efi/libstub/x86: Permit cmdline data to be allocated above 4 GB

We now support cmdline data that is located in memory that is not
32-bit addressable, so relax the allocation limit on systems where
t

efi/libstub/x86: Permit cmdline data to be allocated above 4 GB

We now support cmdline data that is located in memory that is not
32-bit addressable, so relax the allocation limit on systems where
this feature is enabled.

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

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efi/libstub/x86: Permit bootparams struct to be allocated above 4 GB

We now support bootparams structures that are located in memory that
is not 32-bit addressable, so relax the allocation limit on

efi/libstub/x86: Permit bootparams struct to be allocated above 4 GB

We now support bootparams structures that are located in memory that
is not 32-bit addressable, so relax the allocation limit on systems
where this feature is enabled.

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

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efi/libstub/x86: Incorporate eboot.c into libstub

Most of the EFI stub source files of all architectures reside under
drivers/firmware/efi/libstub, where they share a Makefile with special
CFLAGS an

efi/libstub/x86: Incorporate eboot.c into libstub

Most of the EFI stub source files of all architectures reside under
drivers/firmware/efi/libstub, where they share a Makefile with special
CFLAGS and an include file with declarations that are only relevant
for stub code.

Currently, we carry a lot of stub specific stuff in linux/efi.h only
because eboot.c in arch/x86 needs them as well. So let's move eboot.c
into libstub/, and move the contents of eboot.h that we still care
about into efistub.h

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

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efi/x86: Only copy upto the end of setup_header

When copying the setup_header into the boot_params buffer, only the data
that is actually part of the setup_header should be copied.

efi/x86: Only copy upto the end of setup_header

When copying the setup_header into the boot_params buffer, only the data
that is actually part of the setup_header should be copied.

efi_pe_entry() currently copies the entire second sector, which
initializes some of the fields in boot_params beyond the setup_header
with garbage (i.e. part of the real-mode boot code gets copied into
those fields).

This does not cause any issues currently because the fields that are
overwritten are padding, BIOS EDD information that won't get used, and
the E820 table which will get properly filled in later.

Fix this to only copy data that is actually part of the setup_header
structure.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/x86: Remove unused variables

Commit

987053a30016 ("efi/x86: Move command-line initrd loading to efi_main")

made the ramdisk_addr/ramdisk_size variables in efi_pe_entr

efi/x86: Remove unused variables

Commit

987053a30016 ("efi/x86: Move command-line initrd loading to efi_main")

made the ramdisk_addr/ramdisk_size variables in efi_pe_entry unused, but
neglected to delete them.

Delete these unused variables.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/x86: Don't blow away existing initrd

Commit

987053a30016 ("efi/x86: Move command-line initrd loading to efi_main")

moved the command-line initrd loading into efi_main

efi/x86: Don't blow away existing initrd

Commit

987053a30016 ("efi/x86: Move command-line initrd loading to efi_main")

moved the command-line initrd loading into efi_main(), with a check
to ensure that it was attempted only if the EFI stub was booted via
efi_pe_entry rather than the EFI handover entry.

However, in the case where it was booted via handover entry, and thus an
initrd may have already been loaded by the bootloader, it then wrote 0
for the initrd address and size, removing any existing initrd.

Fix this by checking if size is positive before setting the fields in
the bootparams structure.

Fixes: 987053a30016 ("efi/x86: Move command-line initrd loading to efi_main")
Reported-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lkml.kernel.org/r/20200527232602.21596-1-nivedita@alum.mit.edu

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Merge tag 'efi-changes-for-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

More EFI changes for v5.8:

- Rename pr_efi/pr_efi_err to efi_info/efi_err, a

Merge tag 'efi-changes-for-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

More EFI changes for v5.8:

- Rename pr_efi/pr_efi_err to efi_info/efi_err, and use them consistently
- Simplify and unify initrd loading
- Parse the builtin command line on x86 (if provided)
- Implement printk() support, including support for wide character strings
- Some fixes for issues introduced by the first batch of v5.8 changes
- Fix a missing prototypes warning
- Simplify GDT handling in early mixed mode thunking code
- Some other minor fixes and cleanups

Conflicts:
drivers/firmware/efi/libstub/efistub.h

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

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Merge tag 'v5.7-rc7' into efi/core, to refresh the branch and pick up fixes

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

efi/libstub: Use pool allocation for the command line

Now that we removed the memory limit for the allocation of the
command line, there is no longer a need to use the page based
all

efi/libstub: Use pool allocation for the command line

Now that we removed the memory limit for the allocation of the
command line, there is no longer a need to use the page based
allocator so switch to a pool allocation instead.

