linux-kernel - Re: [PATCHv6 2/2] ARM: dma-mapping: remove custom consistent dma region

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: <20120821123451.GV18957@n2100.arm.linux.org.uk>
Date:	Tue, 21 Aug 2012 13:34:51 +0100
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Hiroshi Doyu <hdoyu@...dia.com>
Cc:	Marek Szyprowski <m.szyprowski@...sung.com>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linaro-mm-sig@...ts.linaro.org" <linaro-mm-sig@...ts.linaro.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Arnd Bergmann <arnd@...db.de>,
	Chunsang Jeong <chunsang.jeong@...aro.org>,
	Krishna Reddy <vdumpa@...dia.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Subash Patel <subashrp@...il.com>,
	Minchan Kim <minchan@...nel.org>
Subject: Re: [PATCHv6 2/2] ARM: dma-mapping: remove custom consistent dma
	region

On Tue, Aug 21, 2012 at 02:22:35PM +0300, Hiroshi Doyu wrote:
> The following "__get_vm_area_node()" can take gfp_mask, it means that
> this function is expected to be called from atomic context, but why
> it's _NOT_ allowed _ONLY_ from interrupt context?

One reason is it takes read/write locks without using the IRQ safe
versions for starters (vmap_area_lock and vmlist_lock).  I don't see
any other reasons in that bit of code though.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/