Re: [PATCH v2 1/3] arm64/ras: support sea error recovery

From: Xie XiuQi
Date: Thu Sep 07 2017 - 00:26:20 EST


Hi Borislav,

On 2017/9/6 18:12, Borislav Petkov wrote:
> On Tue, Sep 05, 2017 at 07:06:04PM +0800, Xie XiuQi wrote:
>> With ARM v8.2 RAS Extension, SEA are usually triggered when memory errors
>> are consumed. In some cases, if the error address is in a clean page or a
>> read-only page, there is a chance to recover. Such as error occurs in a
>> instruction page, we can reread this page from disk instead of killing process.
>>
>> Because memory_failure() may sleep, we can not call it directly in SEA exception
>> context. So we saved faulting physical address associated with a process in the
>> ghes handler and set __TIF_SEA_NOTIFY. When we return from SEA exception context
>> and get into do_notify_resume() before the process running, we could check it
>> and call memory_failure() to do recovery. It's safe, because we are in process
>> context.
>>
>> Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>
>> Signed-off-by: Wang Xiongfeng <wangxiongfeng2@xxxxxxxxxx>
>> ---
>> arch/arm64/Kconfig | 11 +++
>> arch/arm64/include/asm/ras.h | 36 +++++++++
>> arch/arm64/include/asm/thread_info.h | 4 +-
>> arch/arm64/kernel/Makefile | 1 +
>> arch/arm64/kernel/ras.c | 143 +++++++++++++++++++++++++++++++++++
>> arch/arm64/kernel/signal.c | 8 ++
>> arch/arm64/mm/fault.c | 27 +++++--
>> drivers/acpi/apei/ghes.c | 4 +-
>> 8 files changed, 223 insertions(+), 11 deletions(-)
>> create mode 100644 arch/arm64/include/asm/ras.h
>> create mode 100644 arch/arm64/kernel/ras.c
>
> Please integrate scripts/checkpatch.pl into your patch creation workflow
> and run all patches through it before submitting:

Sorry for my mistake. I'll fix it, thanks.

