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Re: [PATCH] arm: mark __startcontext as .cantunwind

From: Florian Weimer <fweimer at redhat dot com>
To: Andreas Schwab <schwab at suse dot de>
Cc: libc-alpha at sourceware dot org
Date: Mon, 15 Aug 2016 16:25:55 +0200
Subject: Re: [PATCH] arm: mark __startcontext as .cantunwind
Authentication-results: sourceware.org; auth=none
References: <mvmtwemqkbi.fsf@hawking.suse.de> <7bf48b1e-2681-a755-4f10-cc7905620089@redhat.com> <mvmpopaqj62.fsf@hawking.suse.de>

On 08/15/2016 03:02 PM, Andreas Schwab wrote:

On Aug 15 2016, Florian Weimer <fweimer@redhat.com> wrote:

Why isn't the PC - 2 kludge needed for the other .cantunwind cases?


Because the other uses have regular function calls, so they return back
to the middle of the function that is marked cantunwind.  __startcontext
doesn't contain the function call, but is the address the context
returns to.

Would it be possible to add a C test case to the glibc testsuite?


This is difficult, because a simple call stack won't trigger the bug.


Thanks for the explanation.  Your patch looks okay to me.

Florian

References:
- [PATCH] arm: mark __startcontext as .cantunwind
  - From: Andreas Schwab
- Re: [PATCH] arm: mark __startcontext as .cantunwind
  - From: Florian Weimer
- Re: [PATCH] arm: mark __startcontext as .cantunwind
  - From: Andreas Schwab

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