From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964807AbcLUS27 (ORCPT ); Wed, 21 Dec 2016 13:28:59 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:33114 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935667AbcLUS25 (ORCPT ); Wed, 21 Dec 2016 13:28:57 -0500 From: Nicolai Stange To: Matt Fleming Cc: Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolai Stange Subject: [PATCH 2/2] efi: efi_mem_reserve(): don't reserve through memblock after mm_init() Date: Wed, 21 Dec 2016 19:28:46 +0100 Message-Id: <20161221182846.2968-2-nicstange@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20161221182846.2968-1-nicstange@gmail.com> References: <20161221182846.2968-1-nicstange@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before invoking the arch specific handler, efi_mem_reserve() reserves the given memory region through memblock. efi_mem_reserve() can get called after mm_init() though -- through efi_bgrt_init(), for example. After mm_init(), memblock is dead and should not be used anymore. Let efi_mem_reserve() check whether memblock is dead and not do the reservation if so. Emit a warning from the generic efi_arch mem_reserve() in this case: if the architecture doesn't provide any other means of registering the region as reserved, the operation would be a nop. Fixes: 4bc9f92e64c8 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data") Signed-off-by: Nicolai Stange --- drivers/firmware/efi/efi.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 92914801e388..12b2e3a6d73f 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -403,7 +403,10 @@ u64 __init efi_mem_desc_end(efi_memory_desc_t *md) return end; } -void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} +void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) +{ + WARN(slab_is_available(), "efi_mem_reserve() has no effect"); +} /** * efi_mem_reserve - Reserve an EFI memory region @@ -419,7 +422,7 @@ void __init __weak efi_arch_mem_reserve(phys_addr_t addr, u64 size) {} */ void __init efi_mem_reserve(phys_addr_t addr, u64 size) { - if (!memblock_is_region_reserved(addr, size)) + if (slab_is_available() && !memblock_is_region_reserved(addr, size)) memblock_reserve(addr, size); /* -- 2.11.0