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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /fs/proc/self.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | fs/proc/self.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/fs/proc/self.c b/fs/proc/self.c new file mode 100644 index 000000000..72cd69bca --- /dev/null +++ b/fs/proc/self.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/cache.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/pid_namespace.h> +#include "internal.h" + +/* + * /proc/self: + */ +static const char *proc_self_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); + pid_t tgid = task_tgid_nr_ns(current, ns); + char *name; + + if (!tgid) + return ERR_PTR(-ENOENT); + /* max length of unsigned int in decimal + NULL term */ + name = kmalloc(10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC); + if (unlikely(!name)) + return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD); + sprintf(name, "%u", tgid); + set_delayed_call(done, kfree_link, name); + return name; +} + +static const struct inode_operations proc_self_inode_operations = { + .get_link = proc_self_get_link, +}; + +static unsigned self_inum __ro_after_init; + +int proc_setup_self(struct super_block *s) +{ + struct inode *root_inode = d_inode(s->s_root); + struct proc_fs_info *fs_info = proc_sb_info(s); + struct dentry *self; + int ret = -ENOMEM; + + inode_lock(root_inode); + self = d_alloc_name(s->s_root, "self"); + if (self) { + struct inode *inode = new_inode(s); + if (inode) { + inode->i_ino = self_inum; + inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); + inode->i_mode = S_IFLNK | S_IRWXUGO; + inode->i_uid = GLOBAL_ROOT_UID; + inode->i_gid = GLOBAL_ROOT_GID; + inode->i_op = &proc_self_inode_operations; + d_add(self, inode); + ret = 0; + } else { + dput(self); + } + } + inode_unlock(root_inode); + + if (ret) + pr_err("proc_fill_super: can't allocate /proc/self\n"); + else + fs_info->proc_self = self; + + return ret; +} + +void __init proc_self_init(void) +{ + proc_alloc_inum(&self_inum); +} |