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From: Julien Grall <julien@xen.org>
To: "Jürgen Groß" <jgross@suse.com>, "Simon Leiner" <simon@leiner.me>,
	xen-devel@lists.xenproject.org, sstabellini@kernel.org
Subject: Re: [PATCH 2/2] arm/xen: Add misuse warning to virt_to_gfn
Date: Thu, 27 Aug 2020 09:24:59 +0100
Message-ID: <3a1cad1b-3d78-e5b0-0f68-70c245dbcc1a@xen.org> (raw)
In-Reply-To: <61f11689-8d6b-0407-b76d-ec5c3a57be4c@suse.com>



On 27/08/2020 06:21, Jürgen Groß wrote:
> On 26.08.20 20:37, Julien Grall wrote:
> "Usually" is a bit gross here. The only generic call site I could find
> is xenbus_grant_ring(). All other instances (I counted 22) are not
> generic at all.
> 
>> will only catch one instance and it means we would have to fix the 
>> first instance and then re-run to catch the others.
>>
>> So I think we want to switch to WARN_ON() here.
> 
> No, please don't. In case there would be a frequent path the result
> would be a basically unusable system due to massive console clobbering.

Right, but if that's really happenning then you have a much bigger 
problem on your platform because the address returned will be invalid.

So I still don't see the advantage of WARN_ON_ONCE() here.

Cheers,

> 
> 
> Juergen

-- 
Julien Grall


  reply index

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <Aw: [Linux] [ARM] Granting memory obtained from the DMA API>
2020-08-25  9:31 ` [PATCH 1/2] xen/xenbus: Fix granting of vmalloc'd memory Simon Leiner
2020-08-25  9:31   ` [PATCH 2/2] arm/xen: Add misuse warning to virt_to_gfn Simon Leiner
2020-08-25 12:16     ` Jan Beulich
2020-08-25 23:48       ` Stefano Stabellini
2020-08-26  6:20         ` Jan Beulich
2020-08-26  7:50           ` Simon Leiner
2020-08-26  7:59             ` Jürgen Groß
2020-08-26  8:14               ` Simon Leiner
2020-08-26  8:27                 ` Jürgen Groß
2020-08-26  8:30                   ` Simon Leiner
2020-08-25 23:58     ` Stefano Stabellini
2020-08-26 18:37     ` Julien Grall
2020-08-27  5:21       ` Jürgen Groß
2020-08-27  8:24         ` Julien Grall [this message]
2020-08-27  8:35           ` Jürgen Groß
2020-08-27 16:04             ` Stefano Stabellini
2020-08-25 23:55   ` [PATCH 1/2] xen/xenbus: Fix granting of vmalloc'd memory Stefano Stabellini

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