selftests/bpf: verifier/value_or_null.c converted to inline assembly
authorEduard Zingerman <eddyz87@gmail.com>
Sat, 25 Mar 2023 02:55:20 +0000 (04:55 +0200)
committerAlexei Starovoitov <ast@kernel.org>
Sun, 26 Mar 2023 00:02:06 +0000 (17:02 -0700)
Test verifier/value_or_null.c automatically converted to use inline assembly.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230325025524.144043-40-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/testing/selftests/bpf/prog_tests/verifier.c
tools/testing/selftests/bpf/progs/verifier_value_or_null.c [new file with mode: 0644]
tools/testing/selftests/bpf/verifier/value_or_null.c [deleted file]

index c77df746d650972d523aa1c46f8f120bd7e2d561..54eb21ef9fad075682555a1afa98aa4cfcac0af4 100644 (file)
@@ -36,6 +36,7 @@
 #include "verifier_uninit.skel.h"
 #include "verifier_value_adj_spill.skel.h"
 #include "verifier_value.skel.h"
+#include "verifier_value_or_null.skel.h"
 
 __maybe_unused
 static void run_tests_aux(const char *skel_name, skel_elf_bytes_fn elf_bytes_factory)
@@ -94,3 +95,4 @@ void test_verifier_stack_ptr(void)            { RUN(verifier_stack_ptr); }
 void test_verifier_uninit(void)               { RUN(verifier_uninit); }
 void test_verifier_value_adj_spill(void)      { RUN(verifier_value_adj_spill); }
 void test_verifier_value(void)                { RUN(verifier_value); }
+void test_verifier_value_or_null(void)        { RUN(verifier_value_or_null); }
diff --git a/tools/testing/selftests/bpf/progs/verifier_value_or_null.c b/tools/testing/selftests/bpf/progs/verifier_value_or_null.c
new file mode 100644 (file)
index 0000000..8ff668a
--- /dev/null
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Converted from tools/testing/selftests/bpf/verifier/value_or_null.c */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+#define MAX_ENTRIES 11
+
+struct test_val {
+       unsigned int index;
+       int foo[MAX_ENTRIES];
+};
+
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __uint(max_entries, 1);
+       __type(key, long long);
+       __type(value, struct test_val);
+} map_hash_48b SEC(".maps");
+
+struct {
+       __uint(type, BPF_MAP_TYPE_HASH);
+       __uint(max_entries, 1);
+       __type(key, long long);
+       __type(value, long long);
+} map_hash_8b SEC(".maps");
+
+SEC("tc")
+__description("multiple registers share map_lookup_elem result")
+__success __retval(0)
+__naked void share_map_lookup_elem_result(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r4 = r0;                                        \
+       if r0 == 0 goto l0_%=;                          \
+       r1 = 0;                                         \
+       *(u64*)(r4 + 0) = r1;                           \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("tc")
+__description("alu ops on ptr_to_map_value_or_null, 1")
+__failure __msg("R4 pointer arithmetic on map_value_or_null")
+__naked void map_value_or_null_1(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r4 = r0;                                        \
+       r4 += -2;                                       \
+       r4 += 2;                                        \
+       if r0 == 0 goto l0_%=;                          \
+       r1 = 0;                                         \
+       *(u64*)(r4 + 0) = r1;                           \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("tc")
+__description("alu ops on ptr_to_map_value_or_null, 2")
+__failure __msg("R4 pointer arithmetic on map_value_or_null")
+__naked void map_value_or_null_2(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r4 = r0;                                        \
+       r4 &= -1;                                       \
+       if r0 == 0 goto l0_%=;                          \
+       r1 = 0;                                         \
+       *(u64*)(r4 + 0) = r1;                           \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("tc")
+__description("alu ops on ptr_to_map_value_or_null, 3")
+__failure __msg("R4 pointer arithmetic on map_value_or_null")
+__naked void map_value_or_null_3(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r4 = r0;                                        \
+       r4 <<= 1;                                       \
+       if r0 == 0 goto l0_%=;                          \
+       r1 = 0;                                         \
+       *(u64*)(r4 + 0) = r1;                           \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("tc")
+__description("invalid memory access with multiple map_lookup_elem calls")
+__failure __msg("R4 !read_ok")
+__naked void multiple_map_lookup_elem_calls(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       r8 = r1;                                        \
+       r7 = r2;                                        \
+       call %[bpf_map_lookup_elem];                    \
+       r4 = r0;                                        \
+       r1 = r8;                                        \
+       r2 = r7;                                        \
+       call %[bpf_map_lookup_elem];                    \
+       if r0 == 0 goto l0_%=;                          \
+       r1 = 0;                                         \
+       *(u64*)(r4 + 0) = r1;                           \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("tc")
+__description("valid indirect map_lookup_elem access with 2nd lookup in branch")
+__success __retval(0)
+__naked void with_2nd_lookup_in_branch(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       r8 = r1;                                        \
