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1// SPDX-License-Identifier: GPL-2.02/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */3 4#include <linux/bpf.h>5#include <bpf/bpf_helpers.h>6#include "bpf_misc.h"7#include "test_user_ringbuf.h"8 9char _license[] SEC("license") = "GPL";10 11struct {12 __uint(type, BPF_MAP_TYPE_USER_RINGBUF);13} user_ringbuf SEC(".maps");14 15struct {16 __uint(type, BPF_MAP_TYPE_RINGBUF);17} kernel_ringbuf SEC(".maps");18 19/* inputs */20int pid, err, val;21 22int read = 0;23 24/* Counter used for end-to-end protocol test */25__u64 kern_mutated = 0;26__u64 user_mutated = 0;27__u64 expected_user_mutated = 0;28 29static int30is_test_process(void)31{32 int cur_pid = bpf_get_current_pid_tgid() >> 32;33 34 return cur_pid == pid;35}36 37static long38record_sample(struct bpf_dynptr *dynptr, void *context)39{40 const struct sample *sample = NULL;41 struct sample stack_sample;42 int status;43 static int num_calls;44 45 if (num_calls++ % 2 == 0) {46 status = bpf_dynptr_read(&stack_sample, sizeof(stack_sample), dynptr, 0, 0);47 if (status) {48 bpf_printk("bpf_dynptr_read() failed: %d\n", status);49 err = 1;50 return 1;51 }52 } else {53 sample = bpf_dynptr_data(dynptr, 0, sizeof(*sample));54 if (!sample) {55 bpf_printk("Unexpectedly failed to get sample\n");56 err = 2;57 return 1;58 }59 stack_sample = *sample;60 }61 62 __sync_fetch_and_add(&read, 1);63 return 0;64}65 66static void67handle_sample_msg(const struct test_msg *msg)68{69 switch (msg->msg_op) {70 case TEST_MSG_OP_INC64:71 kern_mutated += msg->operand_64;72 break;73 case TEST_MSG_OP_INC32:74 kern_mutated += msg->operand_32;75 break;76 case TEST_MSG_OP_MUL64:77 kern_mutated *= msg->operand_64;78 break;79 case TEST_MSG_OP_MUL32:80 kern_mutated *= msg->operand_32;81 break;82 default:83 bpf_printk("Unrecognized op %d\n", msg->msg_op);84 err = 2;85 }86}87 88static long89read_protocol_msg(struct bpf_dynptr *dynptr, void *context)90{91 const struct test_msg *msg = NULL;92 93 msg = bpf_dynptr_data(dynptr, 0, sizeof(*msg));94 if (!msg) {95 err = 1;96 bpf_printk("Unexpectedly failed to get msg\n");97 return 0;98 }99 100 handle_sample_msg(msg);101 102 return 0;103}104 105static int publish_next_kern_msg(__u32 index, void *context)106{107 struct test_msg *msg = NULL;108 int operand_64 = TEST_OP_64;109 int operand_32 = TEST_OP_32;110 111 msg = bpf_ringbuf_reserve(&kernel_ringbuf, sizeof(*msg), 0);112 if (!msg) {113 err = 4;114 return 1;115 }116 117 switch (index % TEST_MSG_OP_NUM_OPS) {118 case TEST_MSG_OP_INC64:119 msg->operand_64 = operand_64;120 msg->msg_op = TEST_MSG_OP_INC64;121 expected_user_mutated += operand_64;122 break;123 case TEST_MSG_OP_INC32:124 msg->operand_32 = operand_32;125 msg->msg_op = TEST_MSG_OP_INC32;126 expected_user_mutated += operand_32;127 break;128 case TEST_MSG_OP_MUL64:129 msg->operand_64 = operand_64;130 msg->msg_op = TEST_MSG_OP_MUL64;131 expected_user_mutated *= operand_64;132 break;133 case TEST_MSG_OP_MUL32:134 msg->operand_32 = operand_32;135 msg->msg_op = TEST_MSG_OP_MUL32;136 expected_user_mutated *= operand_32;137 break;138 default:139 bpf_ringbuf_discard(msg, 0);140 err = 5;141 return 1;142 }143 144 bpf_ringbuf_submit(msg, 0);145 146 return 0;147}148 149static void150publish_kern_messages(void)151{152 if (expected_user_mutated != user_mutated) {153 bpf_printk("%lu != %lu\n", expected_user_mutated, user_mutated);154 err = 3;155 return;156 }157 158 bpf_loop(8, publish_next_kern_msg, NULL, 0);159}160 161SEC("fentry/" SYS_PREFIX "sys_prctl")162int test_user_ringbuf_protocol(void *ctx)163{164 long status = 0;165 166 if (!is_test_process())167 return 0;168 169 status = bpf_user_ringbuf_drain(&user_ringbuf, read_protocol_msg, NULL, 0);170 if (status < 0) {171 bpf_printk("Drain returned: %ld\n", status);172 err = 1;173 return 0;174 }175 176 publish_kern_messages();177 178 return 0;179}180 181SEC("fentry/" SYS_PREFIX "sys_getpgid")182int test_user_ringbuf(void *ctx)183{184 if (!is_test_process())185 return 0;186 187 err = bpf_user_ringbuf_drain(&user_ringbuf, record_sample, NULL, 0);188 189 return 0;190}191 192static long193do_nothing_cb(struct bpf_dynptr *dynptr, void *context)194{195 __sync_fetch_and_add(&read, 1);196 return 0;197}198 199SEC("fentry/" SYS_PREFIX "sys_prlimit64")200int test_user_ringbuf_epoll(void *ctx)201{202 long num_samples;203 204 if (!is_test_process())205 return 0;206 207 num_samples = bpf_user_ringbuf_drain(&user_ringbuf, do_nothing_cb, NULL, 0);208 if (num_samples <= 0)209 err = 1;210 211 return 0;212}213