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Commit f1a8b8e3 authored by Yonghong Song's avatar Yonghong Song Committed by Daniel Borkmann
Browse files

bpf: change bpf_probe_write_user to bpf_trace_printk in test_verifier 



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: b6ff6391 ("bpf: fix and add test cases for ARG_CONST_SIZE_OR_ZERO semantics change")
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 6547f424

tools/testing/selftests/bpf/test_verifier.c

+16 −23
Original line number Diff line number Diff line
@@ -4377,11 +4377,10 @@ 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 },
@@ -4481,14 +4480,12 @@ 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 },
@@ -4618,18 +4615,16 @@ 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,

	},
@@ -4760,20 +4755,18 @@ 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,

	},