riscv: support the elf-fdpic binfmt loader

Add support for enabling and using the binfmt_elf_fdpic program loader
on RISC-V platforms. The most important change is to setup registers
during program

riscv: support the elf-fdpic binfmt loader

Add support for enabling and using the binfmt_elf_fdpic program loader
on RISC-V platforms. The most important change is to setup registers
during program load to pass the mapping addresses to the new process.

One of the interesting features of the elf-fdpic loader is that it
also allows appropriately compiled ELF format binaries to be loaded on
nommu systems. Appropriate being those compiled with -pie.

Signed-off-by: Greg Ungerer <gerg@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230711130754.481209-3-gerg@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

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a.out: Remove the a.out implementation

In commit 19e8b701e258 ("a.out: Stop building a.out/osf1 support on
alpha and m68k") the last users of a.out were disabled.

As nothing has turned up to cause

a.out: Remove the a.out implementation

In commit 19e8b701e258 ("a.out: Stop building a.out/osf1 support on
alpha and m68k") the last users of a.out were disabled.

As nothing has turned up to cause this change to be reverted, let's
remove the code implementing a.out support as well.

There may be userspace users of the uapi bits left so the uapi
headers have been left untouched.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Arnd Bergmann <arnd@arndb.de> # arm defconfigs
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/871qrx3hq3.fsf@email.froward.int.ebiederm.org

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xtensa: add FDPIC and static PIE support for noMMU

Define ELFOSABI_XTENSA_FDPIC and use it as an OSABI tag in the ELF
header to distinguish FDPIC ELF files from regular ELF files.
Define ELF_FDPIC_P

xtensa: add FDPIC and static PIE support for noMMU

Define ELFOSABI_XTENSA_FDPIC and use it as an OSABI tag in the ELF
header to distinguish FDPIC ELF files from regular ELF files.
Define ELF_FDPIC_PLAT_INIT and put executable map, interpreter map and
executable dynamic section addresses into registers a4..a6.
Update start_thread macro to preserve register values in the current
register window.
Add definitions for PTRACE_GETFDPIC, PTRACE_GETFDPIC_EXEC and
PTRACE_GETFDPIC_INTERP.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

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m68knommu: allow elf_fdpic loader to be selected

The m68k architecture code is capable of supporting the binfmt_elf_fdpic
loader, so allow it to be configured. It is restricted to nommu
configuratio

m68knommu: allow elf_fdpic loader to be selected

The m68k architecture code is capable of supporting the binfmt_elf_fdpic
loader, so allow it to be configured. It is restricted to nommu
configurations at this time due to the MMU context structures/code not
supporting everything elf_fdpic needs when MMU is enabled.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

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binfmt_flat: Remove shared library support

In a recent discussion[1] it was reported that the binfmt_flat library
support was only ever used on m68k and even on m68k has not been used
in a very long

binfmt_flat: Remove shared library support

In a recent discussion[1] it was reported that the binfmt_flat library
support was only ever used on m68k and even on m68k has not been used
in a very long time.

The structure of binfmt_flat is different from all of the other binfmt
implementations because of this shared library support and it made
life and code review more effort when I refactored the code in fs/exec.c.

Since in practice the code is dead remove the binfmt_flat shared library
support and make maintenance of the code easier.

[1] https://lkml.kernel.org/r/81788b56-5b15-7308-38c7-c7f2502c4e15@linux-m68k.org

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Vladimir Murzin <vladimir.murzin@arm.com> # ARM
Tested-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/87levzzts4.fsf_-_@email.froward.int.ebiederm.org

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binfmt_elf: Introduce KUnit test

Adds simple KUnit test for some binfmt_elf internals: specifically a
regression test for the problem fixed by commit 8904d9cd90ee ("ELF:
fix overflow in total mappin

binfmt_elf: Introduce KUnit test

Adds simple KUnit test for some binfmt_elf internals: specifically a
regression test for the problem fixed by commit 8904d9cd90ee ("ELF:
fix overflow in total mapping size calculation").

$ ./tools/testing/kunit/kunit.py run --arch x86_64 \
--kconfig_add CONFIG_IA32_EMULATION=y '*binfmt_elf'
...
[19:41:08] ================== binfmt_elf (1 subtest) ==================
[19:41:08] [PASSED] total_mapping_size_test
[19:41:08] =================== [PASSED] binfmt_elf ====================
[19:41:08] ============== compat_binfmt_elf (1 subtest) ===============
[19:41:08] [PASSED] total_mapping_size_test
[19:41:08] ================ [PASSED] compat_binfmt_elf ================
[19:41:08] ============================================================
[19:41:08] Testing complete. Passed: 2, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: David Gow <davidgow@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Magnus Groß" <magnus.gross@rwth-aachen.de>
Cc: kunit-dev@googlegroups.com
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
v1: https://lore.kernel.org/lkml/20220224054332.1852813-1-keescook@chromium.org
v2:
- improve commit log
- fix comment URL (Daniel)
- drop redundant KUnit Kconfig help info (Daniel)
- note in Kconfig help that COMPAT builds add a compat test (David)

