| 686b58ce | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Increase section and file alignment to 4k/512
commit 3e3eabe26dc88692d34cf76ca0e0dd331481cc15 upstream.
Align x86 with other EFI architectures, and increase the section
alignment to the E
x86/boot: Increase section and file alignment to 4k/512
commit 3e3eabe26dc88692d34cf76ca0e0dd331481cc15 upstream.
Align x86 with other EFI architectures, and increase the section
alignment to the EFI page size (4k), so that firmware is able to honour
the section permission attributes and map code read-only and data
non-executable.
There are a number of requirements that have to be taken into account:
- the sign tools get cranky when there are gaps between sections in the
file view of the image
- the virtual offset of each section must be aligned to the image's
section alignment
- the file offset *and size* of each section must be aligned to the
image's file alignment
- the image size must be aligned to the section alignment
- each section's virtual offset must be greater than or equal to the
size of the headers.
In order to meet all these requirements, while avoiding the need for
lots of padding to accommodate the .compat section, the latter is placed
at an arbitrary offset towards the end of the image, but aligned to the
minimum file alignment (512 bytes). The space before the .text section
is therefore distributed between the PE header, the .setup section and
the .compat section, leaving no gaps in the file coverage, making the
signing tools happy.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-18-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 476316bb | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Drop PE/COFF .reloc section
commit fa5750521e0a4efbc1af05223da9c4bbd6c21c83 upstream.
Ancient buggy EFI loaders may have required a .reloc section to be
present at some point in time, but
x86/boot: Drop PE/COFF .reloc section
commit fa5750521e0a4efbc1af05223da9c4bbd6c21c83 upstream.
Ancient buggy EFI loaders may have required a .reloc section to be
present at some point in time, but this has not been true for a long
time so the .reloc section can just be dropped.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-16-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 0db81e8e | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Construct PE/COFF .text section from assembler
commit efa089e63b56bdc5eca754b995cb039dd7a5457e upstream.
Now that the size of the setup block is visible to the assembler, it is
possible t
x86/boot: Construct PE/COFF .text section from assembler
commit efa089e63b56bdc5eca754b995cb039dd7a5457e upstream.
Now that the size of the setup block is visible to the assembler, it is
possible to populate the PE/COFF header fields from the asm code
directly, instead of poking the values into the binary using the build
tool. This will make it easier to reorganize the section layout without
having to tweak the build tool in lockstep.
This change has no impact on the resulting bzImage binary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-15-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 0cf3d613 | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Derive file size from _edata symbol
commit aeb92067f6ae994b541d7f9752fe54ed3d108bcc upstream.
Tweak the linker script so that the value of _edata represents the
decompressor binary's file
x86/boot: Derive file size from _edata symbol
commit aeb92067f6ae994b541d7f9752fe54ed3d108bcc upstream.
Tweak the linker script so that the value of _edata represents the
decompressor binary's file size rounded up to the appropriate alignment.
This removes the need to calculate it in the build tool, and will make
it easier to refer to the file size from the header directly in
subsequent changes to the PE header layout.
While adding _edata to the sed regex that parses the compressed
vmlinux's symbol list, tweak the regex a bit for conciseness.
This change has no impact on the resulting bzImage binary when
configured with CONFIG_EFI_STUB=y.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-14-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| c731fbcf | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Define setup size in linker script
commit 093ab258e3fb1d1d3afdfd4a69403d44ce90e360 upstream.
The setup block contains the real mode startup code that is used when
booting from a legacy BI
x86/boot: Define setup size in linker script
commit 093ab258e3fb1d1d3afdfd4a69403d44ce90e360 upstream.
The setup block contains the real mode startup code that is used when
booting from a legacy BIOS, along with the boot_params/setup_data that
is used by legacy x86 bootloaders to pass the command line and initial
ramdisk parameters, among other things.
The setup block also contains the PE/COFF header of the entire combined
image, which includes the compressed kernel image, the decompressor and
the EFI stub.
This PE header describes the layout of the executable image in memory,
and currently, the fact that the setup block precedes it makes it rather
fiddly to get the right values into the right place in the final image.
Let's make things a bit easier by defining the setup_size in the linker
script so it can be referenced from the asm code directly, rather than
having to rely on the build tool to calculate it. For the time being,
add 64 bytes of fixed padding for the .reloc and .compat sections - this
will be removed in a subsequent patch after the PE/COFF header has been
reorganized.
This change has no impact on the resulting bzImage binary when
configured with CONFIG_EFI_MIXED=y.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-13-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 431b39e6 | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Set EFI handover offset directly in header asm
commit eac956345f99dda3d68f4ae6cf7b494105e54780 upstream.
The offsets of the EFI handover entrypoints are available to the
assembler when co
x86/boot: Set EFI handover offset directly in header asm
commit eac956345f99dda3d68f4ae6cf7b494105e54780 upstream.
