From: Shuai Xue <xueshuai@linux.alibaba.com>
To: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: rafael@kernel.org, wangkefeng.wang@huawei.com,
tanxiaofei@huawei.com, mawupeng1@huawei.com, tony.luck@intel.com,
linmiaohe@huawei.com, naoya.horiguchi@nec.com,
james.morse@arm.com, gregkh@linuxfoundation.org, will@kernel.org,
linux-acpi@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
linux-edac@vger.kernel.org,
acpica-devel@lists.linuxfoundation.org, stable@vger.kernel.org,
x86@kernel.org, justin.he@arm.com, ardb@kernel.org,
ying.huang@intel.com, ashish.kalra@amd.com,
baolin.wang@linux.alibaba.com, bp@alien8.de, tglx@linutronix.de,
mingo@redhat.com, dave.hansen@linux.intel.com, jarkko@kernel.org,
lenb@kernel.org, hpa@zytor.com, robert.moore@intel.com,
lvying6@huawei.com, xiexiuqi@huawei.com,
zhuo.song@linux.alibaba.com
Subject: Re: [RESEND PATCH v8 2/2] ACPI: APEI: handle synchronous exceptions in task work
Date: Sat, 7 Oct 2023 10:01:46 +0800 [thread overview]
Message-ID: <645ee424-316b-c093-6113-9abdfb42dab5@linux.alibaba.com> (raw)
In-Reply-To: <20231003082858.GA750796@ik1-406-35019.vs.sakura.ne.jp>
On 2023/10/3 16:28, Naoya Horiguchi wrote:
> On Tue, Sep 19, 2023 at 10:21:27AM +0800, Shuai Xue wrote:
>> 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 <xueshuai@linux.alibaba.com>
>> Tested-by: Ma Wupeng <mawupeng1@huawei.com>
>> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> Reviewed-by: Xiaofei Tan <tanxiaofei@huawei.com>
>> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>> ---
>> 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/mm/memory-failure.c b/mm/memory-failure.c
>> index 4d6e43c88489..80e1ea1cc56d 100644
>> --- a/mm/memory-failure.c
>> +++ b/mm/memory-failure.c
>> @@ -2163,7 +2163,9 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags,
>> *
>> * 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,
>
> The meaning of this comment is understood, but the sentence seems to be
> a little too long. Could you sort this out with bullet points (like below)?
>
> * Return values:
> * 0 - success
> * -EOPNOTSUPP - hwpoison_filter() filtered the error event.
> * -EHWPOISON - sent SIGBUS to the current process with the proper
> * error info by kill_accessing_process().
> * other negative values - failure
>
Of course, will do it.
>> + * other negative error code on failure.
>> */
>> int memory_failure(unsigned long pfn, int flags)
>> {
>> @@ -2445,19 +2447,6 @@ 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);
>> -}
>> -
>
> The declaration of memory_failure_queue_kick() still remains in include/linux/mm.h,
> so you can remove it together.
Good catch, will remove it too.
>
> Thanks,
> Naoya Horiguchi
Thank you for valuable comments.
Best Regards,
Shuai
next prev parent reply other threads:[~2023-10-07 2:02 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-27 4:24 [PATCH] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on action required events Shuai Xue
2022-10-28 17:08 ` Rafael J. Wysocki
2022-10-28 17:25 ` Luck, Tony
2022-11-02 11:53 ` Shuai Xue
2022-11-22 11:40 ` Shuai Xue
2022-11-02 7:07 ` Shuai Xue
2022-12-06 15:33 ` [RFC PATCH 0/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2022-12-07 9:54 ` reply for " Lv Ying
2022-12-07 12:34 ` Bixuan Cui
2022-12-07 12:56 ` Shuai Xue
2022-12-07 14:04 ` Shuai Xue
2022-12-08 2:27 ` Lv Ying
2022-12-06 15:33 ` [RFC PATCH 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2022-12-06 15:33 ` [RFC PATCH 2/2] ACPI: APEI: separate synchronous error handling into task work Shuai Xue
2023-02-27 5:03 ` [PATCH v2 0/2] ACPI: APEI: handle synchronous exceptions with proper si_code Shuai Xue
2023-03-06 0:45 ` Shuai Xue
2023-02-27 5:03 ` [PATCH v2 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-03-16 7:21 ` HORIGUCHI NAOYA(堀口 直也)
2023-03-16 9:57 ` Shuai Xue
2023-03-16 16:45 ` Luck, Tony
2023-03-17 1:12 ` Shuai Xue
2023-02-27 5:03 ` [PATCH v2 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-03-16 7:21 ` HORIGUCHI NAOYA(堀口 直也)
2023-03-16 11:10 ` Shuai Xue
2023-03-17 0:29 ` HORIGUCHI NAOYA(堀口 直也)
2023-03-17 1:24 ` Shuai Xue
2023-03-17 7:24 ` [PATCH v3 0/2] ACPI: APEI: handle synchronous exceptions with proper si_code Shuai Xue
2023-03-20 18:03 ` Rafael J. Wysocki
2023-03-30 6:11 ` Shuai Xue
2023-03-30 9:52 ` Rafael J. Wysocki
2023-03-21 7:17 ` mawupeng
2023-03-22 1:27 ` Shuai Xue
2023-03-17 7:24 ` [PATCH v3 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-03-17 7:24 ` [PATCH v3 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-04-06 12:39 ` Xiaofei Tan
