public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
* bpf: test_verifier: sanitation: alu with different scalars
@ 2019-06-25  8:29 Yauheni Kaliuta
  2019-06-25  9:39 ` Daniel Borkmann
  0 siblings, 1 reply; 3+ messages in thread
From: Yauheni Kaliuta @ 2019-06-25  8:29 UTC (permalink / raw)
  To: Daniel Borkmann; +Cc: linux-kernel, Jiri Olsa, Jiri Benc

Hi!

I'm wondering, how the sanitaion tests (#903 5.2-rc6 for example)
are supposed to work on BE arches:

{
	"sanitation: alu with different scalars 1",
	.insns = {
	BPF_MOV64_IMM(BPF_REG_0, 1),
	BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
	BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
	BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
	BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
	BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
	BPF_EXIT_INSN(),
	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),

reads one byte 0 on BE and 28 on LE (from ->index) since

	struct test_val {
		unsigned int index;
		int foo[MAX_ENTRIES];
	};

        struct test_val value = {
		.index = (6 + 1) * sizeof(int),
		.foo[6] = 0xabcdef12,
	};

	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),

So different branches are taken depending of the endianness.

	BPF_MOV64_IMM(BPF_REG_2, 0),
	BPF_MOV64_IMM(BPF_REG_3, 0x100000),
	BPF_JMP_A(2),
	BPF_MOV64_IMM(BPF_REG_2, 42),
	BPF_MOV64_IMM(BPF_REG_3, 0x100001),
	BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
	BPF_EXIT_INSN(),
	},
	.fixup_map_array_48b = { 1 },
	.result = ACCEPT,
	.retval = 0x100000,
},



-- 
WBR,
Yauheni Kaliuta

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: bpf: test_verifier: sanitation: alu with different scalars
  2019-06-25  8:29 bpf: test_verifier: sanitation: alu with different scalars Yauheni Kaliuta
@ 2019-06-25  9:39 ` Daniel Borkmann
  2019-07-26 10:41   ` Yauheni Kaliuta
  0 siblings, 1 reply; 3+ messages in thread
From: Daniel Borkmann @ 2019-06-25  9:39 UTC (permalink / raw)
  To: Yauheni Kaliuta; +Cc: linux-kernel, Jiri Olsa, Jiri Benc

On 06/25/2019 10:29 AM, Yauheni Kaliuta wrote:
> Hi!
> 
> I'm wondering, how the sanitaion tests (#903 5.2-rc6 for example)
> are supposed to work on BE arches:
> 
> {
> 	"sanitation: alu with different scalars 1",
> 	.insns = {
> 	BPF_MOV64_IMM(BPF_REG_0, 1),
> 	BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
> 	BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
> 	BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
> 	BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
> 	BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
> 	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
> 	BPF_EXIT_INSN(),
> 	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
> 
> reads one byte 0 on BE and 28 on LE (from ->index) since
> 
> 	struct test_val {
> 		unsigned int index;
> 		int foo[MAX_ENTRIES];
> 	};
> 
>         struct test_val value = {
> 		.index = (6 + 1) * sizeof(int),
> 		.foo[6] = 0xabcdef12,
> 	};
> 
> 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
> 
> So different branches are taken depending of the endianness.
> 
> 	BPF_MOV64_IMM(BPF_REG_2, 0),
> 	BPF_MOV64_IMM(BPF_REG_3, 0x100000),
> 	BPF_JMP_A(2),
> 	BPF_MOV64_IMM(BPF_REG_2, 42),
> 	BPF_MOV64_IMM(BPF_REG_3, 0x100001),
> 	BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
> 	BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
> 	BPF_EXIT_INSN(),
> 	},
> 	.fixup_map_array_48b = { 1 },
> 	.result = ACCEPT,
> 	.retval = 0x100000,
> },

Let me get my hands on a s390x box later today and get back to you.

Thanks,
Daniel

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: bpf: test_verifier: sanitation: alu with different scalars
  2019-06-25  9:39 ` Daniel Borkmann
@ 2019-07-26 10:41   ` Yauheni Kaliuta
  0 siblings, 0 replies; 3+ messages in thread
From: Yauheni Kaliuta @ 2019-07-26 10:41 UTC (permalink / raw)
  To: Daniel Borkmann; +Cc: linux-kernel, Jiri Olsa, Jiri Benc

Hi, Daniel,

On Tue, Jun 25, 2019 at 12:39 PM Daniel Borkmann <daniel@iogearbox.net> wrote:
>
> On 06/25/2019 10:29 AM, Yauheni Kaliuta wrote:
> > Hi!
> >
> > I'm wondering, how the sanitaion tests (#903 5.2-rc6 for example)
> > are supposed to work on BE arches:
> >
> > {
> >       "sanitation: alu with different scalars 1",
> >       .insns = {
> >       BPF_MOV64_IMM(BPF_REG_0, 1),
> >       BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
> >       BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
> >       BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
> >       BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
> >       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
> >       BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
> >       BPF_EXIT_INSN(),
> >       BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
> >
> > reads one byte 0 on BE and 28 on LE (from ->index) since
> >
> >       struct test_val {
> >               unsigned int index;
> >               int foo[MAX_ENTRIES];
> >       };
> >
> >         struct test_val value = {
> >               .index = (6 + 1) * sizeof(int),
> >               .foo[6] = 0xabcdef12,
> >       };
> >
> >       BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
> >
> > So different branches are taken depending of the endianness.
> >
> >       BPF_MOV64_IMM(BPF_REG_2, 0),
> >       BPF_MOV64_IMM(BPF_REG_3, 0x100000),
> >       BPF_JMP_A(2),
> >       BPF_MOV64_IMM(BPF_REG_2, 42),
> >       BPF_MOV64_IMM(BPF_REG_3, 0x100001),
> >       BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
> >       BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
> >       BPF_EXIT_INSN(),
> >       },
> >       .fixup_map_array_48b = { 1 },
> >       .result = ACCEPT,
> >       .retval = 0x100000,
> > },
>
> Let me get my hands on a s390x box later today and get back to you.

Any progress with that?

-- 
WBR, Yauheni

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-07-26 10:42 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-06-25  8:29 bpf: test_verifier: sanitation: alu with different scalars Yauheni Kaliuta
2019-06-25  9:39 ` Daniel Borkmann
2019-07-26 10:41   ` Yauheni Kaliuta

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox