From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Pintu Agarwal <pintu.ping@gmail.com>,
Pintu Kumar <quic_pintu@quicinc.com>,
open list <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>,
ebiederm@xmission.com, sfr@canb.auug.org.au, legion@kernel.org,
sashal@kernel.org, chris.hyser@oracle.com, ccross@google.com,
pcc@google.com, dave@stgolabs.net, caoxiaofeng@yulong.com,
david@redhat.com
Subject: Re: [PATCH] sysinfo: include availram field in sysinfo struct
Date: Fri, 7 Jan 2022 22:51:48 +0300 [thread overview]
Message-ID: <YdiZ1BZ7gyMaJQCz@grain> (raw)
In-Reply-To: <20220107120451.z2eqru2tm5mlhla3@wittgenstein>
On Fri, Jan 07, 2022 at 01:04:51PM +0100, Christian Brauner wrote:
> >
> > Wait. The userspace may pass old structure here, and in result we
> > return incorrect layout which won't match old one, no? Old binary
> > code has no clue about this header update.
>
> Yes, that won't work as done.
>
Yup. When I've been developing struct prctl_mm_map I reserved
PR_SET_MM_MAP_SIZE opcode so userspace would be able to query
current structure size and provide memory slab needed to fit
running structure.
As far as I see we can cut off some space from padding (at the
end of the structure) though one need to make a precise check
that there is no alignment holes appear on different architectures
other than x86. This area is pretty sensitive.
next prev parent reply other threads:[~2022-01-07 19:51 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-06 15:34 Pintu Kumar
2022-01-06 16:11 ` Cyrill Gorcunov
2022-01-06 16:49 ` Pintu Agarwal
2022-01-06 17:27 ` Cyrill Gorcunov
2022-01-07 12:04 ` Christian Brauner
2022-01-07 13:44 ` Pintu Agarwal
2022-01-07 16:58 ` Vlastimil Babka
2022-01-07 17:47 ` Pintu Agarwal
2022-01-07 22:18 ` David Laight
2022-01-07 19:51 ` Cyrill Gorcunov [this message]
2022-01-06 17:41 ` David Laight
2022-01-06 17:59 ` Pintu Agarwal
2022-01-06 19:20 ` Eric W. Biederman
2022-01-07 18:07 ` [PATCH v2] " Pintu Kumar
2022-01-07 21:01 ` Cyrill Gorcunov
2022-01-08 16:24 ` Pintu Agarwal
2022-01-10 8:11 ` Cyrill Gorcunov
2022-01-07 22:22 ` David Laight
2022-01-08 16:53 ` Pintu Agarwal
2022-01-08 22:35 ` David Laight
2022-01-10 14:55 ` Pintu Agarwal
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