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From: Lukas Wunner <lukas@wunner.de>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>
Subject: Re: [PATCH v2 1/1] mtd: cfi_cmdset_0001: Factor out do_write_buffer_locked() to reduce stack frame
Date: Wed, 8 Apr 2026 15:40:30 +0200	[thread overview]
Message-ID: <adZazsIA5D-gJ1OS@wunner.de> (raw)
In-Reply-To: <adY7r_YNFjGk9EKZ@ashevche-desk.local>

On Wed, Apr 08, 2026 at 02:27:43PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 08, 2026 at 08:35:52AM +0200, Lukas Wunner wrote:
> > On Wed, Feb 04, 2026 at 02:25:27AM +0100, Andy Shevchenko wrote:
> > > Compiler is not happy about used stack frame:
> > > 
> > > drivers/mtd/chips/cfi_cmdset_0001.c: In function 'do_write_buffer':
> > > drivers/mtd/chips/cfi_cmdset_0001.c:1887:1: error: the frame size of 1296 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
> > > 
> > > Fix this by factoring out do_write_buffer_locked().
> > 
> > FWIW, the issue only occurs with CONFIG_KASAN_STACK=y, so an alternative
> > to refactoring the function is to disable KASAN for this particular file:
> 
> I would like to avoid such big hammers.
> 
> Somehow I lost the track of this patch, I need to find it locally and check
> the status, I will come up with updated one once I found the latest version.

I just wanted to highlight that it's a KASAN-specific issue that doesn't
show up unless CONFIG_KASAN_STACK=y.  I think it's worth mentioning that
in the commit message.

I'm not saying disabling KASAN is the right approach here, but it's one
*possible* approach.  Ideally the number of variables on the stack should
be reduced.  Perhaps alocating them on the heap would be more appropriate
than refactoring the code, I don't know.

Thanks,

Lukas

  reply	other threads:[~2026-04-08 13:40 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-04  1:25 [PATCH v2 1/1] mtd: cfi_cmdset_0001: Factor out do_write_buffer_locked() to reduce stack frame Andy Shevchenko
2026-02-04 21:12 ` Andy Shevchenko
2026-02-05  8:51   ` Miquel Raynal
2026-02-05 15:57     ` Andy Shevchenko
2026-02-05 17:34       ` Miquel Raynal
2026-02-06  5:56         ` Vignesh Raghavendra
2026-02-06  7:44           ` Andy Shevchenko
2026-04-08  6:35 ` Lukas Wunner
2026-04-08 11:27   ` Andy Shevchenko
2026-04-08 13:40     ` Lukas Wunner [this message]
2026-04-08 14:33       ` Andy Shevchenko
2026-04-08 21:17         ` Andy Shevchenko
  -- strict thread matches above, loose matches on Subject: below --
2026-01-24 13:35 Andy Shevchenko
2026-01-24 22:41 ` kernel test robot
2026-02-10 10:05   ` Vignesh Raghavendra
2026-02-10 14:45     ` Andy Shevchenko

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