break doesn't work with thread on mips

[Michael Snyder]

"H . J . Lu" wrote:
> 
> When I do
> 
> # gdb a.out
> (gdb) b main
> Breakpoint 1 at 0x400910: file x.c, line 25.
> (gdb) r
> (gdb) del 1
> (gdb) b main
> reading register sp (#29): No such process.
> 
> That is break no longer works after the program runs if thread is used.
> Why does gdb want to read sp anyway? 

Probably because it has to analyze the prologue of main, 
to place the breakpoint after the prologue.  Many prologue
analyzers will poke around at the stack.