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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Xie Yuanbin <xieyuanbin1@huawei.com>
Cc: viro@zeniv.linux.org.uk, will@kernel.org, nico@fluxnic.net,
	rmk+kernel@armlinux.org.uk, linux@armlinux.org.uk,
	david.laight@runbox.com, rppt@kernel.org, vbabka@suse.cz,
	pfalcato@suse.de, brauner@kernel.org, lorenzo.stoakes@oracle.com,
	kuninori.morimoto.gx@renesas.com, tony@atomide.com, arnd@arndb.de,
	akpm@linux-foundation.org, punitagrawal@gmail.com, hch@lst.de,
	jack@suse.com, rjw@rjwysocki.net, marc.zyngier@arm.com,
	linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	wozizhi@huaweicloud.com, liaohua4@huawei.com, lilinjie8@huawei.com,
	pangliyuan1@huawei.com, wangkefeng.wang@huawei.com
Subject: Re: [RFC PATCH v2 1/2] ARM/mm/fault: always goto bad_area when
 handling with page faults of kernel address
Message-ID: <20251127145127.qUXs_UAE@linutronix.de>
References: <20251127140109.191657-1-xieyuanbin1@huawei.com>
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In-Reply-To: <20251127140109.191657-1-xieyuanbin1@huawei.com>

On 2025-11-27 22:01:08 [+0800], Xie Yuanbin wrote:
> --- a/arch/arm/mm/fault.c
> +++ b/arch/arm/mm/fault.c
> @@ -270,10 +270,15 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
>  	vm_flags_t vm_flags = VM_ACCESS_FLAGS;
>  
>  	if (kprobe_page_fault(regs, fsr))
>  		return 0;
>  
> +	if (unlikely(addr >= TASK_SIZE)) {
> +		fault = 0;
> +		code = SEGV_MAPERR;
> +		goto bad_area;
> +	}
>  
>  	/* Enable interrupts if they were enabled in the parent context. */
>  	if (interrupts_enabled(regs))
>  		local_irq_enable();

What is with the patch I sent wrong?

Sebastian