[PATCH v10 4/6] ARM: add vdso user-space code

Christopher Covington cov at codeaurora.org
Wed Feb 25 08:56:36 PST 2015


Hi Catalin,

On 02/24/2015 05:17 AM, Catalin Marinas wrote:

[snip]

> Writing CNTFRQ from non-secure mode would trap as well.

Are you saying it could A) cause an exception targeting the current EL/mode
but not others, or B) cause an exception targeting the current or another EL/mode?

[snip]

> The detection mechanism would have to involve trapping of an undefined
> instruction but it doesn't need to be done early during boot.

I put detection during early boot because I wanted to potentially change
ELs/modes during early boot.

Thanks,
Chris

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Qualcomm Innovation Center, Inc.
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