efi/gop: Add an option to list out the available GOP modes

Add video=efifb:list option to list the modes that are available.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.

efi/gop: Add an option to list out the available GOP modes

Add video=efifb:list option to list the modes that are available.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-20-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Add definitions for console input and events

Add the required typedefs etc for using con_in's simple text input
protocol, and for using the boottime event services.

Also add the protot

efi/libstub: Add definitions for console input and events

Add the required typedefs etc for using con_in's simple text input
protocol, and for using the boottime event services.

Also add the prototype for the "stall" boot service.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-19-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Implement printk-style logging

Use the efi_printk function in efi_info/efi_err, and add efi_debug. This
allows formatted output at different log levels.

Add the notion of a loglevel in

efi/libstub: Implement printk-style logging

Use the efi_printk function in efi_info/efi_err, and add efi_debug. This
allows formatted output at different log levels.

Add the notion of a loglevel instead of just quiet/not-quiet, and
parse the efi=debug kernel parameter in addition to quiet.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200520170223.GA3333632@rani.riverdale.lan/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Add a basic printf implementation

Copy vsprintf from arch/x86/boot/printf.c to get a simple printf
implementation.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lo

efi/libstub: Add a basic printf implementation

Copy vsprintf from arch/x86/boot/printf.c to get a simple printf
implementation.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-5-nivedita@alum.mit.edu
[ardb: add some missing braces in if...else clauses]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Rename efi_[char16_]printk to efi_[char16_]puts

These functions do not support formatting, unlike printk. Rename them to
puts to make that clear.

Move the implementations of these two

efi/libstub: Rename efi_[char16_]printk to efi_[char16_]puts

These functions do not support formatting, unlike printk. Rename them to
puts to make that clear.

Move the implementations of these two functions next to each other.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-3-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Include dependencies of efistub.h

Add #include directives for include files that efistub.h depends on,
instead of relying on them having been included by the C source files
prior to efi

efi/libstub: Include dependencies of efistub.h

Add #include directives for include files that efistub.h depends on,
instead of relying on them having been included by the C source files
prior to efistub.h.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200518190716.751506-2-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub/x86: Avoid EFI map buffer alloc in allocate_e820()

In allocate_e820(), call the EFI get_memory_map() service directly
instead of indirectly via efi_get_memory_map(). This avoids allocati

efi/libstub/x86: Avoid EFI map buffer alloc in allocate_e820()

In allocate_e820(), call the EFI get_memory_map() service directly
instead of indirectly via efi_get_memory_map(). This avoids allocation
of a buffer and return of the full EFI memory map, which is not needed
here and would otherwise need to be freed.

Routine allocate_e820() only needs to know how many EFI memory
descriptors there are in the map to allocate an adequately sized
e820ext buffer, if it's needed. Note that since efi_get_memory_map()
returns a memory map buffer sized with extra headroom, allocate_e820()
now needs to explicitly factor that into the e820ext size calculation.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Make efi_printk() input argument const char*

To help the compiler figure out that efi_printk() will not modify
the string it is given, make the input argument type const char*.

While a

efi/libstub: Make efi_printk() input argument const char*

To help the compiler figure out that efi_printk() will not modify
the string it is given, make the input argument type const char*.

While at it, simplify the implementation as well.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Fix mixed mode boot issue after macro refactor

Commit

22090f84bc3f ("efi/libstub: unify EFI call wrappers for non-x86")

refactored the macros that are used to provide wrappers for m

efi/libstub: Fix mixed mode boot issue after macro refactor

Commit

22090f84bc3f ("efi/libstub: unify EFI call wrappers for non-x86")

refactored the macros that are used to provide wrappers for mixed-mode
calls on x86, allowing us to boot a 64-bit kernel on 32-bit firmware.

Unfortunately, this broke mixed mode boot due to the fact that
efi_is_native() is not a macro on x86.

All of these macros should go together, so rather than testing each one
to see if it is defined, condition the generic macro definitions on a
new ARCH_HAS_EFISTUB_WRAPPERS, and remove the wrapper definitions on x86
as well if CONFIG_EFI_MIXED is not enabled.

Fixes: 22090f84bc3f ("efi/libstub: unify EFI call wrappers for non-x86")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200504150248.62482-1-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Unify initrd loading across architectures

Factor out the initrd loading into a common function that can be called
both from the generic efi-stub.c and the x86-specific x86-stub.c.

