From: Al Viro <viro@zeniv.linux.org.uk>
To: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>,
linux-mm@kvack.org, Kent Overstreet <kent.overstreet@gmail.com>,
Johannes Weiner <hannes@cmpxchg.org>,
linux-fsdevel@vger.kernel.org
Subject: Re: [RFC] pgflags_t
Date: Wed, 6 Oct 2021 15:46:49 +0000 [thread overview]
Message-ID: <YV3E6Ym1+T6Tyq17@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <21ce511e-7cde-8bdb-b6c6-e1278681ebf6@redhat.com>
On Wed, Oct 06, 2021 at 05:32:39PM +0200, David Hildenbrand wrote:
> It feels to me like using __bitwise for access checks and then still
> modifying the __bitwise fields randomly via a backdoor. But sure, if it
> works, I'll be happy if we can use that.
__bitwise == "can't do anything other than bitwise operations without
an explicit force-cast". All there is to it. Hell, the very first
use had been for things like __le32 et.al., where the primitives
very much do non-bitwise accesses. They are known to be safe (==
do the same thing regardless of the host endianness). Internally
they contain force-casts, precisely so that the caller wouldn't
need to.
next prev parent reply other threads:[~2021-10-06 15:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-06 14:58 Matthew Wilcox
2021-10-06 15:16 ` David Hildenbrand
2021-10-06 15:29 ` Matthew Wilcox
2021-10-06 15:22 ` Al Viro
2021-10-06 15:23 ` David Hildenbrand
2021-10-06 15:28 ` Al Viro
2021-10-06 15:32 ` David Hildenbrand
2021-10-06 15:46 ` Al Viro [this message]
2021-10-06 15:47 ` David Hildenbrand
2021-10-06 15:38 ` Matthew Wilcox
2021-10-06 15:48 ` Al Viro
2021-10-07 14:37 ` Vlastimil Babka
2021-10-07 14:48 ` Matthew Wilcox
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