Commit 2026f206 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add pruning test case for bpf_spin_lock 



Test that when reg->id is not same for the same register of type
PTR_TO_MAP_VALUE between current and old explored state, we currently
return false from regsafe and continue exploring.

Without the fix in prior commit, the test case fails.

Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20221209135733.28851-7-eddyz87@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 4ea2bb15

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

+39 −0
Original line number Diff line number Diff line
@@ -331,3 +331,42 @@ 
	.errstr = "inside bpf_spin_lock",

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

},

{

	"spin_lock: regsafe compare reg->id for map value",

	.insns = {

	BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),

	BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_6, offsetof(struct __sk_buff, mark)),

	BPF_LD_MAP_FD(BPF_REG_1, 0),

	BPF_MOV64_REG(BPF_REG_9, BPF_REG_1),

	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

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

	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),

	BPF_EXIT_INSN(),

	BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_9),

	BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4),

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

	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),

	BPF_EXIT_INSN(),

	BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4),

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

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 1),

	BPF_JMP_IMM(BPF_JA, 0, 0, 1),

	BPF_MOV64_REG(BPF_REG_7, BPF_REG_8),

	BPF_MOV64_REG(BPF_REG_1, BPF_REG_7),

	BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 4),

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

	BPF_MOV64_IMM(BPF_REG_0, 0),

	BPF_EXIT_INSN(),

	},

	.fixup_map_spin_lock = { 2 },

	.result = REJECT,

	.errstr = "bpf_spin_unlock of different lock",

	.prog_type = BPF_PROG_TYPE_SCHED_CLS,

	.flags = BPF_F_TEST_STATE_FREQ,

},