From: Matthew Wilcox <willy@infradead.org>
To: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Alexey Suchkov <aleks.koyf@gmail.com>,
akpm@linux-foundation.org, dywoq.contact@gmail.com,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH] [PATCH v2] mm: initialize 'seq' in gup_fast to remove -Wmaybe-uninitialized warning
Date: Mon, 2 Mar 2026 19:53:27 +0000 [thread overview]
Message-ID: <aaXqt8TD7r5wcrRI@casper.infradead.org> (raw)
In-Reply-To: <20260302194836.2932150-1-joshua.hahnjy@gmail.com>
On Mon, Mar 02, 2026 at 11:48:35AM -0800, Joshua Hahn wrote:
> Unfortunately I think that this patch is still unneeded. The variable seq is
> used in two places, raw_seqcount_try_begin and read_seqcount_retry, and nowhere
> else in the function. Both are guarded by if (gup_flags & FOLL_PIN).
Yeah, historically GCC wasn't great with that pattern. It failed to
notice that the condition was the same and so there was no path through
the code that would use an uninit variable. Hence my question about
what compiler version he's using to see whether we can disregard this
because it's an old compiler that we don't support any more.
next prev parent reply other threads:[~2026-03-02 19:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-02 19:12 [PATCH] " Alexey Suchkov
2026-03-02 19:22 ` Matthew Wilcox
2026-03-02 19:34 ` [PATCH] [PATCH v2] " Alexey Suchkov
2026-03-02 19:44 ` Matthew Wilcox
2026-03-02 19:57 ` Alexey Suchkov
2026-03-02 19:48 ` Joshua Hahn
2026-03-02 19:53 ` Matthew Wilcox [this message]
2026-03-02 20:09 ` Alexey Suchkov
2026-03-02 20:43 ` Andrew Morton
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