From: Al Viro <viro@zeniv.linux.org.uk>
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Alexander Potapenko <glider@google.com>,
Kees Cook <keescook@chromium.org>,
Eric Biggers <ebiggers@google.com>,
Christian Brauner <brauner@kernel.org>,
serge@hallyn.com, paul@paul-moore.com,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: Re: [PATCH v3 2/2] vfs: avoid duplicating creds in faccessat if possible
Date: Sat, 4 Mar 2023 20:18:56 +0000 [thread overview]
Message-ID: <ZAOnsOl+cXk9mTj5@ZenIV> (raw)
In-Reply-To: <CAGudoHGYaWTCnL4GOR+4Lbcfg5qrdOtNjestGZOkgtUaTwdGrQ@mail.gmail.com>
On Fri, Mar 03, 2023 at 09:39:11PM +0100, Mateusz Guzik wrote:
> the allocation routine does not have any information about the size
> available at compilation time, so has to resort to a memset call at
> runtime. Instead, should this be:
>
> f = kmem_cache_alloc(...);
> memset(f, 0, sizeof(*f));
>
> ... the compiler could in principle inititalize stuff as indicated by
> code and emit zerofill for the rest. Interestingly, last I checked
> neither clang nor gcc knew how to do it, they instead resort to a full
> sized memset anyway, which is quite a bummer.
For struct file I wouldn't expect a win from that, TBH.
next prev parent reply other threads:[~2023-03-04 20:19 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-25 15:55 [PATCH v3 1/2] capability: add cap_isidentical Mateusz Guzik
2023-01-25 15:55 ` [PATCH v3 2/2] vfs: avoid duplicating creds in faccessat if possible Mateusz Guzik
2023-02-28 0:44 ` Linus Torvalds
2023-03-02 8:30 ` Christian Brauner
2023-03-02 17:51 ` Linus Torvalds
2023-03-02 18:14 ` Mateusz Guzik
2023-03-02 18:18 ` Al Viro
2023-03-02 18:22 ` Mateusz Guzik
2023-03-02 18:43 ` Al Viro
2023-03-02 18:51 ` Mateusz Guzik
2023-03-02 19:02 ` Al Viro
2023-03-02 19:18 ` Al Viro
2023-03-02 19:03 ` Linus Torvalds
2023-03-02 19:10 ` Linus Torvalds
2023-03-02 19:19 ` Al Viro
2023-03-02 19:54 ` Kees Cook
2023-03-02 20:11 ` Al Viro
2023-03-03 15:30 ` Alexander Potapenko
2023-03-03 17:39 ` Mateusz Guzik
2023-03-03 17:54 ` Linus Torvalds
2023-03-03 19:37 ` Mateusz Guzik
2023-03-03 19:38 ` Mateusz Guzik
2023-03-03 20:08 ` Linus Torvalds
2023-03-03 20:39 ` Mateusz Guzik
2023-03-03 20:58 ` Linus Torvalds
2023-03-03 21:09 ` Mateusz Guzik
2023-03-04 19:01 ` Mateusz Guzik
2023-03-04 20:31 ` Mateusz Guzik
2023-03-04 20:48 ` Linus Torvalds
2023-03-05 17:23 ` David Laight
2023-03-04 1:29 ` Linus Torvalds
2023-03-04 3:25 ` Yury Norov
2023-03-04 3:42 ` Linus Torvalds
2023-03-04 5:51 ` Yury Norov
2023-03-04 16:41 ` David Vernet
2023-03-04 19:02 ` Linus Torvalds
2023-03-04 19:19 ` Linus Torvalds
2023-03-04 20:34 ` Linus Torvalds
2023-03-04 20:51 ` Yury Norov
2023-03-04 21:01 ` Linus Torvalds
2023-03-04 21:03 ` Linus Torvalds
2023-03-04 21:10 ` Linus Torvalds
2023-03-04 23:08 ` Linus Torvalds
2023-03-04 23:52 ` Linus Torvalds
[not found] ` <CA+icZUUH-J3eh=PSEcaHRDtcKB9svA2Qct6RiOq_MFP_+KeBLQ@mail.gmail.com>
2023-03-05 18:17 ` Linus Torvalds
2023-03-05 18:43 ` Linus Torvalds
2023-03-06 5:43 ` Yury Norov
2023-03-04 20:18 ` Al Viro [this message]
2023-03-04 20:42 ` Mateusz Guzik
2023-03-02 19:38 ` Kees Cook
2023-03-02 19:48 ` Eric Biggers
2023-03-02 18:41 ` Al Viro
2023-03-03 14:49 ` Christian Brauner
2023-03-02 18:11 ` Al Viro
2023-03-03 14:27 ` Christian Brauner
2023-02-28 1:14 ` [PATCH v3 1/2] capability: add cap_isidentical Linus Torvalds
2023-02-28 2:46 ` Casey Schaufler
2023-02-28 14:47 ` Mateusz Guzik
2023-02-28 19:39 ` Linus Torvalds
2023-02-28 19:51 ` Linus Torvalds
2023-02-28 20:48 ` Linus Torvalds
2023-02-28 21:21 ` Mateusz Guzik
2023-02-28 21:29 ` Linus Torvalds
2023-03-01 18:13 ` Linus Torvalds
2023-02-28 17:32 ` Serge E. Hallyn
2023-02-28 17:52 ` Casey Schaufler
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