[PATCH V2 net-next 6/6] test_bpf: add tests checking that JIT/interpreter sets A and X to 0.
From: Nicolas Schichan <hidden>
Date: 2015-08-04 13:20:59
Also in:
lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), library code, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Andrew Morton, Linus Torvalds
It is mandatory for the JIT or interpreter to reset the A and X registers to 0 before running the filter. Check that it is the case on various ALU and JMP instructions. Signed-off-by: Nicolas Schichan <redacted> Acked-by: Alexei Starovoitov <redacted> Acked-by: Daniel Borkmann <daniel@iogearbox.net> --- lib/test_bpf.c | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+)
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index e6ef56d..d137739 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c@@ -4931,6 +4931,164 @@ static struct bpf_test tests[] = { }, { {0x40, 0x88ee99ff } }, }, + /* + * verify that the interpreter or JIT correctly sets A and X + * to 0. + */ + { + "ADD default X", + .u.insns = { + /* + * A = 0x42 + * A = A + X + * ret A + */ + BPF_STMT(BPF_LD | BPF_IMM, 0x42), + BPF_STMT(BPF_ALU | BPF_ADD | BPF_X, 0), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x42 } }, + }, + { + "ADD default A", + .u.insns = { + /* + * A = A + 0x42 + * ret A + */ + BPF_STMT(BPF_ALU | BPF_ADD | BPF_K, 0x42), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x42 } }, + }, + { + "SUB default X", + .u.insns = { + /* + * A = 0x66 + * A = A - X + * ret A + */ + BPF_STMT(BPF_LD | BPF_IMM, 0x66), + BPF_STMT(BPF_ALU | BPF_SUB | BPF_X, 0), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x66 } }, + }, + { + "SUB default A", + .u.insns = { + /* + * A = A - -0x66 + * ret A + */ + BPF_STMT(BPF_ALU | BPF_SUB | BPF_K, -0x66), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x66 } }, + }, + { + "MUL default X", + .u.insns = { + /* + * A = 0x42 + * A = A * X + * ret A + */ + BPF_STMT(BPF_LD | BPF_IMM, 0x42), + BPF_STMT(BPF_ALU | BPF_MUL | BPF_X, 0), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x0 } }, + }, + { + "MUL default A", + .u.insns = { + /* + * A = A * 0x66 + * ret A + */ + BPF_STMT(BPF_ALU | BPF_MUL | BPF_K, 0x66), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x0 } }, + }, + { + "DIV default X", + .u.insns = { + /* + * A = 0x42 + * A = A / X ; this halt the filter execution if X is 0 + * ret 0x42 + */ + BPF_STMT(BPF_LD | BPF_IMM, 0x42), + BPF_STMT(BPF_ALU | BPF_DIV | BPF_X, 0), + BPF_STMT(BPF_RET | BPF_K, 0x42), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x0 } }, + }, + { + "DIV default A", + .u.insns = { + /* + * A = A / 1 + * ret A + */ + BPF_STMT(BPF_ALU | BPF_DIV | BPF_K, 0x1), + BPF_STMT(BPF_RET | BPF_A, 0x0), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x0 } }, + }, + { + "JMP EQ default A", + .u.insns = { + /* + * cmp A, 0x0, 0, 1 + * ret 0x42 + * ret 0x66 + */ + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x0, 0, 1), + BPF_STMT(BPF_RET | BPF_K, 0x42), + BPF_STMT(BPF_RET | BPF_K, 0x66), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x42 } }, + }, + { + "JMP EQ default X", + .u.insns = { + /* + * A = 0x0 + * cmp A, X, 0, 1 + * ret 0x42 + * ret 0x66 + */ + BPF_STMT(BPF_LD | BPF_IMM, 0x0), + BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_X, 0x0, 0, 1), + BPF_STMT(BPF_RET | BPF_K, 0x42), + BPF_STMT(BPF_RET | BPF_K, 0x66), + }, + CLASSIC | FLAG_NO_DATA, + {}, + { {0x1, 0x42 } }, + }, }; static struct net_device dev;
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1.9.1