From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jon Medhurst (Tixy)" Subject: Re: [PATCH] arm: Add unwinding annotations for 64bit division functions Date: Thu, 22 Sep 2011 08:28:08 +0100 Message-ID: <1316676488.2053.9.camel@linaro1> References: <1316470297-5063-1-git-send-email-lauraa@codeaurora.org> <2285dff3fee56758b6279062a5a30dc7.squirrel@www.codeaurora.org> <20110921113906.GB2872@arm.com> <20110921115553.GF17169@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110921115553.GF17169@n2100.arm.linux.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Russell King - ARM Linux Cc: Dave Martin , Laura Abbott , Nicolas Pitre , Catalin Marinas , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-arm-msm@vger.kernel.org On Wed, 2011-09-21 at 12:55 +0100, Russell King - ARM Linux wrote: > Instructions such as VFP, kprobes tracing, etc are expected fault > locations, and those are fairly well controlled where they can be placed. > With things like ftrace, it certainly is the case that the unwinder can > theoretically be called from almost anywhere in a function. Actually, kprobes can be places on any instruction in the kernel that isn't in the section .kprobes.text. I also strongly suspect that stack unwinding won't happen correctly across the boundary between the kprobes handling code and the function which was probed - there's an awful lot of stack jiggery pokery going on there. -- Tixy