linux-kernel - Re: [PATCH v4 08/14] powerpc: add support for folded p4d page tables

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]

Message-Id: <20200603120522.7646d56a23088416a7d3fc1a@linux-foundation.org>
Date:   Wed, 3 Jun 2020 12:05:22 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     Mike Rapoport <rppt@...nel.org>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Brian Cain <bcain@...eaurora.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Christophe Leroy <christophe.leroy@....fr>,
        Fenghua Yu <fenghua.yu@...el.com>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Guan Xuetao <gxt@....edu.cn>,
        James Morse <james.morse@....com>,
        Jonas Bonn <jonas@...thpole.se>,
        Julien Thierry <julien.thierry.kdev@...il.com>,
        Ley Foon Tan <ley.foon.tan@...el.com>,
        Marc Zyngier <maz@...nel.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Paul Mackerras <paulus@...ba.org>,
        Rich Felker <dalias@...c.org>,
        Russell King <linux@...linux.org.uk>,
        Stafford Horne <shorne@...il.com>,
        Stefan Kristiansson <stefan.kristiansson@...nalahti.fi>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Tony Luck <tony.luck@...el.com>, Will Deacon <will@...nel.org>,
        Yoshinori Sato <ysato@...rs.sourceforge.jp>,
        kvmarm@...ts.cs.columbia.edu, kvm-ppc@...r.kernel.org,
        linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-hexagon@...r.kernel.org, linux-ia64@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        linuxppc-dev@...ts.ozlabs.org, linux-sh@...r.kernel.org,
        nios2-dev@...ts.rocketboards.org, openrisc@...ts.librecores.org,
        uclinux-h8-devel@...ts.sourceforge.jp,
        Mike Rapoport <rppt@...ux.ibm.com>
Subject: Re: [PATCH v4 08/14] powerpc: add support for folded p4d page
 tables

On Tue, 14 Apr 2020 18:34:49 +0300 Mike Rapoport <rppt@...nel.org> wrote:

> Implement primitives necessary for the 4th level folding, add walks of p4d
> level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.

A bunch of new material just landed in linux-next/powerpc.

The timing is awkward!  I trust this will be going into mainline during
this merge window?  If not, please drop it and repull after -rc1.

arch/powerpc/mm/ptdump/ptdump.c:walk_pagetables() was a problem. 
Here's what I ended up with - please check.

static void walk_pagetables(struct pg_state *st)
{
	unsigned int i;
	unsigned long addr = st->start_address & PGDIR_MASK;
	pgd_t *pgd = pgd_offset_k(addr);

	/*
	 * Traverse the linux pagetable structure and dump pages that are in
	 * the hash pagetable.
	 */
	for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
		p4d_t *p4d = p4d_offset(pgd, 0);

		if (pgd_none(*pgd) || pgd_is_leaf(*pgd))
			note_page(st, addr, 1, p4d_val(*p4d), PGDIR_SIZE);
		else if (is_hugepd(__hugepd(p4d_val(*p4d))))
			walk_hugepd(st, (hugepd_t *)pgd, addr, PGDIR_SHIFT, 1);
		else
			/* pgd exists */
			walk_pud(st, p4d, addr);
	}
}

Mike's series "mm: consolidate definitions of page table accessors"
took quite a lot of damage as well.  Patches which needed rework as a
result of this were:

powerpc-add-support-for-folded-p4d-page-tables-fix.patch
mm-introduce-include-linux-pgtableh.patch
mm-reorder-includes-after-introduction-of-linux-pgtableh.patch
mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte.patch
mm-pgtable-add-shortcuts-for-accessing-kernel-pmd-and-pte-fix-2.patch
mm-consolidate-pte_index-and-pte_offset_-definitions.patch
mm-consolidate-pmd_index-and-pmd_offset-definitions.patch
mm-consolidate-pud_index-and-pud_offset-definitions.patch
mm-consolidate-pgd_index-and-pgd_offset_k-definitions.patch