Re: + seq_read-info-message-about-buggy-next-functions.patch added to -mm tree

[Andrew Morton]

On Mon, 02 Mar 2020 14:31:48 -0500 Qian Cai <cai@xxxxxx> wrote:

> On Mon, 2020-03-02 at 13:20 -0500, Qian Cai wrote:
> > This patch spams the console like crazy while reading sysfs,
> > 
> > # dmesg | grep 'buggy seq_file' | wc -l
> > 4204
> > 
> > [ 9505.321981] LTP: starting read_all_proc (read_all -d /proc -q -r 10)
> > [ 9508.222934] buggy seq_file .next function xt_match_seq_next [x_tables] did
> > not updated position index
> > [ 9508.223319] buggy seq_file .next function xt_match_seq_next [x_tables] did
> > not updated position index
> > [ 9508.223654] buggy seq_file .next function xt_match_seq_next [x_tables] did
> > not updated position index
> > [ 9508.223994] buggy seq_file .next function xt_match_seq_next [x_tables] did
> > not updated position index
> > [ 9508.224337] buggy seq_file .next function xt_match_seq_next [x_tables] did
> > not updated position index
> > ...
> > 
> > 
> > > --- a/fs/seq_file.c~seq_read-info-message-about-buggy-next-functions
> > > +++ a/fs/seq_file.c
> > > @@ -256,9 +256,12 @@ Fill:
> > >  		loff_t pos = m->index;
> > >  
> > >  		p = m->op->next(m, p, &m->index);
> > > -		if (pos == m->index)
> > > -			/* Buggy ->next function */
> > > +		if (pos == m->index) {
> > > +			pr_info("buggy seq_file .next function %ps "
> > > +				"did not updated position index\n",
> > > +				m->op->next);
> 
> This?
> 
> s/pr_info/pr_info_ratelimited/
> 

Fair enough - I made that change.