On 5/20/22 4:37 AM, Shung-Hsi Yu wrote:
It may not be immediately clear why that ld_imm64 test cases are
rejected, especially for test1 and test2 where JMP to the 2nd
instruction of BPF_LD_IMM64 is performed.
Add brief explaination of why each test case in verifier/ld_imm64.c
should be rejected.
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@xxxxxxxx>
---
.../testing/selftests/bpf/verifier/ld_imm64.c | 20 ++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/bpf/verifier/ld_imm64.c b/tools/testing/selftests/bpf/verifier/ld_imm64.c
index f9297900cea6..021312641aaf 100644
--- a/tools/testing/selftests/bpf/verifier/ld_imm64.c
+++ b/tools/testing/selftests/bpf/verifier/ld_imm64.c
@@ -1,5 +1,6 @@
+/* Note: BPF_LD_IMM64 is composed of two instructions of class BPF_LD */
[...]LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
@@ -42,7 +43,7 @@
.result = REJECT,
},
{
- "test4 ld_imm64",
+ "test4 ld_imm64: reject incomplete BPF_LD_IMM64 instruction",
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 0),
BPF_EXIT_INSN(),
@@ -70,7 +71,7 @@
.retval = 1,
},
{
- "test8 ld_imm64",
+ "test8 ld_imm64: reject 1st off!=0",
Let add some space like 'off != 0'. The same for
some of later test names.
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 1, 1),
BPF_RAW_INSN(0, 0, 0, 0, 1),
@@ -80,7 +81,7 @@
.result = REJECT,
},
{
- "test9 ld_imm64",
+ "test9 ld_imm64: reject 2nd off!=0",
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 1),
BPF_RAW_INSN(0, 0, 0, 1, 1),
@@ -90,7 +91,7 @@
.result = REJECT,
},
{
- "test10 ld_imm64",
+ "test10 ld_imm64: reject 2nd dst_reg!=0",
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 1),
BPF_RAW_INSN(0, BPF_REG_1, 0, 0, 1),
@@ -100,7 +101,7 @@
.result = REJECT,
},
{
- "test11 ld_imm64",
+ "test11 ld_imm64: reject 2nd src_reg!=0",
.insns = {
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, 0, 0, 1),
BPF_RAW_INSN(0, 0, BPF_REG_1, 0, 1),
@@ -113,6 +114,7 @@
"test12 ld_imm64",
.insns = {
BPF_MOV64_IMM(BPF_REG_1, 0),
+ /* BPF_REG_1 is interpreted as BPF_PSEUDO_MAP_FD */
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, BPF_REG_1, 0, 1),
BPF_RAW_INSN(0, 0, 0, 0, 0),
BPF_EXIT_INSN(),
@@ -121,7 +123,7 @@
.result = REJECT,
},
{
- "test13 ld_imm64",
+ "test13 ld_imm64: 2nd src_reg!=0",
.insns = {
BPF_MOV64_IMM(BPF_REG_1, 0),
BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, 0, BPF_REG_1, 0, 1),
