tree a794e67bd9124e280768fe61551f0b1229ec10ac
parent 33cfbc003586076cfe0afe7f756046d4f03f6eaf
author Ilias Apalodimas <ilias.apalodimas@linaro.org> 1733150565 +0200
committer Ilias Apalodimas <ilias.apalodimas@linaro.org> 1733382104 +0200

lmb: Fix the allocation of overlapping memory areas with !LMB_NONE

At the moment the LMB allocator will return 'success' immediately on two
consecutive allocations if the second one is smaller and the flags match
without resizing the reserved area.

This is problematic for two reasons, first of all the new updated
allocation won't update the size and we end up holding more memory than
needed, but most importantly it breaks the EFI SCT tests since EFI
now allocates via LMB.

More specifically when EFI requests a specific address twice with the
EFI_ALLOCATE_ADDRESS flag set, the first allocation will succeed and
update the EFI memory map. Due to the LMB behavior the second allocation
will also succeed but the address ranges are already in the EFI memory
map due the first allocation. EFI will then fail to update the memory map,
returning EFI_OUT_OF_RESOURCES instead of EFI_NOT_FOUND which break EFI
conformance.

So let's remove the fast check with is problematic anyway and leave LMB
resize and calculate address properly. LMB will now
- try to resize the reservations for LMB_NONE
- return -1 if the memory is not LMB_NONE and already reserved

The LMB code needs some cleanup in that part, but since we are close to
2025.01 do the easy fix and plan to refactor it later.
Also update the dm tests with the new behavior.

Fixes: commit 22f2c9ed9f53 ("efi: memory: use the lmb API's for allocating and freeing memory")
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>