From: David Sterba <dsterba@suse.cz>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Qu Wenruo <quwenruo.btrfs@gmx.com>, Boris Burkov <boris@bur.io>,
Chris Mason <clm@fb.com>, David Sterba <dsterba@suse.com>,
linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [BUG] fs/btrfs: KASAN "args" initialization gripe in btrfs_ioctl_get_csums()
Date: Mon, 20 Jul 2026 12:52:05 +0200 [thread overview]
Message-ID: <20260720105205.GB10684@twin.jikos.cz> (raw)
In-Reply-To: <44261d8e-4361-4592-9fcf-b5c8d56220ba@paulmck-laptop>
On Tue, Jul 14, 2026 at 03:38:43PM -0700, Paul E. McKenney wrote:
> > > Fix (or at least suppress) this by initializing "args" to "{ 0 }".
> >
> > This is a little weird, as @args is immediately written with
> > copy_from_user().
>
> I was wondering about that myself. Perhaps it refuses to assume that
> the entirety of args is overwritten?
>
> > So I'd say this may be specific to certain compiler version.
> > Mind to provide the name and version of the compiler?
>
> gcc version 11.5.0 20240719 (Red Hat 11.5.0-14) (GCC)
The 'maybe-uninitialized' warning occasionaly catches some arch and
compiler combination that does not recognize the effects of
initialization. The versions I see in fs/btrfs log are 10.2,
loongarch64-gcc 12.3.1, gcc8 on m68k or mips, gcc 5 on ppc. Eventually
reported when -Os is enabled.
prev parent reply other threads:[~2026-07-20 10:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-14 20:32 [BUG] fs/btrfs: KASAN "args" initialization gripe in btrfs_ioctl_get_csums() Paul E. McKenney
2026-07-14 21:55 ` Qu Wenruo
2026-07-14 22:38 ` Paul E. McKenney
2026-07-20 10:52 ` David Sterba [this message]
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