linux-kernel - Re: [PATCH 08/14] zram: check that backends array has at least one backend

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: Windows password security audit tool. GUI, reports in PDF.

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

Date: Sun, 5 May 2024 15:48:32 +0900
From: Sergey Senozhatsky <senozhatsky@...omium.org>
To: Andrew Morton <akpm@...ux-foundation.org>, linux-kbuild@...r.kernel.org
Cc: kernel test robot <lkp@...el.com>, Minchan Kim <minchan@...nel.org>,
	llvm@...ts.linux.dev, oe-kbuild-all@...ts.linux.dev,
	Linux Memory Management List <linux-mm@...ck.org>,
	linux-kernel@...r.kernel.org, linux-block@...r.kernel.org,
	Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: Re: [PATCH 08/14] zram: check that backends array has at least one
 backend

On (24/05/05 14:13), Sergey Senozhatsky wrote:
> On (24/05/05 13:39), Sergey Senozhatsky wrote:
> [..]
> > > I guess just pick one if none were selected.
> 
> How do I pick one if none were selected? Does Kconfig support
> something like that?

This triggers Kconfig error:

config ZRAM_EMPTY_BACKENDS_FIXUP
       bool
       depends on ZRAM && !ZRAM_BACKEND_LZO && !ZRAM_BACKEND_LZ4 && \
               !ZRAM_BACKEND_LZ4HC && !ZRAM_BACKEND_ZSTD && \
               !ZRAM_BACKEND_DEFLATE
       select ZRAM_BACKEND_LZO

drivers/block/zram/Kconfig:17:error: recursive dependency detected!
drivers/block/zram/Kconfig:17:  symbol ZRAM_BACKEND_LZO is selected by ZRAM_EMPTY_BACKENDS_FIXUP
drivers/block/zram/Kconfig:52:  symbol ZRAM_EMPTY_BACKENDS_FIXUP depends on ZRAM_BACKEND_LZO

I'm a little surprised by this - EMPTY_BACKENDS_FIXUP does not depend
on ZRAM_BACKEND_LZO, it depends on NOT ZRAM_BACKEND_LZO.

Let me Cc linux-kbuild. Kbuild folks, how do I workaround this?