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Date: Sun, 08 Jun 2003 04:19:17 -0700 (PDT)
Message-Id: <20030608.041917.21922788.davem@redhat.com>
Subject: Re: [Qemu-devel] Sparc port
From: "David S. Miller" <davem@redhat.com>
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To: qemu-devel@nongnu.org, fabrice.bellard@free.fr

   From: Fabrice Bellard <fabrice.bellard@free.fr>
   Date: Sun, 08 Jun 2003 12:52:59 +0200

   David S. Miller wrote:
   > It is the only clean way to deal with this sparc issue in the long
   > term.
   
   I still have a problem: if a helper function modifies an x86 register 
   which is in a sparc register (say EAX in %l0), then it cannot work 
   because save/restore are done at the beginning of the helper.
   
Then we probably should, as you seem to suggest, generate the helper
functions just like we generate code to execute x86 instructions.

   BTW, another question: how can we know on Sparc if a SIGSEGV or SIGBUS 
   was generated because of a read or a write ? The Linux kernel has the 
   info but it does not seem to be copied to user space. It may be 
   interesting to find a standard way to indicate if it is a read or write 
   which caused the fault (using a field in siginfo_t would be nice).
   
"si_info" is passed into the thread, but unfortunately only when
an rt signal frame is used.

I can't change the existing non-rt signal frame layout else I'll break
a ton of applications, and in particular GCC exception handling.