you can include it in v4.
Eduard Zingerman June 10, 2022, 7:20 p.m. UTC | #2 
> On Fri, 2022-06-10 at 11:14 -0700, Song Liu wrote:
> > Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
> 
> Acked-by: Song Liu <songliubraving@fb.com>
> 
> PS: I already acked v3, so you can include it in v4.

Sorry, my first patch, wasn't sure what to do with the ack. Should I
put it in the changelog or in the commit message?

Thanks,
Eduard
Song Liu June 10, 2022, 8:57 p.m. UTC | #3 
On Fri, Jun 10, 2022 at 12:20 PM Eduard Zingerman <eddyz87@gmail.com> wrote:
>
> > On Fri, 2022-06-10 at 11:14 -0700, Song Liu wrote:
> > > Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
> >
> > Acked-by: Song Liu <songliubraving@fb.com>
> >
> > PS: I already acked v3, so you can include it in v4.
>
> Sorry, my first patch, wasn't sure what to do with the ack. Should I
> put it in the changelog or in the commit message?

You can just add it to the commit message, right next to your
Signed-of-by tag.

Thanks,
Song
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c
new file mode 100644
index 000000000000..d1fbcfef69f2
--- /dev/null
+++ b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c
@@ -0,0 +1,244 @@ 
+#define BTF_TYPES \
+	.btf_strings = "\0int\0i\0ctx\0callback\0main\0", \
+	.btf_types = { \
+	/* 1: int   */ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), \
+	/* 2: int*  */ BTF_PTR_ENC(1), \
+	/* 3: void* */ BTF_PTR_ENC(0), \
+	/* 4: int __(void*) */ BTF_FUNC_PROTO_ENC(1, 1), \
+		BTF_FUNC_PROTO_ARG_ENC(7, 3), \
+	/* 5: int __(int, int*) */ BTF_FUNC_PROTO_ENC(1, 2), \
+		BTF_FUNC_PROTO_ARG_ENC(5, 1), \
+		BTF_FUNC_PROTO_ARG_ENC(7, 2), \
+	/* 6: main      */ BTF_FUNC_ENC(20, 4), \
+	/* 7: callback  */ BTF_FUNC_ENC(11, 5), \
+	BTF_END_RAW \
+	}
+
+#define MAIN_TYPE	6
+#define CALLBACK_TYPE	7
+
+/* can't use BPF_CALL_REL, jit_subprogs adjusts IMM & OFF
+ * fields for pseudo calls
+ */
+#define PSEUDO_CALL_INSN() \
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_CALL, \
+		     INSN_OFF_MASK, INSN_IMM_MASK)
+
+/* can't use BPF_FUNC_loop constant,
+ * do_mix_fixups adjusts the IMM field
+ */
+#define HELPER_CALL_INSN() \
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, INSN_OFF_MASK, INSN_IMM_MASK)
+
+{
+	"inline simple bpf_loop call",
+	.insns = {
+	/* main */
+	/* force verifier state branching to verify logic on first and
+	 * subsequent bpf_loop insn processing steps
+	 */
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 777, 2),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+	BPF_JMP_IMM(BPF_JA, 0, 0, 1),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2),
+
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	/* callback */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.expected_insns = { PSEUDO_CALL_INSN() },
+	.unexpected_insns = { HELPER_CALL_INSN() },
+	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.result = ACCEPT,
+	.runs = 0,
+	.func_info = { { 0, MAIN_TYPE }, { 12, CALLBACK_TYPE } },
+	.func_info_cnt = 2,
+	BTF_TYPES
+},
+{
+	"don't inline bpf_loop call, flags non-zero",
+	.insns = {
+	/* main */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 1),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	/* callback */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.expected_insns = { HELPER_CALL_INSN() },
+	.unexpected_insns = { PSEUDO_CALL_INSN() },
+	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.result = ACCEPT,
+	.runs = 0,
+	.func_info = { { 0, MAIN_TYPE }, { 8, CALLBACK_TYPE } },
+	.func_info_cnt = 2,
+	BTF_TYPES
+},
+{
+	"don't inline bpf_loop call, callback non-constant",
+	.insns = {
+	/* main */
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64),
+	BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 777, 4), /* pick a random callback */
+
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 10),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_JMP_IMM(BPF_JA, 0, 0, 3),
+
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 8),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	/* callback */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	/* callback #2 */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.expected_insns = { HELPER_CALL_INSN() },
+	.unexpected_insns = { PSEUDO_CALL_INSN() },
+	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.result = ACCEPT,
+	.runs = 0,
+	.func_info = {
+		{ 0, MAIN_TYPE },
+		{ 14, CALLBACK_TYPE },
+		{ 16, CALLBACK_TYPE }
+	},
+	.func_info_cnt = 3,
+	BTF_TYPES
+},
+{
+	"bpf_loop_inline and a dead func",
+	.insns = {
+	/* main */
+
+	/* A reference to callback #1 to make verifier count it as a func.
+	 * This reference is overwritten below and callback #1 is dead.
+	 */
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 9),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 8),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	/* callback */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	/* callback #2 */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.expected_insns = { PSEUDO_CALL_INSN() },
+	.unexpected_insns = { HELPER_CALL_INSN() },
+	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.result = ACCEPT,
+	.runs = 0,
+	.func_info = {
+		{ 0, MAIN_TYPE },
+		{ 10, CALLBACK_TYPE },
+		{ 12, CALLBACK_TYPE }
+	},
+	.func_info_cnt = 3,
+	BTF_TYPES
+},
+{
+	"bpf_loop_inline stack locations for loop vars",
+	.insns = {
+	/* main */
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0x77),
+	/* bpf_loop call #1 */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 22),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	/* bpf_loop call #2 */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 16),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	/* call func and exit */
+	BPF_CALL_REL(2),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	/* func */
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -32, 0x55),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2),
+	BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6),
+	BPF_RAW_INSN(0, 0, 0, 0, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0),
+	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop),
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	/* callback */
+	BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1),
+	BPF_EXIT_INSN(),
+	},
+	.expected_insns = {
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0x77),
+	SKIP_INSNS(),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -40),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -32),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -24),
+	SKIP_INSNS(),
+	/* offsets are the same as in the first call */
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -40),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -32),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -24),
+	SKIP_INSNS(),
+	BPF_ST_MEM(BPF_DW, BPF_REG_10, -32, 0x55),
+	SKIP_INSNS(),
+	/* offsets differ from main because of different offset
+	 * in BPF_ST_MEM instruction
+	 */
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -56),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -48),
+	BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -40),
+	},
+	.unexpected_insns = { HELPER_CALL_INSN() },
+	.prog_type = BPF_PROG_TYPE_TRACEPOINT,
+	.result = ACCEPT,
+	.func_info = {
+		{ 0, MAIN_TYPE },
+		{ 16, MAIN_TYPE },
+		{ 25, CALLBACK_TYPE },
+	},
+	.func_info_cnt = 3,
+	BTF_TYPES
+},
+
+#undef HELPER_CALL_INSN
+#undef PSEUDO_CALL_INSN
+#undef CALLBACK_TYPE
+#undef MAIN_TYPE
+#undef BTF_TYPES