On Fri, May 20, 2022 at 05:27:12PM -0700, Yonghong Song wrote:
>
>
> 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.
Okay, will do that in the next version. Thanks!
> > .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),
>
