DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:date:from:to:subject:message-id:reply-to
	:references:mime-version:content-type:in-reply-to; q=dns; s=
	default; b=d28c5YxRGv+TCBk+9iBiGnY9fjQKEnoO20j3Wa4mRcxRO8puGYkeJ
	Arr/pzMH/xpgigjpdUFN2dSkrwuYqpZZ59vbxsWoHCrFv1QTtQf7iTYsa3gQsjrr
	THbn17UpPf8MerXxObULlv+srblx9TA33iv7y+wHhjDFUTzOoZ9xkI=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Date: Fri, 8 Nov 2019 10:08:23 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Stack trace question
Message-ID: <20191108090823.GX3372@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <BY5PR09MB3972C23692B35F20CBB63948A57B0 AT BY5PR09MB3972 DOT namprd09 DOT prod DOT outlook DOT com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha256;	protocol="application/pgp-signature"; boundary="hNG1vEeyG8BCaHbQ"
Content-Disposition: inline
In-Reply-To: <BY5PR09MB3972C23692B35F20CBB63948A57B0@BY5PR09MB3972.namprd09.prod.outlook.com>
User-Agent: Mutt/1.12.1 (2019-06-15)

--hNG1vEeyG8BCaHbQ
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Nov  8 05:55, Lavrentiev, Anton (NIH/NLM/NCBI) [C] via cygwin wrote:
> Hi all,
>=20
> I have the following stack trace (64 bit Cygwin app), and I can't
> figure how the same frame RBP at 000FFFFC7B0 can be listed 3
> consecutive times for various functions (RIPs).

The functions in question are signal handling stuff, partially written in
assembler.  They don't change $rbp at all.

> Also if I follow the
> stack trace with gdb (and the trace is all within Cygwin.dll based at
> 180040000), it does not make any sense (it was a simple abort() in the
> application due to some external condition; no segfault or any other
> nasty kind of stuff)...  The program does not use SYSV IPC at all (so
> the appearance of shmat() is highly suspicious).
>=20
> Can there be something wrong as to how the stack trace gets generated?

If so, I'm not aware of that.  Cygwin uses the ntdll RtlVirtualUnwind and
RtlLookupFunctionEntry functions on 64 bit to iterate over the stack.

One problem in your stackdump may be that, apparently, a longjmp has
been performed (sigsetjmp is on the stack which is weird anyway).  Stuff
like that *may* indicate that the stack is broken.


Corinna

--=20
Corinna Vinschen
Cygwin Maintainer

--hNG1vEeyG8BCaHbQ
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=7fME
-----END PGP SIGNATURE-----

--hNG1vEeyG8BCaHbQ--