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73 lines
1.7 KiB
73 lines
1.7 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#include <linux/cache.h> |
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#include <linux/sched.h> |
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#include <linux/slab.h> |
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#include <linux/pid_namespace.h> |
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#include "internal.h" |
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/* |
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* /proc/self: |
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*/ |
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static const char *proc_self_get_link(struct dentry *dentry, |
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struct inode *inode, |
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struct delayed_call *done) |
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{ |
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struct pid_namespace *ns = proc_pid_ns(inode->i_sb); |
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pid_t tgid = task_tgid_nr_ns(current, ns); |
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char *name; |
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if (!tgid) |
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return ERR_PTR(-ENOENT); |
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/* max length of unsigned int in decimal + NULL term */ |
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name = kmalloc(10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC); |
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if (unlikely(!name)) |
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return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD); |
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sprintf(name, "%u", tgid); |
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set_delayed_call(done, kfree_link, name); |
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return name; |
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} |
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static const struct inode_operations proc_self_inode_operations = { |
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.get_link = proc_self_get_link, |
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}; |
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static unsigned self_inum __ro_after_init; |
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int proc_setup_self(struct super_block *s) |
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{ |
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struct inode *root_inode = d_inode(s->s_root); |
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struct proc_fs_info *fs_info = proc_sb_info(s); |
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struct dentry *self; |
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int ret = -ENOMEM; |
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inode_lock(root_inode); |
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self = d_alloc_name(s->s_root, "self"); |
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if (self) { |
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struct inode *inode = new_inode(s); |
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if (inode) { |
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inode->i_ino = self_inum; |
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inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); |
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inode->i_mode = S_IFLNK | S_IRWXUGO; |
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inode->i_uid = GLOBAL_ROOT_UID; |
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inode->i_gid = GLOBAL_ROOT_GID; |
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inode->i_op = &proc_self_inode_operations; |
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d_add(self, inode); |
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ret = 0; |
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} else { |
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dput(self); |
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} |
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} |
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inode_unlock(root_inode); |
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if (ret) |
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pr_err("proc_fill_super: can't allocate /proc/self\n"); |
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else |
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fs_info->proc_self = self; |
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return ret; |
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} |
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void __init proc_self_init(void) |
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{ |
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proc_alloc_inum(&self_inum); |
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}
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