linux-kernel - Re: [PATCH V8 04/44] x86/pkeys: Add additional PKEY helper macros

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:   Wed, 2 Feb 2022 12:26:44 -0800
From:   Dave Hansen <dave.hansen@...el.com>
To:     Ira Weiny <ira.weiny@...el.com>
Cc:     Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Rick Edgecombe <rick.p.edgecombe@...el.com>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH V8 04/44] x86/pkeys: Add additional PKEY helper macros

On 2/2/22 12:21, Ira Weiny wrote:
> On Fri, Jan 28, 2022 at 02:47:30PM -0800, Dave Hansen wrote:
>> #define PKR_WD_MASK(pkey)	(PKR_WD_BIT << PKR_PKEY_SHIFT(pkey))
>>
>> Which says, "generate a write-disabled mask for this pkey".
> 
> I think the confusion comes from me having used these as mask values rather
> than what PKR_AD_KEY() was intended to be used for.
> 
> In the previous patch PKR_AD_KEY() is used to set up the default user pkey
> value...
> 
> u32 init_pkru_value = PKR_AD_KEY( 1) | PKR_AD_KEY( 2) | PKR_AD_KEY( 3) |
> 		      PKR_AD_KEY( 4) | PKR_AD_KEY( 5) | PKR_AD_KEY( 6) |
> 		      PKR_AD_KEY( 7) | PKR_AD_KEY( 8) | PKR_AD_KEY( 9) |
> 		      PKR_AD_KEY(10) | PKR_AD_KEY(11) | PKR_AD_KEY(12) |
> 		      PKR_AD_KEY(13) | PKR_AD_KEY(14) | PKR_AD_KEY(15);
> 

Hah, I'm complaining about my own code.

> u32 init_pkru_value = PKR_AD_MASK( 1) | PKR_AD_MASK( 2) | PKR_AD_MASK( 3) |
> 		      PKR_AD_MASK( 4) | PKR_AD_MASK( 5) | PKR_AD_MASK( 6) |
> 		      PKR_AD_MASK( 7) | PKR_AD_MASK( 8) | PKR_AD_MASK( 9) |
> 		      PKR_AD_MASK(10) | PKR_AD_MASK(11) | PKR_AD_MASK(12) |
> 		      PKR_AD_MASK(13) | PKR_AD_MASK(14) | PKR_AD_MASK(15);
> 
> It seems odd to me.  Does it seem odd to you?

Looks OK to me.  It's build a "value" out of a bunch of individual masks.

> Looking at the final code I think I'm going to just drop the usages in this
> patch and add PKR_WD_KEY() where it is used first.
> 
> Also, how about PKR_KEY_INIT_{AD|WD|RW}() as a name?

For the PKR_AD_KEY() macro?