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 avo

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: Check return value of efi_parse_options

efi_parse_options can fail if it is unable to allocate space for a copy
of the command line. Check the return value to make sure it s

efi/libstub: Check return value of efi_parse_options

efi_parse_options can fail if it is unable to allocate space for a copy
of the command line. Check the return value to make sure it succeeded.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-12-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/x86: Support builtin command line

Add support for the x86 CMDLINE_BOOL and CMDLINE_OVERRIDE configuration
options.

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

efi/x86: Support builtin command line

Add support for the x86 CMDLINE_BOOL and CMDLINE_OVERRIDE configuration
options.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-11-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-s

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/x86: Move command-line initrd loading to efi_main

Consolidate the initrd loading in efi_main.

The command line options now need to be parsed only once.

Signed-off-by: A

efi/x86: Move command-line initrd loading to efi_main

Consolidate the initrd loading in efi_main.

The command line options now need to be parsed only once.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-9-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/x86: Use efi_err for error messages

Use efi_err instead of bare efi_printk for error messages.

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

efi/x86: Use efi_err for error messages

Use efi_err instead of bare efi_printk for error messages.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-5-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-b

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/x86: Use correct size for boot_params

struct boot_params is only 4096 bytes, not 16384. Fix this by using
sizeof(struct boot_params) instead of hardcoding the incorrect value.

efi/x86: Use correct size for boot_params

struct boot_params is only 4096 bytes, not 16384. Fix this by using
sizeof(struct boot_params) instead of hardcoding the incorrect value.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-2-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

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efi/libstub/x86: Avoid getter function for efi_is64

We no longer need to take special care when using global variables
in the EFI stub, so switch to a simple symbol reference for efi_is6

efi/libstub/x86: Avoid getter function for efi_is64

We no longer need to take special care when using global variables
in the EFI stub, so switch to a simple symbol reference for efi_is64.

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
c

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
ca

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

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: Always relocate the kernel for EFI handover entry

Commit

d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary")

tries to avoid relocating the kerne

efi/x86: Always relocate the kernel for EFI handover entry

Commit

d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary")

tries to avoid relocating the kernel in the EFI stub as far as possible.

However, 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 that will
call the EFI stub handover entry, together with additional sections and
potentially an initrd. When this image is constructed, by for example
dracut, the initrd is placed after the bzImage without ensuring that at
least init_size bytes are available for the bzImage. If the kernel is
not relocated by the EFI stub, this could result in the compressed
kernel's startup code in head_{32,64}.S overwriting the initrd.

To prevent this, unconditionally relocate the kernel if the EFI stub was
entered via the handover entry point.

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

Fixes: d5cdf4cfeac9 ("efi/x86: Don't relocate the kernel unless necessary")
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/20200406180614.429454-2-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200409130434.6736-5-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 bzIm

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: Remove redundant assignment to pointer hdr

The pointer hdr is being assigned a value that is never read and
it is being updated later with a new value. The assignment is

efi/libstub/x86: Remove redundant assignment to pointer hdr

The pointer hdr is being assigned a value that is never read and
it is being updated later with a new value. The assignment is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200402102537.503103-1-colin.king@canonical.com
Link: https://lore.kernel.org/r/20200409130434.6736-3-ardb@kernel.org

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efi/x86: Fix cast of image argument

handle_protocol() expects void **, not void *.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kerne

efi/x86: Fix cast of image argument

handle_protocol() expects void **, not void *.

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/20200305143642.820865-1-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-28-ardb@kernel.org

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