From: Greg KH <gregkh@linuxfoundation.org>
To: Matthew Wilcox <willy@infradead.org>, Arnd Bergmann <arnd@arndb.de>
Cc: Roberto Sassu <roberto.sassu@huawei.com>,
zohar@linux.ibm.com, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH 03/12] digest_lists: Basic definitions
Date: Sun, 27 Jun 2021 17:35:55 +0200 [thread overview]
Message-ID: <YNia23bDCGRZ74OG@kroah.com> (raw)
In-Reply-To: <YNiX7nyQIS/eg+VC@casper.infradead.org>
On Sun, Jun 27, 2021 at 04:23:26PM +0100, Matthew Wilcox wrote:
> On Sun, Jun 27, 2021 at 12:53:47PM +0200, Greg KH wrote:
> > > +enum ops { DIGEST_LIST_ADD, DIGEST_LIST_DEL, DIGEST_LIST_OP__LAST };
> > > +
> >
> > For enums you export to userspace, you need to specify the values so
> > that all compilers get them right.
>
> I've never heard that rule before. Where does it come from?
> https://en.cppreference.com/w/c/language/enum
> says:
>
> If enumeration-constant is not followed by = constant-expression,
> its value is the value one greater than the value of the previous
> enumerator in the same enumeration. The value of the first enumerator
> (if it does not use = constant-expression) is zero.
>
I thought it was in the Documentation/driver-api/ioctl.rst file, but I
can't find it right now. Maybe it was something that Arnd said?
Arnd, is this still an issue? For some reason I thought it was always
good to have uapi .h enums be explicit as to the value in them,
otherwise some C compilers might produce other values if they were not
specified?
thanks,
greg k-h
next prev parent reply other threads:[~2021-06-27 15:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-25 16:56 [RFC][PATCH 00/12] Huawei Digest Lists Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 01/12] ima: Add digest, algo, measured parameters to ima_measure_critical_data() Roberto Sassu
2021-06-25 18:26 ` Mimi Zohar
2021-06-25 16:56 ` [RFC][PATCH 02/12] digest_lists: Overview Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 03/12] digest_lists: Basic definitions Roberto Sassu
2021-06-27 10:53 ` Greg KH
2021-06-27 15:23 ` Matthew Wilcox
2021-06-27 15:35 ` Greg KH [this message]
2021-06-28 8:30 ` Roberto Sassu
2021-06-28 8:46 ` Greg KH
2021-06-28 9:27 ` Roberto Sassu
2021-06-28 9:32 ` Greg KH
2021-06-28 9:51 ` Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 04/12] digest_lists: Objects Roberto Sassu
2021-06-27 10:56 ` Greg KH
2021-06-28 8:14 ` Roberto Sassu
2021-06-28 8:47 ` Greg KH
2021-06-25 16:56 ` [RFC][PATCH 05/12] digest_lists: Methods Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 06/12] digest_lists: Parser Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 07/12] digest_lists: Interfaces - digest_list_add, digest_list_del Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 08/12] digest_lists: Interfaces - digest_lists_loaded Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 09/12] digest_lists: Interfaces - digest_label Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 10/12] digest_lists: Interfaces - digest_query Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 11/12] digest_lists: Interfaces - digests_count Roberto Sassu
2021-06-25 16:56 ` [RFC][PATCH 12/12] digest_lists: Tests Roberto Sassu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YNia23bDCGRZ74OG@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=arnd@arndb.de \
--cc=linux-doc@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=roberto.sassu@huawei.com \
--cc=willy@infradead.org \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).