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From: Johan Almbladh <johan.almbladh@anyfinetworks.com>
To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	iii@linux.ibm.com
Cc: kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	Johan Almbladh <johan.almbladh@anyfinetworks.com>
Subject: [PATCH bpf-next 09/13] bpf/tests: Add JMP tests with small offsets
Date: Thu,  2 Sep 2021 20:52:25 +0200	[thread overview]
Message-ID: <20210902185229.1840281-10-johan.almbladh@anyfinetworks.com> (raw)
In-Reply-To: <20210902185229.1840281-1-johan.almbladh@anyfinetworks.com>

This patch adds a set of tests for JMP to verify that the JITed jump
offset is calculated correctly. We pretend that the verifier has inserted
any zero extensions to make the jump-over operations JIT to one
instruction each, in order to control the exact JITed jump offset.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
---
 lib/test_bpf.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 183ead9445ba..c3d772f663da 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -10707,6 +10707,77 @@ static struct bpf_test tests[] = {
 		.fill_helper = bpf_fill_jmp32_jsle_reg,
 		.nr_testruns = NR_PATTERN_RUNS,
 	},
+	/* Short relative jumps */
+	{
+		"Short relative jump: offset=0",
+		.u.insns_int = {
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_JMP_IMM(BPF_JEQ, R0, 0, 0),
+			BPF_EXIT_INSN(),
+			BPF_ALU32_IMM(BPF_MOV, R0, -1),
+		},
+		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+		{ },
+		{ { 0, 0 } },
+	},
+	{
+		"Short relative jump: offset=1",
+		.u.insns_int = {
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_JMP_IMM(BPF_JEQ, R0, 0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU32_IMM(BPF_MOV, R0, -1),
+		},
+		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+		{ },
+		{ { 0, 0 } },
+	},
+	{
+		"Short relative jump: offset=2",
+		.u.insns_int = {
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_JMP_IMM(BPF_JEQ, R0, 0, 2),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU32_IMM(BPF_MOV, R0, -1),
+		},
+		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+		{ },
+		{ { 0, 0 } },
+	},
+	{
+		"Short relative jump: offset=3",
+		.u.insns_int = {
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_JMP_IMM(BPF_JEQ, R0, 0, 3),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU32_IMM(BPF_MOV, R0, -1),
+		},
+		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+		{ },
+		{ { 0, 0 } },
+	},
+	{
+		"Short relative jump: offset=4",
+		.u.insns_int = {
+			BPF_ALU64_IMM(BPF_MOV, R0, 0),
+			BPF_JMP_IMM(BPF_JEQ, R0, 0, 4),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_ALU32_IMM(BPF_ADD, R0, 1),
+			BPF_EXIT_INSN(),
+			BPF_ALU32_IMM(BPF_MOV, R0, -1),
+		},
+		INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+		{ },
+		{ { 0, 0 } },
+	},
 	/* Staggered jump sequences, immediate */
 	{
 		"Staggered jumps: JMP_JA",
-- 
2.25.1


  parent reply	other threads:[~2021-09-02 18:52 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-02 18:52 [PATCH bpf-next 00/13] bpf/tests: Extend JIT test suite coverage Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 01/13] bpf/tests: Allow different number of runs per test case Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 02/13] bpf/tests: Reduce memory footprint of test suite Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 03/13] bpf/tests: Add exhaustive tests of ALU shift values Johan Almbladh
2021-09-03  6:39   ` kernel test robot
2021-09-03  6:39     ` kernel test robot
2021-09-02 18:52 ` [PATCH bpf-next 04/13] bpf/tests: Add exhaustive tests of ALU operand magnitudes Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 05/13] bpf/tests: Add exhaustive tests of JMP " Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 06/13] bpf/tests: Add staggered JMP and JMP32 tests Johan Almbladh
2021-09-03  8:22   ` Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 07/13] bpf/tests: Add exhaustive test of LD_IMM64 immediate magnitudes Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 08/13] bpf/tests: Add test case flag for verifier zero-extension Johan Almbladh
2021-09-02 18:52 ` Johan Almbladh [this message]
2021-09-02 18:52 ` [PATCH bpf-next 10/13] bpf/tests: Add JMP tests with degenerate conditional Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 11/13] bpf/tests: Expand branch conversion JIT test Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 12/13] bpf/tests: Add more BPF_END byte order conversion tests Johan Almbladh
2021-09-02 18:52 ` [PATCH bpf-next 13/13] bpf/tests: Add tail call limit test with external function call Johan Almbladh

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