From patchwork Tue Jun 6 07:42:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuai Xue X-Patchwork-Id: 689799 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D7D8C7EE37 for ; Tue, 6 Jun 2023 07:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236529AbjFFHqa (ORCPT ); Tue, 6 Jun 2023 03:46:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237056AbjFFHpH (ORCPT ); Tue, 6 Jun 2023 03:45:07 -0400 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A56A91984; Tue, 6 Jun 2023 00:42:52 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R131e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=ay29a033018046060; MF=xueshuai@linux.alibaba.com; NM=1; PH=DS; RN=25; SR=0; TI=SMTPD_---0VkVSyCt_1686037366; Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0VkVSyCt_1686037366) by smtp.aliyun-inc.com; Tue, 06 Jun 2023 15:42:47 +0800 From: Shuai Xue To: rafael@kernel.org, wangkefeng.wang@huawei.com, tanxiaofei@huawei.com, mawupeng1@huawei.com, tony.luck@intel.com, naoya.horiguchi@nec.com Cc: linux-acpi@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xueshuai@linux.alibaba.com, justin.he@arm.com, akpm@linux-foundation.org, ardb@kernel.org, ashish.kalra@amd.com, baolin.wang@linux.alibaba.com, bp@alien8.de, cuibixuan@linux.alibaba.com, dave.hansen@linux.intel.com, james.morse@arm.com, jarkko@kernel.org, lenb@kernel.org, linmiaohe@huawei.com, lvying6@huawei.com, xiexiuqi@huawei.com, zhuo.song@linux.alibaba.com Subject: [RESEND PATCH v7 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Date: Tue, 6 Jun 2023 15:42:37 +0800 Message-Id: <20230606074238.97166-2-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230606074238.97166-1-xueshuai@linux.alibaba.com> References: <20230606074238.97166-1-xueshuai@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org There are two major types of uncorrected recoverable (UCR) errors : - Action Required (AR): The error is detected and the processor already consumes the memory. OS requires to take action (for example, offline failure page/kill failure thread) to recover this uncorrectable error. - Action Optional (AO): The error is detected out of processor execution context. Some data in the memory are corrupted. But the data have not been consumed. OS is optional to take action to recover this uncorrectable error. The essential difference between AR and AO errors is that AR is a synchronous event, while AO is an asynchronous event. The hardware will signal a synchronous exception (Machine Check Exception on X86 and Synchronous External Abort on Arm64) when an error is detected and the memory access has been architecturally executed. When APEI firmware first is enabled, a platform may describe one error source for the handling of synchronous errors (e.g. MCE or SEA notification ), or for handling asynchronous errors (e.g. SCI or External Interrupt notification). In other words, we can distinguish synchronous errors by APEI notification. For AR errors, kernel will kill current process accessing the poisoned page by sending SIGBUS with BUS_MCEERR_AR. In addition, for AO errors, kernel will notify the process who owns the poisoned page by sending SIGBUS with BUS_MCEERR_AO in early kill mode. However, the GHES driver always sets mf_flags to 0 so that all UCR errors are handled as AO errors in memory failure. To this end, set memory failure flags as MF_ACTION_REQUIRED on synchronous events. Fixes: ba61ca4aab47 ("ACPI, APEI, GHES: Add hardware memory error recovery support")' Signed-off-by: Shuai Xue Tested-by: Ma Wupeng Reviewed-by: Kefeng Wang Reviewed-by: Xiaofei Tan Reviewed-by: Baolin Wang --- drivers/acpi/apei/ghes.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 34ad071a64e9..c479b85899f5 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -101,6 +101,20 @@ static inline bool is_hest_type_generic_v2(struct ghes *ghes) return ghes->generic->header.type == ACPI_HEST_TYPE_GENERIC_ERROR_V2; } +/* + * A platform may describe one error source for the handling of synchronous + * errors (e.g. MCE or SEA), or for handling asynchronous errors (e.g. SCI + * or External Interrupt). On x86, the HEST notifications are always + * asynchronous, so only SEA on ARM is delivered as a synchronous + * notification. + */ +static inline bool is_hest_sync_notify(struct ghes *ghes) +{ + u8 notify_type = ghes->generic->notify.type; + + return notify_type == ACPI_HEST_NOTIFY_SEA; +} + /* * This driver