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From: David Miller <davem@davemloft.net>
To: joe@perches.com
Cc: thierry.reding@gmail.com, hkallweit1@gmail.com, andrew@lunn.ch,
	nic_swsd@realtek.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] r8169: Avoid pointer aliasing
Date: Tue, 05 Feb 2019 11:14:04 -0800 (PST)	[thread overview]
Message-ID: <20190205.111404.1429981997134153696.davem@davemloft.net> (raw)
In-Reply-To: <8553086eaec167846992f1cff12aa388cee81767.camel@perches.com>

From: Joe Perches <joe@perches.com>
Date: Tue, 05 Feb 2019 10:42:54 -0800

> On Mon, 2019-02-04 at 19:20 -0800, David Miller wrote:
>> From: Thierry Reding <thierry.reding@gmail.com>
>> Date: Mon,  4 Feb 2019 17:42:13 +0100
>> 
>> > @@ -7316,7 +7325,7 @@ static int rtl_get_ether_clk(struct rtl8169_private *tp)
>> >  static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>> >  {
>> >       const struct rtl_cfg_info *cfg = rtl_cfg_infos + ent->driver_data;
>> > -     u8 mac_addr[ETH_ALEN] __aligned(4) = {};
>> > +     u8 mac_addr[ETH_ALEN] = {};
>> >       struct rtl8169_private *tp;
>> 
>> I agree with Heiner, you have to provide at least 2 byte alignment for this
>> buffer due to the reasons he stated.
> 
> It's declared after a pointer so it is already is 2 byte aligned.
> 
> A lot of drivers wouldn't work otherwise.

That's assuming a lot about what the compiler will do when it allocates
local variables to the stack.

I want it _explicit_.

  reply	other threads:[~2019-02-05 19:14 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-04 16:42 [PATCH v2 1/2] r8169: Load MAC address from device tree if present Thierry Reding
2019-02-04 16:42 ` [PATCH v2 2/2] r8169: Avoid pointer aliasing Thierry Reding
2019-02-04 16:59   ` Andrew Lunn
2019-02-04 18:44   ` Heiner Kallweit
2019-02-05  3:20   ` David Miller
2019-02-05 18:42     ` Joe Perches
2019-02-05 19:14       ` David Miller [this message]
2019-02-05 19:19         ` Joe Perches
2019-02-06  7:25           ` Michal Kubecek
2019-02-05 20:04       ` Eric Dumazet
2019-02-05 20:18         ` Joe Perches
2019-02-05 20:23           ` Eric Dumazet
2019-02-05 20:23           ` Heiner Kallweit
2019-02-04 19:30 ` [PATCH v2 1/2] r8169: Load MAC address from device tree if present Heiner Kallweit
2019-02-06  2:27 [PATCH v2 2/2] r8169: Avoid pointer aliasing Paul Zimmerman
2019-02-06  2:52 ` Joe Perches
2019-02-06  3:25   ` Paul Zimmerman
2019-02-06  3:49     ` Joe Perches

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