+       r7 = r2;                                        \
+       call %[bpf_map_lookup_elem];                    \
+       r2 = 10;                                        \
+       if r2 != 0 goto l0_%=;                          \
+       r1 = r8;                                        \
+       r2 = r7;                                        \
+       call %[bpf_map_lookup_elem];                    \
+l0_%=: r4 = r0;                                        \
+       if r0 == 0 goto l1_%=;                          \
+       r1 = 0;                                         \
+       *(u64*)(r4 + 0) = r1;                           \
+l1_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("socket")
+__description("invalid map access from else condition")
+__failure __msg("R0 unbounded memory access")
+__failure_unpriv __msg_unpriv("R0 leaks addr")
+__flag(BPF_F_ANY_ALIGNMENT)
+__naked void map_access_from_else_condition(void)
+{
+       asm volatile ("                                 \
+       r1 = 0;                                         \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_48b] ll;                        \
+       call %[bpf_map_lookup_elem];                    \
+       if r0 == 0 goto l0_%=;                          \
+       r1 = *(u32*)(r0 + 0);                           \
+       if r1 >= %[__imm_0] goto l1_%=;                 \
+       r1 += 1;                                        \
+l1_%=: r1 <<= 2;                                       \
+       r0 += r1;                                       \
+       r1 = %[test_val_foo];                           \
+       *(u64*)(r0 + 0) = r1;                           \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_48b),
+         __imm_const(__imm_0, MAX_ENTRIES-1),
+         __imm_const(test_val_foo, offsetof(struct test_val, foo))
+       : __clobber_all);
+}
+
+SEC("tc")
+__description("map lookup and null branch prediction")
+__success __retval(0)
+__naked void lookup_and_null_branch_prediction(void)
+{
+       asm volatile ("                                 \
+       r1 = 10;                                        \
+       *(u64*)(r10 - 8) = r1;                          \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r6 = r0;                                        \
+       if r6 == 0 goto l0_%=;                          \
+       if r6 != 0 goto l0_%=;                          \
+       r10 += 10;                                      \
+l0_%=: exit;                                           \
+"      :
+       : __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+SEC("cgroup/skb")
+__description("MAP_VALUE_OR_NULL check_ids() in regsafe()")
+__failure __msg("R8 invalid mem access 'map_value_or_null'")
+__failure_unpriv __msg_unpriv("")
+__flag(BPF_F_TEST_STATE_FREQ)
+__naked void null_check_ids_in_regsafe(void)
+{
+       asm volatile ("                                 \
+       r1 = 0;                                         \
+       *(u64*)(r10 - 8) = r1;                          \
+       /* r9 = map_lookup_elem(...) */                 \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r9 = r0;                                        \
+       /* r8 = map_lookup_elem(...) */                 \
+       r2 = r10;                                       \
+       r2 += -8;                                       \
+       r1 = %[map_hash_8b] ll;                         \
+       call %[bpf_map_lookup_elem];                    \
+       r8 = r0;                                        \
+       /* r7 = ktime_get_ns() */                       \
+       call %[bpf_ktime_get_ns];                       \
+       r7 = r0;                                        \
+       /* r6 = ktime_get_ns() */                       \
+       call %[bpf_ktime_get_ns];                       \
+       r6 = r0;                                        \
+       /* if r6 > r7 goto +1    ; no new information about the state is derived from\
+        *                       ; this check, thus produced verifier states differ\
+        *                       ; only in 'insn_idx'   \
+        * r9 = r8               ; optionally share ID between r9 and r8\
+        */                                             \
+       if r6 > r7 goto l0_%=;                          \
+       r9 = r8;                                        \
+l0_%=: /* if r9 == 0 goto <exit> */                    \
+       if r9 == 0 goto l1_%=;                          \
+       /* read map value via r8, this is not always    \
+        * safe because r8 might be not equal to r9.    \
+        */                                             \
+       r0 = *(u64*)(r8 + 0);                           \
+l1_%=: /* exit 0 */                                    \
+       r0 = 0;                                         \
+       exit;                                           \
+"      :
+       : __imm(bpf_ktime_get_ns),
+         __imm(bpf_map_lookup_elem),
+         __imm_addr(map_hash_8b)
+       : __clobber_all);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/verifier/value_or_null.c b/tools/testing/selftests/bpf/verifier/value_or_null.c
deleted file mode 100644 (file)
index 52a8bca..0000000
+++ /dev/null
@@ -1,220 +0,0 @@
-{
-       "multiple registers share map_lookup_elem result",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .result = ACCEPT,
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS
-},
