Re: [PATCH v3 4/6] blktrace: fix debugfs use after free

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Apr 29, 2020 at 11:45:42AM +0000, Luis Chamberlain wrote:
> On Wed, Apr 29, 2020 at 04:26:37AM -0700, Christoph Hellwig wrote:
> > I can't say I'm a fan of all these long backtraces in commit logs..
> > 
> > > +static struct dentry *blk_debugfs_dir_register(const char *name)
> > > +{
> > > +	return debugfs_create_dir(name, blk_debugfs_root);
> > > +}
> > 
> > I don't think we really need this helper.
> 
> We don't export blk_debugfs_root, didn't think we'd want to, and
> since only a few scew funky drivers would use the struct gendisk
> and also support BLKTRACE, I didn't think we'd want to export it
> now.
> 
> A new block private symbol namespace alright?

Err, that function is static and has two callers.

> > This could be simplified down to:
> > 
> > 	if (bdev && bdev != bdev->bd_contains)
> > 		return bdev->bd_part->debugfs_dir;
> > 	return q->debugfs_dir;
> >
> > Given that bd_part is in __blkdev_get very near bd_contains.
> 
> Ah neat.
> 
> > Also given that this patch completely rewrites blk_trace_debugfs_dir is
> > there any point in the previous patch?
> 
> Still think it helps with making this patch easier to read, but I don't
> care, lemme know if I should just fold it.

In fact I'm not even sure we need the helper.  Modulo the comment
this just becomes a:

	if (bdev && bdev != bdev->bd_contains)
 		dir = bdev->bd_part->debugfs_dir;
	else
	 	dir = q->debugfs_dir;

in do_blk_trace_setup.



[Index of Archives]     [Linux RAID]     [Linux SCSI]     [Linux ATA RAID]     [IDE]     [Linux Wireless]     [Linux Kernel]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Device Mapper]

  Powered by Linux