diff mbox series

[bpf-next,4/4] selftests/bpf: add reason of rejection in ld_imm64

Message ID 20220520113728.12708-5-shung-hsi.yu@suse.com (mailing list archive)
State New
Headers show
Series bpf: verifier: remove redundant opcode checks | expand

Commit Message

Shung-Hsi Yu May 20, 2022, 11:37 a.m. UTC 
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@suse.com>
---
 .../testing/selftests/bpf/verifier/ld_imm64.c | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

Comments

Yonghong Song May 21, 2022, 12:27 a.m. UTC | #1 
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@suse.com>
> ---
>   .../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),
Shung-Hsi Yu May 24, 2022, 4:49 a.m. UTC | #2 
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@suse.com>
> > ---
> >   .../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),
>
diff mbox series

Patch

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 */
 {
-	"test1 ld_imm64",
+	"test1 ld_imm64: reject JMP to 2nd instruction of BPF_LD_IMM64",
 	.insns = {
 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
 	BPF_LD_IMM64(BPF_REG_0, 0),
@@ -14,7 +15,7 @@ 
 	.result = REJECT,
 },
 {
-	"test2 ld_imm64",
+	"test2 ld_imm64: reject JMP to 2nd instruction of BPF_LD_IMM64",
 	.insns = {
 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
 	BPF_LD_IMM64(BPF_REG_0, 0),
@@ -28,7 +29,7 @@ 
 	.result = REJECT,
 },
 {
-	"test3 ld_imm64",
+	"test3 ld_imm64: reject incomplete BPF_LD_IMM64 instruction",
 	.insns = {
 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1),
 	BPF_RAW_INSN(BPF_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",
 	.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),