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authorJohan Almbladh <[email protected]>2021-09-14 11:18:37 +0200
committerDaniel Borkmann <[email protected]>2021-09-28 09:26:28 +0200
commitd4ff9ee2dc0bbbdba204e215c8b6bf58f5773994 (patch)
treeb700bd3094bb59693716cb7df8fe2e1aa33ab718
parent27cc6dac6ec816cc31be9031edbee3e519234471 (diff)
bpf/tests: Add JMP tests with small offsets
This patch adds a set of tests for JMP to verify that the JITed jump offset is calculated correctly. We pretend that the verifier has inserted any zero extensions to make the jump-over operations JIT to one instruction each, in order to control the exact JITed jump offset. Signed-off-by: Johan Almbladh <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
-rw-r--r--lib/test_bpf.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 0c1c8cccf254..2eb1d0e4aff3 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -10709,6 +10709,77 @@ static struct bpf_test tests[] = {
.fill_helper = bpf_fill_jmp32_jsle_reg,
.nr_testruns = NR_PATTERN_RUNS,
},
+ /* Short relative jumps */
+ {
+ "Short relative jump: offset=0",
+ .u.insns_int = {
+ BPF_ALU64_IMM(BPF_MOV, R0, 0),
+ BPF_JMP_IMM(BPF_JEQ, R0, 0, 0),
+ BPF_EXIT_INSN(),
+ BPF_ALU32_IMM(BPF_MOV, R0, -1),
+ },
+ INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+ { },
+ { { 0, 0 } },
+ },
+ {
+ "Short relative jump: offset=1",
+ .u.insns_int = {
+ BPF_ALU64_IMM(BPF_MOV, R0, 0),
+ BPF_JMP_IMM(BPF_JEQ, R0, 0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_EXIT_INSN(),
+ BPF_ALU32_IMM(BPF_MOV, R0, -1),
+ },
+ INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+ { },
+ { { 0, 0 } },
+ },
+ {
+ "Short relative jump: offset=2",
+ .u.insns_int = {
+ BPF_ALU64_IMM(BPF_MOV, R0, 0),
+ BPF_JMP_IMM(BPF_JEQ, R0, 0, 2),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_EXIT_INSN(),
+ BPF_ALU32_IMM(BPF_MOV, R0, -1),
+ },
+ INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+ { },
+ { { 0, 0 } },
+ },
+ {
+ "Short relative jump: offset=3",
+ .u.insns_int = {
+ BPF_ALU64_IMM(BPF_MOV, R0, 0),
+ BPF_JMP_IMM(BPF_JEQ, R0, 0, 3),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_EXIT_INSN(),
+ BPF_ALU32_IMM(BPF_MOV, R0, -1),
+ },
+ INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+ { },
+ { { 0, 0 } },
+ },
+ {
+ "Short relative jump: offset=4",
+ .u.insns_int = {
+ BPF_ALU64_IMM(BPF_MOV, R0, 0),
+ BPF_JMP_IMM(BPF_JEQ, R0, 0, 4),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_ALU32_IMM(BPF_ADD, R0, 1),
+ BPF_EXIT_INSN(),
+ BPF_ALU32_IMM(BPF_MOV, R0, -1),
+ },
+ INTERNAL | FLAG_NO_DATA | FLAG_VERIFIER_ZEXT,
+ { },
+ { { 0, 0 } },
+ },
/* Staggered jump sequences, immediate */
{
"Staggered jumps: JMP_JA",