2023-04-07 2:21 ` Shuai Xue
2023-04-08 9:13 ` [PATCH v4 0/2] ACPI: APEI: handle synchronous exceptions with proper si_code Shuai Xue
2023-04-08 9:13 ` [PATCH v4 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-04-08 9:13 ` [PATCH v4 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-04-11 1:44 ` Xiaofei Tan
2023-04-11 3:16 ` Shuai Xue
2023-04-11 9:02 ` Xiaofei Tan
2023-04-11 9:48 ` Shuai Xue
2023-04-11 10:48 ` [PATCH v5 0/2] ACPI: APEI: handle synchronous exceptions with proper si_code Shuai Xue
2023-04-11 10:48 ` [PATCH v5 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-04-11 14:17 ` Kefeng Wang
2023-04-12 2:54 ` Shuai Xue
2023-04-12 3:55 ` Xiaofei Tan
2023-04-13 1:42 ` Shuai Xue
2023-04-11 10:48 ` [PATCH v5 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-04-11 14:28 ` Kefeng Wang
2023-04-12 2:58 ` Shuai Xue
2023-04-12 4:05 ` Xiaofei Tan
2023-04-13 1:49 ` Shuai Xue
2023-04-12 11:27 ` [PATCH v6 0/2] ACPI: APEI: handle synchronous exceptions with proper si_code Shuai Xue
2023-04-12 11:28 ` [PATCH v6 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-04-12 11:28 ` [PATCH v6 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-04-17 1:14 ` [PATCH v7 0/2] ACPI: APEI: handle synchronous exceptions with proper si_code Shuai Xue
2023-04-24 6:24 ` Shuai Xue
2023-05-08 1:55 ` Shuai Xue
2023-04-17 1:14 ` [PATCH v7 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-04-17 1:14 ` [PATCH v7 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-09-19 2:21 ` [RESEND PATCH v8 0/2] ACPI: APEI: handle synchronous errors in task work with proper si_code Shuai Xue
2023-09-19 2:21 ` [RESEND PATCH v8 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-09-25 14:43 ` Jarkko Sakkinen
2023-09-26 6:23 ` Shuai Xue
2023-09-19 2:21 ` [RESEND PATCH v8 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-09-25 15:00 ` Jarkko Sakkinen
2023-09-26 6:38 ` Shuai Xue
2023-10-03 8:28 ` Naoya Horiguchi
2023-10-07 2:01 ` Shuai Xue [this message]
2023-10-07 7:28 ` [PATCH v9 0/2] ACPI: APEI: handle synchronous errors in task work with proper si_code Shuai Xue
2023-11-21 1:48 ` Shuai Xue
2023-11-23 15:07 ` Borislav Petkov
2023-11-25 6:44 ` Shuai Xue
2023-11-25 12:10 ` Borislav Petkov
2023-11-26 12:25 ` Shuai Xue
2023-11-29 18:54 ` Borislav Petkov
2023-11-30 2:58 ` Shuai Xue
2023-11-30 14:40 ` Borislav Petkov
2023-11-30 17:43 ` James Morse
2023-12-01 2:58 ` Shuai Xue
2023-11-30 17:39 ` James Morse
2023-12-01 3:37 ` Shuai Xue
2023-10-07 7:28 ` [PATCH v9 1/2] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-11-30 17:39 ` James Morse
2023-12-01 5:22 ` Shuai Xue
2023-10-07 7:28 ` [PATCH v9 2/2] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-11-30 17:39 ` James Morse
2023-12-01 7:03 ` Shuai Xue
2023-12-18 6:45 ` [PATCH v10 0/4] ACPI: APEI: handle synchronous errors in task work with proper si_code Shuai Xue
2023-12-18 6:45 ` [PATCH v10 1/4] ACPI: APEI: set memory failure flags as MF_ACTION_REQUIRED on synchronous events Shuai Xue
2023-12-18 6:53 ` Greg KH
2023-12-21 13:55 ` Rafael J. Wysocki
2023-12-22 1:07 ` Shuai Xue
2023-12-18 6:45 ` [PATCH v10 2/4] ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered Shuai Xue
2023-12-18 6:54 ` Greg KH
2023-12-18 6:45 ` [PATCH v10 3/4] mm: memory-failure: move memory_failure() return value documentation to function declaration Shuai Xue
2023-12-18 6:54 ` Greg KH
2023-12-18 6:45 ` [PATCH v10 4/4] ACPI: APEI: handle synchronous exceptions in task work Shuai Xue
2023-12-18 6:54 ` Greg KH
2024-02-04 8:01 ` [PATCH v11 0/3] ACPI: APEI: handle synchronous exceptions in task work to send correct SIGBUS si_code Shuai Xue
2024-02-19 1:46 ` Shuai Xue
2024-02-04 8:01 ` [PATCH v11 1/3] ACPI: APEI: send SIGBUS to current task if synchronous memory error not recovered Shuai Xue
2024-02-19 9:25 ` Borislav Petkov
2024-02-22 2:07 ` Shuai Xue
2024-02-23 5:26 ` Dan Williams
2024-02-23 12:08 ` Jonathan Cameron
2024-02-23 12:17 ` Jonathan Cameron
2024-02-24 6:08 ` Shuai Xue
2024-02-26 10:29 ` Borislav Petkov
2024-02-27 1:23 ` Shuai Xue
2024-02-24 19:42 ` Dan Williams
2024-02-24 19:40 ` Dan Williams
2024-02-04 8:01 ` [PATCH v11 2/3] mm: memory-failure: move return value documentation to function declaration Shuai Xue
2024-02-26 10:46 ` Borislav Petkov
2024-02-27 1:27 ` Shuai Xue
2024-02-04 8:01 ` [PATCH v11 3/3] ACPI: APEI: handle synchronous exceptions in task work to send correct SIGBUS si_code Shuai Xue
2024-02-29 7:05 ` Shuai Xue
2024-03-08 10:18 ` Borislav Petkov
2024-03-12 6:05 ` Shuai Xue
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