linux-kernel - Re: [PATCH v7 0/5] riscv: Add support to no-FPU systems

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] [day] [month] [year] [list]

Message-ID: <20181004053042.GA31734@andestech.com>
Date:   Thu, 4 Oct 2018 13:30:42 +0800
From:   Alan Kao <alankao@...estech.com>
To:     Palmer Dabbelt <palmer@...ive.com>
CC:     <linux-kernel@...r.kernel.org>, <linux-riscv@...ts.infradead.org>,
        <albert@...ive.com>, Christoph Hellwig <hch@...radead.org>,
        Andrew Waterman <andrew@...ive.com>,
        Arnd Bergmann <arnd@...db.de>,
        Darius Rad <darius@...espec.com>, <greentime@...estech.com>,
        <vincentc@...estech.com>, <zong@...estech.com>,
        <nickhu@...estech.com>
Subject: Re: [PATCH v7 0/5] riscv: Add support to no-FPU systems

On Thu, Sep 06, 2018 at 02:45:04AM -0700, Palmer Dabbelt wrote:
> On Sun, 26 Aug 2018 18:07:50 PDT (-0700), alankao@...estech.com wrote:
> >This patchset adds an option, CONFIG_FPU, to enable/disable floating-
> >point procedures.
> >
> >Kernel's new behavior will be as follows:
> >
> >* with CONFIG_FPU=y
> >  All FPU codes are reserved.  If no FPU is found during booting, a
> >  global flag will be set, and those functions will be bypassed with
> >  condition check to that flag.
> >
> >* with CONFIG_FPU=n
> >  No floating-point instructions in kernel and all related settings
> >  are excluded.
> >
> >Changes in v7:
> > - Remove "fd" attribute from KBUILD_CFLAGS.
> >
> >Changes in v6 (PATCH 0005 only):
> > - Make the flag checking neater.
> >
> >Changes in v5:
> > - Invert the polarity of checking flag from no_fpu to has_fpu.
> >
> >Changes in v4:
> > - Append a new patch to detect existence of FPU and followups.
> > - Add SPDX header to newly created fpu.S.
> > - Fix a build error, sorry for that.
> > - Fix wording, style, etc.
> >
> >Changes in v3:
> > - Refactor the whole patch into independent ones.
> >
> >Changes in v2:
> > - Various code cleanups and style fixes.
> >
> >
> >Alan Kao (5):
> >  Extract FPU context operations from entry.S
> >  Refactor FPU code in signal setup/return procedures
> >  Cleanup ISA string setting
> >  Allow to disable FPU support
> >  Auto-detect whether a FPU exists
> >
> > arch/riscv/Kconfig                 |   9 +++
> > arch/riscv/Makefile                |  19 +++---
> > arch/riscv/include/asm/switch_to.h |  12 +++-
> > arch/riscv/kernel/Makefile         |   1 +
> > arch/riscv/kernel/cpufeature.c     |   8 +++
> > arch/riscv/kernel/entry.S          |  87 -----------------------
> > arch/riscv/kernel/fpu.S            | 106 +++++++++++++++++++++++++++++
> > arch/riscv/kernel/process.c        |   6 +-
> > arch/riscv/kernel/signal.c         |  75 ++++++++++++--------
> > 9 files changed, 196 insertions(+), 127 deletions(-)
> > create mode 100644 arch/riscv/kernel/fpu.S
> 
> Thanks!  I'll add this to our for-next branch.

Any updates?