linux-kernel - Re: [patch 1/2] x86: track memtype for RAM in page struct

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: <20080914142213.GA28162@elte.hu>
Date:	Sun, 14 Sep 2008 16:22:13 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	Venkatesh Pallipadi <venkatesh.pallipadi@...el.com>,
	arjan@...ux.intel.com, tglx@...utronix.de, hpa@...or.com,
	andi@...stfloor.org, linux-kernel@...r.kernel.org,
	Suresh Siddha <suresh.b.siddha@...el.com>,
	Nick Piggin <nickpiggin@...oo.com.au>,
	Christoph Lameter <cl@...ux-foundation.org>
Subject: Re: [patch 1/2] x86: track memtype for RAM in page struct


* Jeremy Fitzhardinge <jeremy@...p.org> wrote:

> > it should be defined in include/asm-x86/page.h though, not in 
> > page-flags.h - other architectures are using this flag for other 
> > purposes.
> 
> No, other shared-use flags are all defined in page-flags.h:
> 
> enum pageflags {
> [...]
> 	__NR_PAGEFLAGS,
> 
> 	/* Filesystems */
> 	PG_checked = PG_owner_priv_1,
> 
> 	/* XEN */
> 	PG_pinned = PG_owner_priv_1,
> 	PG_savepinned = PG_dirty,
> 
> 	/* SLOB */
> 	PG_slob_page = PG_active,
> 	PG_slob_free = PG_private,
> 
> 	/* SLUB */
> 	PG_slub_frozen = PG_active,
> 	PG_slub_debug = PG_error,
> };
> 
> 
> We could #ifdef CONFIG_X86 just to make it clear we're talking about a 
> specific X86 usage.  But page-flags.h does seem to have become the 
> central authority on all struct page flags usage.

well, in case of the PG_arch_* flags, they are all defined in 
architecture files:

./include/asm-parisc/pgtable.h:#define PG_dcache_dirty         PG_arch_1
./include/asm-mips/cacheflush.h:#define PG_dcache_dirty			PG_arch_1
./arch/sparc64/mm/init.c:#define PG_dcache_dirty		PG_arch_1
./arch/sh/include/cpu-sh4/cpu/cacheflush.h:#define PG_mapped	PG_arch_1
./arch/sh/include/cpu-sh3/cpu/cacheflush.h:#define PG_mapped	PG_arch_1
./arch/arm/include/asm/cacheflush.h:#define PG_dcache_dirty PG_arch_1

they are explicitly reserved for per architecture details.

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/