-{
-       "alu ops on ptr_to_map_value_or_null, 1",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -2),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, 2),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .errstr = "R4 pointer arithmetic on map_value_or_null",
-       .result = REJECT,
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS
-},
-{
-       "alu ops on ptr_to_map_value_or_null, 2",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
-       BPF_ALU64_IMM(BPF_AND, BPF_REG_4, -1),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .errstr = "R4 pointer arithmetic on map_value_or_null",
-       .result = REJECT,
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS
-},
-{
-       "alu ops on ptr_to_map_value_or_null, 3",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
-       BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 1),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .errstr = "R4 pointer arithmetic on map_value_or_null",
-       .result = REJECT,
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS
-},
-{
-       "invalid memory access with multiple map_lookup_elem calls",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_MOV64_REG(BPF_REG_8, BPF_REG_1),
-       BPF_MOV64_REG(BPF_REG_7, BPF_REG_2),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
-       BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .result = REJECT,
-       .errstr = "R4 !read_ok",
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS
-},
-{
-       "valid indirect map_lookup_elem access with 2nd lookup in branch",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_MOV64_REG(BPF_REG_8, BPF_REG_1),
-       BPF_MOV64_REG(BPF_REG_7, BPF_REG_2),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_IMM(BPF_REG_2, 10),
-       BPF_JMP_IMM(BPF_JNE, BPF_REG_2, 0, 3),
-       BPF_MOV64_REG(BPF_REG_1, BPF_REG_8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_4, BPF_REG_0),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .result = ACCEPT,
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS
-},
-{
-       "invalid map access from else condition",
-       .insns = {
-       BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6),
-       BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
-       BPF_JMP_IMM(BPF_JGE, BPF_REG_1, MAX_ENTRIES-1, 1),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 1),
-       BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 2),
-       BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_1),
-       BPF_ST_MEM(BPF_DW, BPF_REG_0, 0, offsetof(struct test_val, foo)),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_48b = { 3 },
-       .errstr = "R0 unbounded memory access",
-       .result = REJECT,
-       .errstr_unpriv = "R0 leaks addr",
-       .result_unpriv = REJECT,
-       .flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
-},
-{
-       "map lookup and null branch prediction",
-       .insns = {
-       BPF_MOV64_IMM(BPF_REG_1, 10),
-       BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1, -8),
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1, 0),
-       BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 2),
-       BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 0, 1),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_10, 10),
-       BPF_EXIT_INSN(),
-       },
-       .fixup_map_hash_8b = { 4 },
-       .prog_type = BPF_PROG_TYPE_SCHED_CLS,
-       .result = ACCEPT,
-},
-{
-       "MAP_VALUE_OR_NULL check_ids() in regsafe()",
-       .insns = {
-       BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
-       /* r9 = map_lookup_elem(...) */
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1,
-                     0),
-       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
-       /* r8 = map_lookup_elem(...) */
-       BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
-       BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
-       BPF_LD_MAP_FD(BPF_REG_1,
-                     0),
-       BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
-       BPF_MOV64_REG(BPF_REG_8, BPF_REG_0),
-       /* r7 = ktime_get_ns() */
-       BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
-       BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
-       /* r6 = ktime_get_ns() */
-       BPF_EMIT_CALL(BPF_FUNC_ktime_get_ns),
-       BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
-       /* if r6 > r7 goto +1    ; no new information about the state is derived from
-        *                       ; this check, thus produced verifier states differ
-        *                       ; only in 'insn_idx'
-        * r9 = r8               ; optionally share ID between r9 and r8
-        */
-       BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
-       BPF_MOV64_REG(BPF_REG_9, BPF_REG_8),
-       /* if r9 == 0 goto <exit> */
-       BPF_JMP_IMM(BPF_JEQ, BPF_REG_9, 0, 1),
-       /* read map value via r8, this is not always
-        * safe because r8 might be not equal to r9.
-        */
-       BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_8, 0),
-       /* exit 0 */
-       BPF_MOV64_IMM(BPF_REG_0, 0),
-       BPF_EXIT_INSN(),
-       },
-       .flags = BPF_F_TEST_STATE_FREQ,
-       .fixup_map_hash_8b = { 3, 9 },
-       .result = REJECT,
-       .errstr = "R8 invalid mem access 'map_value_or_null'",
-       .result_unpriv = REJECT,
-       .errstr_unpriv = "",
-       .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
-},