From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 13 May 2024 10:30:14 +0000
Subject: [PATCH] modify sin led gpio
---
kernel/kernel/bpf/inode.c | 315 ++++++++++++++++++++++++++++++++++++++--------------
1 files changed, 228 insertions(+), 87 deletions(-)
diff --git a/kernel/kernel/bpf/inode.c b/kernel/kernel/bpf/inode.c
index 11fade8..6b14b4c 100644
--- a/kernel/kernel/bpf/inode.c
+++ b/kernel/kernel/bpf/inode.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Minimal file system backend for holding eBPF maps and programs,
* used by bpf(2) object pinning.
@@ -5,10 +6,6 @@
* Authors:
*
* Daniel Borkmann <daniel@iogearbox.net>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * version 2 as published by the Free Software Foundation.
*/
#include <linux/init.h>
@@ -17,26 +14,32 @@
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
#include <linux/kdev_t.h>
-#include <linux/parser.h>
#include <linux/filter.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
+#include "preload/bpf_preload.h"
enum bpf_type {
BPF_TYPE_UNSPEC = 0,
BPF_TYPE_PROG,
BPF_TYPE_MAP,
+ BPF_TYPE_LINK,
};
static void *bpf_any_get(void *raw, enum bpf_type type)
{
switch (type) {
case BPF_TYPE_PROG:
- raw = bpf_prog_inc(raw);
+ bpf_prog_inc(raw);
break;
case BPF_TYPE_MAP:
- raw = bpf_map_inc(raw, true);
+ bpf_map_inc_with_uref(raw);
+ break;
+ case BPF_TYPE_LINK:
+ bpf_link_inc(raw);
break;
default:
WARN_ON_ONCE(1);
@@ -55,6 +58,9 @@
case BPF_TYPE_MAP:
bpf_map_put_with_uref(raw);
break;
+ case BPF_TYPE_LINK:
+ bpf_link_put(raw);
+ break;
default:
WARN_ON_ONCE(1);
break;
@@ -65,20 +71,32 @@
{
void *raw;
- *type = BPF_TYPE_MAP;
raw = bpf_map_get_with_uref(ufd);
- if (IS_ERR(raw)) {
- *type = BPF_TYPE_PROG;
- raw = bpf_prog_get(ufd);
+ if (!IS_ERR(raw)) {
+ *type = BPF_TYPE_MAP;
+ return raw;
}
- return raw;
+ raw = bpf_prog_get(ufd);
+ if (!IS_ERR(raw)) {
+ *type = BPF_TYPE_PROG;
+ return raw;
+ }
+
+ raw = bpf_link_get_from_fd(ufd);
+ if (!IS_ERR(raw)) {
+ *type = BPF_TYPE_LINK;
+ return raw;
+ }
+
+ return ERR_PTR(-EINVAL);
}
static const struct inode_operations bpf_dir_iops;
static const struct inode_operations bpf_prog_iops = { };
static const struct inode_operations bpf_map_iops = { };
+static const struct inode_operations bpf_link_iops = { };
static struct inode *bpf_get_inode(struct super_block *sb,
const struct inode *dir,
@@ -116,6 +134,8 @@
*type = BPF_TYPE_PROG;
else if (inode->i_op == &bpf_map_iops)
*type = BPF_TYPE_MAP;
+ else if (inode->i_op == &bpf_link_iops)
+ *type = BPF_TYPE_LINK;
else
return -EACCES;
@@ -339,13 +359,23 @@
&bpffs_map_fops : &bpffs_obj_fops);
}
+static int bpf_mklink(struct dentry *dentry, umode_t mode, void *arg)
+{
+ struct bpf_link *link = arg;
+
+ return bpf_mkobj_ops(dentry, mode, arg, &bpf_link_iops,
+ bpf_link_is_iter(link) ?
+ &bpf_iter_fops : &bpffs_obj_fops);
+}
+
static struct dentry *
bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
{
/* Dots in names (e.g. "/sys/fs/bpf/foo.bar") are reserved for future
- * extensions.
+ * extensions. That allows popoulate_bpffs() create special files.
*/
- if (strchr(dentry->d_name.name, '.'))
