On Wed, 2023-07-12 at 23:08 -0700, Yonghong Song wrote:
> Add unit tests for new ldsx insns. The test includes sign-extension
> with a single value or with a value range.
>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
> .../selftests/bpf/prog_tests/verifier.c | 2 +
> .../selftests/bpf/progs/verifier_ldsx.c | 115 ++++++++++++++++++
> 2 files changed, 117 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/verifier_ldsx.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
> index c375e59ff28d..6eec6a9463c8 100644
> --- a/tools/testing/selftests/bpf/prog_tests/verifier.c
> +++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
> @@ -31,6 +31,7 @@
> #include "verifier_int_ptr.skel.h"
> #include "verifier_jeq_infer_not_null.skel.h"
> #include "verifier_ld_ind.skel.h"
> +#include "verifier_ldsx.skel.h"
> #include "verifier_leak_ptr.skel.h"
> #include "verifier_loops1.skel.h"
> #include "verifier_lwt.skel.h"
> @@ -133,6 +134,7 @@ void test_verifier_helper_value_access(void) { RUN(verifier_helper_value_access
> void test_verifier_int_ptr(void) { RUN(verifier_int_ptr); }
> void test_verifier_jeq_infer_not_null(void) { RUN(verifier_jeq_infer_not_null); }
> void test_verifier_ld_ind(void) { RUN(verifier_ld_ind); }
> +void test_verifier_ldsx(void) { RUN(verifier_ldsx); }
> void test_verifier_leak_ptr(void) { RUN(verifier_leak_ptr); }
> void test_verifier_loops1(void) { RUN(verifier_loops1); }
> void test_verifier_lwt(void) { RUN(verifier_lwt); }
> diff --git a/tools/testing/selftests/bpf/progs/verifier_ldsx.c b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> new file mode 100644
> index 000000000000..cd90913583b9
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/verifier_ldsx.c
> @@ -0,0 +1,115 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/bpf.h>
> +#include <bpf/bpf_helpers.h>
> +#include "bpf_misc.h"
> +
> +SEC("socket")
> +__description("LDSX, S8")
> +__success __success_unpriv __retval(-2)
> +__naked void ldsx_s8(void)
> +{
> + asm volatile (" \
> + r1 = 0x3fe; \
> + *(u64 *)(r10 - 8) = r1; \
> + r0 = *(s8 *)(r10 - 8); \
> + exit; \
> +" ::: __clobber_all);
> +}
> +
> +SEC("socket")
> +__description("LDSX, S16")
> +__success __success_unpriv __retval(-2)
> +__naked void ldsx_s16(void)
> +{
> + asm volatile (" \
> + r1 = 0x3fffe; \
> + *(u64 *)(r10 - 8) = r1; \
> + r0 = *(s16 *)(r10 - 8); \
> + exit; \
> +" ::: __clobber_all);
> +}
> +
> +SEC("socket")
> +__description("LDSX, S32")
> +__success __success_unpriv __retval(-2)
> +__naked void ldsx_s32(void)
> +{
> + asm volatile (" \
> + r1 = 0xfffffffe; \
> + *(u64 *)(r10 - 8) = r1; \
> + r0 = *(s32 *)(r10 - 8); \
> + exit; \
> +" ::: __clobber_all);
> +}
Note that __retval is a 32-bit value, so if I change
r0 = *(s32 *)(r10 - 8); to
r0 = *(u32 *)(r10 - 8);
^
__retval would be the same, probably better to add
some shift right as a last instruction or something
like that.
(Also applies to a similar test in the movsx tests).
> +
> +SEC("socket")
> +__description("LDSX, S8 range checking")
> +__success __success_unpriv __retval(1)
> +__naked void ldsx_s8_range(void)
Maybe add __log_level(2) and a few
__msg("... R1_w=scalar(smin=-128,smax=127)") ?
So that verifier range logic is checked as well.
> +{
> + asm volatile (" \
> + call %[bpf_get_prandom_u32]; \
> + *(u64 *)(r10 - 8) = r0; \
> + r1 = *(s8 *)(r10 - 8); \
> + /* r1 with s8 range */ \
> + if r1 s> 0x7f goto l0_%=; \
> + if r1 s< -0x80 goto l0_%=; \
> + r0 = 1; \
> +l1_%=: \
> + exit; \
> +l0_%=: \
> + r0 = 2; \
> + goto l1_%=; \
> +" :
> + : __imm(bpf_get_prandom_u32)
> + : __clobber_all);
> +}
> +
> +SEC("socket")
> +__description("LDSX, S16 range checking")
> +__success __success_unpriv __retval(1)
> +__naked void ldsx_s16_range(void)
> +{
> + asm volatile (" \
> + call %[bpf_get_prandom_u32]; \
> + *(u64 *)(r10 - 8) = r0; \
> + r1 = *(s16 *)(r10 - 8); \
> + /* r1 with s16 range */ \
> + if r1 s> 0x7fff goto l0_%=; \
> + if r1 s< -0x8000 goto l0_%=; \
> + r0 = 1; \
> +l1_%=: \
> + exit; \
> +l0_%=: \
> + r0 = 2; \
> + goto l1_%=; \
> +" :
> + : __imm(bpf_get_prandom_u32)
> + : __clobber_all);
> +}
> +
> +SEC("socket")
> +__description("LDSX, S32 range checking")
> +__success __success_unpriv __retval(1)
> +__naked void ldsx_s32_range(void)
> +{
> + asm volatile (" \
> + call %[bpf_get_prandom_u32]; \
> + *(u64 *)(r10 - 8) = r0; \
> + r1 = *(s32 *)(r10 - 8); \
> + /* r1 with s16 range */ \
> + if r1 s> 0x7fffFFFF goto l0_%=; \
> + if r1 s< -0x80000000 goto l0_%=; \
> + r0 = 1; \
> +l1_%=: \
> + exit; \
> +l0_%=: \
> + r0 = 2; \
> + goto l1_%=; \
> +" :
> + : __imm(bpf_get_prandom_u32)
> + : __clobber_all);
> +}
> +
> +char _license[] SEC("license") = "GPL";
