Messages in this thread | | | Date | Fri, 30 Sep 2022 00:38:08 +0100 | From | Al Viro <> | Subject | Re: [CFT][PATCH] proc: Update /proc/net to point at the accessing threads network namespace |
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On Thu, Sep 29, 2022 at 05:48:29PM -0500, Eric W. Biederman wrote:
> +static const char *proc_net_symlink_get_link(struct dentry *dentry, > + struct inode *inode, > + struct delayed_call *done) > +{ > + struct pid_namespace *ns = proc_pid_ns(inode->i_sb); > + pid_t tid = task_pid_nr_ns(current, ns); > + char *name; > + > + if (!tid) > + return ERR_PTR(-ENOENT); > + name = kmalloc(10 + 4 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC); > + if (unlikely(!name)) > + return dentry ? ERR_PTR(-ENOMEM) : ERR_PTR(-ECHILD); > + sprintf(name, "%u/net", tid); > + set_delayed_call(done, kfree_link, name); > + return name; > +}
Just to troll adobriyan a bit:
static const char *dynamic_get_link(struct delayed_call *done, bool is_rcu, const char *fmt, ...) { va_list args; char *body;
va_start(args, fmt); body = kvasprintf(is_rcu ? GFP_ATOMIC : GFP_KERNEL, fmt, args); va_end(args);
if (unlikely(!body)) return is_rcu ? ERR_PTR(-ECHILD) : ERR_PTR(-ENOMEM); set_delayed_call(done, kfree_link, body); return body; }
static const char *proc_net_symlink_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { struct pid_namespace *ns = proc_pid_ns(inode->i_sb); pid_t tid = task_pid_nr_ns(current, ns);
if (!tid) return ERR_PTR(-ENOENT); return dyname_get_link(done, !dentry, "%u/net", tid); }
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);
if (!tgid) return ERR_PTR(-ENOENT); return dynamic_get_link(done, !dentry, "%u", tgid); }
static const char *proc_thread_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); pid_t pid = task_pid_nr_ns(current, ns);
if (!pid) return ERR_PTR(-ENOENT); return dynamic_get_link(done, !dentry, "%u/task/%u", tgid, pid); }
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