linux-kernel - RE: [External] Re: [PATCH 2/4] mm: pgalloc: support address-conditional pmd allocation

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, 21 Feb 2024 15:54:38 +0000
From: Maxwell Bland <mbland@...orola.com>
To: David Hildenbrand <david@...hat.com>,
        Christophe Leroy
	<christophe.leroy@...roup.eu>,
        "linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>
CC: "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "agordeev@...ux.ibm.com" <agordeev@...ux.ibm.com>,
        "akpm@...ux-foundation.org" <akpm@...ux-foundation.org>,
        "andreyknvl@...il.com" <andreyknvl@...il.com>,
        "andrii@...nel.org"
	<andrii@...nel.org>,
        "aneesh.kumar@...nel.org" <aneesh.kumar@...nel.org>,
        "aou@...s.berkeley.edu" <aou@...s.berkeley.edu>,
        "ardb@...nel.org"
	<ardb@...nel.org>, "arnd@...db.de" <arnd@...db.de>,
        "ast@...nel.org"
	<ast@...nel.org>,
        "borntraeger@...ux.ibm.com" <borntraeger@...ux.ibm.com>,
        "bpf@...r.kernel.org" <bpf@...r.kernel.org>,
        "brauner@...nel.org"
	<brauner@...nel.org>,
        "catalin.marinas@....com" <catalin.marinas@....com>,
        "cl@...ux.com" <cl@...ux.com>,
        "daniel@...earbox.net" <daniel@...earbox.net>,
        "dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
        "dennis@...nel.org" <dennis@...nel.org>,
        "dvyukov@...gle.com"
	<dvyukov@...gle.com>,
        "glider@...gle.com" <glider@...gle.com>,
        "gor@...ux.ibm.com" <gor@...ux.ibm.com>,
        "guoren@...nel.org"
	<guoren@...nel.org>,
        "haoluo@...gle.com" <haoluo@...gle.com>,
        "hca@...ux.ibm.com" <hca@...ux.ibm.com>,
        "hch@...radead.org"
	<hch@...radead.org>,
        "john.fastabend@...il.com" <john.fastabend@...il.com>,
        "jolsa@...nel.org" <jolsa@...nel.org>,
        "kasan-dev@...glegroups.com"
	<kasan-dev@...glegroups.com>,
        "kpsingh@...nel.org" <kpsingh@...nel.org>,
        "linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
        "linux@...linux.org.uk" <linux@...linux.org.uk>,
        "linux-efi@...r.kernel.org"
	<linux-efi@...r.kernel.org>,
        "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
        "linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
        "lstoakes@...il.com" <lstoakes@...il.com>,
        "mark.rutland@....com"
	<mark.rutland@....com>,
        "martin.lau@...ux.dev" <martin.lau@...ux.dev>,
        "meted@...ux.ibm.com" <meted@...ux.ibm.com>,
        "michael.christie@...cle.com"
	<michael.christie@...cle.com>,
        "mjguzik@...il.com" <mjguzik@...il.com>,
        "mpe@...erman.id.au" <mpe@...erman.id.au>,
        "mst@...hat.com" <mst@...hat.com>,
        "muchun.song@...ux.dev" <muchun.song@...ux.dev>,
        "naveen.n.rao@...ux.ibm.com"
	<naveen.n.rao@...ux.ibm.com>,
        "npiggin@...il.com" <npiggin@...il.com>,
        "palmer@...belt.com" <palmer@...belt.com>,
        "paul.walmsley@...ive.com"
	<paul.walmsley@...ive.com>,
        "quic_nprakash@...cinc.com"
	<quic_nprakash@...cinc.com>,
        "quic_pkondeti@...cinc.com"
	<quic_pkondeti@...cinc.com>,
        "rick.p.edgecombe@...el.com"
	<rick.p.edgecombe@...el.com>,
        "ryabinin.a.a@...il.com"
	<ryabinin.a.a@...il.com>,
        "ryan.roberts@....com" <ryan.roberts@....com>,
        "samitolvanen@...gle.com" <samitolvanen@...gle.com>,
        "sdf@...gle.com"
	<sdf@...gle.com>,
        "song@...nel.org" <song@...nel.org>,
        "surenb@...gle.com"
	<surenb@...gle.com>,
        "svens@...ux.ibm.com" <svens@...ux.ibm.com>,
        "tj@...nel.org" <tj@...nel.org>, "urezki@...il.com" <urezki@...il.com>,
        "vincenzo.frascino@....com" <vincenzo.frascino@....com>,
        "will@...nel.org"
	<will@...nel.org>,
        "wuqiang.matt@...edance.com" <wuqiang.matt@...edance.com>,
        "yonghong.song@...ux.dev" <yonghong.song@...ux.dev>,
        "zlim.lnx@...il.com"
	<zlim.lnx@...il.com>,
        Andrew Wheeler <awheeler@...orola.com>
Subject: RE: [External] Re: [PATCH 2/4] mm: pgalloc: support
 address-conditional pmd allocation

> On February 21, 2024 3:27 AM David Hildenbrand wrote
> On 21.02.24 08:13, Christophe Leroy wrote:
> > Le 20/02/2024 à 21:32, Maxwell Bland a écrit :
> >>
> >> While other descriptors (e.g. pud) allow allocations conditional on
> >> which virtual address is allocated, pmd descriptor allocations do not.
> >> However, adding support for this is straightforward and is beneficial to
> >> future kernel development targeting the PMD memory granularity.
> >>
> >> As many architectures already implement pmd_populate_kernel in an
> >> address-generic manner, it is necessary to roll out support
> >> incrementally. For this purpose a preprocessor flag,
> >
> > Is it really worth it ? It is only 48 call sites that need to be
> > updated. It would avoid that processor flag and avoid introducing that
> > pmd_populate_kernel_at() in kernel core.
> 
> +1, let's avoid that if possible.

Will fix, thank you!

Maxwell