Re: [PATCH] proc: add proc_seq_release

From: Christoph Hellwig
Date: Mon Jun 11 2018 - 02:16:04 EST

On Sun, Jun 10, 2018 at 03:51:24AM +0800, Chunyu Hu wrote:
> kmemleak reported some memory leak on reading proc files. After adding
> some debug lines, find that proc_seq_fops is using seq_release as
> release handler, which won't handle the free of 'private' field of
> seq_file, while in fact the open handler proc_seq_open could create
> the private data with __seq_open_private when state_size is greater
> than zero. So after reading files created with proc_create_seq_private,
> such as /proc/timer_list and /proc/vmallocinfo, the private mem of a
> seq_file is not freed. Fix it by adding the paired proc_seq_release
> as the default release handler of proc_seq_ops instead of seq_release.

Indeed, thanks for the patch.

Reviewed-by: Christoph Hellwig <hch@xxxxxx>