linux-kernel - Re: [PATCH 12/12] efi: make const array 'apple' static

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: <CAKv+Gu86v9-Cj3bxEPWXCMRnE7S76kGdu7to3cOoLMgTTcH_xg@mail.gmail.com>
Date:   Fri, 9 Mar 2018 08:07:11 +0000
From:   Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     linux-efi@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Colin Ian King <colin.king@...onical.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 12/12] efi: make const array 'apple' static

On 9 March 2018 at 08:04, Ingo Molnar <mingo@...nel.org> wrote:
>
> * Ard Biesheuvel <ard.biesheuvel@...aro.org> wrote:
>
>> > Also, would it make sense to rename it to something more descriptive like
>> > "apple_unicode_str[]" or so?
>> >
>> > Plus an unicode string literal initializer would be pretty descriptive as well,
>> > instead of the weird looking character array, i.e. something like:
>> >
>> >   static efi_char16_t const apple_unicode_str[] = u"Apple";
>> >
>> > ... or so?
>> >
>>
>> is u"xxx" the same as L"xxx"?
>
> So "L" literals map to wchar_t, which wide character type is implementation
> specific IIRC, could be 16-bit or 32-bit wide.
>
> u"" literals OTOH are specified by the C11 spec to be char16_t, i.e. 16-bit wide
> characters - which I assume is the EFI type as well?
>
>> In any case, this is for historical reasons: at some point (and I
>> don't remember the exact details) we had a conflict at link time with
>> objects using 4 byte wchar_t, so we started using this notation to be
>> independent of the size of wchar_t. That issue no longer exists so we
>> should be able to get rid of this.
>
> Yes, my guess is that those problems were due to L"xyz" mapping to wchar_t and
> having a different type in the kernel build and the host build side - but u"xyz"
> should solve that.
>

Excellent!

Do you mind taking this patch as is? I will follow up with a patch
that updates all occurrences of this pattern (we have a few of them),
i.e., use u"" notation and move them to file scope.