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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /fs/proc/self.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/proc/self.c')
-rw-r--r--fs/proc/self.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/fs/proc/self.c b/fs/proc/self.c
new file mode 100644
index 0000000000..ecc4da8d26
--- /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_set_ctime_current(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);
+}