From: Vadim Fedorenko <vadim.fedorenko@linux.dev>
To: 林妙倩 <linmq006@gmail.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
Thomas Gleixner <tglx@linutronix.de>,
Grygorii Strashko <grygorii.strashko@ti.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org
Subject: Re: [PATCH] net: ethernet: ti: Prevent divide-by-zero in cpts_calc_mult_shift()
Date: Thu, 28 Aug 2025 14:01:23 +0100 [thread overview]
Message-ID: <e177027d-9286-4a30-9656-e0395094b2c1@linux.dev> (raw)
In-Reply-To: <CAH-r-ZH+0rsji1f9eEaVDtG3XcMCD_EnAHAMwr8DuqO4D4Ps=w@mail.gmail.com>
On 28/08/2025 13:38, æå¦å© wrote:
> Hi, Vadim
>
> Vadim Fedorenko <vadim.fedorenko@linux.dev> 于2025年8月28日周四 20:06写道：
>>
>> On 28/08/2025 10:22, Miaoqian Lin wrote:
>>> cpts_calc_mult_shift() has a potential divide-by-zero in this line:
>>>
>>> do_div(maxsec, freq);
>>>
>>> due to the fact that clk_get_rate() can return zero in certain error
>>> conditions.
>>
>> Have you seen this happening in the real environment, or is it just
>> analysis of the code? I don't see a reason for these "certain error
>> conditions" to happen...
>
> This is from code analysis, not from real environment.
> The !CONFIG_HAVE_CLK version of clk_get_rate() returns zero.
> With CONFIG_COMPILE_TEST && !CONFIG_HAVE_CLK could have the problem.
> This may be theoretical.
!CONFIG_HAVE_CLK will have cpts_create() doing nothing as defined in
cpts.h and it means the patch fixes impossible scenario.
NAck
prev parent reply other threads:[~2025-08-28 13:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-28 9:22 Miaoqian Lin
2025-08-28 9:28 ` Greg Kroah-Hartman
2025-08-28 12:05 ` Vadim Fedorenko
2025-08-28 12:38 ` 林妙倩
2025-08-28 13:01 ` Vadim Fedorenko [this message]
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