From mboxrd@z Thu Jan 1 00:00:00 1970 From: cov@codeaurora.org (Christopher Covington) Date: Wed, 25 Feb 2015 11:56:36 -0500 Subject: [PATCH v10 4/6] ARM: add vdso user-space code In-Reply-To: <20150224101754.GA27420@e104818-lin.cambridge.arm.com> References: <1411413485-7675-1-git-send-email-nathan_lynch@mentor.com> <1411413485-7675-5-git-send-email-nathan_lynch@mentor.com> <20150213105447.GB3508@e104818-lin.cambridge.arm.com> <20150213141425.GA4713@localhost> <20150213153253.GA23801@e104818-lin.cambridge.arm.com> <54E7AC90.40209@codeaurora.org> <20150224101754.GA27420@e104818-lin.cambridge.arm.com> Message-ID: <54EDFEC4.7060600@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project