Adds potential sources of randomness: RDRAND, RDTSC, or the i8254.

This moves the pre-alternatives inline rdrand function into the header so
both pieces of code can use it. Availability of RDRAND is then controlled
by CONFIG_ARCH_RANDOM, if someone wants to disable it even for kASLR.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-4-git-send-email-keescook@chromium.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

This allows decompress_kernel to return a new location for the kernel to
be relocated to. Additionally, enforces CONFIG_PHYSICAL_START as the
minimum relocation position when building with CONFIG_RELOCATABLE.

With CONFIG_RANDOMIZE_BASE set, the choose_kernel_location routine
will select a new location to decompress the kernel, though here it is
presently a no-op. The kernel command line option "nokaslr" is introduced
to bypass these routines.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-3-git-send-email-keescook@chromium.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Refactor the CPU flags handling out of the cpucheck routines so that
they can be reused by the future ASLR routines (in order to detect CPU
features like RDRAND and RDTSC).

This reworks has_eflag() and has_fpu() to be used on both 32-bit and
64-bit, and refactors the calls to cpuid to make them PIC-safe on 32-bit.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-2-git-send-email-keescook@chromium.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Prior to 9b706aee ("x86: trivial printk optimizations") this was
36 because it had 26 characters and 10 digits but now it's just
16 hex digits so the sanity check needs updated.

This function is always called with a valid "base" so it doesn't
make a difference to how the kernel works, it's just a cleanup.

Reported-by: Alexey Petrenko <alexey.petrenko@oracle.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Below is a patch that fixes sparse error
"arch/x86/boot/string.c:119:8: warning: symbol 'strlen' was not
declared." by declaring it in arch/x86/boot/boot.h.

Signed-off-by: Fred Chen <fchen@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1376417580-11554-1-git-send-email-fchen@linux.vnet.ibm.com


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Moves the relocation handling into C, after decompression. This requires
that the decompressed size is passed to the decompression routine as
well so that relocations can be found. Only kernels that need relocation
support will use the code (currently just x86_32), but this is laying
the ground work for 64-bit using it in support of KASLR.

Based on work by Neill Clift and Michael Davidson.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/20130708161517.GA4832@www.outflux.net


Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Specify memory size in pages, not bytes.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Integrates the LZ4 decompression code to the arm pre-boot code.

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During build we open a file, read that but do not close it. Fix
that by sticking fclose() at the right place.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: http://lkml.kernel.org/r/1371628383-11216-1-git-send-email-jslaby@suse.cz


Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org

ExitBootServices is absolutely supposed to return a failure if any
ExitBootServices event handler changes the memory map.  Basically the
get_map loop should run again if ExitBootServices returns an error the
first time.  I would say it would be fair that if ExitBootServices gives
an error the second time then Linux would be fine in returning control
back to BIOS.

The second change is the following line:

again:
        size += sizeof(*mem_map) * 2;

Originally you were incrementing it by the size of one memory map entry.
The issue here is all related to the low_alloc routine you are using.
In this routine you are making allocations to get the memory map itself.
Doing this allocation or allocations can affect the memory map by more
than one record.

[ mfleming - changelog, code style ]
Signed-off-by: Zach Bobroff <zacharyb@ami.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

This patch reworks the UEFI anti-bricking code, including an effective
reversion of cc5a080c and 31ff2f20. It turns out that calling
QueryVariableInfo() from boot services results in some firmware
implementations jumping to physical addresses even after entering virtual
mode, so until we have 1:1 mappings for UEFI runtime space this isn't
going to work so well.

Reverting these gets us back to the situation where we'd refuse to create
variables on some systems because they classify deleted variables as "used"
until the firmware triggers a garbage collection run, which they won't do
until they reach a lower threshold. This results in it being impossible to
install a bootloader, which is unhelpful.

Feedback from Samsung indicates that the firmware doesn't need more than
5KB of storage space for its own purposes, so that seems like a reasonable
threshold. However, there's still no guarantee that a platform will attempt
garbage collection merely because it drops below this threshold. It seems
that this is often only triggered if an attempt to write generates a
genuine EFI_OUT_OF_RESOURCES error. We can force that by attempting to
create a variable larger than the remaining space. This should fail, but if
it somehow succeeds we can then immediately delete it.

