From: Yonghong Song <yhs@fb.com>
Date: Tue, 21 Nov 2017 11:23:40 -0800
Subject: bpf: change bpf_probe_write_user to bpf_trace_printk in test_verifier
Patch-mainline: v4.15-rc1
Git-commit: f1a8b8e3d98b0b3d1d88d119f52cc85d05ab3189
References: bsc#1083647

There are four tests in test_verifier using bpf_probe_write_user
helper. These four tests will emit the following kernel messages
  [   12.974753] test_verifier[220] is installing a program with bpf_probe_write_user
                                    helper that may corrupt user memory!
  [   12.979285] test_verifier[220] is installing a program with bpf_probe_write_user
                                    helper that may corrupt user memory!
  ......

This may confuse certain users. This patch replaces bpf_probe_write_user
with bpf_trace_printk. The test_verifier already uses bpf_trace_printk
earlier in the test and a trace_printk warning message has been printed.
So this patch does not emit any more kernel messages.

Fixes: b6ff63911232 ("bpf: fix and add test cases for ARG_CONST_SIZE_OR_ZERO semantics change")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Gary Lin <glin@suse.com>
---
 tools/testing/selftests/bpf/test_verifier.c |   39 +++++++++++-----------------
 1 file changed, 16 insertions(+), 23 deletions(-)

--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -3877,11 +3877,10 @@ static struct bpf_test tests[] = {
 			BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
 			BPF_LD_MAP_FD(BPF_REG_1, 0),
 			BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
-			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
-			BPF_MOV64_IMM(BPF_REG_1, 0),
-			BPF_MOV64_REG(BPF_REG_2, BPF_REG_0),
-			BPF_MOV64_IMM(BPF_REG_3, 0),
-			BPF_EMIT_CALL(BPF_FUNC_probe_write_user),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3),
+			BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_EMIT_CALL(BPF_FUNC_trace_printk),
 			BPF_EXIT_INSN(),
 		},
 		.fixup_map2 = { 3 },
@@ -3981,14 +3980,12 @@ static struct bpf_test tests[] = {
 			BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
 			BPF_LD_MAP_FD(BPF_REG_1, 0),
 			BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
-			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
 			BPF_ALU64_IMM(BPF_ADD, BPF_REG_1,
 				offsetof(struct test_val, foo)),
-			BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
-			BPF_MOV64_IMM(BPF_REG_1, 0),
-			BPF_MOV64_IMM(BPF_REG_3, 0),
-			BPF_EMIT_CALL(BPF_FUNC_probe_write_user),
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_EMIT_CALL(BPF_FUNC_trace_printk),
 			BPF_EXIT_INSN(),
 		},
 		.fixup_map2 = { 3 },
@@ -4118,18 +4115,16 @@ static struct bpf_test tests[] = {
 			BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
 			BPF_LD_MAP_FD(BPF_REG_1, 0),
 			BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
-			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5),
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
 			BPF_MOV64_IMM(BPF_REG_3, 0),
 			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
-			BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
-			BPF_MOV64_IMM(BPF_REG_1, 0),
-			BPF_MOV64_IMM(BPF_REG_3, 0),
-			BPF_EMIT_CALL(BPF_FUNC_probe_write_user),
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_EMIT_CALL(BPF_FUNC_trace_printk),
 			BPF_EXIT_INSN(),
 		},
 		.fixup_map2 = { 3 },
-		.errstr = "R2 min value is outside of the array range",
+		.errstr = "R1 min value is outside of the array range",
 		.result = REJECT,
 		.prog_type = BPF_PROG_TYPE_TRACEPOINT,
 	},
@@ -4260,20 +4255,18 @@ static struct bpf_test tests[] = {
 			BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0),
 			BPF_LD_MAP_FD(BPF_REG_1, 0),
 			BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
-			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7),
+			BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
 			BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
 			BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
 			BPF_JMP_IMM(BPF_JGT, BPF_REG_3,
-				offsetof(struct test_val, foo), 4),
+				offsetof(struct test_val, foo), 3),
 			BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_3),
-			BPF_MOV64_REG(BPF_REG_2, BPF_REG_1),
-			BPF_MOV64_IMM(BPF_REG_1, 0),
-			BPF_MOV64_IMM(BPF_REG_3, 0),
-			BPF_EMIT_CALL(BPF_FUNC_probe_write_user),
+			BPF_MOV64_IMM(BPF_REG_2, 0),
+			BPF_EMIT_CALL(BPF_FUNC_trace_printk),
 			BPF_EXIT_INSN(),
 		},
 		.fixup_map2 = { 3 },
-		.errstr = "R2 min value is outside of the array range",
+		.errstr = "R1 min value is outside of the array range",
 		.result = REJECT,
 		.prog_type = BPF_PROG_TYPE_TRACEPOINT,
 	},