From c1ff181ffabc292abcd1832a1c83aac2bc499e71 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 14 Jan 2022 22:09:52 +0530 Subject: [PATCH] selftests/bpf: Extend kfunc selftests Use the prog_test kfuncs to test the referenced PTR_TO_BTF_ID kfunc support, and PTR_TO_CTX, PTR_TO_MEM argument passing support. Also testing the various failure cases for invalid kfunc prototypes. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220114163953.1455836-10-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- net/bpf/test_run.c | 129 +++++++++++++++++- .../selftests/bpf/prog_tests/kfunc_call.c | 6 + .../selftests/bpf/progs/kfunc_call_test.c | 52 ++++++- tools/testing/selftests/bpf/verifier/calls.c | 75 ++++++++++ 4 files changed, 258 insertions(+), 4 deletions(-) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 7796a8c747a0..93ba56507240 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -233,6 +233,105 @@ struct sock * noinline bpf_kfunc_call_test3(struct sock *sk) return sk; } +struct prog_test_ref_kfunc { + int a; + int b; + struct prog_test_ref_kfunc *next; +}; + +static struct prog_test_ref_kfunc prog_test_struct = { + .a = 42, + .b = 108, + .next = &prog_test_struct, +}; + +noinline struct prog_test_ref_kfunc * +bpf_kfunc_call_test_acquire(unsigned long *scalar_ptr) +{ + /* randomly return NULL */ + if (get_jiffies_64() % 2) + return NULL; + return &prog_test_struct; +} + +noinline void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) +{ +} + +struct prog_test_pass1 { + int x0; + struct { + int x1; + struct { + int x2; + struct { + int x3; + }; + }; + }; +}; + +struct prog_test_pass2 { + int len; + short arr1[4]; + struct { + char arr2[4]; + unsigned long arr3[8]; + } x; +}; + +struct prog_test_fail1 { + void *p; + int x; +}; + +struct prog_test_fail2 { + int x8; + struct prog_test_pass1 x; +}; + +struct prog_test_fail3 { + int len; + char arr1[2]; + char arr2[0]; +}; + +noinline void bpf_kfunc_call_test_pass_ctx(struct __sk_buff *skb) +{ +} + +noinline void bpf_kfunc_call_test_pass1(struct prog_test_pass1 *p) +{ +} + +noinline void bpf_kfunc_call_test_pass2(struct prog_test_pass2 *p) +{ +} + +noinline void bpf_kfunc_call_test_fail1(struct prog_test_fail1 *p) +{ +} + +noinline void bpf_kfunc_call_test_fail2(struct prog_test_fail2 *p) +{ +} + +noinline void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p) +{ +} + +noinline void bpf_kfunc_call_test_mem_len_pass1(void *mem, int mem__sz) +{ +} + +noinline void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len) +{ +} + +noinline void bpf_kfunc_call_test_mem_len_fail2(u64 *mem, int len) +{ +} + __diag_pop(); ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO); @@ -241,8 +340,31 @@ BTF_SET_START(test_sk_check_kfunc_ids) BTF_ID(func, bpf_kfunc_call_test1) BTF_ID(func, bpf_kfunc_call_test2) BTF_ID(func, bpf_kfunc_call_test3) +BTF_ID(func, bpf_kfunc_call_test_acquire) +BTF_ID(func, bpf_kfunc_call_test_release) +BTF_ID(func, bpf_kfunc_call_test_pass_ctx) +BTF_ID(func, bpf_kfunc_call_test_pass1) +BTF_ID(func, bpf_kfunc_call_test_pass2) +BTF_ID(func, bpf_kfunc_call_test_fail1) +BTF_ID(func, bpf_kfunc_call_test_fail2) +BTF_ID(func, bpf_kfunc_call_test_fail3) +BTF_ID(func, bpf_kfunc_call_test_mem_len_pass1) +BTF_ID(func, bpf_kfunc_call_test_mem_len_fail1) +BTF_ID(func, bpf_kfunc_call_test_mem_len_fail2) BTF_SET_END(test_sk_check_kfunc_ids) +BTF_SET_START(test_sk_acquire_kfunc_ids) +BTF_ID(func, bpf_kfunc_call_test_acquire) +BTF_SET_END(test_sk_acquire_kfunc_ids) + +BTF_SET_START(test_sk_release_kfunc_ids) +BTF_ID(func, bpf_kfunc_call_test_release) +BTF_SET_END(test_sk_release_kfunc_ids) + +BTF_SET_START(test_sk_ret_null_kfunc_ids) +BTF_ID(func, bpf_kfunc_call_test_acquire) +BTF_SET_END(test_sk_ret_null_kfunc_ids) + static void *bpf_test_init(const union bpf_attr *kattr, u32 size, u32 headroom, u32 tailroom) { @@ -1063,8 +1185,11 @@ out: } static const struct btf_kfunc_id_set bpf_prog_test_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &test_sk_check_kfunc_ids, + .owner = THIS_MODULE, + .check_set = &test_sk_check_kfunc_ids, + .acquire_set = &test_sk_acquire_kfunc_ids, + .release_set = &test_sk_release_kfunc_ids, + .ret_null_set = &test_sk_ret_null_kfunc_ids, }; static int __init bpf_prog_test_run_init(void) diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c index 7d7445ccc141..b39a4f09aefd 