4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 33412b8673135b18ea42beb7f5117ed0091798b6 ]
Commit:
3ea86495aef2 ("efi/arm: preserve early mapping of UEFI memory map longer for BGRT")
deferred the unmap of the early mapping of the UEFI memory map to accommodate the ACPI BGRT code, which looks up the memory type that backs the BGRT table to validate it against the requirements of the UEFI spec.
Unfortunately, this causes problems on ARM, which does not permit early mappings to persist after paging_init() is called, resulting in a WARN() splat. Since we don't support the BGRT table on ARM anway, let's revert ARM to the old behaviour, which is to take down the early mapping at the end of efi_init().
Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: linux-efi@vger.kernel.org Fixes: 3ea86495aef2 ("efi/arm: preserve early mapping of UEFI memory ...") Link: http://lkml.kernel.org/r/20181114175544.12860-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/efi/arm-init.c | 4 ++++ drivers/firmware/efi/arm-runtime.c | 2 +- drivers/firmware/efi/memmap.c | 3 +++ 3 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index 388a929baf95..1a6a77df8a5e 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -265,6 +265,10 @@ void __init efi_init(void) (params.mmap & ~PAGE_MASK)));
init_screen_info(); + + /* ARM does not permit early mappings to persist across paging_init() */ + if (IS_ENABLED(CONFIG_ARM)) + efi_memmap_unmap(); }
static int __init register_gop_device(void) diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c index 922cfb813109..a00934d263c5 100644 --- a/drivers/firmware/efi/arm-runtime.c +++ b/drivers/firmware/efi/arm-runtime.c @@ -110,7 +110,7 @@ static int __init arm_enable_runtime_services(void) { u64 mapsize;
- if (!efi_enabled(EFI_BOOT) || !efi_enabled(EFI_MEMMAP)) { + if (!efi_enabled(EFI_BOOT)) { pr_info("EFI services will not be available.\n"); return 0; } diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c index 5fc70520e04c..1907db2b38d8 100644 --- a/drivers/firmware/efi/memmap.c +++ b/drivers/firmware/efi/memmap.c @@ -118,6 +118,9 @@ int __init efi_memmap_init_early(struct efi_memory_map_data *data)
void __init efi_memmap_unmap(void) { + if (!efi_enabled(EFI_MEMMAP)) + return; + if (!efi.memmap.late) { unsigned long size;