The offsets of the EFI handover entrypoints are available to the
assembler when constructing the header, so there is no need to set them
from the build tool afterwards.
This change has no impact on the resulting bzImage binary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-12-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 8e102324 | 15-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Grab kernel_info offset from zoffset header directly
commit 2e765c02dcbfc2a8a4527c621a84b9502f6b9bd2 upstream.
Instead of parsing zoffset.h and poking the kernel_info offset value
into th
x86/boot: Grab kernel_info offset from zoffset header directly
commit 2e765c02dcbfc2a8a4527c621a84b9502f6b9bd2 upstream.
Instead of parsing zoffset.h and poking the kernel_info offset value
into the header from the build tool, just grab the value directly in the
asm file that describes this header.
This change has no impact on the resulting bzImage binary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915171623.655440-11-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| a38801ba | 12-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Drop references to startup_64
commit b618d31f112bea3d2daea19190d63e567f32a4db upstream.
The x86 boot image generation tool assign a default value to startup_64
and subsequently parses the
x86/boot: Drop references to startup_64
commit b618d31f112bea3d2daea19190d63e567f32a4db upstream.
The x86 boot image generation tool assign a default value to startup_64
and subsequently parses the actual value from zoffset.h but it never
actually uses the value anywhere. So remove this code.
This change has no impact on the resulting bzImage binary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230912090051.4014114-25-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 08796fc9 | 12-Sep-2023 |
Ard Biesheuvel <ardb@kernel.org> |
x86/boot: Drop redundant code setting the root device
commit 7448e8e5d15a3c4df649bf6d6d460f78396f7e1e upstream.
The root device defaults to 0,0 and is no longer configurable at build
time [0], so t
x86/boot: Drop redundant code setting the root device
commit 7448e8e5d15a3c4df649bf6d6d460f78396f7e1e upstream.
The root device defaults to 0,0 and is no longer configurable at build
time [0], so there is no need for the build tool to ever write to this
field.
[0] 079f85e624189292 ("x86, build: Do not set the root_dev field in bzImage")
This change has no impact on the resulting bzImage binary.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230912090051.4014114-23-ardb@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| d5cdf4cf | 08-Mar-2020 |
Arvind Sankar <nivedita@alum.mit.edu> |
efi/x86: Don't relocate the kernel unless necessary
Add alignment slack to the PE image size, so that we can realign the
decompression buffer within the space allocated for the image.
Only relocate
efi/x86: Don't relocate the kernel unless necessary
Add alignment slack to the PE image size, so that we can realign the
decompression buffer within the space allocated for the image.
Only relocate the kernel if it has been loaded at an unsuitable address:
- Below LOAD_PHYSICAL_ADDR, or
- Above 64T for 64-bit and 512MiB for 32-bit
For 32-bit, the upper limit is conservative, but the exact limit can be
difficult to calculate.
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/20200303221205.4048668-6-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-20-ardb@kernel.org
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| 97aa2765 | 12-Feb-2020 |
Ard Biesheuvel <ardb@kernel.org> |
efi/x86: Add true mixed mode entry point into .compat section
Currently, mixed mode is closely tied to the EFI handover protocol
and relies on intimate knowledge of the bootparams structure, setup
h
efi/x86: Add true mixed mode entry point into .compat section
Currently, mixed mode is closely tied to the EFI handover protocol
and relies on intimate knowledge of the bootparams structure, setup
header etc, all of which are rather byzantine and entirely specific
to x86.
Even though no other EFI supported architectures are currently known
that could support something like mixed mode, it still makes sense to
abstract a bit from this, and make it part of a generic Linux on EFI
boot protocol.
To that end, add a .compat section to the mixed mode binary, and populate
it with the PE machine type and entry point address, allowing firmware
implementations to match it to their native machine type, and invoke
non-native binaries using a secondary entry point.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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| 832187f0 | 12-Feb-2020 |
Ard Biesheuvel <ardb@kernel.org> |
efi/x86: Drop redundant .bss section
In commit
c7fb93ec51d462ec ("x86/efi: Include a .bss section within the PE/COFF headers")
we added a separate .bss section to the PE/COFF header of the compr
efi/x86: Drop redundant .bss section
In commit
c7fb93ec51d462ec ("x86/efi: Include a .bss section within the PE/COFF headers")
we added a separate .bss section to the PE/COFF header of the compressed
kernel describing the static memory footprint of the decompressor, to
ensure that it has enough headroom to decompress itself.
We can achieve the exact same result by increasing the virtual size of
the .text section, without changing the raw size, which, as per the
PE/COFF specification, requires the loader to zero initialize the delta.
Doing so frees up a slot in the section table, which we will use later
to describe the mixed mode entrypoint.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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