All other calls to allocate memory seem to make some noise already, with the
exception of two calls (for gop, uga) in the setup_graphics path.

The purpose is to be noisy on worrysome errors immediately.

commit fb86b244 ("x86/efi: Add better error logging to EFI boot
stub") introduces printing false alarms for lots of hardware. Rather
than playing Whack a Mole with non-fatal exit conditions, try the other
way round.

This is per Matt Fleming's suggestion:

> Where I think we could improve things
> is by adding efi_printk() message in certain error paths. Clearly, not
> all error paths need such messages, e.g. the EFI_INVALID_PARAMETER path
> you highlighted above, but it makes sense for memory allocation and PCI
> read failures.

Link: http://article.gmane.org/gmane.linux.kernel.efi/4628Signed-off-by: NAndre Müller <andre.muller@web.de>
Cc: Ulf Winkelvos <ulf@winkelvos.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

We need a way to customize the behaviour of the EFI boot stub, in
particular, we need a way to disable the "chunking" workaround, used
when reading files from the EFI System Partition.

One of my machines doesn't cope well when reading files in 1MB chunks to
a buffer above the 4GB mark - it appears that the "chunking" bug
workaround triggers another firmware bug. This was only discovered with
commit 4bf7111f ("x86/efi: Support initrd loaded above 4G"), and
that commit is perfectly valid. The symptom I observed was a corrupt
initrd rather than any kind of crash.

efi= is now used to specify EFI parameters in two very different
execution environments, the EFI boot stub and during kernel boot.

There is also a slight performance optimization by enabling efi=nochunk,
but that's offset by the fact that you're more likely to run into
firmware issues, at least on x86. This is the rationale behind leaving
the workaround enabled by default.

Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're
using the current value of 1MB.
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The EFI boot stub goes to great pains to relocate the kernel image to
an appropriately aligned address, as indicated by the ->kernel_alignment
field in the bzImage header.  However, for the PE stub entry case, we
can request that the EFI PE/COFF loader do the work for us.

Fix by exposing the desired alignment via the SectionAlignment field
in the PE/COFF headers.  Despite its name, this field provides an
overall alignment requirement for the loaded file.  (Naturally, the
FileAlignment field describes the alignment for individual sections.)

There is no way in the PE/COFF headers to express the concept of
min_alignment; we therefore do not expose the minimum (as opposed to
preferred) alignment.
Signed-off-by: NMichael Brown <mbrown@fensystems.co.uk>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Hopefully this will enable us to better debug:
https://bugzilla.kernel.org/show_bug.cgi?id=68761Signed-off-by: NUlf Winkelvos <ulf@winkelvos.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This patch changes both x86 and arm64 efistub implementations
from #including shared .c files under drivers/firmware/efi to
building shared code as a static library.

The x86 code uses a stub built into the boot executable which
uncompresses the kernel at boot time. In this case, the library is
linked into the decompressor.

In the arm64 case, the stub is part of the kernel proper so the library
is linked into the kernel proper as well.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The PE/COFF headers currently describe only the initialised-data
portions of the image, and result in no space being allocated for the
uninitialised-data portions.  Consequently, the EFI boot stub will end
up overwriting unexpected areas of memory, with unpredictable results.

Fix by including a .bss section in the PE/COFF headers (functionally
equivalent to the init_size field in the bzImage header).
Signed-off-by: NMichael Brown <mbrown@fensystems.co.uk>
Cc: Thomas Bächler <thomas@archlinux.org>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

In order to move from the #include "../../../xxxxx.c" anti-pattern used
by both the x86 and arm64 versions of the stub to a static library
linked into either the kernel proper (arm64) or a separate boot
executable (x86), there is some prepatory work required.

