Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'bpf-support-bpf_get_func_arg-for-bpf_trace_raw_tp'
Menglong Dong says:
====================
bpf: support bpf_get_func_arg() for BPF_TRACE_RAW_TP
Support bpf_get_func_arg() for BPF_TRACE_RAW_TP by getting the function
argument count from "prog->aux->attach_func_proto" during verifier inline.
Changes v5 -> v4:
* some format adjustment in the 1st patch
* v4: https://lore.kernel.org/bpf/20260120073046.324342-1-dongml2@chinatelecom.cn/
Changes v4 -> v3:
* fix the error of using bpf_get_func_arg() for BPF_TRACE_ITER
* v3: https://lore.kernel.org/bpf/20260119023732.130642-1-dongml2@chinatelecom.cn/
Changes v3 -> v2:
* remove unnecessary NULL checking for prog->aux->attach_func_proto
* v2: https://lore.kernel.org/bpf/20260116071739.121182-1-dongml2@chinatelecom.cn/
Changes v2 -> v1:
* for nr_args, skip first 'void *__data' argument in btf_trace_##name
typedef
* check the result4 and result5 in the selftests
* v1: https://lore.kernel.org/bpf/20260116035024.98214-1-dongml2@chinatelecom.cn/
====================
Link: https://patch.msgid.link/20260121044348.113201-1-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
+87
-6
+18
-4
kernel/bpf/verifier.c
+18
-4
kernel/bpf/verifier.c
···
23741
23741
/* Implement bpf_get_func_arg inline. */
23742
23742
if (prog_type == BPF_PROG_TYPE_TRACING &&
23743
23743
insn->imm == BPF_FUNC_get_func_arg) {
23744
-
/* Load nr_args from ctx - 8 */
23745
-
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
23744
+
if (eatype == BPF_TRACE_RAW_TP) {
23745
+
int nr_args = btf_type_vlen(prog->aux->attach_func_proto);
23746
+
23747
+
/* skip 'void *__data' in btf_trace_##name() and save to reg0 */
23748
+
insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args - 1);
23749
+
} else {
23750
+
/* Load nr_args from ctx - 8 */
23751
+
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
23752
+
}
23746
23753
insn_buf[1] = BPF_JMP32_REG(BPF_JGE, BPF_REG_2, BPF_REG_0, 6);
23747
23754
insn_buf[2] = BPF_ALU64_IMM(BPF_LSH, BPF_REG_2, 3);
23748
23755
insn_buf[3] = BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_1);
···
23801
23794
/* Implement get_func_arg_cnt inline. */
23802
23795
if (prog_type == BPF_PROG_TYPE_TRACING &&
23803
23796
insn->imm == BPF_FUNC_get_func_arg_cnt) {
23804
-
/* Load nr_args from ctx - 8 */
23805
-
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
23797
+
if (eatype == BPF_TRACE_RAW_TP) {
23798
+
int nr_args = btf_type_vlen(prog->aux->attach_func_proto);
23799
+
23800
+
/* skip 'void *__data' in btf_trace_##name() and save to reg0 */
23801
+
insn_buf[0] = BPF_MOV64_IMM(BPF_REG_0, nr_args - 1);
23802
+
} else {
23803
+
/* Load nr_args from ctx - 8 */
23804
+
insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, -8);
23805
+
}
23806
23806
23807
23807
new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1);
23808
23808
if (!new_prog)
+8
-2
kernel/trace/bpf_trace.c
+8
-2
kernel/trace/bpf_trace.c
···
1734
1734
case BPF_FUNC_d_path:
1735
1735
return &bpf_d_path_proto;
1736
1736
case BPF_FUNC_get_func_arg:
1737
-
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
1737
+
if (bpf_prog_has_trampoline(prog) ||
1738
+
prog->expected_attach_type == BPF_TRACE_RAW_TP)
1739
+
return &bpf_get_func_arg_proto;
1740
+
return NULL;
1738
1741
case BPF_FUNC_get_func_ret:
1739
1742
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