isn't really modular, however for the time being, * continuing to use module_param is the easiest way to remain @@ -477,7 +491,7 @@ static bool ghes_do_memory_failure(u64 physical_addr, int flags) } static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, - int sev) + int sev, bool sync) { int flags = -1; int sec_sev = ghes_severity(gdata->error_severity); @@ -491,7 +505,7 @@ static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, (gdata->flags & CPER_SEC_ERROR_THRESHOLD_EXCEEDED)) flags = MF_SOFT_OFFLINE; if (sev == GHES_SEV_RECOVERABLE && sec_sev == GHES_SEV_RECOVERABLE) - flags = 0; + flags = sync ? MF_ACTION_REQUIRED : 0; if (flags != -1) return ghes_do_memory_failure(mem_err->physical_addr, flags); @@ -499,9 +513,11 @@ static bool ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, return false; } -static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, int sev) +static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, + int sev, bool sync) { struct cper_sec_proc_arm *err = acpi_hest_get_payload(gdata); + int flags = sync ? MF_ACTION_REQUIRED : 0; bool queued = false; int sec_sev, i; char *p; @@ -526,7 +542,7 @@ static bool ghes_handle_arm_hw_error(struct acpi_hest_generic_data *gdata, int s * and don't filter out 'corrected' error here. */ if (is_cache && has_pa) { - queued = ghes_do_memory_failure(err_info->physical_fault_addr, 0); + queued = ghes_do_memory_failure(err_info->physical_fault_addr, flags); p += err_info->length; continue; } @@ -647,6 +663,7 @@ static bool ghes_do_proc(struct ghes *ghes, const guid_t *fru_id = &guid_null; char *fru_text = ""; bool queued = false; + bool sync = is_hest_sync_notify(ghes); sev = ghes_severity(estatus->error_severity); apei_estatus_for_each_section(estatus, gdata) { @@ -664,13 +681,13 @@ static bool ghes_do_proc(struct ghes *ghes, atomic_notifier_call_chain(&ghes_report_chain, sev, mem_err); arch_apei_report_mem_error(sev, mem_err); - queued = ghes_handle_memory_failure(gdata, sev); + queued = ghes_handle_memory_failure(gdata, sev, sync); } else if (guid_equal(sec_type, &CPER_SEC_PCIE)) { ghes_handle_aer(gdata); } else if (guid_equal(sec_type, &CPER_SEC_PROC_ARM)) { - queued = ghes_handle_arm_hw_error(gdata, sev); + queued = ghes_handle_arm_hw_error(gdata, sev, sync); } else { void *err = acpi_hest_get_payload(gdata); From patchwork Tue Jun 6 07:42:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuai Xue X-Patchwork-Id: 689800 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A02F6C7EE2A for ; Tue, 6 Jun 2023 07:46:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236493AbjFFHqV (ORCPT ); Tue, 6 Jun 2023 03:46:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237087AbjFFHpR (ORCPT ); Tue, 6 Jun 2023 03:45:17 -0400 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8175E1986; Tue, 6 Jun 2023 00:42:54 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R201e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=ay29a033018046049; MF=xueshuai@linux.alibaba.com; NM=1; PH=DS; RN=25; SR=0; TI=SMTPD_---0VkVSyE6_1686037368; Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0VkVSyE6_1686037368) by smtp.aliyun-inc.com; Tue, 06 Jun 2023 15:42:49 +0800 From: Shuai Xue To: rafael@kernel.org, wangkefeng.wang@huawei.com, tanxiaofei@huawei.com, mawupeng1@huawei.com, tony.luck@intel.com, naoya.horiguchi@nec.com Cc: linux-acpi@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, xueshuai@linux.alibaba.com, justin.he@arm.com, akpm@linux-foundation.org, ardb@kernel.org, ashish.kalra@amd.com, baolin.wang@linux.alibaba.com, bp@alien8.de, cuibixuan@linux.alibaba.com, dave.hansen@linux.intel.com, james.morse@arm.com, jarkko@kernel.org, lenb@kernel.org, linmiaohe@huawei.com, lvying6@huawei.com, xiexiuqi@huawei.com, zhuo.song@linux.alibaba.com Subject: [RESEND PATCH v7 2/2] ACPI: APEI: handle synchronous exceptions in task work Date: Tue, 6 Jun 2023 15:42:38 +0800 Message-Id: <20230606074238.97166-3-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230606074238.97166-1-xueshuai@linux.alibaba.com> References: <20230606074238.97166-1-xueshuai@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org Hardware errors could be signaled by synchronous interrupt, e.g. when an error is detected by a background scrubber, or signaled by synchronous exception, e.g. when an uncorrected error is consumed. Both synchronous and asynchronous error are queued and handled by a