RFA: change to ia64-linux-tdep.c

[J. Johnston]

Kevin Buettner wrote:
> On Oct 15,  6:03pm, J. Johnston wrote:
> 
> 
>>The following changes the code in ia64_linux_sigcontext_register_address to use 
>>the fact that the sigframe has the address of the sigcontext area stored at 
>>offset 16 from the stack pointer.  This change avoids using a magic constant to 
>>find the start of the sigcontext area which may change in various kernel 
>>versions as fields are added or subtracted to the sigframe.
>>
>>Code has been tested with signal handling test cases.
>>
>>The following is an excerpt of the linux kernel sigframe.h code:
>>
>>struct sigframe {
>>         /*
>>          * Place signal handler args where user-level unwinder can find them 
>>easily.
>>          * DO NOT MOVE THESE.  They are part of the IA-64 Linux ABI and there 
>>is         * user-level code that depends on their presence!
>>          */
>>         unsigned long arg0;             /* signum */
>>         unsigned long arg1;             /* siginfo pointer */
>>         unsigned long arg2;             /* sigcontext pointer */
>>         /*
>>          * End of architected state.
>>          */
>>
>>Ok to Commit?
> 
> 
> Yes.  Definitely!
> 
> Thanks for doing this.
> 
> Kevin
> 

Patch checked into mainline.  Should patch be checked into gdb 6.0?

-- Jeff J.