+ if ((dir->i_mode & S_IALLUGO) &&
+ strchr(dentry->d_name.name, '.'))
return ERR_PTR(-EPERM);
return simple_lookup(dir, dentry, flags);
@@ -383,7 +413,28 @@
.unlink = simple_unlink,
};
-static int bpf_obj_do_pin(const struct filename *pathname, void *raw,
+/* pin iterator link into bpffs */
+static int bpf_iter_link_pin_kernel(struct dentry *parent,
+ const char *name, struct bpf_link *link)
+{
+ umode_t mode = S_IFREG | S_IRUSR;
+ struct dentry *dentry;
+ int ret;
+
+ inode_lock(parent->d_inode);
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (IS_ERR(dentry)) {
+ inode_unlock(parent->d_inode);
+ return PTR_ERR(dentry);
+ }
+ ret = bpf_mkobj_ops(dentry, mode, link, &bpf_link_iops,
+ &bpf_iter_fops);
+ dput(dentry);
+ inode_unlock(parent->d_inode);
+ return ret;
+}
+
+static int bpf_obj_do_pin(const char __user *pathname, void *raw,
enum bpf_type type)
{
struct dentry *dentry;
@@ -392,7 +443,7 @@
umode_t mode;
int ret;
- dentry = kern_path_create(AT_FDCWD, pathname->name, &path, 0);
+ dentry = user_path_create(AT_FDCWD, pathname, &path, 0);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
@@ -415,6 +466,9 @@
case BPF_TYPE_MAP:
ret = vfs_mkobj(dentry, mode, bpf_mkmap, raw);
break;
+ case BPF_TYPE_LINK:
+ ret = vfs_mkobj(dentry, mode, bpf_mklink, raw);
+ break;
default:
ret = -EPERM;
}
@@ -425,30 +479,22 @@
int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
{
- struct filename *pname;
enum bpf_type type;
void *raw;
int ret;
- pname = getname(pathname);
- if (IS_ERR(pname))
- return PTR_ERR(pname);
-
raw = bpf_fd_probe_obj(ufd, &type);
- if (IS_ERR(raw)) {
- ret = PTR_ERR(raw);
- goto out;
- }
+ if (IS_ERR(raw))
+ return PTR_ERR(raw);
- ret = bpf_obj_do_pin(pname, raw, type);
+ ret = bpf_obj_do_pin(pathname, raw, type);
if (ret != 0)
bpf_any_put(raw, type);
-out:
- putname(pname);
+
return ret;
}
-static void *bpf_obj_do_get(const struct filename *pathname,
+static void *bpf_obj_do_get(const char __user *pathname,
enum bpf_type *type, int flags)
{
struct inode *inode;
@@ -456,7 +502,7 @@
void *raw;
int ret;
- ret = kern_path(pathname->name, LOOKUP_FOLLOW, &path);
+ ret = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW, &path);
if (ret)
return ERR_PTR(ret);
@@ -483,36 +529,29 @@
int bpf_obj_get_user(const char __user *pathname, int flags)
{
enum bpf_type type = BPF_TYPE_UNSPEC;
- struct filename *pname;
- int ret = -ENOENT;
int f_flags;
void *raw;
+ int ret;
f_flags = bpf_get_file_flag(flags);
if (f_flags < 0)
return f_flags;
- pname = getname(pathname);
- if (IS_ERR(pname))
- return PTR_ERR(pname);
-
- raw = bpf_obj_do_get(pname, &type, f_flags);
- if (IS_ERR(raw)) {
- ret = PTR_ERR(raw);
- goto out;
- }
+ raw = bpf_obj_do_get(pathname, &type, f_flags);
+ if (IS_ERR(raw))
+ return PTR_ERR(raw);
if (type == BPF_TYPE_PROG)
ret = bpf_prog_new_fd(raw);
else if (type == BPF_TYPE_MAP)
ret = bpf_map_new_fd(raw, f_flags);
+ else if (type == BPF_TYPE_LINK)
+ ret = (f_flags != O_RDWR) ? -EINVAL : bpf_link_new_fd(raw);
else
- goto out;
