This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC 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: DWARF-2 unwinder versus MIPS n32

From: David Daney <ddaney at avtrex dot com>
To: Daniel Jacobowitz <drow at false dot org>
Cc: GCC Mailing List <gcc at gcc dot gnu dot org>
Date: Thu, 07 Jun 2007 09:05:13 -0700
Subject: Re: DWARF-2 unwinder versus MIPS n32
References: <20070607152920.GA27680@caradoc.them.org> <46682A21.2070901@avtrex.com>

David Daney wrote:

Daniel Jacobowitz wrote:
I'm trying to track down why unwinding through a signal frame crashes
on MIPS n32.  David, I'm pretty sure you introduced the crash here:
2006-11-20 David Daney <ddaney@avtrex.com>
        * config/mips/linux-unwind.h (mips_fallback_frame_state): Adjust
        PC to point to following instruction.
I don't doubt that there are problems here. I was going to clean up the compiler warnings that are now generated in that code, but it looks like more major work is needed.

I might add that something like this patch is required. The PC must be incremented so that proper unwinding is obtained if the fault occurs on the first instruction of a function.

Before this patch there was a special o32 only hack in libgcj that adjusted the value of the PC in the sigcontext saved on the stack before calling the unwinder. The idea was to place all the code needed to unwind through signal frames into MD_FALLBACK_FRAME_STATE_FOR.

David Daney

References:
- DWARF-2 unwinder versus MIPS n32
  - From: Daniel Jacobowitz
- Re: DWARF-2 unwinder versus MIPS n32
  - From: David Daney

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