linux-kernel - Re: [PATCH v8 3/3] x86: vdso: Wire up getrandom() vDSO implementation

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: <CAHmME9rp+Nx_S8OgABzadc1+j_FrSRbUvGu2r9W_svrr+HMjSg@mail.gmail.com>
Date:   Mon, 28 Nov 2022 21:02:47 +0100
From:   "Jason A. Donenfeld" <Jason@...c4.com>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     linux-kernel@...r.kernel.org, patches@...ts.linux.dev,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-crypto@...r.kernel.org, linux-api@...r.kernel.org,
        x86@...nel.org, Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Adhemerval Zanella Netto <adhemerval.zanella@...aro.org>,
        "Carlos O'Donell" <carlos@...hat.com>,
        Florian Weimer <fweimer@...hat.com>,
        Christian Brauner <brauner@...nel.org>,
        Samuel Neves <sneves@....uc.pt>
Subject: Re: [PATCH v8 3/3] x86: vdso: Wire up getrandom() vDSO implementation

Hi Arnd,

On Mon, Nov 28, 2022 at 8:57 PM Arnd Bergmann <arnd@...db.de> wrote:
>
> On Mon, Nov 28, 2022, at 20:23, Jason A. Donenfeld wrote:
> > On Mon, Nov 28, 2022 at 08:18:12PM +0100, Arnd Bergmann wrote:
> >> On Mon, Nov 28, 2022, at 12:18, Jason A. Donenfeld wrote:
> >
> > That's more or less how v7 was, but Thomas thought the x86 stuff should
> > be separate. So for v8, the organization is:
> >
> > 1) generic syscall
> > 2) generic vdso
> > 3) x86 wiring
> >
> > The primary advantage is that future archs wanting to add this now can
> > just look at commit (3) only, and make a similar commit for that new
> > arch.
> >
> > If you think a different organization outweighs that advantage, can you
> > spell out what division of patches you want, and I'll do that for v9?
> > Or maybe this v8 is okay?
>
> My interest is that at the end of the series, all architectures
> are hooked up with the same syscall number, which avoids confusion
> and merge conflicts when we add the next syscall to all tables.
>
> How about one patch to add all the syscall table entries, and then
> have the x86 specific change just turn on the Kconfig symbol that
> actually enables the syscall?

Okay, I can split it that way. If I gather your meaning correctly:

1) generic syscall C code
2) #define __NR_... in asm-generic/unistd.h x86/.../unistd.h,
x86/.../syscall_64.tbl
3) generic vdso C code
4) hook up x86 vdso, and select the right Kconfig symbol to start
compiling the code

Is that what you have in mind? If so, I'll name (2) "arch: wire up
vgetrandom_alloc() syscall number".

Jason