Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH] function:stacktrace/mips: Fix function:stacktrace for
 mips
To:     tsbogend@alpha.franken.de
Cc:     linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
        liulichao@loongson.cn
References: <20200528123640.4285-1-yuanjunqing66@163.com>
From:   yuanjunqing <yuanjunqing66@163.com>
Message-ID: <11c90f15-0a25-e628-c8db-53343c351085@163.com>
Date:   Fri, 29 May 2020 17:29:08 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.7.0
MIME-Version: 1.0
In-Reply-To: <20200528123640.4285-1-yuanjunqing66@163.com>
Content-Type: text/plain; charset=gbk
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

May I ask if you have received this email.

?? 2020/5/28 ????8:36, YuanJunQing д??:
> ftrace_call as global symbol in ftrace_caller(), this
> will cause function:stacktrace can not work well.
> i.e. echo do_IRQ:stacktrace > set_ftrace_filte
>
> 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