From: Jan Kara <jack@suse.cz>
To: cgzones@googlemail.com
Cc: x86@kernel.org, linux-alpha@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org,
linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org,
linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
sparclinux@vger.kernel.org, linux-fsdevel@vger.kernel.org,
audit@vger.kernel.org, linux-arch@vger.kernel.org,
linux-api@vger.kernel.org, linux-security-module@vger.kernel.org,
selinux@vger.kernel.org,
Richard Henderson <richard.henderson@linaro.org>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Michal Simek <monstr@monstr.eu>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
"James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
Helge Deller <deller@gmx.de>,
Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
"Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Sven Schnelle <svens@linux.ibm.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
"David S. Miller" <davem@davemloft.net>,
Andreas Larsson <andreas@gaisler.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>, Chris Zankel <chris@zankel.net>,
Max Filippov <jcmvbkbc@gmail.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Paul Moore <paul@paul-moore.com>, Eric Paris <eparis@redhat.com>,
Arnd Bergmann <arnd@arndb.de>, Jens Axboe <axboe@kernel.dk>,
Pavel Begunkov <asml.silence@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Sohil Mehta <sohil.mehta@intel.com>,
Palmer Dabbelt <palmer@sifive.com>,
Miklos Szeredi <mszeredi@redhat.com>,
Nhat Pham <nphamcs@gmail.com>,
Casey Schaufler <casey@schaufler-ca.com>,
Florian Fainelli <florian.fainelli@broadcom.com>,
Kees Cook <keescook@chromium.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Mark Rutland <mark.rutland@arm.com>,
io-uring@vger.kernel.org
Subject: Re: [PATCH v3 2/2] fs/xattr: add *at family syscalls
Date: Tue, 30 Apr 2024 12:09:02 +0200 [thread overview]
Message-ID: <20240430100902.iwmeszr2jzv4wyo7@quack3> (raw)
In-Reply-To: <20240426162042.191916-1-cgoettsche@seltendoof.de>
On Fri 26-04-24 18:20:14, Christian Göttsche wrote:
> From: Christian Göttsche <cgzones@googlemail.com>
>
> Add the four syscalls setxattrat(), getxattrat(), listxattrat() and
> removexattrat(). Those can be used to operate on extended attributes,
> especially security related ones, either relative to a pinned directory
> or on a file descriptor without read access, avoiding a
> /proc/<pid>/fd/<fd> detour, requiring a mounted procfs.
>
> One use case will be setfiles(8) setting SELinux file contexts
> ("security.selinux") without race conditions and without a file
> descriptor opened with read access requiring SELinux read permission.
>
> Use the do_{name}at() pattern from fs/open.c.
>
> Pass the value of the extended attribute, its length, and for
> setxattrat(2) the command (XATTR_CREATE or XATTR_REPLACE) via an added
> struct xattr_args to not exceed six syscall arguments and not
> merging the AT_* and XATTR_* flags.
>
> Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
The patch looks good to me. Just a few nits below:
> -static int path_setxattr(const char __user *pathname,
> +static int do_setxattrat(int dfd, const char __user *pathname, unsigned int at_flags,
Can we please stay within 80 columns (happens in multiple places in the
patch)? I don't insist but it makes things easier to read in some setups so
I prefer it.
> @@ -852,13 +908,21 @@ listxattr(struct dentry *d, char __user *list, size_t size)
> return error;
> }
>
> -static ssize_t path_listxattr(const char __user *pathname, char __user *list,
> - size_t size, unsigned int lookup_flags)
> +static ssize_t do_listxattrat(int dfd, const char __user *pathname, char __user *list,
> + size_t size, int flags)
So I like how in previous syscalls you have 'at_flags', 'lookup_flags', and
'xattr_flags'. That makes things much easier to digest. Can you please stay
with that convention here as well and call this argument 'at_flags'? Also I
think the argument ordering like "dfd, pathname, at_flags, list, size" is
more consistent with other syscalls you define.
