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  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]
Date:   Sun, 05 May 2019 12:05:32 -0400
From:   Rik van Riel <>
To:     Sebastian Gottschall <>,
        Ingo Molnar <>, Jiri Kosina <>
Cc:     Sebastian Andrzej Siewior <>,
        Andy Lutomirski <>,
        Greg KH <>,
        LKML <>,
        "H. Peter Anvin" <>,
        "Jason A. Donenfeld" <>,
        Ard Biesheuvel <>,
        Dave Hansen <>,
        Ingo Molnar <>,
        Nicolai Stange <>,
        Paolo Bonzini <>,
        Radim Krčmář <>,
        Thomas Gleixner <>,,, Jiri Kosina <>
Subject: Re: [PATCH] x86/fpu: Remove the _GPL from the
 kernel_fpu_begin/end() export

On Sat, 2019-05-04 at 04:28 +0200, Sebastian Gottschall wrote:

> Using fpu code in kernel space in a kernel module is a derived work
> of 
> the kernel itself?
> dont get me wrong, but this is absurd. i mean you limit the use of
> cpu 
> instructions. the use
> of cpu instructions should be free of any licensing issue. i would
> even 
> argument you are violating
> the license of the cpu ower given to the kernel by executing it, by 
> restricting its use for no reason

Using FPU code in kernel space in a kernel module
does not require the use of kernel_fpu_begin/end().

The kernel module could simply disable preemption,
save the FPU registers, use the FPU, restore the
FPU registers, and reenable preemption.

However, using kernel_fpu_begin/end() does get that
module some nice optimizations that are specific to

All Rights Reversed.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)

Powered by blists - more mailing lists