Re: [Libunwind-devel] Reg: Libunwind with threads lib and system calls

[Arun Sharma]

On Wed, Feb 22, 2012 at 11:49 PM, POKHARAKAR Sandeep
<address@hidden> wrote:
> Hello Arun,
>
> Could you share the concept, How stack has been captured if frame pointers 
> not available?
> May be any document reference or code snippet?

Even though frame pointer may be invalid, the stack pointer is valid
at all times. The compiler generates unwind info that can be thought
as a table of:

%rip, %reg  -> where to find the value of %reg at %rip

References:

http://code.google.com/p/google-breakpad/wiki/SymbolFiles (read the
section on stack CFI)

My attempt at documenting some of this:

http://bit.ly/w5IrVK (Haven't written up part2 yet).

 -Arun