On Wed, 19 Jan 2011, Loïc Minier wrote:

>  actually, I thought ltrace was still a toolchain WG topic, but it had
>  been moved to developer platform:
>  https://wiki.linaro.org/Releases/1105/TechnicalTopics#Developer%20Platform
>  https://blueprints.launchpad.net/ubuntu/+spec/other-linaro-n-profiling-tools
> 
>  oddly, ltrace was apparently verified to work

It may work by accident, if you're lucky enough for ltrace to land on 
some instructions that happen to be in the Thumb1 subset that 
PTRACE_SINGLESTEP supports, and that no SMP races affected the test.
But we know that it cannot be reliable as is.

> On Wed, Jan 19, 2011, Nicolas Pitre wrote:
> > On Wed, 19 Jan 2011, Loïc Minier wrote:
> > 
> > >         Hey
> > > 
> > >  I think we need to keep an eye on this and be ready to check ltrace if
> > >  this gets merged
> > 
> > I think ltrace is broken already and needs to be fixed regardless. 
> > 
> > Motivations for the removal of PTRACE_SINGLESTEP on ARM are:
> > 
> > 1.) Only a subset of ARMv7 instructions are supported
> > 2.) Thumb-2 is unsupported
> > 3.) The code is not SMP safe
> > 
> > As we are using ARMv7, Thumb-2 and SMP in the Linaro images, this makes 
> > ltrace tripply broken.
> > 
> > 
> > Nicolas
> 
> > _______________________________________________
> > linaro-toolchain mailing list
> > linaro-toolchain@lists.linaro.org
> > http://lists.linaro.org/mailman/listinfo/linaro-toolchain
> 
> 
> -- 
> Loïc Minier
> 
> _______________________________________________
> linaro-toolchain mailing list
> linaro-toolchain@lists.linaro.org
> http://lists.linaro.org/mailman/listinfo/linaro-toolchain
> 
_______________________________________________
linaro-toolchain mailing list
linaro-toolchain@lists.linaro.org
http://lists.linaro.org/mailman/listinfo/linaro-toolchain

Reply via email to