Re: [PATCH v7 02/11] proc: add proc_fs_info struct to store proc information

From: Oleg Nesterov
Date: Tue Jan 28 2020 - 08:43:56 EST


On 01/25, Alexey Gladkov wrote:
>
> static int proc_init_fs_context(struct fs_context *fc)
> {
> struct proc_fs_context *ctx;
> + struct pid_namespace *pid_ns;
>
> ctx = kzalloc(sizeof(struct proc_fs_context), GFP_KERNEL);
> if (!ctx)
> return -ENOMEM;
>
> - ctx->pid_ns = get_pid_ns(task_active_pid_ns(current));
> + pid_ns = get_pid_ns(task_active_pid_ns(current));
> +
> + if (!pid_ns->proc_mnt) {
> + ctx->fs_info = kzalloc(sizeof(struct proc_fs_info), GFP_KERNEL);
> + if (!ctx->fs_info) {
> + kfree(ctx);
> + return -ENOMEM;
> + }
> + ctx->fs_info->pid_ns = pid_ns;
> + } else {
> + ctx->fs_info = proc_sb_info(pid_ns->proc_mnt->mnt_sb);
> + }
> +

it seems that this code lacks put_pid_ns() if pid_ns->proc_mnt != NULL
or if kzalloc() fails?

Or, better,

pid_ns = task_active_pid_ns();

if (!pid_ns->proc_mnt) {
ctx->fs_info = kzalloc();
...
ctx->fs_info->pid_ns = get_pid_ns(pid_ns);
}

No?

Oleg.