This patch does the following:
- move forward declarations of functions shared between the arch
  specific and the generic parts of the stub to include/linux/efi.h
- move forward declarations of functions shared between various .c files
  of the generic stub code to a new local header file called "efistub.h"
- add #includes to all .c files which were formerly relying on the
  #includor to include the correct header files
- remove all static modifiers from functions which will need to be
  externally visible once we move to a static library
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This moves definitions depended upon both by code under arch/x86/boot
and under drivers/firmware/efi to <asm/efi.h>. This is in preparation of
turning the stub code under drivers/firmware/efi into a static library.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

For boot efi kernel directly without bootloader.
If the kernel support XLF_CAN_BE_LOADED_ABOVE_4G, we should
not limit initrd under hdr->initrd_add_max.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Changes kASLR from being compile-time selectable (blocked by
CONFIG_HIBERNATION), to being boot-time selectable (with hibernation
available by default) via the "kaslr" kernel command line.
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

commit 7d453eee ("x86/efi: Wire up CONFIG_EFI_MIXED") introduced a
regression for the functionality to load kernels above 4G. The relevant
(incorrect) reasoning behind this change can be seen in the commit
message,

  "The xloadflags field in the bzImage header is also updated to reflect
  that the kernel supports both entry points by setting both of
  XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y.
  XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is
  guaranteed to be addressable with 32-bits."

This is obviously bogus since 32-bit EFI loaders will never place the
kernel above the 4G mark. So this restriction is entirely unnecessary.

But things are worse than that - since we want to encourage people to
always compile with CONFIG_EFI_MIXED=y so that their kernels work out of
the box for both 32-bit and 64-bit firmware, commit 7d453eee
effectively disables XLF_CAN_BE_LOADED_ABOVE_4G completely.

Remove the overzealous and superfluous restriction and restore the
XLF_CAN_BE_LOADED_ABOVE_4G functionality.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1402140380-15377-1-git-send-email-matt@console-pimps.orgSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

By changing code16gcc.h from a C header to an assembly header and use
the -Wa,... option to gcc to force it to be added to the assembly
input, we can avoid the problems with gcc reordering code bits on us.

If we have -m16, we still use it, of course.
Suggested-by: NKevin O'Connor <kevin@koconnor.net>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-xw8ibgdemucl9fz3i1bymu6w@git.kernel.org

Given the fact that we removed inclusion of boot.h from boot/string.c
does not look like we need misc.h inclusion in compressed/string.c. So
remove it.

misc.h was also pulling in string_32.h which in turn had macros for
memcmp and memcpy. So we don't need to #undef memcmp and memcpy anymore.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1398447972-27896-3-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

string.c does not require whole of boot.h. Just inclusion of linux/types.h
and ctypes.h seems to be sufficient.

Keep list of stuff being included in string.c to bare minimal so that
string.c can be included in other places easily.

For example, Currently boot/compressed/string.c includes boot/string.c
but looks like it does not want boot/boot.h. Hence there is a define
in boot/compressed/misc.h "define BOOT_BOOT_H" which prevents inclusion
of boot.h in compressed/string.c. And compressed/string.c is forced to
include misc.h just for that reason.

So by removing inclusion of boot.h, we can also get rid of inclusion of
misch.h in compressed/misc.c.

This also enables including of boot/string.c in purgatory/ code relatively
easily.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1398447972-27896-2-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>

As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.

Tree sweep for arch/x86/*
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

arch/x86/crypto/sha1_avx2_x86_64_asm.S introduced _end as a local
symbol, which broke the build under certain circumstances.  Although
the wisdom of _end as a local symbol can definitely be questioned, the
build should not break for that reason.

Thus, filter the output of nm to only get global symbols of
appropriate type.
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Cc: Chandramouli Narayanan <mouli@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-uxm3j3w3odglcwhafwq5tjqu@git.kernel.org

We really only need one phys and one virt function call, and then only
one assembly function to make firmware calls.

Since we are not using the C type system anyway, we're not really losing
much by deleting the macros apart from no longer having a check that
we are passing the correct number of parameters. The lack of duplicated
code seems like a worthwhile trade-off.

Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Instead of truncating UTF-16 assuming all characters is ASCII,
properly convert it to UTF-8.
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
[ Bug and style fixes. ]
Signed-off-by: NRoy Franz <roy.franz@linaro.org>
Signed-off-by: NLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

We're currently passing the file handle for the root file system to
efi_file_read() and efi_file_close(), instead of the file handle for the
file we wish to read/close.

While this has worked up until now, it seems that it has only been by
pure luck. Olivier explains,

 "The issue is the UEFI Fat driver might return the same function for
  'fh->read()' and 'h->read()'. While in our case it does not work with
  a different implementation of EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. In our
  case, we return a different pointer when reading a directory and
  reading a file."

