changes to runtime string functions

[Mike Mason]

On ppc64, the script fails with the following errors:

In file included from /usr/local/share/systemtap/runtime/stack.c:35,
                 from /tmp/stapv9kJvf/stap_7af9c5831b3c85cc5edb0c48e39ead40_1111.c:32:
/usr/local/share/systemtap/runtime/stack-ppc64.c: In function '__stp_stack_print':
/usr/local/share/systemtap/runtime/stack-ppc64.c:60: error: 'str' undeclared (first use in this function)
/usr/local/share/systemtap/runtime/stack-ppc64.c:60: error: (Each undeclared identifier is reported only once
/usr/local/share/systemtap/runtime/stack-ppc64.c:60: error: for each function it appears in.)
/usr/local/share/systemtap/runtime/stack-ppc64.c:60: error: 'STP_STRING_SIZE' undeclared (first use in this function)


Martin Hunt wrote:
> I have checked in a rewrite of the string functions in the runtime.
> This is part of an effort to increase performance and reduce memory
> usage. Many functions were eliminated and the symbol and stack code
> required major editing. Only a few tapset functions needed to be
> modified to use the new code and everything appears to be running fine
> on x86_64 and i386. It would be nice if people with access to other
> architectures could test and report back if there are any problems. Also
> if you have embedded code that is not checked in and you use any of the
> old string functions, you may need to update your code.
> 
> The most likely affected code is the stack trace stuff.  Please try this
> and see if it looks OK.
> 
> function print_stuff () {
>         print_regs()
>         print_backtrace()
>         print("--------\n")
>         bt = backtrace()
>         printf("the stack is %s\n", bt)
>         print("--------\n")
>         print_stack(bt)
>         print("--------\n")
> }
> 
> probe kernel.function("uptime_read_proc") {
>         print("NOW IN UPTIME\n")
>         print_stuff ()
> }
> 
> After starting this probe, run "uptime" to trigger it.
> 
> Martin
> 
>