Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 4.4 15/50] s390/alternative: use a copy of the facility
 bit mask
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Cc:     stable@vger.kernel.org,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        David Hildenbrand <david@redhat.com>,
        Cornelia Huck <cohuck@redhat.com>
References: <20180427135655.623669681@linuxfoundation.org>
 <20180427135656.637526548@linuxfoundation.org>
From:   Jiri Slaby <jslaby@suse.cz>
Openpgp: preference=signencrypt
Autocrypt: addr=jslaby@suse.cz; prefer-encrypt=mutual; keydata=
 xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j
 rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk
 rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ
 i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx
 wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx
 ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H
 cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL
 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps
 w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm
 YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSBKaXJpIFNsYWJ5
 IDxqaXJpc2xhYnlAZ21haWwuY29tPsLBewQTAQIAJQIbAwYLCQgHAwIGFQgCCQoLBBYCAwEC
 HgECF4AFAk6S6P4CGQEACgkQvSWxBAa0cEl1Sg//UMXp//d4lP57onXMC2y8gafT1ap/xuss
 IvXR+3jSdJCHRaUFTPY2hN0ahCAyBQq8puUa6zaXco5jIzsVjLGVfO/s9qmvBTKw9aP6eTU7
 77RLssLlQYhRzh7vapRRp4xDBLvBGBv9uvWORx6dtRjh+e0J0nKKce8VEY+jiXv1NipWf+RV
 vg1gVbAjBnT+5RbJYtIDhogyuBFg14ECKgvy1Do6tg9Hr/kU4ta6ZBEUTh18Io7f0vr1Mlh4
 yl2ytuUNymUlkA/ExBNtOhOJq/B087SmGwSLmCRoo5VcRIYK29dLeX6BzDnmBG+mRE63IrKD
 kf/ZCIwZ7cSbZaGo+gqoEpIqu5spIe3n3JLZQGnF45MR+TfdAUxNQ4F1TrjWyg5Fo30blYYU
 z6+5tQbaDoBbcSEV9bDt6UOhCx033TrdToMLpee6bUAKehsUctBlfYXZP2huZ5gJxjINRnlI
 gKTATBAXF+7vMhgyZ9h7eARG6LOdVRwhIFUMGbRCCMXrLLnQf6oAHyVnsZU1+JWANGFBjsyy
 fRP2+d8TrlhzN9FoIGYiKjATR9CpJZoELFuKLfKOBsc7DfEBpsdusLT0vlzR6JaGae78Od5+
 ljzt88OGNyjCRIb6Vso0IqEavtGOcYG8R5gPhMV9n9/bCIVqM5KWJf/4mRaySZp7kcHyJSb0
 O6nOwU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02
 XFTIt4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P
 +nJWYIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYV
 nZAKDiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNe
 LuS8f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+B
 avGQ8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUF
 Bqgk3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpo
 tgK4/57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPD
 GHo739Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBK
 HQxz1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkF
 Ak6S54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH
 /1ldwRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+
 Kzdr90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj
 9YLxjhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbc
 ezWIwZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+d
 yTKLwLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330m
 kR4gW6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/
 tJ98f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCu
 jlYQDFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmf
 faK/S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg=
Message-ID: <ded98294-4341-2c96-7ed7-115721af8164@suse.cz>
Date:   Fri, 4 May 2018 09:37:20 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.7.0
MIME-Version: 1.0
In-Reply-To: <20180427135656.637526548@linuxfoundation.org>
Content-Type: text/plain; charset=utf-8
Content-Language: en-GB
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 04/27/2018, 03:58 PM, Greg Kroah-Hartman wrote:
> 4.4-stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: Martin Schwidefsky <schwidefsky@de.ibm.com>
> 
> 
> [ Upstream commit cf1489984641369611556bf00c48f945c77bcf02 ]
> 
> To be able to switch off specific CPU alternatives with kernel parameters
> make a copy of the facility bit mask provided by STFLE and use the copy
> for the decision to apply an alternative.
...
> --- a/arch/s390/include/asm/facility.h
> +++ b/arch/s390/include/asm/facility.h
> @@ -13,6 +13,24 @@
>  
>  #define MAX_FACILITY_BIT (256*8)	/* stfle_fac_list has 256 bytes */

I wonder if the below (plus __test_facility) is correct in 4.4, given
MAX_FACILITY_BIT is defined as such and not as sizeof(stfle_fac_list *
8) as in upstream?

> +static inline void __set_facility(unsigned long nr, void *facilities)
> +{
> +	unsigned char *ptr = (unsigned char *) facilities;
> +
> +	if (nr >= MAX_FACILITY_BIT)
> +		return;
> +	ptr[nr >> 3] |= 0x80 >> (nr & 7);
> +}
> +
> +static inline void __clear_facility(unsigned long nr, void *facilities)
> +{
> +	unsigned char *ptr = (unsigned char *) facilities;
> +
> +	if (nr >= MAX_FACILITY_BIT)
> +		return;
> +	ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
> +}
> +
>  static inline int __test_facility(unsigned long nr, void *facilities)
>  {
>  	unsigned char *ptr;
> --- a/arch/s390/include/asm/lowcore.h
> +++ b/arch/s390/include/asm/lowcore.h
> @@ -170,7 +170,8 @@ struct _lowcore {
>  	__u8	pad_0x0e20[0x0f00-0x0e20];	/* 0x0e20 */
>  
>  	/* Extended facility list */
> -	__u64	stfle_fac_list[32];		/* 0x0f00 */
> +	__u64	stfle_fac_list[16];		/* 0x0f00 */
> +	__u64	alt_stfle_fac_list[16];		/* 0x0f80 */
>  	__u8	pad_0x1000[0x11b0-0x1000];	/* 0x1000 */

thanks,
-- 
js
suse labs