This is the mail archive of the binutils@sourceware.org mailing list for the binutils project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: Preventing preemption of 'protected' symbols in GNU ld 2.26

From: Jeff Law <law at redhat dot com>
To: Cary Coutant <ccoutant at gmail dot com>
Cc: "H.J. Lu" <hjl dot tools at gmail dot com>, Joe Groff <jgroff at apple dot com>, Alan Modra <amodra at gmail dot com>, Binutils <binutils at sourceware dot org>
Date: Wed, 30 Mar 2016 18:52:55 -0600
Subject: Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
Authentication-results: sourceware.org; auth=none
References: <AB592ABD-D6D7-4D2F-A0D6-45738F168DC4 at apple dot com> <BEDD88C6-7F80-45DA-9021-10587244AAE5 at apple dot com> <CAMe9rOq6rmvH458nufzfZnnU_=_n1yysbLzERNy-LWvEmjmN1A at mail dot gmail dot com> <983472E1-A1BC-4970-9CF9-0138A6BAD16D at apple dot com> <CAMe9rOqTTwirymAY6ORp6D_GnCsMc_hYEdy1NbZpG6x5vQc5DQ at mail dot gmail dot com> <6AAD87D2-90F9-4AD7-A195-AC91B76EA6AE at apple dot com> <CAMe9rOqNcYnm1YocG-m7XNDE0g68YQAGe=ULP-G98gaatpxSeA at mail dot gmail dot com> <CAJimCsHfT=cfb4kZysB2W_1HFfOq==TpP=wa47XPGB41MHmGyQ at mail dot gmail dot com> <56FB5061 dot 9010303 at redhat dot com> <CAJimCsGNESdZwgYfo6mkwsoj2j7o+odOTF4gKuWpAUDGXDU1+A at mail dot gmail dot com>

On 03/30/2016 06:40 PM, Cary Coutant wrote:

It would help me immensely on the GCC side if things if you and Alan could
easily summarize correct behavior and the impact if we were to just revert
HJ's change.  A testcase would be amazingly helpful too.


It looks like it's not just the one change. There's this patch:

    https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01871.html

which took the idea that protected can still be pre-empted by a COPY
relocation and extended it to three more targets that use COPY
relocations.

I wonder how many other patches have been based on the same misunderstanding?

I don't think it was many -- I certainly recall the arm/aarch64 variant.There may have been one other varasm.c change in this space or I mightbe conflating it with the arm/aarch64 change. Tracking those down isnaturally part of this work.


jeff

Follow-Ups:
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Ramana Radhakrishnan

References:
- Fwd: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Joe Groff
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: H.J. Lu
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Joe Groff
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: H.J. Lu
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Joe Groff
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: H.J. Lu
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Cary Coutant
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Jeff Law
- Re: Preventing preemption of 'protected' symbols in GNU ld 2.26
  - From: Cary Coutant

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]