linux-kernel - Re: [PATCH v1] x86/platform/intel-mid: Revert "Make 'bt_sfi

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]

Date:   Thu, 28 Dec 2017 13:53:41 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Julia Lawall <julia.lawall@...6.fr>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
        Darren Hart <dvhart@...radead.org>,
        platform-driver-x86@...r.kernel.org,
        Bhumika Goyal <bhumirks@...il.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH v1] x86/platform/intel-mid: Revert "Make 'bt_sfi_data'
 const"


* Julia Lawall <julia.lawall@...6.fr> wrote:

> > > [...] There does seem to be a few cases where the field actually does hold an
> > > integer.  I guess this is not a problem?
> >
> > Could you point to such an example?
> 
> drivers/thermal/intel_soc_dts_thermal.c:#define BYT_SOC_DTS_APIC_IRQ	86
> 
> and then:
> 
> static const struct x86_cpu_id soc_thermal_ids[] = {
>         { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_SILVERMONT1, 0,
>                 BYT_SOC_DTS_APIC_IRQ},
>         {}
> };
> 
> and finally:
> 
>  soc_dts_thres_irq = (int)match_cpu->driver_data;
> 
> Also:
> 
> arch/x86/kernel/apic/apic.c
> 
> #define DEADLINE_MODEL_MATCH_REV(model, rev)    \
> 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev
> }
> 
> DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X,      0x0b000020),
> DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE,     0x22),
> etc. (all 2-digit numbers in the remaining case).

Ok - I think in these cases the resulting long->pointer type conversion is a _lot_ 
less dangerous than the pointer->long conversion which caused the regression.

So unless the resulting code is excessively ugly, this feels like the right 
approach to me.

Thanks,

	Ingo