> @@ -870,16 +934,22 @@ static ssize_t path_listxattr(const char __user *pathname, char __user *list,
> return error;
> }
>
> +SYSCALL_DEFINE5(listxattrat, int, dfd, const char __user *, pathname, char __user *, list,
> + size_t, size, int, flags)
> +{
> + return do_listxattrat(dfd, pathname, list, size, flags);
> +}
> +
Same comment as above - "flags" -> "at_flags" and reorder args please.
> @@ -917,13 +987,21 @@ removexattr(struct mnt_idmap *idmap, struct dentry *d,
> return vfs_removexattr(idmap, d, kname);
> }
>
> -static int path_removexattr(const char __user *pathname,
> - const char __user *name, unsigned int lookup_flags)
> +static int do_removexattrat(int dfd, const char __user *pathname,
> + const char __user *name, int flags)
> {
Same comment as above - "flags" -> "at_flags" and reorder args please.
> @@ -939,16 +1017,22 @@ static int path_removexattr(const char __user *pathname,
> return error;
> }
>
> +SYSCALL_DEFINE4(removexattrat, int, dfd, const char __user *, pathname,
> + const char __user *, name, int, flags)
> +{
Same comment as above - "flags" -> "at_flags" and reorder args please.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
prev parent reply other threads:[~2024-04-30 10:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 16:20 [PATCH v3 2/2] fs/xattr: add *at family syscalls Christian Göttsche
2024-04-26 17:38 ` Arnd Bergmann
2024-04-30 10:09 ` Jan Kara [this message]
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=20240430100902.iwmeszr2jzv4wyo7@quack3 \
--to=jack@suse.cz \
--cc=James.Bottomley@HansenPartnership.com \
--cc=agordeev@linux.ibm.com \
--cc=andreas@gaisler.com \
--cc=aneesh.kumar@kernel.org \
--cc=arnd@arndb.de \
--cc=asml.silence@gmail.com \
--cc=audit@vger.kernel.org \
--cc=axboe@kernel.dk \
--cc=borntraeger@linux.ibm.com \
--cc=bp@alien8.de \
--cc=brauner@kernel.org \
--cc=casey@schaufler-ca.com \
--cc=catalin.marinas@arm.com \
--cc=cgzones@googlemail.com \
--cc=chris@zankel.net \
--cc=christophe.leroy@csgroup.eu \
--cc=dalias@libc.org \
--cc=dave.hansen@linux.intel.com \
--cc=davem@davemloft.net \
--cc=deller@gmx.de \
--cc=eparis@redhat.com \
--cc=florian.fainelli@broadcom.com \
--cc=geert@linux-m68k.org \
--cc=glaubitz@physik.fu-berlin.de \
--cc=gor@linux.ibm.com \
--cc=hca@linux.ibm.com \
--cc=hpa@zytor.com \
--cc=ink@jurassic.park.msu.ru \
--cc=io-uring@vger.kernel.org \
--cc=jcmvbkbc@gmail.com \
--cc=keescook@chromium.org \
--cc=linux-alpha@vger.kernel.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-parisc@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=linux-sh@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=mattst88@gmail.com \
--cc=mingo@redhat.com \
--cc=monstr@monstr.eu \
--cc=mpe@ellerman.id.au \
--cc=mszeredi@redhat.com \
--cc=naveen.n.rao@linux.ibm.com \
--cc=nphamcs@gmail.com \
--cc=npiggin@gmail.com \
--cc=palmer@sifive.com \
--cc=paul@paul-moore.com \
--cc=peterz@infradead.org \
--cc=richard.henderson@linaro.org \
--cc=rick.p.edgecombe@intel.com \
--cc=selinux@vger.kernel.org \
--cc=sohil.mehta@intel.com \
--cc=sparclinux@vger.kernel.org \
--cc=svens@linux.ibm.com \
--cc=tglx@linutronix.de \
--cc=tsbogend@alpha.franken.de \
--cc=viro@zeniv.linux.org.uk \
--cc=will@kernel.org \
--cc=x86@kernel.org \
--cc=ysato@users.sourceforge.jp \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).