linux-kernel - Re: [RFC 1/4] asm-generic/uaccess: don't define inline functions if noinline lib/* in use

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6eb7587b-c3bc-691d-9d27-d4e687114a42@synopsys.com>
Date:   Wed, 15 Jan 2020 23:01:48 +0000
From:   Vineet Gupta <Vineet.Gupta1@...opsys.com>
To:     Arnd Bergmann <arnd@...db.de>,
        Vineet Gupta <Vineet.Gupta1@...opsys.com>
CC:     Khalid Aziz <khalid.aziz@...cle.com>,
        Andrey Konovalov <andreyknvl@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        "Peter Zijlstra" <peterz@...radead.org>,
        Christian Brauner <christian.brauner@...ntu.com>,
        Kees Cook <keescook@...omium.org>,
        "Ingo Molnar" <mingo@...nel.org>, Aleksa Sarai <cyphar@...har.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        "open list:SYNOPSYS ARC ARCHITECTURE" 
        <linux-snps-arc@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        linux-arch <linux-arch@...r.kernel.org>
Subject: Re: [RFC 1/4] asm-generic/uaccess: don't define inline functions if
 noinline lib/* in use

On 1/14/20 12:57 PM, Arnd Bergmann wrote:
> On Tue, Jan 14, 2020 at 9:08 PM Vineet Gupta <Vineet.Gupta1@...opsys.com> wrote:
>> There are 2 generic varaints of strncpy_from_user() / strnlen_user()
>>  (1). inline version in asm-generic/uaccess.h
>>  (2). optimized word-at-a-time version in lib/*
>>
>> This patch disables #1 if #2 selected. This allows arches to continue
>> reusing asm-generic/uaccess.h for rest of code
>>
>> This came up when switching ARC to generic word-at-a-time interface
>>
>> Signed-off-by: Vineet Gupta <vgupta@...opsys.com>
> This looks like a useful change, but I think we can do even better: It
> seems that
> there are no  callers of __strnlen_user or __strncpy_from_user  in the
> kernel today, so these should not be defined either when the Kconfig symbols
> are set. Also, I would suggest moving the 'extern' declaration for the two
> functions into the #else branch of the conditional so it does not need to be
> duplicated.

Given where things seem to be heading, do u still want an updated patch for this
or do u plan to ditch the inline version in short term anyways.

-Vineet