I've tested this on the UEFI machines I have available, but I don't have
a Samsung and so can't verify that it avoids the bricking problem.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Lee, Chun-Y <jlee@suse.com> [ dummy variable cleanup ]
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

arch/x86/boot/compressed/head_64.S includes <asm/pgtable_types.h> and
 <asm/page_types.h> but it doesn't look like it needs them. So remove them.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/5191FAE2.4020403@cn.fujitsu.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

We need to check the runtime sys_table for the EFI version the firmware
specifies instead of just checking for a NULL QueryVariableInfo.  Older
implementations of EFI don't have QueryVariableInfo but the runtime is
a smaller structure, so the pointer to it may be pointing off into garbage.

This is apparently the case with several Apple firmwares that support EFI
1.10, and the current check causes them to no longer boot.  Fix based on
a suggestion from Matthew Garrett.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Fix this:

arch/x86/boot/compressed/eboot.c: In function ‘setup_efi_vars’:
arch/x86/boot/compressed/eboot.c:269:2: warning: passing argument 1 of ‘efi_call_phys’ makes pointer from integer without a cast [enabled by default]
In file included from arch/x86/boot/compressed/eboot.c:12:0:
/w/kernel/linux/arch/x86/include/asm/efi.h:8:33: note: expected ‘void *’ but argument is of type ‘long unsigned int’

after cc5a080c ("efi: Pass boot services variable info to runtime
code").

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Refactor the relocs tool so that the same tool can handle 32- and
64-bit ELF.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-5-git-send-email-keescook@chromium.org

Since the ELF structures and access macros change size based on 32 vs
64 bits, build a separate 32-bit relocs tool (for handling realmode
and 32-bit relocations), and a 64-bit relocs tool (for handling 64-bit
kernel relocations).

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1365797627-20874-5-git-send-email-keescook@chromium.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

EFI variables can be flagged as being accessible only within boot services.
This makes it awkward for us to figure out how much space they use at
runtime. In theory we could figure this out by simply comparing the results
from QueryVariableInfo() to the space used by all of our variables, but
that fails if the platform doesn't garbage collect on every boot. Thankfully,
calling QueryVariableInfo() while still inside boot services gives a more
reliable answer. This patch passes that information from the EFI boot stub
up to the efi platform code.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

eboot.o and efi_stub_$(BITS).o didn't get added to "targets", and hence
their .cmd files don't get included by the build machinery, leading to
the files always getting rebuilt.

Rather than adding the two files individually, take the opportunity and
add $(VMLINUX_OBJS) to "targets" instead, thus allowing the assignment
at the top of the file to be shrunk quite a bit.

At the same time, remove a pointless flags override line - the variable
assigned to was misspelled anyway, and the options added are
meaningless for assembly sources.

[ hpa: the patch is not minimal, but I am taking it for -urgent anyway
  since the excess impact of the patch seems to be small enough. ]

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/515C5D2502000078000CA6AD@nat28.tlf.novell.com


Cc: Matthew Garrett <mjg@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

In startup_32, the running code still uses the initial GDT
located in setup. Thus, __BOOT_DS is preferred. Currently
__KERNEL_DS is lucky to equal to __BOOT_DS, but this is
not always a safe way.

Signed-off-by: Lans Zhang <lans.zhang2008@gmail.com>
Link: http://lkml.kernel.org/r/51300267.6000008@gmail.com


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

When initrd file didn't put at the same place with stub kernel, we
need give the file path of initrd, but need use backslash to separate
directory and file. It's not friendly to unix/linux user, and not so
intuitive for bootloader forward paramters to efi stub kernel by
chainloading.

This patch add support to handle_ramdisks for allow slash in file path
of initrd, it convert slash to backlash when parsing path.

In additional, this patch also separates print code of efi_char16_t from
efi_printk, and print out the path/filename of initrd when failed to open
initrd file. It's good for debug and discover typo.

Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Now 64bit entry is fixed on 0x200, can not be changed anymore.

Update the comments to reflect that.

