This is the mail archive of the mailing list for the binutils 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: Using linker script to mark .debug_frame allocatable

Matt Fleming wrote:
On Wed, Jul 29, 2009 at 11:13:19AM -0400, Daniel Jacobowitz wrote:
On Wed, Jul 29, 2009 at 03:18:06PM +0100, Matt Fleming wrote:
Basically because the DWARF frame info is currently in the .debug_frame
section and I assumed that if no .eh_frame section was generated during
the partial link of the kernel source, I can move the .debug_frame input
section into a .eh_frame output section and it still wouldn't be

Is there a way to force all DWARF debug frame info to be output into a
.eh_frame section?
Compile with unwind tables.  ARM's got an option to do this already
(though that does not result in .eh_frame - ARM is special - it would
on other platforms).

I thought that the unwind tables had an architecture-specific layout? Or in any case, had more architecture-specific information encoded in their entries than the DWARF info in .debug_frame?

DWARF based .eh_frame sections don't really have any architecture-specific things in them. The register numbering conventions are not needed when unwinding, only if you wanted to catch an exception and restore the registers, which I don't think you do in the kernel. I think the only architecture-specific code you would need is something to find the first CFA given the machine state at the unwind point.

I would compile the whole thing with -fasynchronous-unwind-tables or -funwind-tables and use the resulting .eh_frame sections. That is what they are there for. Trying to make .debug_frame into an allocatable section seems hacky to me.

Good luck, it is something I have thought about doing myself.

David Daney

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