Convert /proc/$PID/cmdline to seq_file interface. XXX
This one must be buggy. seq_file buffer is adjustable, so userspace can execute itself with huge command line (which can be arbitrarily long now), then read 1 byte. Voila, whole command line now is in kmalloced/vmalloced memory. Imposing limit is trivial but equally lame to current PAGE_SIZE limit. Signed-off-by: Alexey Dobriyan <[email protected]> --- fs/proc/base.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -200,9 +200,17 @@ static int proc_root_link(struct dentry *dentry, struct path *path) return result; } -static int proc_pid_cmdline(struct task_struct *task, char *buffer) +static int proc_pid_cmdline(struct seq_file *m, struct pid_namespace *ns, + struct pid *pid, struct task_struct *task) { - return get_cmdline(task, buffer, PAGE_SIZE); + /* + * Rely on struct seq_operations::show() being called once + * per internal buffer allocation. See single_open(), traverse(). + * + * Rely on internal buffer autoexpansion if it was entirely filled. + */ + m->count += get_cmdline(task, m->buf, m->size); + return 0; } static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns, @@ -2567,7 +2575,7 @@ static const struct pid_entry tgid_base_stuff[] = { #ifdef CONFIG_HAVE_ARCH_TRACEHOOK ONE("syscall", S_IRUSR, proc_pid_syscall), #endif - INF("cmdline", S_IRUGO, proc_pid_cmdline), + ONE("cmdline", S_IRUGO, proc_pid_cmdline), ONE("stat", S_IRUGO, proc_tgid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_pid_maps_operations), @@ -2903,7 +2911,7 @@ static const struct pid_entry tid_base_stuff[] = { #ifdef CONFIG_HAVE_ARCH_TRACEHOOK ONE("syscall", S_IRUSR, proc_pid_syscall), #endif - INF("cmdline", S_IRUGO, proc_pid_cmdline), + ONE("cmdline", S_IRUGO, proc_pid_cmdline), ONE("stat", S_IRUGO, proc_tid_stat), ONE("statm", S_IRUGO, proc_pid_statm), REG("maps", S_IRUGO, proc_tid_maps_operations), -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