Also put info about it in boot.txt

-v2: fix some grammar error

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-27-git-send-email-yinghai@kernel.org


Cc: Rob Landley <rob@landley.net>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

xloadflags bit 1 indicates that we can load the kernel and all data
structures above 4G; it is set if kernel is relocatable and 64bit.

bootloader will check if xloadflags bit 1 is set to decide if
it could load ramdisk and kernel high above 4G.

bootloader will fill value to ext_ramdisk_image/size for high 32bits
when it load ramdisk above 4G.
kernel use get_ramdisk_image/size to use ext_ramdisk_image/size to get
right positon for ramdisk.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Rob Landley <rob@landley.net>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Gokul Caushik <caushik1@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joe Millenbach <jmillenbach@gmail.com>
Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

commit 08da5a2c

    x86_64: Early segment setup for VT

sets up LDT and TR into a valid state in order to speed up boot
decompression under VT.

Those code are put in code64, and it is using GDT that is only
loaded from code32 path.

That breaks booting with 64bit bootloader that does not go through
code32 path and jump to startup_64 directly, and it has different
GDT.

Move those lines into code32 after their GDT is loaded.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-21-git-send-email-yinghai@kernel.org


Cc: Zachary Amsden <zamsden@gmail.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

We need to move some code to 32bit section in following patch:

   x86, boot: Move lldt/ltr out of 64bit code section

but that will push startup_64 down from 0x200.

According to hpa, we can not change startup_64 position and that
is an ABI.

We could move function verify_cpu and no_longmode down, because
verify_cpu is used via function call and no_longmode will not
return, then we don't need to add extra code for jumping back.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-20-git-send-email-yinghai@kernel.org


Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

boot/compressed/misc.c is used for bzImage in 64bit and 32bit, and
cmd_line_ptr could point to buffer that is above 4g, cmd_line_ptr
should be 64bit otherwise high 32bit will be capped out.

So need to change data type to unsigned long, that will be 64bit get
correct address of command line buffer.

And it is still ok with 32bit bzImage, because unsigned long on 32bit kernel
is still 32bit.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-19-git-send-email-yinghai@kernel.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

cmdline.c::__cmdline_find_option... are shared between 16-bit setup code
and 32/64 bit decompressor code.

for 32/64 only path via kexec, we should not check if ptr is less 1M.
as those cmdline could be put above 1M, or even 4G.

Move out accessible checking out of __cmdline_find_option()
So decompressor in misc.c can parse cmdline correctly.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-18-git-send-email-yinghai@kernel.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Add an accessor function for the command line address.
Later we will add support for holding a 64-bit address via ext_cmd_line_ptr.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-17-git-send-email-yinghai@kernel.org


Cc: Gokul Caushik <caushik1@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joe Millenbach <jmillenbach@gmail.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

It looks like the original commit that copied the rom contents from
efi always copied the rom, and the fixup in setup_efi_pci from commit
886d751a ("x86, efi: correct precedence of operators in
setup_efi_pci") broke that.

This resulted in macbook pro's no longer finding the rom images, and
thus not being able to use the radeon card any more.

The solution is to just remove the check for now, and always copy the
rom if available.

Reported-by: Vitaly Budovski <vbudovski+news@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Use the new sentinel field to detect bootloaders which fail to follow
protocol and don't initialize fields in struct boot_params that they
do not explicitly initialize to zero.

Based on an original patch and research by Yinghai Lu.
Changed by hpa to be invoked both in the decompression path and in the
kernel proper; the latter for the case where a bootloader takes over
decompression.

Originally-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

We have historically hard-coded entry points in head.S just so it's easy
to build the executable/bzImage headers with references to them.

Unfortunately, this leads to boot loaders abusing these "known" addresses
even when they are *explicitly* told that they "should look at the ELF
header to find this address, as it may change in the future". And even
when the address in question *has* actually been changed in the past,
without fanfare or thought to compatibility.

Thus we have bootloaders doing stunningly broken things like jumping
to offset 0x200 in the kernel startup code in 64-bit mode, *hoping*
that startup_64 is still there (it has moved at least once
before). And hoping that it's actually a 64-bit kernel despite the
fact that we don't give them any indication of that fact.

