Re: [RFC PATCH 01/11] Add basic support for gcc profilerinstrumentation

[Chris Wright]

* Steven Rostedt (rostedt@xxxxxxxxxxx) wrote:
> Hmm, I know paravirt-ops had an issue with mcount in the RT tree. I can't
> remember the exact issues, but it did have something to do with the way
> parameters were passed in.
> 
> Chris, do you remember what the issues were?

Yes, paravirt ops have a well-specified calling convention (register
based).  There was a cleanup that Andi did that caused the problem
because it removed all the "fastcall" annotations since -mregparm=3
is now always on for i386.  Since MCOUNT disables REGPARM the calling
convention changes (caller pushes to stack, callee expects register)
chaos ensues.  I sent a patch to fix that quite some months back, but
it went stale and I neglected to update it.  Would you like me to dig
it up refresh and resend?

thanks,
-chris
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