[LLVMdev] Fix crash in llvm_gcda_emit_arcs()

[Bill Wendling]

Hi Joseph and Nick,

I'll take a look at this soon. :-)

-bw

On Sep 5, 2013, at 10:51 AM, Joseph Kain <joekain at gmail.com> wrote:

> Hi Nick and Bill,
> 
> Attached is a new version of the patch that checks against cur_buffer_size. This works with the cases I've been using but again I haven't run the official tests on this change.
> 
> Thanks,
> Joseph Kain
> 
> 
> 
> On Thu, Sep 5, 2013 at 9:46 AM, Joseph Kain <joekain at gmail.com> wrote:
> Hi Nick,
> 
> Thanks for looking over my patch.  I'd be happy to add the compare against cur_buffer_size.  I'll try to write up such a change today and then send a new patch to the list.
> 
> Joseph Kain
> 
> 
> On Thu, Sep 5, 2013 at 1:37 AM, Nick Lewycky <nicholas at mxc.ca> wrote:
> Bill, could you take a look at this? I don't have a checkout of compiler-rt that builds.
> 
> It seems obviously-correct to me, but I wish it did a compare against cur_buffer_size to make sure it's in range.
> 
> Nick
> 
> Joseph Kain wrote:
> Hi,
> 
> I've been seeing a crash in llvm_gcda_emit_arcs() on x86_64.  The crash
> occurs executing a movdqa instruction with an unaligned src address.
>   The attached patch to the compiler-rt project fixes the problem by
> using memcpy() to read data from the write_buffer[] in GCDAProfiling.c.
> 
> This is my first patch submission to llvm so please let me know if I've
> missed any steps.  I'm not on the mailing list so please include me on
> any replies.
> 
> I haven't run the tests on this change but would be happy to do so if
> someone could point me to documentation on how to do so.  I couldn't
> find testing instructions linked from
> http://llvm.org/docs/DeveloperPolicy.html.  I have built the change and
> run it with the programs I was testing originally.  With this change the
> crash no longer occurs.
> 
> Thanks,
> Joseph Kain
> 
> 
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> 
> 
> 
> -- 
> Joseph Kain
> 
> 
> 
> -- 
> Joseph Kain
> <memcpy-to-writebuffer-2.patch>