From 72a58a63a164b4e9d2d914e65caeb551846883f1 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 14 Nov 2018 09:55:42 -0800 Subject: efi/arm/libstub: Pack FDT after populating it Commit: 24d7c494ce46 ("efi/arm-stub: Round up FDT allocation to mapping size") increased the allocation size for the FDT image created by the stub to a fixed value of 2 MB, to simplify the former code that made several attempts with increasing values for the size. This is reasonable given that the allocation is of type EFI_LOADER_DATA, which is released to the kernel unless it is explicitly memblock_reserve()d by the early boot code. However, this allocation size leaked into the 'size' field of the FDT header metadata, and so the entire allocation remains occupied by the device tree binary, even if most of it is not used to store device tree information. So call fdt_pack() to shrink the FDT data structure to its minimum size after populating all the fields, so that the remaining memory is no longer wasted. Signed-off-by: Ard Biesheuvel Cc: # v4.12+ Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Fixes: 24d7c494ce46 ("efi/arm-stub: Round up FDT allocation to mapping size") Link: http://lkml.kernel.org/r/20181114175544.12860-4-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- drivers/firmware/efi/libstub/fdt.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/firmware/efi/libstub') diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 8830fa601e45..0c0d2312f4a8 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -158,6 +158,10 @@ static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, return efi_status; } } + + /* shrink the FDT back to its minimum size */ + fdt_pack(fdt); + return EFI_SUCCESS; fdt_set_fail: -- cgit v1.2.3 From eff896288872d687d9662000ec9ae11b6d61766f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 14 Nov 2018 09:55:43 -0800 Subject: efi/arm: Defer persistent reservations until after paging_init() The new memory EFI reservation feature we introduced to allow memory reservations to persist across kexec may trigger an unbounded number of calls to memblock_reserve(). The memblock subsystem can deal with this fine, but not before memblock resizing is enabled, which we can only do after paging_init(), when the memory we reallocate the array into is actually mapped. So break out the memreserve table processing into a separate routine and call it after paging_init() on arm64. On ARM, because of limited reviewing bandwidth of the maintainer, we cannot currently fix this, so instead, disable the EFI persistent memreserve entirely on ARM so we can fix it later. Tested-by: Marc Zyngier Signed-off-by: Ard Biesheuvel Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20181114175544.12860-5-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar --- drivers/firmware/efi/libstub/arm-stub.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/firmware/efi/libstub') diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 30ac0c975f8a..3d36142cf812 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -75,6 +75,9 @@ void install_memreserve_table(efi_system_table_t *sys_table_arg) efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID; efi_status_t status; + if (IS_ENABLED(CONFIG_ARM)) + return; + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv), (void **)&rsv); if (status != EFI_SUCCESS) { -- cgit v1.2.3