From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) by kanga.kvack.org (Postfix) with ESMTP id 26E756B69DD for ; Mon, 3 Dec 2018 13:06:48 -0500 (EST) Received: by mail-oi1-f199.google.com with SMTP id w80so8787296oiw.19 for ; Mon, 03 Dec 2018 10:06:48 -0800 (PST) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id n1si6879652otn.272.2018.12.03.10.06.46 for ; Mon, 03 Dec 2018 10:06:46 -0800 (PST) From: James Morse Subject: [PATCH v7 03/25] ACPI / APEI: Switch estatus pool to use vmalloc memory Date: Mon, 3 Dec 2018 18:05:51 +0000 Message-Id: <20181203180613.228133-4-james.morse@arm.com> In-Reply-To: <20181203180613.228133-1-james.morse@arm.com> References: <20181203180613.228133-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-acpi@vger.kernel.org Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Borislav Petkov , Marc Zyngier , Christoffer Dall , Will Deacon , Catalin Marinas , Naoya Horiguchi , Rafael Wysocki , Len Brown , Tony Luck , Dongjiu Geng , Xie XiuQi , Fan Wu , James Morse The ghes code is careful to parse and round firmware's advertised memory requirements for CPER records, up to a maximum of 64K. However when ghes_estatus_pool_expand() does its work, it splits the requested size into PAGE_SIZE granules. This means if firmware generates 5K of CPER records, and correctly describes this in the table, __process_error() will silently fail as it is unable to allocate more than PAGE_SIZE. Switch the estatus pool to vmalloc() memory. On x86 vmalloc() memory may fault and be fixed up by vmalloc_fault(). To prevent this call vmalloc_sync_all() before an NMI handler could discover the memory. Signed-off-by: James Morse --- drivers/acpi/apei/ghes.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index e8503c7d721f..c15264f2dc4b 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -170,40 +170,40 @@ static int ghes_estatus_pool_init(void) return 0; } -static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool, +static void ghes_estatus_pool_free_chunk(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data) { - free_page(chunk->start_addr); + vfree((void *)chunk->start_addr); } static void ghes_estatus_pool_exit(void) { gen_pool_for_each_chunk(ghes_estatus_pool, - ghes_estatus_pool_free_chunk_page, NULL); + ghes_estatus_pool_free_chunk, NULL); gen_pool_destroy(ghes_estatus_pool); } static int ghes_estatus_pool_expand(unsigned long len) { - unsigned long i, pages, size, addr; - int ret; + unsigned long size, addr; ghes_estatus_pool_size_request += PAGE_ALIGN(len); size = gen_pool_size(ghes_estatus_pool); if (size >= ghes_estatus_pool_size_request) return 0; - pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE; - for (i = 0; i < pages; i++) { - addr = __get_free_page(GFP_KERNEL); - if (!addr) - return -ENOMEM; - ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1); - if (ret) - return ret; - } - return 0; + addr = (unsigned long)vmalloc(PAGE_ALIGN(len)); + if (!addr) + return -ENOMEM; + + /* + * New allocation must be visible in all pgd before it can be found by + * an NMI allocating from the pool. + */ + vmalloc_sync_all(); + + return gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1); } static int map_gen_v2(struct ghes *ghes) -- 2.19.2