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elfcore: Replace CONFIG_{IA64, UML} checks with a new option

As arm64 is about to introduce MTE-specific phdrs in the core dump, add
a common CONFIG_ARCH_BINFMT_ELF_EXTRA_PHDRS option currently sele

elfcore: Replace CONFIG_{IA64, UML} checks with a new option

As arm64 is about to introduce MTE-specific phdrs in the core dump, add
a common CONFIG_ARCH_BINFMT_ELF_EXTRA_PHDRS option currently selectable
by UML_X86 and IA64.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Link: https://lore.kernel.org/r/20220131165456.2160675-2-catalin.marinas@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

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binfmt: remove support for em86 (alpha only)

We have a fairly specific alpha binary loader in Linux: running x86
(i386, i486) binaries via the em86 [1] emulator. As noted in the Kconfig
option, the

binfmt: remove support for em86 (alpha only)

We have a fairly specific alpha binary loader in Linux: running x86
(i386, i486) binaries via the em86 [1] emulator. As noted in the Kconfig
option, the same behavior can be achieved via binfmt_misc, for example,
more nowadays used for running qemu-user.

An example on how to get binfmt_misc running with em86 can be found in
Documentation/admin-guide/binfmt-misc.rst

The defconfig does not have CONFIG_BINFMT_EM86=y set. And doing a
make defconfig && make olddefconfig
results in
# CONFIG_BINFMT_EM86 is not set

... as we don't seem to have any supported Linux distirbution for alpha
anymore, there isn't really any "default" user of that feature anymore.

Searching for "CONFIG_BINFMT_EM86=y" reveals mostly discussions from
around 20 years ago, like [2] describing how to get netscape via em86
running via em86, or [3] discussing that running wine or installing
Win 3.11 through em86 would be a nice feature.

The latest binaries available for em86 are from 2000, version 2.2.1 [4] --
which translates to "unsupported"; further, em86 doesn't even work with
glibc-2.x but only with glibc-2.0 [4, 5]. These are clear signs that
there might not be too many em86 users out there, especially users
relying on modern Linux kernels.

Even though the code footprint is relatively small, let's just get rid
of this blast from the past that's effectively unused.

[1] http://ftp.dreamtime.org/pub/linux/Linux-Alpha/em86/v0.4/docs/em86.html
[2] https://static.lwn.net/1998/1119/a/alpha-netscape.html
[3] https://groups.google.com/g/linux.debian.alpha/c/AkGuQHeCe0Y
[4] http://zeniv.linux.org.uk/pub/linux/alpha/em86/v2.2-1/relnotes.2.2.1.html
[5] https://forum.teamspeak.com/archive/index.php/t-1477.html

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Cc: linux-alpha@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Matt Turner <mattst88@gmail.com>

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binfmt_flat: allow not offsetting data start

Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset
the data start"") restored offsetting the start of the data section by
a number of w

binfmt_flat: allow not offsetting data start

Commit 2217b9826246 ("binfmt_flat: revert "binfmt_flat: don't offset
the data start"") restored offsetting the start of the data section by
a number of words defined by MAX_SHARED_LIBS. As a result, since
MAX_SHARED_LIBS is never 0, a gap between the text and data sections
always exists. For architectures which cannot support a such gap
between the text and data sections (e.g. riscv nommu), flat binary
programs cannot be executed.

To allow an architecture to request no data start offset to allow for
contiguous text and data sections for binaries flagged with
FLAT_FLAG_RAM, introduce the new config option
CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET. Using this new option, the
macro DATA_START_OFFSET_WORDS is conditionally defined in binfmt_flat.c
to MAX_SHARED_LIBS for architectures tolerating or needing the data
start offset (CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET disabled case)
and to 0 when CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET is enabled.
DATA_START_OFFSET_WORDS is used in load_flat_file() to calculate the
data section length and start position.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

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c6x: remove architecture

The c6x architecture was added to the kernel in 2011 at a time when
running Linux on DSPs was widely seen as the logical evolution.
It appears the trend has gone back to run

c6x: remove architecture

The c6x architecture was added to the kernel in 2011 at a time when
running Linux on DSPs was widely seen as the logical evolution.
It appears the trend has gone back to running Linux on Arm based SoCs
with DSP, using a better supported software ecosystem, and having better
real-time behavior for the DSP code. An example of this is TI's own
Keystone2 platform.

The upstream kernel port appears to no longer have any users. Mark
Salter remained avaialable to review patches, but mentioned that
he no longer has access to working hardware himself. Without any
users, it's best to just remove the code completely to reduce the
work for cross-architecture code changes.

Many thanks to Mark for maintaining the code for the past ten years.

Link: https://lore.kernel.org/lkml/41dc7795afda9f776d8cd0d3075f776cf586e97c.camel@redhat.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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Kconfig: regularize selection of CONFIG_BINFMT_ELF

with mips converted to use of fs/config_binfmt_elf.c, there's no
need to keep selects of that thing all over arch/* - we can simply
turn into def_b

Kconfig: regularize selection of CONFIG_BINFMT_ELF

with mips converted to use of fs/config_binfmt_elf.c, there's no
need to keep selects of that thing all over arch/* - we can simply
turn into def_bool y if COMPAT && BINFMT_ELF (in fs/Kconfig.binfmt)
and get rid of all selects.