Sign

efi/libstub: Unify initrd loading across architectures

Factor out the initrd loading into a common function that can be called
both from the generic efi-stub.c and the x86-specific x86-stub.c.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-10-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Move pr_efi/pr_efi_err into efi namespace

Rename pr_efi to efi_info and pr_efi_err to efi_err to make it more
obvious that they are part of the EFI stub and not generic printk infra.

S

efi/libstub: Move pr_efi/pr_efi_err into efi namespace

Rename pr_efi to efi_info and pr_efi_err to efi_err to make it more
obvious that they are part of the EFI stub and not generic printk infra.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-4-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Add a helper function to split 64-bit values

In several places 64-bit values need to be split up into two 32-bit
fields, in order to be backward-compatible with the old 32-bit ABIs.

In

efi/libstub: Add a helper function to split 64-bit values

In several places 64-bit values need to be split up into two 32-bit
fields, in order to be backward-compatible with the old 32-bit ABIs.

Instead of open-coding this, add a helper function to set a 64-bit value
as two 32-bit fields.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-3-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Drop __pure getters for EFI stub options

The practice of using __pure getter functions to access global
variables in the EFI stub dates back to the time when we had to
carefully prevent

efi/libstub: Drop __pure getters for EFI stub options

The practice of using __pure getter functions to access global
variables in the EFI stub dates back to the time when we had to
carefully prevent GOT entries from being emitted, because we
could not rely on the toolchain to do this for us.

Today, we use the hidden visibility pragma for all EFI stub source
files, which now all live in the same subdirectory, and we apply a
sanity check on the objects, so we can get rid of these getter
functions and simply refer to global data objects directly.

So switch over the remaining boolean variables carrying options set
on the kernel command line.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Drop __pure getter for efi_system_table

The practice of using __pure getter functions to access global
variables in the EFI stub dates back to the time when we had to
carefully prevent

efi/libstub: Drop __pure getter for efi_system_table

The practice of using __pure getter functions to access global
variables in the EFI stub dates back to the time when we had to
carefully prevent GOT entries from being emitted, because we
could not rely on the toolchain to do this for us.

Today, we use the hidden visibility pragma for all EFI stub source
files, which now all live in the same subdirectory, and we apply a
sanity check on the objects, so we can get rid of these getter
functions and simply refer to global data objects directly.

Start with efi_system_table(), and convert it into a global variable.
While at it, make it a pointer-to-const, because we can.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi: Kill __efistub_global

Now that both arm and x86 are using the linker script to place the EFI
stub's global variables in the correct section, remove __efistub_global.

Signed-off-by: Arvind Sank

efi: Kill __efistub_global

Now that both arm and x86 are using the linker script to place the EFI
stub's global variables in the correct section, remove __efistub_global.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200416151227.3360778-4-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/x86: Remove __efistub_global and add relocation check

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
int

efi/x86: Remove __efistub_global and add relocation check

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
into .data in the linker script for the compressed kernel.

Add relocation checking for x86 as well to catch non-PC-relative
relocations that require runtime processing, since the EFI stub does not
do any runtime relocation processing.

This will catch, for example, data relocations created by static
initializers of pointers.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200416151227.3360778-3-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/arm: Remove __efistub_global annotation

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
into .data in the

efi/arm: Remove __efistub_global annotation

Instead of using __efistub_global to force variables into the .data
section, leave them in the .bss but pull the EFI stub's .bss section
into .data in the linker script for the compressed kernel.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200416151227.3360778-2-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Move efi_relocate_kernel() into separate source file

Move efi_relocate_kernel() into a separate source file, so that it
only gets pulled into builds for architectures that use it. Since

efi/libstub: Move efi_relocate_kernel() into separate source file

Move efi_relocate_kernel() into a separate source file, so that it
only gets pulled into builds for architectures that use it. Since
efi_relocate_kernel() is the only user of efi_low_alloc(), let's
move that over as well.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Add API function to allocate aligned memory

Break out the code to create an aligned page allocation from mem.c
and move it into a function efi_allocate_pages_aligned() in alignedmem.c.

efi/libstub: Add API function to allocate aligned memory

Break out the code to create an aligned page allocation from mem.c
and move it into a function efi_allocate_pages_aligned() in alignedmem.c.
Update efi_allocate_pages() to invoke it unless the minimum alignment
equals the EFI page size (4 KB), in which case the ordinary page
allocator is sufficient. This way, efi_allocate_pages_aligned() will
only be pulled into the build if it is actually being used (which will
be on arm64 only in the immediate future)