Fixing this actually clears up the two functions because we can drop one
of the arguments, and instead only pass a file 'handle' argument.
Reported-by: NOlivier Martin <olivier.martin@arm.com>
Reviewed-by: NOlivier Martin <olivier.martin@arm.com>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

code32_start should point at the start of the protected mode code, and
*not* at the beginning of the bzImage. This is much easier to do in
assembly so document that callers of make_boot_params() need to fill out
code32_start.

The fallout from this bug is that we would end up relocating the image
but copying the image at some offset, resulting in what appeared to be
memory corruption.
Reported-by: NThomas Bächler <thomas@archlinux.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

commit 54b52d87 ("x86/efi: Build our own EFI services pointer
table") introduced a regression because the 64-bit file_size()
implementation passed a pointer to a 32-bit data object, instead of a
pointer to a 64-bit object.

Because the firmware treats the object as 64-bits regardless it was
reading random values from the stack for the upper 32-bits.

This resulted in people being unable to boot their machines, after
seeing the following error messages,

    Failed to get file info size
    Failed to alloc highmem for files
Reported-by: NDzmitry Sledneu <dzmitry.sledneu@gmail.com>
Reported-by: NKoen Kooi <koen@dominion.thruhere.net>
Tested-by: NKoen Kooi <koen@dominion.thruhere.net>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The ARM EFI boot stub doesn't need to care about the efi_early
infrastructure that x86 requires in order to do mixed mode thunking. So
wrap everything up in an efi_call_early() macro.

This allows x86 to do the necessary indirection jumps to call whatever
firmware interface is necessary (native or mixed mode), but also allows
the ARM folks to mask the fact that they don't support relocation in the
boot stub and need to pass 'sys_table_arg' to every function.

[ hpa: there are no object code changes from this patch ]
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20140326091011.GB2958@console-pimps.org
Cc: Roy Franz <roy.franz@linaro.org>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Many Pentium M systems disable PAE but may have a functionally usable PAE
implementation. This adds the "forcepae" parameter which bypasses the boot
check for PAE, and sets the CPU as being PAE capable. Using this parameter
will taint the kernel with TAINT_CPU_OUT_OF_SPEC.
Signed-off-by: NChris Bainbridge <chris.bainbridge@gmail.com>
Link: http://lkml.kernel.org/r/20140307114040.GA4997@localhostAcked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Currently compressed/misc.c needs to link against memset(). I think one of
the reasons of this need is inclusion of various header files which define
static inline functions and use memset() inside these. For example,
include/linux/bitmap.h

I think trying to include "../string.h" and using builtin version of memset
does not work because by the time "#define memset" shows up, it is too
late. Some other header file has already used memset() and expects to
find a definition during link phase.

Currently we have a C definitoin of memset() in misc.c. Move it to
compressed/string.c so that others can use it if need be.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-6-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Try to treat memcmp() in same way as memcpy() and memset(). Provide a
declaration in boot/string.h and by default user gets a memcmp() which
maps to builtin function.

Move optimized definition of memcmp() in boot/string.c. Now a user can
do #undef memcmp and link against string.c to use optimzied memcmp().

It also simplifies boot/compressed/string.c where we had to redefine
memcmp(). That extra definition is gone now.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-5-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Move optimized versions of memcpy to compressed/string.c This will allow
any other code to use these functions too if need be in future. Again
trying to put definition in a common place instead of hiding it in misc.c
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-4-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Create a separate arch/x86/boot/string.h file to provide declaration of
some of the common string functions.

By default memcpy, memset and memcmp functions will default to gcc
builtin functions. If code wants to use an optimized version of any
of these functions, they need to #undef the respective macro and link
against a local file providing definition of undefed function.

For example, arch/x86/boot/* code links against copy.S to get memcpy()
and memcmp() definitions. arch/86/boot/compressed/* links against
compressed/string.c.

There are quite a few places in arch/x86/ where these functions are
used. Idea is to try to consilidate  their declaration and possibly
definitions so that it can be reused.

I am planning to reuse boot/string.h in arch/x86/purgatory/ and use
gcc builtin functions for memcpy, memset and memcmp.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-3-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

With CONFIG_X86_32=y, string_32.h gets pulled in compressed/string.c by
"misch.h". string_32.h defines a macro to map memcmp to __builtin_memcmp().
And that macro in turn changes the name of memcmp() defined here and
converts it to __builtin_memcmp().