This patch should hopefully remove the temptation to abuse internal
addresses in future, where sternly worded comments have not sufficed.
Instead of having hard-coded addresses and saying "please don't abuse
these", we actually pull the addresses out of the ELF payload into
zoffset.h, and make build.c shove them back into the right places in
the bzImage header.

Rather than including zoffset.h into build.c and thus having to rebuild
the tool for every kernel build, we parse it instead. The parsing code
is small and simple.

This patch doesn't actually move any of the interesting entry points, so
any offending bootloader will still continue to "work" after this patch
is applied. For some version of "work" which includes jumping into the
compressed payload and crashing, if the bzImage it's given is a 32-bit
kernel. No change there then.

[ hpa: some of the issues in the description are addressed or
  retconned by the 2.12 boot protocol.  This patch has been edited to
  only remove fixed addresses that were *not* thus retconned. ]

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>

The 'Attributes' argument to pci->Attributes() function is 64-bit. So
when invoking in 32-bit mode it takes two registers, not just one.

This fixes memory corruption when booting via the 32-bit EFI boot stub.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>

If the bootloader calls the EFI handover entry point as a standard function
call, then it'll have a return address on the stack. We need to pop that
before calling efi_main(), or the arguments will all be out of position on
the stack.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>

When booting under OVMF we have precisely one GOP device, and it
implements the ConOut protocol.

We break out of the loop when we look at it... and then promptly abort
because 'first_gop' never gets set. We should set first_gop *before*
breaking out of the loop. Yes, it doesn't really mean "first" any more,
but that doesn't matter. It's only a flag to indicate that a suitable
GOP was found.

In fact, we'd do just as well to initialise 'width' to zero in this
function, then just check *that* instead of first_gop. But I'll do the
minimal fix for now (and for stable@).

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org


Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>

Define the 2.12 bzImage boot protocol: add xloadflags and additional
fields to allow the command line, initramfs and struct boot_params to
live above the 4 GiB mark.

The xloadflags now communicates if this is a 64-bit kernel with the
legacy 64-bit entry point and which of the EFI handover entry points
are supported.

Avoid adding new read flags to loadflags because of claimed
bootloaders testing the whole byte for == 1 to determine bzImageness
at least until the issue can be researched further.

This is based on patches by Yinghai Lu and David Woodhouse.

Originally-by: Yinghai Lu <yinghai@kernel.org>
Originally-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org
Cc: Rob Landley <rob@landley.net>
Cc: Gokul Caushik <caushik1@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joe Millenbach <jmillenbach@gmail.com>

Fix four similar build warnings on 32-bit (casts between different
size pointers and integers).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Stefan Hasko <hasko.stevo@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

With the current code, the condition in the if() doesn't make much sense due to
precedence of operators.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Link: http://lkml.kernel.org/r/1356030701-16284-25-git-send-email-sasha.levin@oracle.com


Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

EFI provides support for providing PCI ROMs via means other than the ROM
BAR. This support vanishes after we've exited boot services, so add support
for stashing copies of the ROMs in setup_data if they're not otherwise
available.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>

Building for Athlon/Duron/K7 results in the following build error,

arch/x86/boot/compressed/eboot.o: In function `__constant_memcpy3d':
eboot.c:(.text+0x385): undefined reference to `_mmx_memcpy'
arch/x86/boot/compressed/eboot.o: In function `efi_main':
eboot.c:(.text+0x1a22): undefined reference to `_mmx_memcpy'

because the boot stub code doesn't link with the kernel proper, and
therefore doesn't have access to the 3DNow version of memcpy. So,
follow the example of misc.c and #undef memcpy so that we use the
version provided by misc.c.

See https://bugzilla.kernel.org/show_bug.cgi?id=50391



Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Ryan Underwood <nemesis@icequake.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Commit 2e064b1e (x86, efi: Fix issue of overlapping .reloc section for
EFI_STUB) removed a dummy reloc added by commit 291f3632 (x86, efi: EFI
boot stub support), but forgot to remove the dummy long used by that
reloc.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Lee G Rosenbaum <lee.g.rosenbaum@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>