Feedback-ID: i56a14606:Fastmail
User-Agent: Cyrus-JMAP/3.9.0-alpha0-156-g081acc5ed5-fm-20230206.001-g081acc5e
Mime-Version: 1.0
Message-Id: <2c8a8539-649c-47d2-b416-6d607cba5956@app.fastmail.com>
In-Reply-To: <CAOgh=FzCOvv86HG=AhCBDW6cUHDnzq8UPBgmYPR12PNNMRNx0w@mail.gmail.com>
References: <20230211091302.4576-1-lina@asahilina.net>
 <CAOgh=FzCOvv86HG=AhCBDW6cUHDnzq8UPBgmYPR12PNNMRNx0w@mail.gmail.com>
Date:   Mon, 13 Feb 2023 20:22:28 +0100
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     "Eric Curtin" <ecurtin@redhat.com>,
        "Asahi Lina" <lina@asahilina.net>
Cc:     "Hector Martin" <marcan@marcan.st>,
        "Sven Peter" <sven@svenpeter.dev>,
        "Alyssa Rosenzweig" <alyssa@rosenzweig.io>, asahi@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] soc: apple: rtkit: Do not copy the reg state structure to the
 stack
Content-Type: text/plain
Precedence: bulk

On Mon, Feb 13, 2023, at 18:15, Eric Curtin wrote:
> On Sat, 11 Feb 2023 at 09:21, Asahi Lina <lina@asahilina.net> wrote:
>>
>> The register state struct is 848 bytes, which ends up bloating the
>> apple_rtkit_crashlog_dump_regs stack frame beyond 1024 on some
>> 32-bit platforms, triggering compile warnings.
>>
>> This doesn't matter for 64BIT/ARM64, but there's also no good reason to
>> copy the structure to the stack in this case. We can use __packed to
>> avoid alignment issues, there are no double-read hazards, and this is a
>> fatal error path so performance does not matter.
>>
>> Fixes: 22991d8d5725 ("soc: apple: rtkit: Add register dump decoding to crashlog")
>> Signed-off-by: Asahi Lina <lina@asahilina.net>
> Reviewed-by: Eric Curtin <ecurtin@redhat.com>

Merged now, thanks a lot for the fix!

     Arnd