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![David S. Miller](/assets/img/avatar_default.png)
Resolved kernel/bpf/btf.c using instructions from merge commit
69138b34a7
Signed-off-by: David S. Miller <davem@davemloft.net>
136 lines
2.8 KiB
C
136 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/umh.h>
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#include <linux/bpfilter.h>
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#include <linux/sched.h>
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#include <linux/sched/signal.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include "msgfmt.h"
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extern char bpfilter_umh_start;
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extern char bpfilter_umh_end;
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static void shutdown_umh(void)
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{
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struct umd_info *info = &bpfilter_ops.info;
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struct pid *tgid = info->tgid;
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if (tgid) {
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kill_pid(tgid, SIGKILL, 1);
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wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
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bpfilter_umh_cleanup(info);
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}
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}
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static void __stop_umh(void)
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{
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if (IS_ENABLED(CONFIG_INET))
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shutdown_umh();
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}
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static int bpfilter_send_req(struct mbox_request *req)
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{
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struct mbox_reply reply;
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loff_t pos = 0;
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ssize_t n;
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if (!bpfilter_ops.info.tgid)
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return -EFAULT;
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pos = 0;
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n = kernel_write(bpfilter_ops.info.pipe_to_umh, req, sizeof(*req),
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&pos);
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if (n != sizeof(*req)) {
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pr_err("write fail %zd\n", n);
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goto stop;
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}
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pos = 0;
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n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply),
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&pos);
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if (n != sizeof(reply)) {
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pr_err("read fail %zd\n", n);
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goto stop;
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}
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return reply.status;
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stop:
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__stop_umh();
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return -EFAULT;
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}
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static int bpfilter_process_sockopt(struct sock *sk, int optname,
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sockptr_t optval, unsigned int optlen,
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bool is_set)
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{
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struct mbox_request req = {
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.is_set = is_set,
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.pid = current->pid,
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.cmd = optname,
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.addr = (uintptr_t)optval.user,
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.len = optlen,
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};
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if (uaccess_kernel() || sockptr_is_kernel(optval)) {
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pr_err("kernel access not supported\n");
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return -EFAULT;
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}
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return bpfilter_send_req(&req);
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}
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static int start_umh(void)
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{
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struct mbox_request req = { .pid = current->pid };
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int err;
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/* fork usermode process */
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err = fork_usermode_driver(&bpfilter_ops.info);
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if (err)
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return err;
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pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid));
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/* health check that usermode process started correctly */
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if (bpfilter_send_req(&req) != 0) {
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shutdown_umh();
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return -EFAULT;
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}
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return 0;
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}
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static int __init load_umh(void)
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{
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int err;
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err = umd_load_blob(&bpfilter_ops.info,
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&bpfilter_umh_start,
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&bpfilter_umh_end - &bpfilter_umh_start);
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if (err)
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return err;
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mutex_lock(&bpfilter_ops.lock);
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err = start_umh();
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if (!err && IS_ENABLED(CONFIG_INET)) {
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bpfilter_ops.sockopt = &bpfilter_process_sockopt;
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bpfilter_ops.start = &start_umh;
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}
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mutex_unlock(&bpfilter_ops.lock);
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if (err)
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umd_unload_blob(&bpfilter_ops.info);
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return err;
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}
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static void __exit fini_umh(void)
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{
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mutex_lock(&bpfilter_ops.lock);
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if (IS_ENABLED(CONFIG_INET)) {
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shutdown_umh();
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bpfilter_ops.start = NULL;
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bpfilter_ops.sockopt = NULL;
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}
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mutex_unlock(&bpfilter_ops.lock);
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umd_unload_blob(&bpfilter_ops.info);
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}
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module_init(load_umh);
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module_exit(fini_umh);
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MODULE_LICENSE("GPL");
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