linux-kernel - Re: [RFC v2 01/39] Kconfig: introduce HAS_IOPORT option and select it as necessary

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: <alpine.DEB.2.21.2205061415100.52331@angie.orcam.me.uk>
Date:   Fri, 6 May 2022 14:16:56 +0100 (BST)
From:   "Maciej W. Rozycki" <macro@...am.me.uk>
To:     Arnd Bergmann <arnd@...nel.org>
cc:     Bjorn Helgaas <helgaas@...nel.org>,
        Niklas Schnelle <schnelle@...ux.ibm.com>,
        Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-arch <linux-arch@...r.kernel.org>,
        linux-pci <linux-pci@...r.kernel.org>,
        Richard Henderson <rth@...ddle.net>,
        Ivan Kokshaysky <ink@...assic.park.msu.ru>,
        Matt Turner <mattst88@...il.com>,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Michal Simek <monstr@...str.eu>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        "James E.J. Bottomley" <James.Bottomley@...senpartnership.com>,
        Helge Deller <deller@....de>,
        Michael Ellerman <mpe@...erman.id.au>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Yoshinori Sato <ysato@...rs.sourceforge.jp>,
        Rich Felker <dalias@...c.org>,
        "David S. Miller" <davem@...emloft.net>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@...nel.org>,
        "open list:ALPHA PORT" <linux-alpha@...r.kernel.org>,
        "moderated list:ARM PORT" <linux-arm-kernel@...ts.infradead.org>,
        "open list:IA64 (Itanium) PLATFORM" <linux-ia64@...r.kernel.org>,
        "open list:M68K ARCHITECTURE" <linux-m68k@...ts.linux-m68k.org>,
        "open list:MIPS" <linux-mips@...r.kernel.org>,
        "open list:PARISC ARCHITECTURE" <linux-parisc@...r.kernel.org>,
        "open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)" 
        <linuxppc-dev@...ts.ozlabs.org>,
        "open list:RISC-V ARCHITECTURE" <linux-riscv@...ts.infradead.org>,
        "open list:SUPERH" <linux-sh@...r.kernel.org>,
        "open list:SPARC + UltraSPARC (sparc/sparc64)" 
        <sparclinux@...r.kernel.org>
Subject: Re: [RFC v2 01/39] Kconfig: introduce HAS_IOPORT option and select
 it as necessary

On Fri, 6 May 2022, Arnd Bergmann wrote:

> >  So what happens if the instruction is given an I/O rather than memory BAR
> > as the relevant argument?  Is the address space indicator bit (bit #0)
> > simply ignored or what?
> 
> Not sure. My best guess is that it would actually work as you'd expect,
> but is deliberately left out of the architecture specification so they don't
> have to to validate the correctness.  Note that only a small number of
> PCIe cards are actually supported by IBM, and I think the firmware
> only passes devices to the OS if they are whitelisted.

 That makes sense, thanks!

  Maciej