linux-kernel - Re: [PATCH v5] x86, tboot: iomem fixes

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Date:	Tue, 06 Aug 2013 15:27:17 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Qiaowei Ren <qiaowei.ren@...el.com>
CC:	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
	linux-kernel@...r.kernel.org, Gang Wei <gang.wei@...el.com>
Subject: Re: [PATCH v5] x86, tboot: iomem fixes

On 07/20/2013 09:26 AM, Qiaowei Ren wrote:
>  
>  	/* now map TXT heap */
> -	heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
> -			    *(u64 *)(config + TXTCR_HEAP_SIZE));
> +	heap_base = ioremap(readl(config + TXTCR_HEAP_BASE),
> +			    readl(config + TXTCR_HEAP_SIZE));

You are changing u64 references to readl()... this means you are doing
only 32-bit reads.

>  	iounmap(config);
>  	if (!heap_base)
>  		return NULL;
>  
>  	/* walk heap to SinitMleData */
>  	/* skip BiosData */
> -	heap_ptr = heap_base + *(u64 *)heap_base;
> +	heap_ptr = heap_base + readq(heap_base);
>  	/* skip OsMleData */
> -	heap_ptr += *(u64 *)heap_ptr;
> +	heap_ptr += readq(heap_ptr);
>  	/* skip OsSinitData */
> -	heap_ptr += *(u64 *)heap_ptr;
> +	heap_ptr += readq(heap_ptr);

As I believe Ingo already commented on, readq() only exists on 64 bits.

You can #include <asm-generic/io-64-nonatomic-lo-hi.h> to remedy that.

>  	/* now points to SinitMleDataSize; set to SinitMleData */
>  	heap_ptr += sizeof(u64);
>  	/* get addr of DMAR table */
> +	dmar_tbl_off = readl(heap_ptr +
> +			offsetof(struct sinit_mle_data, vtd_dmars_off));
>  	dmar_tbl = (struct acpi_table_header *)(heap_ptr +
> -		   ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
> -		   sizeof(u64));
> +			dmar_tbl_off - sizeof(u64));
>  
>  	/* don't unmap heap because dmar.c needs access to this */
>  

If you are using accessors here, what about dmar_tbl itself?

	-hpa



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