From owner-freebsd-arm@freebsd.org  Tue Feb  7 18:55:56 2017
Return-Path: <owner-freebsd-arm@freebsd.org>
Delivered-To: freebsd-arm@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id DCB2FCD443C
 for <freebsd-arm@mailman.ysv.freebsd.org>;
 Tue,  7 Feb 2017 18:55:56 +0000 (UTC)
 (envelope-from freebsdml@marino.st)
Received: from shepard.synsport.com (mail.synsport.com [208.69.230.148])
 (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id BA2D91BFE
 for <freebsd-arm@freebsd.org>; Tue,  7 Feb 2017 18:55:56 +0000 (UTC)
 (envelope-from freebsdml@marino.st)
Received: from [127.0.0.1] (ip72-204-83-236.fv.ks.cox.net [72.204.83.236])
 (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits))
 (No client certificate requested)
 by shepard.synsport.com (Postfix) with ESMTP id 78ED743CC8;
 Tue,  7 Feb 2017 12:54:12 -0600 (CST)
Subject: Re: ARM64: PC/IP not saved in signal frame
Reply-To: marino@freebsd.org
References: <530c18cd-d50d-4709-a0ca-22324a0cb592@marino.st>
To: freebsd-arm@freebsd.org
Cc: Andreas Tobler <andreastt@gmail.com>
From: John Marino <freebsdml@marino.st>
Message-ID: <86279411-3979-edab-7ba2-4a1e3fa6429e@marino.st>
Date: Tue, 7 Feb 2017 12:55:51 -0600
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101
 Thunderbird/45.1.1
MIME-Version: 1.0
In-Reply-To: <530c18cd-d50d-4709-a0ca-22324a0cb592@marino.st>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
X-Antivirus: avast! (VPS 170206-3, 02/06/2017), Outbound message
X-Antivirus-Status: Clean
X-BeenThere: freebsd-arm@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: "Porting FreeBSD to ARM processors." <freebsd-arm.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-arm>,
 <mailto:freebsd-arm-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arm/>
List-Post: <mailto:freebsd-arm@freebsd.org>
List-Help: <mailto:freebsd-arm-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-arm>,
 <mailto:freebsd-arm-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 07 Feb 2017 18:55:57 -0000

On 2/7/2017 12:47, John Marino wrote:
> Hi guys,
> I've been struggling to provide unwind support on the aarch64-*-freebsd*
> target of FreeBSD.  The only working example on this arch is
> aarch64-linux (attached).  I think I'm 99% done with the freebsd version
> (attached) but the last value that needs to be pass to the
> _Unwind_FrameState is the program counter offset.
>
> I know the PC is not register-based on aarch64.  Linux still saves the
> value in the signal context, but AFAICT FreeBSD does not.
>
> Can somebody
> A) confirm that the program counter is missing from the saved signal
> context
> B) confirm that it needs to be added for proper signal frame unwinding?
>
> Alternatively, maybe somebody can figure out a solution given the
> current freebsd structures, but I'm losing hope on that one. (line 99)

Apparently attachments are stripped out on this mail list.
You can see the headers here:
https://leaf.dragonflybsd.org/~marino/linux-unwind.h
https://leaf.dragonflybsd.org/~marino/freebsd-unwind.h

John