Commit 8dd5e756 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
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selftests/bpf: Add verifier tests for trusted kfunc args 



Make sure verifier rejects the bad cases and ensure the good case keeps
working. The selftests make use of the bpf_kfunc_call_test_ref kfunc
added in the previous patch only for verification.

Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-11-memxor@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ef69aa3a

tools/testing/selftests/bpf/verifier/calls.c

+53 −0
Original line number Diff line number Diff line
@@ -218,6 +218,59 @@ 
	.result = REJECT,

	.errstr = "variable ptr_ access var_off=(0x0; 0x7) disallowed",

},

{

	"calls: invalid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID",

	.insns = {

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),

	BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),

	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),

	BPF_EXIT_INSN(),

	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),

	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 16),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

	.fixup_kfunc_btf_id = {

		{ "bpf_kfunc_call_test_acquire", 3 },

		{ "bpf_kfunc_call_test_ref", 8 },

		{ "bpf_kfunc_call_test_ref", 10 },

	},

	.result_unpriv = REJECT,

	.result = REJECT,

	.errstr = "R1 must be referenced",

},

{

	"calls: valid kfunc call: referenced arg needs refcounted PTR_TO_BTF_ID",

	.insns = {

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8),

	BPF_ST_MEM(BPF_DW, BPF_REG_1, 0, 0),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),

	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),

	BPF_EXIT_INSN(),

	BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),

	BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0),

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

	.fixup_kfunc_btf_id = {

		{ "bpf_kfunc_call_test_acquire", 3 },

		{ "bpf_kfunc_call_test_ref", 8 },

		{ "bpf_kfunc_call_test_release", 10 },

	},

	.result_unpriv = REJECT,

	.result = ACCEPT,

},

{

	"calls: basic sanity",

	.insns = {