2015-06-25

On Thu, Jun 25, 2015 at 6:08 AM, Linux Kernel Mailing List

<linux-kernel@vger.kernel.org> wrote:

> Gitweb: http://git.kernel.org/linus/;a=commit;h=2ae416b142b625c58c9ccb039aa3ef48ad0e9bae

> Commit: 2ae416b142b625c58c9ccb039aa3ef48ad0e9bae

> Parent: e81f2d22370f8231cb7f13f454bcc8c0eb4e23f2

> Refname: refs/heads/master

> Author: Laurent Dufour <ldufour@linux.vnet.ibm.com>

> AuthorDate: Wed Jun 24 16:56:16 2015 -0700

> Committer: Linus Torvalds <torvalds@linux-foundation.org>

> CommitDate: Wed Jun 24 17:49:41 2015 -0700

>

> mm: new mm hook framework

>

> CRIU is recreating the process memory layout by remapping the checkpointee

> memory area on top of the current process (criu). This includes remapping

> the vDSO to the place it has at checkpoint time.

>

> However some architectures like powerpc are keeping a reference to the

> vDSO base address to build the signal return stack frame by calling the

> vDSO sigreturn service. So once the vDSO has been moved, this reference

> is no more valid and the signal frame built later are not usable.

>

> This patch serie is introducing a new mm hook framework, and a new

> arch_remap hook which is called when mremap is done and the mm lock still

> hold. The next patch is adding the vDSO remap and unmap tracking to the

> powerpc architecture.

>

> This patch (of 3):

>

> This patch introduces a new set of header file to manage mm hooks:

> - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)

> - a generic header (include/linux/mm-arch-hooks.h)

>

> The architecture which need to overwrite a hook as to redefine it in its

> header file, while architecture which doesn't need have nothing to do.

>

> The default hooks are defined in the generic header and are used in the

> case the architecture is not defining it.

>

> In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should

> be moved here.

>

> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>

> Suggested-by: Andrew Morton <akpm@linux-foundation.org>

> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>

> Cc: Hugh Dickins <hughd@google.com>

> Cc: Rik van Riel <riel@redhat.com>

> Cc: Mel Gorman <mgorman@suse.de>

> Cc: Pavel Emelyanov <xemul@parallels.com>

> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>

> Cc: Paul Mackerras <paulus@samba.org>

> Cc: Michael Ellerman <mpe@ellerman.id.au>

> Cc: Ingo Molnar <mingo@kernel.org>

> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

> ---

> arch/alpha/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/arc/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/arm/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/arm64/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/avr32/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/blackfin/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/c6x/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/cris/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/frv/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/hexagon/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/ia64/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/m32r/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/m68k/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/metag/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/microblaze/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/mips/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/mn10300/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/nios2/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/openrisc/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/parisc/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/powerpc/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/s390/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/score/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/sh/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/sparc/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/tile/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/um/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/unicore32/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/x86/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> arch/xtensa/include/asm/mm-arch-hooks.h | 15 +++++++++++++++

> include/linux/mm-arch-hooks.h | 16 ++++++++++++++++

Touching all arch/ directories without a CC to linux-arch?

> 31 files changed, 466 insertions(+)

>

> diff --git a/arch/alpha/include/asm/mm-arch-hooks.h b/arch/alpha/include/asm/mm-arch-hooks.h

> new file mode 100644

> index 0000000..b07fd86

> --- /dev/null

> +++ b/arch/alpha/include/asm/mm-arch-hooks.h

> @@ -0,0 +1,15 @@

> +/*

> + * Architecture specific mm hooks

> + *

> + * Copyright (C) 2015, IBM Corporation

> + * Author: Laurent Dufour <ldufour@linux.vnet.ibm.com>

Cool, copyright on an empty header!

> + *

> + * This program is free software; you can redistribute it and/or modify

> + * it under the terms of the GNU General Public License version 2 as

> + * published by the Free Software Foundation.

> + */

> +

> +#ifndef _ASM_ALPHA_MM_ARCH_HOOKS_H

> +#define _ASM_ALPHA_MM_ARCH_HOOKS_H

> +

> +#endif /* _ASM_ALPHA_MM_ARCH_HOOKS_H */

[...]

IMHO this screams for the generic version in include/asm-generic/,

and "generic-y += mm-arch-hooks.h" in arch/*/include/asm/Kbuild/.

Gr{oetje,eeting}s,

Geert

--

Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But

when I'm talking to journalists I just say "programmer" or something like that.

-- Linus Torvalds

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