I thought that's not the intention though. We probably want to provide
our own optimized definition of memcmp(). If yes, then undef the memcmp
before we define a new memcmp.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/1395170800-11059-2-git-send-email-vgoyal@redhat.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The name in struct bootparam is ->initrd_addr_max and not ramdisk_max.
Fix that.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1394633584-5509-2-git-send-email-bp@alien8.deSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

The kbuild test robot reported the following errors, introduced with
commit 54b52d87 ("x86/efi: Build our own EFI services pointer
table"),

 arch/x86/boot/compressed/head_32.o: In function `efi32_config':
>> (.data+0x58): undefined reference to `efi_call_phys'

 arch/x86/boot/compressed/head_64.o: In function `efi64_config':
>> (.data+0x90): undefined reference to `efi_call6'

Wrap the efi*_config structures in #ifdef CONFIG_EFI_STUB so that we
don't make references to EFI functions if they're not compiled in.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The kbuild test robot reported the following errors that were introduced
with commit 993c30a0 ("x86, tools: Consolidate #ifdef code"),

  arch/x86/boot/tools/build.c: In function 'update_pecoff_setup_and_reloc':
>> arch/x86/boot/tools/build.c:252:1: error: parameter name omitted
    static inline void update_pecoff_setup_and_reloc(unsigned int) {}
    ^
  arch/x86/boot/tools/build.c: In function 'update_pecoff_text':
>> arch/x86/boot/tools/build.c:253:1: error: parameter name omitted
    static inline void update_pecoff_text(unsigned int, unsigned int) {}
    ^
>> arch/x86/boot/tools/build.c:253:1: error: parameter name omitted

   arch/x86/boot/tools/build.c: In function 'main':
>> arch/x86/boot/tools/build.c:372:2: warning: implicit declaration of function 'efi_stub_entry_update' [-Wimplicit-function-declaration]
    efi_stub_entry_update();
    ^
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Some EFI firmware makes use of the FPU during boottime services and
clearing X86_CR4_OSFXSR by overwriting %cr4 causes the firmware to
crash.

Add the PAE bit explicitly instead of trashing the existing contents,
leaving the rest of the bits as the firmware set them.

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

Add the Kconfig option and bump the kernel header version so that boot
loaders can check whether the handover code is available if they want.

The xloadflags field in the bzImage header is also updated to reflect
that the kernel supports both entry points by setting both of
XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y.
XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is
guaranteed to be addressable with 32-bits.

Note that no boot loaders should be using the bits set in xloadflags to
decide which entry point to jump to. The entire scheme is based on the
concept that 32-bit bootloaders always jump to ->handover_offset and
64-bit loaders always jump to ->handover_offset + 512. We set both bits
merely to inform the boot loader that it's safe to use the native
handover offset even if the machine type in the PE/COFF header claims
otherwise.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.

Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,

    (1) 32-bit loader: handover_offset
    (2) 64-bit loader: handover_offset + 512

Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.

To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.

(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Make the decision which code path to take at runtime based on
efi_early->is64.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Implement the transition code to go from IA32e mode to protected mode in
the EFI boot stub. This is required to use 32-bit EFI services from a
64-bit kernel.

Since EFI boot stub is executed in an identity-mapped region, there's
not much we need to do before invoking the 32-bit EFI boot services.
However, we do reload the firmware's global descriptor table
(efi32_boot_gdt) in case things like timer events are still running in
the firmware.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

It's not possible to dereference the EFI System table directly when
booting a 64-bit kernel on a 32-bit EFI firmware because the size of
pointers don't match.

In preparation for supporting the above use case, build a list of
function pointers on boot so that callers don't have to worry about
converting pointer sizes through multiple levels of indirection.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

The traditional approach of using machine-specific types such as
'unsigned long' does not allow the kernel to interact with firmware
running in a different CPU mode, e.g. 64-bit kernel with 32-bit EFI.

Add distinct EFI structure definitions for both 32-bit and 64-bit so
that we can use them in the 32-bit and 64-bit code paths.
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Instead of littering main() with #ifdef CONFIG_EFI_STUB, move the logic
into separate functions that do nothing if the config option isn't set.
This makes main() much easier to read.
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

handover_offset is now filled out by build.c. Don't set a default value
as it will be overwritten anyway.
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>