lkml.org 
[lkml]   [2022]   [Aug]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 3/4] LoongArch: Add stacktrace support
From
Date


On 2022/8/1 下午11:30, Huacai Chen wrote:
> Hi, Qing,
>
> On Mon, Aug 1, 2022 at 8:17 PM Qing Zhang <zhangqing@loongson.cn> wrote:
>>
>> Use common arch_stack_walk infrastructure to avoid duplicated code and
>> avoid taking care of the stack storage and filtering.
>> Add sra (means __schedule return address) and scfa (means __schedule call
>> frame address) to thread_info and store it in switch_to().
>>
>> Now we can print the process stack by cat /proc/*/stack and can better
>> support ftrace.
>>
>> Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
>> ---
>> arch/loongarch/Kconfig | 5 ++++
>> arch/loongarch/include/asm/processor.h | 9 +++++++
>> arch/loongarch/include/asm/switch_to.h | 14 ++++++----
>> arch/loongarch/include/asm/uaccess.h | 4 +--
>> arch/loongarch/kernel/Makefile | 1 +
>> arch/loongarch/kernel/asm-offsets.c | 2 ++
>> arch/loongarch/kernel/process.c | 3 +++
>> arch/loongarch/kernel/stacktrace.c | 37 ++++++++++++++++++++++++++
>> arch/loongarch/kernel/switch.S | 2 ++
>> 9 files changed, 70 insertions(+), 7 deletions(-)
>> create mode 100644 arch/loongarch/kernel/stacktrace.c
>>
>> diff --git a/arch/loongarch/include/asm/uaccess.h b/arch/loongarch/include/asm/uaccess.h
>> index 2b44edc604a2..a8ae2af4025a 100644
>> --- a/arch/loongarch/include/asm/uaccess.h
>> +++ b/arch/loongarch/include/asm/uaccess.h
>> @@ -229,13 +229,13 @@ extern unsigned long __copy_user(void *to, const void *from, __kernel_size_t n);
>> static inline unsigned long __must_check
>> raw_copy_from_user(void *to, const void __user *from, unsigned long n)
>> {
>> - return __copy_user(to, from, n);
>> + return __copy_user(to, (__force const void *)from, n);
>> }
>>
>> static inline unsigned long __must_check
>> raw_copy_to_user(void __user *to, const void *from, unsigned long n)
>> {
>> - return __copy_user(to, from, n);
>> + return __copy_user((__force void *)to, from, n);
> Why this? Does it have something to do with stacktrace?
>
> Huacai

Hi, huacai

This is kernel test robot report sparse warnings:
I reproduced locally and found that other architectures calling
__copy_user also use __force conversion, Is this modification appropriate?

kernel/trace/trace_events_user.c: note: in included file (through
include/linux/uaccess.h, include/linux/sched/task.h,
include/linux/sched/signal.h, ...):
arch/loongarch/include/asm/uaccess.h:232:32: sparse: sparse:
incorrect type in argument 2 (different address spaces) @@ expected
void const *from @@ got void const [noderef] __user *from @@
arch/loongarch/include/asm/uaccess.h:232:32: sparse: expected
void const *from
arch/loongarch/include/asm/uaccess.h:232:32: sparse: got void
const [noderef] __user *from

Thanks,
-Qing


\
 
 \ /
  Last update: 2022-08-02 03:21    [W:0.068 / U:0.020 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site