>
> ERROR: code indent should use tabs where possible
> #200: FILE: arch/arm64/kernel/ras.c:42:
> + atomic_t inuse;$
>
> WARNING: please, no spaces at the start of a line
> #200: FILE: arch/arm64/kernel/ras.c:42:
> + atomic_t inuse;$
>
> ERROR: code indent should use tabs where possible
> #201: FILE: arch/arm64/kernel/ras.c:43:
> + struct task_struct *t;$
>
> WARNING: please, no spaces at the start of a line
> #201: FILE: arch/arm64/kernel/ras.c:43:
> + struct task_struct *t;$
>
> ERROR: code indent should use tabs where possible
> #202: FILE: arch/arm64/kernel/ras.c:44:
> + __u64 paddr;$
>
> WARNING: please, no spaces at the start of a line
> #202: FILE: arch/arm64/kernel/ras.c:44:
> + __u64 paddr;$
>
> ERROR: code indent should use tabs where possible
> #207: FILE: arch/arm64/kernel/ras.c:49:
> + struct sea_info *si;$
>
> WARNING: please, no spaces at the start of a line
> #207: FILE: arch/arm64/kernel/ras.c:49:
> + struct sea_info *si;$
>
> ERROR: code indent should use tabs where possible
> #209: FILE: arch/arm64/kernel/ras.c:51:
> + for (si = sea_info; si < &sea_info[SEA_INFO_MAX]; si++) {$
>
> WARNING: please, no spaces at the start of a line
> #209: FILE: arch/arm64/kernel/ras.c:51:
> + for (si = sea_info; si < &sea_info[SEA_INFO_MAX]; si++) {$
>
> ERROR: code indent should use tabs where possible
> #210: FILE: arch/arm64/kernel/ras.c:52:
> + if (atomic_cmpxchg(&si->inuse, 0, 1) == 0) {$
>
> WARNING: please, no spaces at the start of a line
> #210: FILE: arch/arm64/kernel/ras.c:52:
> + if (atomic_cmpxchg(&si->inuse, 0, 1) == 0) {$
>
> ERROR: code indent should use tabs where possible
> #211: FILE: arch/arm64/kernel/ras.c:53:
> + si->t = current;$
>
> WARNING: please, no spaces at the start of a line
> #211: FILE: arch/arm64/kernel/ras.c:53:
> + si->t = current;$
>
> ERROR: code indent should use tabs where possible
> #212: FILE: arch/arm64/kernel/ras.c:54:
> + si->paddr = addr;$
>
> WARNING: please, no spaces at the start of a line
> #212: FILE: arch/arm64/kernel/ras.c:54:
> + si->paddr = addr;$
>
> ERROR: code indent should use tabs where possible
> #213: FILE: arch/arm64/kernel/ras.c:55:
> + return true;$
>
> WARNING: please, no spaces at the start of a line
> #213: FILE: arch/arm64/kernel/ras.c:55:
> + return true;$
>
> ERROR: code indent should use tabs where possible
> #214: FILE: arch/arm64/kernel/ras.c:56:
> + }$
>
> WARNING: please, no spaces at the start of a line
> #214: FILE: arch/arm64/kernel/ras.c:56:
> + }$
>
> ERROR: code indent should use tabs where possible
> #215: FILE: arch/arm64/kernel/ras.c:57:
> + }$
>
> WARNING: please, no spaces at the start of a line
> #215: FILE: arch/arm64/kernel/ras.c:57:
> + }$
>
> ERROR: code indent should use tabs where possible
> #223: FILE: arch/arm64/kernel/ras.c:65:
> + struct sea_info *si;$
>
> WARNING: please, no spaces at the start of a line
> #223: FILE: arch/arm64/kernel/ras.c:65:
> + struct sea_info *si;$
>
> ERROR: code indent should use tabs where possible
> #225: FILE: arch/arm64/kernel/ras.c:67:
> + for (si = sea_info; si < &sea_info[SEA_INFO_MAX]; si++)$
>
> WARNING: please, no spaces at the start of a line
> #225: FILE: arch/arm64/kernel/ras.c:67:
> + for (si = sea_info; si < &sea_info[SEA_INFO_MAX]; si++)$
>
> ERROR: code indent should use tabs where possible
> #226: FILE: arch/arm64/kernel/ras.c:68:
> + if (atomic_read(&si->inuse) && si->t == current)$
>
> WARNING: please, no spaces at the start of a line
> #226: FILE: arch/arm64/kernel/ras.c:68:
> + if (atomic_read(&si->inuse) && si->t == current)$
>
> ERROR: code indent should use tabs where possible
> #227: FILE: arch/arm64/kernel/ras.c:69:
> + return si;$
>
> WARNING: please, no spaces at the start of a line
> #227: FILE: arch/arm64/kernel/ras.c:69:
> + return si;$
>
> ERROR: code indent should use tabs where possible
> #228: FILE: arch/arm64/kernel/ras.c:70:
> + return NULL;$
>
> WARNING: please, no spaces at the start of a line
> #228: FILE: arch/arm64/kernel/ras.c:70:
> + return NULL;$
>
> ERROR: code indent should use tabs where possible
> #233: FILE: arch/arm64/kernel/ras.c:75:
> + atomic_set(&si->inuse, 0);$
>
> WARNING: please, no spaces at the start of a line
> #233: FILE: arch/arm64/kernel/ras.c:75:
> + atomic_set(&si->inuse, 0);$
>
> WARNING: braces {} are not necessary for single statement blocks
> #265: FILE: arch/arm64/kernel/ras.c:107:
> + if (memory_failure(pfn, 0, flags) < 0) {
> + fail++;
> + }
>
> WARNING: braces {} are not necessary for single statement blocks
> #293: FILE: arch/arm64/kernel/ras.c:135:
> + if (err_info->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR) {
> + info_saved |= sea_save_info(err_info->physical_fault_addr);
> + }
>
> total: 17 errors, 21 warnings, 299 lines checked
>
> NOTE: For some of the reported defects, checkpatch may be able to
> mechanically convert to the typical style using --fix or --fix-inplace.
>
> NOTE: Whitespace errors detected.
> You may wish to use scripts/cleanpatch or scripts/cleanfile
>
> Your patch has style problems, please review.
>
> NOTE: If any of the errors are false positives, please report
> them to the maintainer, see CHECKPATCH in MAINTAINERS.
>

--
Thanks,
Xie XiuQi