From: "Arnd Bergmann" <arnd@arndb.de>
To: "Gregory Price" <gregory.price@memverge.com>
Cc: "Gregory Price" <gourry.memverge@gmail.com>,
linux-mm@kvack.org, jgroves@micron.com, ravis.opensrc@micron.com,
sthanneeru@micron.com, emirakhur@micron.com, Hasan.Maruf@amd.com,
linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-api@vger.kernel.org,
Linux-Arch <linux-arch@vger.kernel.org>,
linux-kernel@vger.kernel.org,
"Andrew Morton" <akpm@linux-foundation.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Andy Lutomirski" <luto@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Michal Hocko" <mhocko@kernel.org>, "Tejun Heo" <tj@kernel.org>,
ying.huang@intel.com, "Jonathan Corbet" <corbet@lwn.net>,
rakie.kim@sk.com, hyeongtak.ji@sk.com, honggyu.kim@sk.com,
vtavarespetr@micron.com, "Peter Zijlstra" <peterz@infradead.org>,
"Frank van der Linden" <fvdl@google.com>
Subject: Re: [RFC PATCH 07/11] mm/mempolicy: add userland mempolicy arg structure
Date: Thu, 07 Dec 2023 16:43:03 +0100 [thread overview]
Message-ID: <cddbf290-021a-49d5-8729-e98cb099ff67@app.fastmail.com> (raw)
In-Reply-To: <ZXHdhVeel1dOxlYJ@memverge.com>
On Thu, Dec 7, 2023, at 15:58, Gregory Price wrote:
> On Thu, Dec 07, 2023 at 08:13:22AM +0100, Arnd Bergmann wrote:
>> On Thu, Dec 7, 2023, at 01:27, Gregory Price wrote:
>>
>> Aside from this, you should avoid holes in the data structure.
>> On 64-bit architectures, the layout above has holes after
>> policy_node and after addr_node.
>>
>> Arnd
>
> doh, clearly i didn't stop to think about alignment. Good eye.
> I'll redo this with __u/s members and fix the holes.
>
> Didn't stop to think about compat pointers. I don't think the
> u64_to_user_ptr pattern is offensive, so i'll make that change.
> At least I don't see what the other options are beyond compat.
Ok, sounds good.
I see you already call wrappers for compat mode to convert
iovec and nodemask layouts for the indirect pointers, and they
look correct. If you wanted to do handle the compat syscalls
using the same entry point, you could add the same kind of
helper to copy the mempolicy args from user space with an
optional conversion, but not having to do this is clearly
easier.
Arnd
next prev parent reply other threads:[~2023-12-07 15:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-07 0:27 [RFC PATCH 00/11] mempolicy2, mbind2, and weighted interleave Gregory Price
2023-12-07 0:27 ` [RFC PATCH 01/11] mm/mempolicy: implement the sysfs-based weighted_interleave interface Gregory Price
2023-12-07 21:56 ` Davidlohr Bueso
2023-12-07 22:17 ` Davidlohr Bueso
2023-12-08 0:11 ` Gregory Price
2023-12-07 0:27 ` [RFC PATCH 02/11] mm/mempolicy: introduce MPOL_WEIGHTED_INTERLEAVE for weighted interleaving Gregory Price
2023-12-07 0:27 ` [RFC PATCH 03/11] mm/mempolicy: refactor sanitize_mpol_flags for reuse Gregory Price
2023-12-07 0:27 ` [RFC PATCH 04/11] mm/mempolicy: create struct mempolicy_args for creating new mempolicies Gregory Price
2023-12-07 0:27 ` [RFC PATCH 05/11] mm/mempolicy: refactor kernel_get_mempolicy for code re-use Gregory Price
2023-12-07 0:27 ` [RFC PATCH 06/11] mm/mempolicy: allow home_node to be set by mpol_new Gregory Price
2023-12-07 0:27 ` [RFC PATCH 07/11] mm/mempolicy: add userland mempolicy arg structure Gregory Price
2023-12-07 7:13 ` Arnd Bergmann
2023-12-07 14:58 ` Gregory Price
2023-12-07 15:43 ` Arnd Bergmann [this message]
2023-12-08 0:05 ` Gregory Price
2023-12-07 0:27 ` [RFC PATCH 08/11] mm/mempolicy: add set_mempolicy2 syscall Gregory Price
2023-12-07 0:27 ` [RFC PATCH 10/11] mm/mempolicy: add the mbind2 syscall Gregory Price
2023-12-07 0:27 ` [RFC PATCH 11/11] mm/mempolicy: extend set_mempolicy2 and mbind2 to support weighted interleave Gregory Price
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