Re: [PATCH] function:stacktrace/mips: Fix function:stacktrace for mips

[WANG Xuerui <kernel@xen0n.name>]

On 2020/5/29 17:29, yuanjunqing wrote:

> May I ask if you have received this email.

At least I have received the complete thread in my inbox, so others may 
well have no problem.

It's not polite to ping maintainers just one day after sending your 
patch BTW; keep the patch submitting guide[1] under your pillow.

Lastly, don't top-post even though your message body is short.


[1]: 
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#don-t-get-discouraged-or-impatient


And a bit of review while we're at it...

>
> 在 2020/5/28 下午8:36, YuanJunQing 写道:
>> ftrace_call as global symbol in ftrace_caller(), this
>> will cause function:stacktrace can not work well.
Chinglish. I can't understand this despite being a Chinese myself...
>> i.e. echo do_IRQ:stacktrace > set_ftrace_filte
The commit message is truncated? I can't seem to make sense of this line.
>>
>> Signed-off-by: YuanJunQing <yuanjunqing66@163.com>
>> ---
>>   arch/mips/kernel/mcount.S | 13 +++++++++++--
>>   1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
>> index cff52b283e03..cd5545764e5f 100644
>> --- a/arch/mips/kernel/mcount.S
>> +++ b/arch/mips/kernel/mcount.S
>> @@ -87,8 +87,15 @@ EXPORT_SYMBOL(_mcount)
>>   	PTR_LA   t1, _etext
>>   	sltu     t3, t1, a0	/* t3 = (a0 > _etext) */
>>   	or       t1, t2, t3
>> +	PTR_LA	 t2, stlab-4 	/* t2: "function:stacktrace" return address */
>> +	move	 a1, AT		/* arg2: parent's return address */
>>   	beqz     t1, ftrace_call
>> -	 nop
>> +	 nop			/* "function:stacktrace" return address */
>> +stlab:
>> +	PTR_LA	t2, stlab-4
>> +	/* ftrace_call_end: ftrace_call return address */
>> +	beq	t2,ra, ftrace_call_end
>> +	nop
>>   #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
>>   	PTR_SUBU a0, a0, 16	/* arg1: adjust to module's recorded callsite */
>>   #else
>> @@ -98,7 +105,9 @@ EXPORT_SYMBOL(_mcount)
>>   	.globl ftrace_call
>>   ftrace_call:
>>   	nop	/* a placeholder for the call to a real tracing function */
>> -	 move	a1, AT		/* arg2: parent's return address */
>> +	move	ra, t2		/* t2: "function:stacktrace" return address */
>> +
>> +ftrace_call_end:
>>   
>>   #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>>   	.globl ftrace_graph_call