linux-kernel - Re: [PATCH 07/13] s390: make setup_zero

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] [day] [month] [year] [list]
Message-ID: <Z9GxozjZTKOGDPv1@kernel.org>
Date: Wed, 12 Mar 2025 18:09:07 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Ard Biesheuvel <ardb@...nel.org>
Cc: Heiko Carstens <hca@...ux.ibm.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Alexander Gordeev <agordeev@...ux.ibm.com>,
	Andreas Larsson <andreas@...sler.com>,
	Andy Lutomirski <luto@...nel.org>, Arnd Bergmann <arnd@...db.de>,
	Borislav Petkov <bp@...en8.de>, Brian Cain <bcain@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"David S. Miller" <davem@...emloft.net>,
	Dinh Nguyen <dinguyen@...nel.org>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Gerald Schaefer <gerald.schaefer@...ux.ibm.com>,
	Guo Ren <guoren@...nel.org>, Helge Deller <deller@....de>,
	Huacai Chen <chenhuacai@...nel.org>, Ingo Molnar <mingo@...hat.com>,
	Jiaxun Yang <jiaxun.yang@...goat.com>,
	Johannes Berg <johannes@...solutions.net>,
	John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>,
	Madhavan Srinivasan <maddy@...ux.ibm.com>,
	Matt Turner <mattst88@...il.com>, Max Filippov <jcmvbkbc@...il.com>,
	Michael Ellerman <mpe@...erman.id.au>,
	Michal Simek <monstr@...str.eu>,
	Palmer Dabbelt <palmer@...belt.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Richard Weinberger <richard@....at>,
	Russell King <linux@...linux.org.uk>,
	Stafford Horne <shorne@...il.com>,
	Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
	Thomas Gleixner <tglx@...utronix.de>,
	Vasily Gorbik <gor@...ux.ibm.com>, Vineet Gupta <vgupta@...nel.org>,
	Will Deacon <will@...nel.org>, linux-alpha@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-snps-arc@...ts.infradead.org,
	linux-arm-kernel@...ts.infradead.org, linux-csky@...r.kernel.org,
	linux-hexagon@...r.kernel.org, loongarch@...ts.linux.dev,
	linux-m68k@...ts.linux-m68k.org, linux-mips@...r.kernel.org,
	linux-openrisc@...r.kernel.org, linux-parisc@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org, linux-riscv@...ts.infradead.org,
	linux-s390@...r.kernel.org, linux-sh@...r.kernel.org,
	sparclinux@...r.kernel.org, linux-um@...ts.infradead.org,
	linux-arch@...r.kernel.org, linux-mm@...ck.org, x86@...nel.org
Subject: Re: [PATCH 07/13] s390: make setup_zero_pages() use memblock

On Wed, Mar 12, 2025 at 04:56:59PM +0100, Ard Biesheuvel wrote:
> On Tue, 11 Mar 2025 at 06:56, Mike Rapoport <rppt@...nel.org> wrote:
> >
> > On Fri, Mar 07, 2025 at 04:28:15PM +0100, Heiko Carstens wrote:
> > > On Thu, Mar 06, 2025 at 08:51:17PM +0200, Mike Rapoport wrote:
> > > > From: "Mike Rapoport (Microsoft)" <rppt@...nel.org>
> > > >
> > > > Allocating the zero pages from memblock is simpler because the memory is
> > > > already reserved.
> > > >
> > > > This will also help with pulling out memblock_free_all() to the generic
> > > > code and reducing code duplication in arch::mem_init().
> > > >
> > > > Signed-off-by: Mike Rapoport (Microsoft) <rppt@...nel.org>
> > > > ---
> > > >  arch/s390/mm/init.c | 14 +++-----------
> > > >  1 file changed, 3 insertions(+), 11 deletions(-)
> > >
> > > Acked-by: Heiko Carstens <hca@...ux.ibm.com>
> > >
> > > > -   empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
> > > > +   empty_zero_page = (unsigned long)memblock_alloc(PAGE_SIZE << order, order);
> > > >     if (!empty_zero_page)
> > > >             panic("Out of memory in setup_zero_pages");
> > >
> > > This could have been converted to memblock_alloc_or_panic(), but I
> > > guess this can also be done at a later point in time.
> >
> > Duh, I should have remembered about memblock_alloc_or_panic() :)
> >
> > @Andrew, can you please pick this as a fixup?
> >
> > From 344fec8519e5152c25809c9277b54a68f9cde0e9 Mon Sep 17 00:00:00 2001
> > From: "Mike Rapoport (Microsoft)" <rppt@...nel.org>
> > Date: Tue, 11 Mar 2025 07:51:27 +0200
> > Subject: [PATCH] s390: use memblock_alloc_or_panic() in setup_zero_page()
> >
> > Signed-off-by: Mike Rapoport (Microsoft) <rppt@...nel.org>
> > ---
> >  arch/s390/mm/init.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
> > index ab8ece3c41f1..c6a97329d7e7 100644
> > --- a/arch/s390/mm/init.c
> > +++ b/arch/s390/mm/init.c
> > @@ -81,9 +81,7 @@ static void __init setup_zero_pages(void)
> >         while (order > 2 && (total_pages >> 10) < (1UL << order))
> >                 order--;
> >
> > -       empty_zero_page = (unsigned long)memblock_alloc(PAGE_SIZE << order, order);
> > -       if (!empty_zero_page)
> > -               panic("Out of memory in setup_zero_pages");
> > +       empty_zero_page = (unsigned long)memblock_alloc_or_panic(PAGE_SIZE << order, order);
> >
> 
> memblock_alloc_or_panic() takes the alignment is in bytes, no? So
> shouldn't the second argument be BIT(order)?

The second argument should be PAGE_SIZE. Thanks for catching that!

-- 
Sincerely yours,
Mike.