Commit graph

6 commits

Author SHA1 Message Date
Ard Biesheuvel
2aa6501b2f efi/x86: Free EFI memory map only when installing a new one.
[ Commit 75dde792d6f6c2d0af50278bd374bf0c512fe196 upstream ]

The logic in __efi_memmap_init() is shared between two different
execution flows:
- mapping the EFI memory map early or late into the kernel VA space, so
  that its entries can be accessed;
- the x86 specific cloning of the EFI memory map in order to insert new
  entries that are created as a result of making a memory reservation
  via a call to efi_mem_reserve().

In the former case, the underlying memory containing the kernel's view
of the EFI memory map (which may be heavily modified by the kernel
itself on x86) is not modified at all, and the only thing that changes
is the virtual mapping of this memory, which is different between early
and late boot.

In the latter case, an entirely new allocation is created that carries a
new, updated version of the kernel's view of the EFI memory map. When
installing this new version, the old version will no longer be
referenced, and if the memory was allocated by the kernel, it will leak
unless it gets freed.

The logic that implements this freeing currently lives on the code path
that is shared between these two use cases, but it should only apply to
the latter. So move it to the correct spot.

While at it, drop the dummy definition for non-x86 architectures, as
that is no longer needed.

Cc: <stable@vger.kernel.org>
Fixes: f0ef6523475f ("efi: Fix efi_memmap_alloc() leaks")
Tested-by: Ashish Kalra <Ashish.Kalra@amd.com>
Link: https://lore.kernel.org/all/36ad5079-4326-45ed-85f6-928ff76483d3@amd.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 14:19:35 +01:00
Ard Biesheuvel
0c7592211f efi: xen: Set EFI_PARAVIRT for Xen dom0 boot on all architectures
[ Commit d85e3e34940788578eeffd94e8b7e1d28e7278e9 upstream ]

Currently, the EFI_PARAVIRT flag is only used by Xen dom0 boot on x86,
even though other architectures also support pseudo-EFI boot, where the
core kernel is invoked directly and provided with a set of data tables
that resemble the ones constructed by the EFI stub, which never actually
runs in that case.

Let's fix this inconsistency, and always set this flag when booting dom0
via the EFI boot path. Note that Xen on x86 does not provide the EFI
memory map in this case, whereas other architectures do, so move the
associated EFI_PARAVIRT check into the x86 platform code.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 14:19:35 +01:00
Ard Biesheuvel
67c6fa1332 efi: memmap: Move manipulation routines into x86 arch tree
[ Commit fdc6d38d64a20c542b1867ebeb8dd03b98829336 upstream ]

The EFI memory map is a description of the memory layout as provided by
the firmware, and only x86 manipulates it in various different ways for
its own memory bookkeeping. So let's move the memmap routines that are
only used by x86 into the x86 arch tree.

[ardb: minor tweaks for linux-5.10.y backport]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 14:19:35 +01:00
Liu Zixian
2ebdb3338e efi: Correct comment on efi_memmap_alloc
[ Commit db01ea882bf601252dad57242655da17fd9ad2f5 upstream ]

Returning zero means success now.

Signed-off-by: Liu Zixian <liuzixian4@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 14:19:35 +01:00
Zheng Zhi Yuan
ccac9a75ec drivers: fix typo in firmware/efi/memmap.c
[ Commit 1df4d1724baafa55e9803414ebcdf1ca702bc958 upstream ]

This patch fixes the spelling error in firmware/efi/memmap.c, changing
it to the correct word.

Signed-off-by: Zheng Zhi Yuan <kevinjone25@g.ncu.edu.tw>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-19 14:19:35 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00