linux-kernel - Re: [PATCH] ipc: Convert ipcs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200418131509.fb3c19bf450d618be797c030@linux-foundation.org>
Date:   Sat, 18 Apr 2020 13:15:09 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Matthew Wilcox <willy@...radead.org>
Cc:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        Manfred Spraul <manfred@...orfullife.com>,
        Davidlohr Bueso <dave@...olabs.net>
Subject: Re: [PATCH] ipc: Convert ipcs_idr to XArray

On Thu, 26 Mar 2020 08:14:18 -0700 Matthew Wilcox <willy@...radead.org> wrote:

> From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
> 
> The XArray has better loops than the IDR has, removing the need to
> open-code them.  We also don't need to call idr_destroy() any more.
> Allocating the ID is a little tricky due to needing to get 'seq'
> correct.  Open-code a variant of __xa_alloc() which lets us set the
> ID and the seq before depositing the pointer in the array.

hm, this goes rather deep.  Manfred & Davidlohr, are you able to run
this through some testing?

>
> ...
>
> --- a/ipc/util.c
> +++ b/ipc/util.c
> @@ -104,12 +104,20 @@ static const struct rhashtable_params ipc_kht_params = {
>  	.automatic_shrinking	= true,
>  };
>  
> +#ifdef CONFIG_CHECKPOINT_RESTORE

The code grew a few additional CONFIG_CHECKPOINT_RESTORE ifdefs. 
What's going on here?  Why is CRIU special in ipc/?

> +#define set_restore_id(ids, x)	ids->restore_id = x
> +#define get_restore_id(ids)	ids->restore_id
> +#else
> +#define set_restore_id(ids, x)	do { } while (0)
> +#define get_restore_id(ids)	(-1)
> +#endif

Well these are ugly.  Can't all this be done in C?

>
> ...
>