dedicated kthread in workqueue. commit 7f17b4a121d0 ("ACPI: APEI: Kick the memory_failure() queue for synchronous errors") keep track of whether memory_failure() work was queued, and make task_work pending to flush out the workqueue so that the work for synchronous error is processed before returning to user-space. The trick ensures that the corrupted page is unmapped and poisoned. And after returning to user-space, the task starts at current instruction which triggering a page fault in which kernel will send SIGBUS to current process due to VM_FAULT_HWPOISON. However, the memory failure recovery for hwpoison-aware mechanisms does not work as expected. For example, hwpoison-aware user-space processes like QEMU register their customized SIGBUS handler and enable early kill mode by seting PF_MCE_EARLY at initialization. Then the kernel will directy notify the process by sending a SIGBUS signal in memory failure with wrong si_code: the actual user-space process accessing the corrupt memory location, but its memory failure work is handled in a kthread context, so it will send SIGBUS with BUS_MCEERR_AO si_code to the actual user-space process instead of BUS_MCEERR_AR in kill_proc(). To this end, separate synchronous and asynchronous error handling into different paths like X86 platform does: - valid synchronous errors: queue a task_work to synchronously send SIGBUS before ret_to_user. - valid asynchronous errors: queue a work into workqueue to asynchronously handle memory failure. - abnormal branches such as invalid PA, unexpected severity, no memory failure config support, invalid GUID section, OOM, etc. Then for valid synchronous errors, the current context in memory failure is exactly belongs to the task consuming poison data and it will send SIBBUS with proper si_code. Fixes: 7f17b4a121d0 ("ACPI: APEI: Kick the memory_failure() queue for synchronous errors") Signed-off-by: Shuai Xue Tested-by: Ma Wupeng Reviewed-by: Kefeng Wang Reviewed-by: Xiaofei Tan Reviewed-by: Baolin Wang --- arch/x86/kernel/cpu/mce/core.c | 9 +--- drivers/acpi/apei/ghes.c | 84 +++++++++++++++++++++------------- include/acpi/ghes.h | 3 -- mm/memory-failure.c | 17 ++----- 4 files changed, 56 insertions(+), 57 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 2eec60f50057..2ebaaa494ac4 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1311,17 +1311,10 @@ static void kill_me_maybe(struct callback_head *cb) return; } - /* - * -EHWPOISON from memory_failure() means that it already sent SIGBUS - * to the current process with the proper error info, - * -EOPNOTSUPP means hwpoison_filter() filtered the error event, - * - * In both cases, no further processing is required. - */ if (ret == -EHWPOISON || ret == -EOPNOTSUPP) return; - pr_err("Memory error not recovered"); + pr_err("Sending SIGBUS to current task due to memory error not recovered"); kill_me_now(cb); } diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index c479b85899f5..b41d4e462b36 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -452,28 +452,41 @@ static void ghes_clear_estatus(struct ghes *ghes, } /* - * Called as task_work before returning to user-space. - * Ensure any queued work has been done before we return to the context that - * triggered the notification. + * struct sync_task_work - for synchronous RAS event + * + * @twork: callback_head for task work + * @pfn: page frame number of corrupted page + * @flags: fine tune action taken + * + * Structure to pass task work to be handled before + * ret_to_user via task_work_add(). */ -static void ghes_kick_task_work(struct callback_head *head) +struct sync_task_work { + struct callback_head twork; + u64 pfn; + int flags; +}; + +static void memory_failure_cb(struct callback_head *twork) { - struct acpi_hest_generic_status *estatus; - struct ghes_estatus_node *estatus_node; - u32 node_len; + int ret; + struct sync_task_work *twcb = + container_of(twork, struct sync_task_work, twork); - estatus_node = container_of(head, struct ghes_estatus_node, task_work); - if (IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE)) - memory_failure_queue_kick(estatus_node->task_work_cpu); + ret = memory_failure(twcb->pfn, twcb->flags); + kfree(twcb); - estatus = GHES_ESTATUS_FROM_NODE(estatus_node); - node_len = GHES_ESTATUS_NODE_LEN(cper_estatus_len(estatus)); - gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, node_len); + if (!ret || ret == -EHWPOISON || ret == -EOPNOTSUPP) + return; + + pr_err("Sending SIGBUS to current task due to memory error not recovered"); + force_sig(SIGBUS); } static bool ghes_do_memory_failure(u64 physical_addr, int flags) { unsigned long pfn; + struct sync_task_work *twcb; if (!IS_ENABLED(CONFIG_ACPI_APEI_MEMORY_FAILURE)) return false; @@ -486,6 +499,18 @@ static bool ghes_do_memory_failure(u64 physical_addr, int flags) return false; } + if (flags == MF_ACTION_REQUIRED && current->mm) { + twcb = kmalloc(sizeof(*twcb), GFP_ATOMIC); + if (!twcb) + return false; + + twcb->pfn = pfn; + twcb->flags = flags; + init_task_work(&twcb->twork, memory_failure_cb); + task_work_add(current, &twcb->twork, TWA_RESUME); + return true; + } + memory_failure_queue(pfn, flags); return true; } @@ -654,7 +679,7 @@ static void ghes_defer_non_standard_event(struct acpi_hest_generic_data *gdata, schedule_work(&entry->work); } -static bool ghes_do_proc(struct ghes *ghes, +static void ghes_do_proc(struct ghes *ghes, const struct acpi_hest_generic_status *estatus) { int sev, sec_sev; @@ -698,7 +723,14 @@ static bool ghes_do_proc(struct ghes *ghes, } } - return queued; + /* + * If no memory failure work is queued for abnormal synchronous + * errors, do a force kill. + */ + if (sync && !queued) { + pr_err("Sending SIGBUS to current task due to memory error not recovered"); + force_sig(SIGBUS); + } } static void __ghes_print_estatus(const char *pfx, @@ -1000,9 +1032,7 @@ static void ghes_proc_in_irq(struct irq_work *irq_work) struct ghes_estatus_node *estatus_node; struct acpi_hest_generic *generic; struct acpi_hest_generic_status *estatus; - bool task_work_pending; u32 len, node_len; - int ret; llnode = llist_del_all(&ghes_estatus_llist); /* @@ -1017,25 +1047,16 @@ static void ghes_proc_in_irq(struct irq_work *irq_work) estatus = GHES_ESTATUS_FROM_NODE(estatus_node); len = cper_estatus_len(estatus); node_len = GHES_ESTATUS_NODE_LEN(len); - task_work_pending = ghes_do_proc(estatus_node->ghes, estatus); + + ghes_do_proc(estatus_node->ghes, estatus); + if (!ghes_estatus_cached(estatus)) { generic = estatus_node->generic; if (ghes_print_estatus(NULL, generic, estatus)) ghes_estatus_cache_add(generic, estatus); } - - if (task_work_pending && current->mm) { - estatus_node->task_work.func = ghes_kick_task_work; - estatus_node->task_work_cpu = smp_processor_id(); - ret = task_work_add(current, &estatus_node->task_work, - TWA_RESUME); - if (ret) - estatus_node->task_work.func = NULL; - } - - if (!estatus_node->task_work.func) - gen_pool_free(ghes_estatus_pool, - (unsigned long)estatus_node, node_len); + gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, + node_len); llnode = next; } @@ -1096,7 +1117,6 @@ static int ghes_in_nmi_queue_one_entry(struct ghes *ghes, estatus_node->ghes = ghes; estatus_node->generic = ghes->generic; - estatus_node->task_work.func = NULL; estatus = GHES_ESTATUS_FROM_NODE(estatus_node); if (__ghes_read_estatus(estatus, buf_paddr, fixmap_idx, len)) { diff --git a/include/acpi/ghes.h b/include/acpi/ghes.h index 3c8bba9f1114..e5e0c308d27f 100644 --- a/include/acpi/ghes.h +++ b/include/acpi/ghes.h @@ -35,9 +35,6 @@ struct ghes_estatus_node { struct llist_node llnode; struct acpi_hest_generic *generic; struct ghes *ghes; - - int task_work_cpu; - struct callback_head task_work; }; struct ghes_estatus_cache { diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5b663eca1f29..50e9583051ed 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2134,7 +2134,9 @@ static DEFINE_MUTEX(mf_mutex); * * Return: 0 for successfully handled the memory error, * -EOPNOTSUPP for hwpoison_filter() filtered the error event, - * < 0(except -EOPNOTSUPP) on failure. + * -EHWPOISON for already sent SIGBUS to the current process with + * the proper error info, + * other negative error code on failure. */ int memory_failure(unsigned long pfn, int flags) { @@ -2416,19 +2418,6 @@ static void memory_failure_work_func(struct work_struct *work) } } -/* - * Process memory_failure work queued on the specified CPU. - * Used to avoid return-to-userspace racing with the memory_failure workqueue. - */ -void memory_failure_queue_kick(int cpu) -{ - struct memory_failure_cpu *mf_cpu; - - mf_cpu = &per_cpu(memory_failure_cpu, cpu); - cancel_work_sync(&mf_cpu->work); - memory_failure_work_func(&mf_cpu->work); -} - static int __init memory_failure_init(void) { struct memory_failure_cpu *mf_cpu;