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c @@ -27,6 +27,12 @@ static void test_main(void) ASSERT_OK(err, "bpf_prog_test_run(test2)"); ASSERT_EQ(retval, 3, "test2-retval"); + prog_fd = skel->progs.kfunc_call_test_ref_btf_id.prog_fd; + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4), + NULL, NULL, (__u32 *)&retval, NULL); + ASSERT_OK(err, "bpf_prog_test_run(test_ref_btf_id)"); + ASSERT_EQ(retval, 0, "test_ref_btf_id-retval"); + kfunc_call_test_lskel__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_test.c b/tools/testing/selftests/bpf/progs/kfunc_call_test.c index 8a8cf59017aa..5aecbb9fdc68 100644 --- a/tools/testing/selftests/bpf/progs/kfunc_call_test.c +++ b/tools/testing/selftests/bpf/progs/kfunc_call_test.c @@ -1,13 +1,20 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2021 Facebook */ -#include +#include #include -#include "bpf_tcp_helpers.h" extern int bpf_kfunc_call_test2(struct sock *sk, __u32 a, __u32 b) __ksym; extern __u64 bpf_kfunc_call_test1(struct sock *sk, __u32 a, __u64 b, __u32 c, __u64 d) __ksym; +extern struct prog_test_ref_kfunc *bpf_kfunc_call_test_acquire(unsigned long *sp) __ksym; +extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym; +extern void bpf_kfunc_call_test_pass_ctx(struct __sk_buff *skb) __ksym; +extern void bpf_kfunc_call_test_pass1(struct prog_test_pass1 *p) __ksym; +extern void bpf_kfunc_call_test_pass2(struct prog_test_pass2 *p) __ksym; +extern void bpf_kfunc_call_test_mem_len_pass1(void *mem, int len) __ksym; +extern void bpf_kfunc_call_test_mem_len_fail2(__u64 *mem, int len) __ksym; + SEC("tc") int kfunc_call_test2(struct __sk_buff *skb) { @@ -44,4 +51,45 @@ int kfunc_call_test1(struct __sk_buff *skb) return ret; } +SEC("tc") +int kfunc_call_test_ref_btf_id(struct __sk_buff *skb) +{ + struct prog_test_ref_kfunc *pt; + unsigned long s = 0; + int ret = 0; + + pt = bpf_kfunc_call_test_acquire(&s); + if (pt) { + if (pt->a != 42 || pt->b != 108) + ret = -1; + bpf_kfunc_call_test_release(pt); + } + return ret; +} + +SEC("tc") +int kfunc_call_test_pass(struct __sk_buff *skb) +{ + struct prog_test_pass1 p1 = {}; + struct prog_test_pass2 p2 = {}; + short a = 0; + __u64 b = 0; + long c = 0; + char d = 0; + int e = 0; + + bpf_kfunc_call_test_pass_ctx(skb); + bpf_kfunc_call_test_pass1(&p1); + bpf_kfunc_call_test_pass2(&p2); + + bpf_kfunc_call_test_mem_len_pass1(&a, sizeof(a)); + bpf_kfunc_call_test_mem_len_pass1(&b, sizeof(b)); + bpf_kfunc_call_test_mem_len_pass1(&c, sizeof(c)); + bpf_kfunc_call_test_mem_len_pass1(&d, sizeof(d)); + bpf_kfunc_call_test_mem_len_pass1(&e, sizeof(e)); + bpf_kfunc_call_test_mem_len_fail2(&b, -1); + + return 0; +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index d7b74eb28333..829be2b9e08e 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -21,6 +21,81 @@ .prog_type = BPF_PROG_TYPE_TRACEPOINT, .result = ACCEPT, }, +{ + "calls: invalid kfunc call: ptr_to_mem to struct with non-scalar", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = REJECT, + .errstr = "arg#0 pointer type STRUCT prog_test_fail1 must point to scalar", + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_fail1", 2 }, + }, +}, +{ + "calls: invalid kfunc call: ptr_to_mem to struct with nesting depth > 4", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = REJECT, + .errstr = "max struct nesting depth exceeded\narg#0 pointer type STRUCT prog_test_fail2", + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_fail2", 2 }, + }, +}, +{ + "calls: invalid kfunc call: ptr_to_mem to struct with FAM", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = REJECT, + .errstr = "arg#0 pointer type STRUCT prog_test_fail3 must point to scalar", + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_fail3", 2 }, + }, +}, +{ + "calls: invalid kfunc call: reg->type != PTR_TO_CTX", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = REJECT, + .errstr = "arg#0 expected pointer to ctx, but got PTR", + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_pass_ctx", 2 }, + }, +}, +{ + "calls: invalid kfunc call: void * not allowed in func proto without mem size arg", + .insns = { + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = REJECT, + .errstr = "arg#0 pointer type UNKNOWN must point to scalar", + .fixup_kfunc_btf_id = { + { "bpf_kfunc_call_test_mem_len_fail1", 2 }, + }, +}, { "calls: basic sanity", .insns = {