From: Arnd Bergmann <arnd@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-arch <linux-arch@vger.kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Vineet Gupta <vgupta@synopsys.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Brian Cain <bcain@codeaurora.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>, Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Sid Manning <sidneym@codeaurora.org>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Rapoport <rppt@kernel.org>,
"open list:SYNOPSYS ARC ARCHITECTURE"
<linux-snps-arc@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
moderated list:H8/300 ARCHITECTURE
Subject: Re: [PATCH 5/6] [v2] asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user
Date: Mon, 17 May 2021 09:27:01 +0200 [thread overview]
Message-ID: <CAK8P3a2eDeSgB76SyzcpmQmV3uR1jwtOjZUoG9UYfDnYAWGyog@mail.gmail.com> (raw)
In-Reply-To: <20210517062018.GC23581@lst.de>
On Mon, May 17, 2021 at 8:20 AM Christoph Hellwig <hch@lst.de> wrote:
>
> On Sat, May 15, 2021 at 12:18:02PM +0200, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > Consolidate the asm-generic implementation with the library version
> > that is used everywhere else.
> >
> > These are the three versions for NOMMU kernels,
>
> I don't get the three versions part?
Right, that was confusing. Rewording to
| The inline version is used on three NOMMU architectures and is
| particularly inefficient when it scans the string one byte at a time
| twice. It also lacks a check for user_addr_max(), but this is
| probably ok on NOMMU targets.
|
| Consolidate the asm-generic implementation with the library version
| that is used everywhere else. This version is generalized enough to
| work efficiently on both MMU and NOMMU targets, and using the
| same code everywhere reduces the potential for subtle bugs.
> > + select GENERIC_STRNCPY_FROM_USER
> > + select GENERIC_STRNLEN_USER
>
> Given that most architetures select the generic version I wonder
> if it might be worth to add another patch to invert the logic so
> that architectures with their own implementation need to sekect a symbol.
Done now, using 'CONFIG_ARCH_HAS_{STRNCPY_FROM,STRNLEN}_USER'.
There are still seven or eight architectures that provide their own though.
> > +extern long strncpy_from_user(char *dst, const char __user *src, long count);
> > +extern long strnlen_user(const char __user *src, long n);
>
> No need for the extern here.
Removed.
Arnd
next prev parent reply other threads:[~2021-05-17 7:27 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-15 10:17 [PATCH 0/6] [v2] asm-generic: strncpy_from_user/strnlen_user cleanup Arnd Bergmann
2021-05-15 10:17 ` [PATCH 1/6] [v2] asm-generic/uaccess.h: remove __strncpy_from_user/__strnlen_user Arnd Bergmann
2021-05-15 10:17 ` [PATCH 2/6] [v2] h8300: remove stale strncpy_from_user Arnd Bergmann
2021-05-15 10:18 ` [PATCH 3/6] [v2] hexagon: use generic strncpy/strnlen from_user Arnd Bergmann
2021-05-17 6:16 ` Christoph Hellwig
2021-05-17 6:46 ` Arnd Bergmann
2021-05-15 10:18 ` [PATCH 4/6] [v2] arc: " Arnd Bergmann
2021-05-17 6:16 ` Christoph Hellwig
2021-05-17 6:47 ` Arnd Bergmann
2021-05-15 10:18 ` [PATCH 5/6] [v2] asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user Arnd Bergmann
2021-05-17 6:20 ` Christoph Hellwig
2021-05-17 7:27 ` Arnd Bergmann [this message]
2021-05-15 10:18 ` [PATCH 6/6] [v2] asm-generic: remove extra strn{cpy_from, len}_user declarations Arnd Bergmann
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