+ return -ENOENT;
if (ret < 0)
bpf_any_put(raw, type);
-out:
- putname(pname);
return ret;
}
@@ -524,6 +563,8 @@
return ERR_PTR(ret);
if (inode->i_op == &bpf_map_iops)
+ return ERR_PTR(-EINVAL);
+ if (inode->i_op == &bpf_link_iops)
return ERR_PTR(-EINVAL);
if (inode->i_op != &bpf_prog_iops)
return ERR_PTR(-EACCES);
@@ -537,7 +578,8 @@
if (!bpf_prog_get_ok(prog, &type, false))
return ERR_PTR(-EINVAL);
- return bpf_prog_inc(prog);
+ bpf_prog_inc(prog);
+ return prog;
}
struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
@@ -567,9 +609,8 @@
return 0;
}
-static void bpf_destroy_inode_deferred(struct rcu_head *head)
+static void bpf_free_inode(struct inode *inode)
{
- struct inode *inode = container_of(head, struct inode, i_rcu);
enum bpf_type type;
if (S_ISLNK(inode->i_mode))
@@ -579,71 +620,140 @@
free_inode_nonrcu(inode);
}
-static void bpf_destroy_inode(struct inode *inode)
-{
- call_rcu(&inode->i_rcu, bpf_destroy_inode_deferred);
-}
-
static const struct super_operations bpf_super_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
.show_options = bpf_show_options,
- .destroy_inode = bpf_destroy_inode,
+ .free_inode = bpf_free_inode,
};
enum {
OPT_MODE,
- OPT_ERR,
};
-static const match_table_t bpf_mount_tokens = {
- { OPT_MODE, "mode=%o" },
- { OPT_ERR, NULL },
+static const struct fs_parameter_spec bpf_fs_parameters[] = {
+ fsparam_u32oct ("mode", OPT_MODE),
+ {}
};
struct bpf_mount_opts {
umode_t mode;
};
-static int bpf_parse_options(char *data, struct bpf_mount_opts *opts)
+static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
- substring_t args[MAX_OPT_ARGS];
- int option, token;
- char *ptr;
+ struct bpf_mount_opts *opts = fc->fs_private;
+ struct fs_parse_result result;
+ int opt;
- opts->mode = S_IRWXUGO;
-
- while ((ptr = strsep(&data, ",")) != NULL) {
- if (!*ptr)
- continue;
-
- token = match_token(ptr, bpf_mount_tokens, args);
- switch (token) {
- case OPT_MODE:
- if (match_octal(&args[0], &option))
- return -EINVAL;
- opts->mode = option & S_IALLUGO;
- break;
+ opt = fs_parse(fc, bpf_fs_parameters, param, &result);
+ if (opt < 0)
/* We might like to report bad mount options here, but
* traditionally we've ignored all mount options, so we'd
* better continue to ignore non-existing options for bpf.
*/
- }
+ return opt == -ENOPARAM ? 0 : opt;
+
+ switch (opt) {
+ case OPT_MODE:
+ opts->mode = result.uint_32 & S_IALLUGO;
+ break;
}
return 0;
}
-static int bpf_fill_super(struct super_block *sb, void *data, int silent)
+struct bpf_preload_ops *bpf_preload_ops;
+EXPORT_SYMBOL_GPL(bpf_preload_ops);
+
+static bool bpf_preload_mod_get(void)
+{
+ /* If bpf_preload.ko wasn't loaded earlier then load it now.
+ * When bpf_preload is built into vmlinux the module's __init
+ * function will populate it.
+ */
+ if (!bpf_preload_ops) {
+ request_module("bpf_preload");
+ if (!bpf_preload_ops)
+ return false;
+ }
+ /* And grab the reference, so the module doesn't disappear while the
+ * kernel is interacting with the kernel module and its UMD.