Several architectures got those selects wrong (e.g. you could
end up with sparc64 sans BINFMT_ELF, with select violating
dependencies, etc.)

Randy Dunlap has spotted some of those; IMO this is simpler than
his fix, but it depends upon the stuff that would need to be
backported, so we might end up using his variant for -stable.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasi

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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sh: remove sh5 support

sh5 never became a product and has probably never really worked.

Remove it by recursively deleting all associated Kconfig options
and all corresponding files.

Reviewed-by: G

sh: remove sh5 support

sh5 never became a product and has probably never really worked.

Remove it by recursively deleting all associated Kconfig options
and all corresponding files.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rich Felker <dalias@libc.org>

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docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.or

docs: filesystems: fix renamed references

Some filesystem references got broken by a previous patch
series I submitted. Address those.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: David Sterba <dsterba@suse.com> # fs/affs/Kconfig
Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

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elf: Allow arch to tweak initial mmap prot flags

An arch may want to tweak the mmap prot flags for an
ELFexecutable's initial mappings. For example, arm64 is going to
need to add PROT_BTI for execu

elf: Allow arch to tweak initial mmap prot flags

An arch may want to tweak the mmap prot flags for an
ELFexecutable's initial mappings. For example, arm64 is going to
need to add PROT_BTI for executable pages in an ELF process whose
executable is marked as using Branch Target Identification (an
ARMv8.5-A control flow integrity feature).

So that this can be done in a generic way, add a hook
arch_elf_adjust_prot() to modify the prot flags as desired: arches
can select CONFIG_HAVE_ELF_PROT and implement their own backend
where necessary.

By default, leave the prot flags unchanged.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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ELF: UAPI and Kconfig additions for ELF program properties

Pull the basic ELF definitions relating to the
NT_GNU_PROPERTY_TYPE_0 note from Yu-Cheng Yu's earlier x86 shstk
series.

Signed-off-by: Mar

ELF: UAPI and Kconfig additions for ELF program properties

Pull the basic ELF definitions relating to the
NT_GNU_PROPERTY_TYPE_0 note from Yu-Cheng Yu's earlier x86 shstk
series.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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binfmt_flat: make support for old format binaries optional

No need to carry the extra code around, given that systems using flat
binaries are generally very resource constrained.

Signed-off-by: Chr

binfmt_flat: make support for old format binaries optional

No need to carry the extra code around, given that systems using flat
binaries are generally very resource constrained.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

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binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option

Allow architectures to opt into ARCH_HAS_BINFMT_FLAT support instead of
assuming that all nommu ports support the format.

Signed-off-by: Christoph Hel

binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option

Allow architectures to opt into ARCH_HAS_BINFMT_FLAT support instead of
assuming that all nommu ports support the format.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

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binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable

This will eventually allow us to kill the need for an <asm/flat.h> for
many cases.

Signed-off-by: Christoph Hellwig <hch@lst.de

binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable

This will eventually allow us to kill the need for an <asm/flat.h> for
many cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

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binfmt_flat: remove flat_old_ram_flag

Instead add a Kconfig variable that only h8300 selects.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt

No need to have this in the top-level Kconfig.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Randy Dunlap <rdunlap@i

kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt

No need to have this in the top-level Kconfig.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

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docs: Fix more broken references

As we move stuff around, some doc references are broken. Fix some of
them via this script:
./scripts/documentation-file-ref-check --fix

Manually checked that produ

docs: Fix more broken references

As we move stuff around, some doc references are broken. Fix some of
them via this script:
./scripts/documentation-file-ref-check --fix

Manually checked that produced results are valid.

Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

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treewide: simplify Kconfig dependencies for removed archs

A lot of Kconfig symbols have architecture specific dependencies.
In those cases that depend on architectures we have already removed,
they

treewide: simplify Kconfig dependencies for removed archs

A lot of Kconfig symbols have architecture specific dependencies.
In those cases that depend on architectures we have already removed,
they can be omitted.

Acked-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

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ARM: enable elf_fdpic on systems with an MMU

Provide the necessary changes to be able to execute ELF-FDPIC binaries
on ARM systems with an MMU.

The default for CONFIG_BINFMT_ELF_FDPIC is also set t

ARM: enable elf_fdpic on systems with an MMU

Provide the necessary changes to be able to execute ELF-FDPIC binaries
on ARM systems with an MMU.

The default for CONFIG_BINFMT_ELF_FDPIC is also set to n if the regular
ELF loader is already configured so not to force FDPIC support on
everyone. Given that CONFIG_BINFMT_ELF depends on CONFIG_MMU, this means
CONFIG_BINFMT_ELF_FDPIC will still default to y when !MMU.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mickael GUENE <mickael.guene@st.com>
Tested-by: Vincent Abriou <vincent.abriou@st.com>
Tested-by: Andras Szemzo <szemzo.andras@gmail.com>

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