From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f197.google.com (mail-ot0-f197.google.com [74.125.82.197]) by kanga.kvack.org (Postfix) with ESMTP id 1BF6D6B0286 for ; Tue, 26 Jun 2018 13:02:53 -0400 (EDT) Received: by mail-ot0-f197.google.com with SMTP id p13-v6so8452647otl.23 for ; Tue, 26 Jun 2018 10:02:53 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id n11-v6si613140otl.127.2018.06.26.10.02.51 for ; Tue, 26 Jun 2018 10:02:51 -0700 (PDT) From: James Morse Subject: [PATCH v5 15/20] ACPI / APEI: Only use queued estatus entry during _in_nmi_notify_one() Date: Tue, 26 Jun 2018 18:01:11 +0100 Message-Id: <20180626170116.25825-16-james.morse@arm.com> In-Reply-To: <20180626170116.25825-1-james.morse@arm.com> References: <20180626170116.25825-1-james.morse@arm.com> 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 , Tyler Baicar , Dongjiu Geng , Xie XiuQi , Punit Agrawal , jonathan.zhang@cavium.com, James Morse Each struct ghes has an worst-case sized buffer for storing the estatus. If an error is being processed by ghes_proc() in process context this buffer will be in use. If the error source then triggers an NMI-like notification, the same buffer will be used by _in_nmi_notify_one() to stage the estatus data, before __process_error() copys it into a queued estatus entry. Merge __process_error()s work into _in_nmi_notify_one() so that the queued estatus entry is used from the beginning. Use the new ghes_peek_estatus() so we know how much memory to allocate from the ghes_estatus_pool before we read the records. Reported-by: Borislav Petkov Signed-off-by: James Morse --- drivers/acpi/apei/ghes.c | 45 ++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 23 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 1d59d85b38d2..f196f8797fc1 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -713,40 +713,32 @@ static void ghes_print_queued_estatus(void) } } -/* Save estatus for further processing in IRQ context */ -static void __process_error(struct ghes *ghes, - struct acpi_hest_generic_status *ghes_estatus) +static int _in_nmi_notify_one(struct ghes *ghes, int fixmap_idx) { + int sev, rc = 0; u32 len, node_len; + phys_addr_t buf_paddr; struct ghes_estatus_node *estatus_node; struct acpi_hest_generic_status *estatus; - if (ghes_estatus_cached(ghes_estatus)) - return; + rc = ghes_peek_estatus(ghes, fixmap_idx, &buf_paddr, &len); + if (rc) + return rc; - len = cper_estatus_len(ghes_estatus); node_len = GHES_ESTATUS_NODE_LEN(len); estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool, node_len); if (!estatus_node) - return; + return -ENOMEM; estatus_node->ghes = ghes; estatus_node->generic = ghes->generic; estatus = GHES_ESTATUS_FROM_NODE(estatus_node); - memcpy(estatus, ghes_estatus, len); - llist_add(&estatus_node->llnode, &ghes_estatus_llist); -} - -static int _in_nmi_notify_one(struct ghes *ghes, int fixmap_idx) -{ - int sev; - phys_addr_t buf_paddr; - struct acpi_hest_generic_status *estatus = ghes->estatus; - if (ghes_read_estatus(ghes, estatus, &buf_paddr, fixmap_idx)) { + if (__ghes_read_estatus(estatus, buf_paddr, len, fixmap_idx)) { ghes_clear_estatus(estatus, buf_paddr, fixmap_idx); - return -ENOENT; + rc = -ENOENT; + goto no_work; } sev = ghes_severity(estatus->error_severity); @@ -755,13 +747,20 @@ static int _in_nmi_notify_one(struct ghes *ghes, int fixmap_idx) __ghes_panic(ghes, estatus); } - if (!buf_paddr) - return 0; - - __process_error(ghes, estatus); ghes_clear_estatus(estatus, buf_paddr, fixmap_idx); - return 0; + if (!buf_paddr || ghes_estatus_cached(estatus)) + goto no_work; + + llist_add(&estatus_node->llnode, &ghes_estatus_llist); + + return rc; + +no_work: + gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, + node_len); + + return rc; } static int ghes_estatus_queue_notified(struct list_head *rcu_list, -- 2.17.1