+ */
+ if (!try_module_get(bpf_preload_ops->owner)) {
+ pr_err("bpf_preload module get failed.\n");
+ return false;
+ }
+ return true;
+}
+
+static void bpf_preload_mod_put(void)
+{
+ if (bpf_preload_ops)
+ /* now user can "rmmod bpf_preload" if necessary */
+ module_put(bpf_preload_ops->owner);
+}
+
+static DEFINE_MUTEX(bpf_preload_lock);
+
+static int populate_bpffs(struct dentry *parent)
+{
+ struct bpf_preload_info objs[BPF_PRELOAD_LINKS] = {};
+ struct bpf_link *links[BPF_PRELOAD_LINKS] = {};
+ int err = 0, i;
+
+ /* grab the mutex to make sure the kernel interactions with bpf_preload
+ * UMD are serialized
+ */
+ mutex_lock(&bpf_preload_lock);
+
+ /* if bpf_preload.ko wasn't built into vmlinux then load it */
+ if (!bpf_preload_mod_get())
+ goto out;
+
+ if (!bpf_preload_ops->info.tgid) {
+ /* preload() will start UMD that will load BPF iterator programs */
+ err = bpf_preload_ops->preload(objs);
+ if (err)
+ goto out_put;
+ for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+ links[i] = bpf_link_by_id(objs[i].link_id);
+ if (IS_ERR(links[i])) {
+ err = PTR_ERR(links[i]);
+ goto out_put;
+ }
+ }
+ for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
+ err = bpf_iter_link_pin_kernel(parent,
+ objs[i].link_name, links[i]);
+ if (err)
+ goto out_put;
+ /* do not unlink successfully pinned links even
+ * if later link fails to pin
+ */
+ links[i] = NULL;
+ }
+ /* finish() will tell UMD process to exit */
+ err = bpf_preload_ops->finish();
+ if (err)
+ goto out_put;
+ }
+out_put:
+ bpf_preload_mod_put();
+out:
+ mutex_unlock(&bpf_preload_lock);
+ for (i = 0; i < BPF_PRELOAD_LINKS && err; i++)
+ if (!IS_ERR_OR_NULL(links[i]))
+ bpf_link_put(links[i]);
+ return err;
+}
+
+static int bpf_fill_super(struct super_block *sb, struct fs_context *fc)
{
static const struct tree_descr bpf_rfiles[] = { { "" } };
- struct bpf_mount_opts opts;
+ struct bpf_mount_opts *opts = fc->fs_private;
struct inode *inode;
int ret;
-
- ret = bpf_parse_options(data, &opts);
- if (ret)
- return ret;
ret = simple_fill_super(sb, BPF_FS_MAGIC, bpf_rfiles);
if (ret)
@@ -654,21 +764,50 @@
inode = sb->s_root->d_inode;
inode->i_op = &bpf_dir_iops;
inode->i_mode &= ~S_IALLUGO;
- inode->i_mode |= S_ISVTX | opts.mode;
-
+ populate_bpffs(sb->s_root);
+ inode->i_mode |= S_ISVTX | opts->mode;
return 0;
}
-static struct dentry *bpf_mount(struct file_system_type *type, int flags,
- const char *dev_name, void *data)
+static int bpf_get_tree(struct fs_context *fc)
{
- return mount_nodev(type, flags, data, bpf_fill_super);
+ return get_tree_nodev(fc, bpf_fill_super);
+}
+
+static void bpf_free_fc(struct fs_context *fc)
+{
+ kfree(fc->fs_private);
+}
+
+static const struct fs_context_operations bpf_context_ops = {
+ .free = bpf_free_fc,
+ .parse_param = bpf_parse_param,
+ .get_tree = bpf_get_tree,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int bpf_init_fs_context(struct fs_context *fc)
+{
+ struct bpf_mount_opts *opts;
+
+ opts = kzalloc(sizeof(struct bpf_mount_opts), GFP_KERNEL);
+ if (!opts)
+ return -ENOMEM;
+
+ opts->mode = S_IRWXUGO;
+
+ fc->fs_private = opts;
+ fc->ops = &bpf_context_ops;
+ return 0;
}
static struct file_system_type bpf_fs_type = {
.owner = THIS_MODULE,
.name = "bpf",
- .mount = bpf_mount,
+ .init_fs_context = bpf_init_fs_context,
+ .parameters = bpf_fs_parameters,
.kill_sb = kill_litter_super,
};
@@ -676,6 +815,8 @@
{
int ret;
+ mutex_init(&bpf_preload_lock);
+
ret = sysfs_create_mount_point(fs_kobj, "bpf");
if (ret)
return ret;
--
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