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/gop: Allow specifying mode number on command line

Add the ability to choose a video mode for the selected gop by using a
command-line argument of the form
video=efifb:mode=<n>

Signed-off-by: A

efi/gop: Allow specifying mode number on command line

Add the ability to choose a video mode for the selected gop by using a
command-line argument of the form
video=efifb:mode=<n>

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200320020028.1936003-12-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/gop: Add prototypes for query_mode and set_mode

Add prototypes and argmap for the Graphics Output Protocol's QueryMode
and SetMode functions.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu

efi/gop: Add prototypes for query_mode and set_mode

Add prototypes and argmap for the Graphics Output Protocol's QueryMode
and SetMode functions.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200320020028.1936003-11-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: unify EFI call wrappers for non-x86

We have wrappers around EFI calls so that x86 can define special
versions for mixed mode, while all other architectures can use the
same simple defin

efi/libstub: unify EFI call wrappers for non-x86

We have wrappers around EFI calls so that x86 can define special
versions for mixed mode, while all other architectures can use the
same simple definition that just issues the call directly.
In preparation for the arrival of yet another architecture that doesn't
need anything special here (RISC-V), let's move the default definition
into a shared header.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub: Make initrd file loader configurable

Loading an initrd passed via the kernel command line is deprecated: it
is limited to files that reside in the same volume as the one the kernel
itse

efi/libstub: Make initrd file loader configurable

Loading an initrd passed via the kernel command line is deprecated: it
is limited to files that reside in the same volume as the one the kernel
itself was loaded from, and we have more flexible ways to achieve the
same. So make it configurable so new architectures can decide not to
enable it.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/x86: Move efi stub globals from .bss to .data

Commit

3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")

removed the .bss section from the bzImage.

However, while a P

efi/x86: Move efi stub globals from .bss to .data

Commit

3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")

removed the .bss section from the bzImage.

However, while a PE loader is required to zero-initialize the .bss
section before calling the PE entry point, the EFI handover protocol
does not currently document any requirement that .bss be initialized by
the bootloader prior to calling the handover entry.

When systemd-boot is used to boot a unified kernel image [1], the image
is constructed by embedding the bzImage as a .linux section in a PE
executable that contains a small stub loader from systemd together with
additional sections and potentially an initrd. As the .bss section
within the bzImage is no longer explicitly present as part of the file,
it is not initialized before calling the EFI handover entry.
Furthermore, as the size of the embedded .linux section is only the size
of the bzImage file itself, the .bss section's memory may not even have
been allocated.

In particular, this can result in efi_disable_pci_dma being true even
when it was not specified via the command line or configuration option,
which in turn causes crashes while booting on some systems.

To avoid issues, place all EFI stub global variables into the .data
section instead of .bss. As of this writing, only boolean flags for a
few command line arguments and the sys_table pointer were in .bss and
will now move into the .data section.

[1] https://systemd.io/BOOT_LOADER_SPECIFICATION/#type-2-efi-unified-kernel-images

Fixes: 3ee372ccce4d ("x86/boot/compressed/64: Remove .bss/.pgtable from bzImage")
Reported-by: Sergey Shatunov <me@prok.pw>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200406180614.429454-1-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200409130434.6736-4-ardb@kernel.org

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efi/libstub/x86: Use Exit() boot service to exit the stub on errors

Currently, we either return with an error [from efi_pe_entry()] or
enter a deadloop [in efi_main()] if any fatal errors occur duri

efi/libstub/x86: Use Exit() boot service to exit the stub on errors

Currently, we either return with an error [from efi_pe_entry()] or
enter a deadloop [in efi_main()] if any fatal errors occur during
execution of the EFI stub. Let's switch to calling the Exit() EFI boot
service instead in both cases, so that we
a) can get rid of the deadloop, and simply return to the boot manager
if any errors occur during execution of the stub, including during
the call to ExitBootServices(),
b) can also return cleanly from efi_pe_entry() or efi_main() in mixed
mode, once we introduce support for LoadImage/StartImage based mixed
mode in the next patch.

Note that on systems running downstream GRUBs [which do not use LoadImage
or StartImage to boot the kernel, and instead, pass their own image
handle as the loaded image handle], calling Exit() will exit from GRUB
rather than from the kernel, but this is a tolerable side effect.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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