1740
1743
case BPF_FUNC_get_func_arg_cnt:
1741
-
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
1744
+
if (bpf_prog_has_trampoline(prog) ||
1745
+
prog->expected_attach_type == BPF_TRACE_RAW_TP)
1746
+
return &bpf_get_func_arg_cnt_proto;
1747
+
return NULL;
1742
1748
case BPF_FUNC_get_attach_cookie:
1743
1749
if (prog->type == BPF_PROG_TYPE_TRACING &&
1744
1750
prog->expected_attach_type == BPF_TRACE_RAW_TP)
+3
tools/testing/selftests/bpf/prog_tests/get_func_args_test.c
+3
tools/testing/selftests/bpf/prog_tests/get_func_args_test.c
···
33
33
34
34
ASSERT_EQ(topts.retval >> 16, 1, "test_run");
35
35
ASSERT_EQ(topts.retval & 0xffff, 1234 + 29, "test_run");
36
+
ASSERT_OK(trigger_module_test_read(1), "trigger_read");
36
37
37
38
ASSERT_EQ(skel->bss->test1_result, 1, "test1_result");
38
39
ASSERT_EQ(skel->bss->test2_result, 1, "test2_result");
39
40
ASSERT_EQ(skel->bss->test3_result, 1, "test3_result");
40
41
ASSERT_EQ(skel->bss->test4_result, 1, "test4_result");
42
+
ASSERT_EQ(skel->bss->test5_result, 1, "test5_result");
43
+
ASSERT_EQ(skel->bss->test6_result, 1, "test6_result");
41
44
42
45
cleanup:
43
46
get_func_args_test__destroy(skel);
+44
tools/testing/selftests/bpf/progs/get_func_args_test.c
+44
tools/testing/selftests/bpf/progs/get_func_args_test.c
···
121
121
test4_result &= err == 0 && ret == 1234;
122
122
return 0;
123
123
}
124
+
125
+
__u64 test5_result = 0;
126
+
SEC("tp_btf/bpf_testmod_fentry_test1_tp")
127
+
int BPF_PROG(tp_test1)
128
+
{
129
+
__u64 cnt = bpf_get_func_arg_cnt(ctx);
130
+
__u64 a = 0, z = 0;
131
+
__s64 err;
132
+
133
+
test5_result = cnt == 1;
134
+
135
+
err = bpf_get_func_arg(ctx, 0, &a);
136
+
test5_result &= err == 0 && ((int) a == 1);
137
+
138
+
/* not valid argument */
139
+
err = bpf_get_func_arg(ctx, 1, &z);
140
+
test5_result &= err == -EINVAL;
141
+
142
+
return 0;
143
+
}
144
+
145
+
__u64 test6_result = 0;
146
+
SEC("tp_btf/bpf_testmod_fentry_test2_tp")
147
+
int BPF_PROG(tp_test2)
148
+
{
149
+
__u64 cnt = bpf_get_func_arg_cnt(ctx);
150
+
__u64 a = 0, b = 0, z = 0;
151
+
__s64 err;
152
+
153
+
test6_result = cnt == 2;
154
+
155
+
/* valid arguments */
156
+
err = bpf_get_func_arg(ctx, 0, &a);
157
+
test6_result &= err == 0 && (int) a == 2;
158
+
159
+
err = bpf_get_func_arg(ctx, 1, &b);
160
+
test6_result &= err == 0 && b == 3;
161
+
162
+
/* not valid argument */
163
+
err = bpf_get_func_arg(ctx, 2, &z);
164
+
test6_result &= err == -EINVAL;
165
+
166
+
return 0;
167
+
}
+10
tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
+10
tools/testing/selftests/bpf/test_kmods/bpf_testmod-events.h
···
63
63
sizeof(struct bpf_testmod_test_writable_ctx)
64
64
);
65
65
66
+
DECLARE_TRACE(bpf_testmod_fentry_test1,
67
+
TP_PROTO(int a),
68
+
TP_ARGS(a)
69
+
);
70
+
71
+
DECLARE_TRACE(bpf_testmod_fentry_test2,
72
+
TP_PROTO(int a, u64 b),
73
+
TP_ARGS(a, b)
74
+
);
75
+
66
76
#endif /* _BPF_TESTMOD_EVENTS_H */
67
77
68
78
#undef TRACE_INCLUDE_PATH
+4
tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
+4
tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
···
412
412
413
413
noinline int bpf_testmod_fentry_test1(int a)
414
414
{
415
+
trace_bpf_testmod_fentry_test1_tp(a);
416
+
415
417
return a + 1;
416
418
}
417
419
418
420
noinline int bpf_testmod_fentry_test2(int a, u64 b)
419
421
{
422
+
trace_bpf_testmod_fentry_test2_tp(a, b);
423
+
420
424
return a + b;
421
425
}
422
426