Hello,

I was finding that for a non-GNU/Linux SVR4 PPC platform malloc() was 
failing because RS6000 TOC func-ptr code was being selected:

       /* Handle RS/6000 function pointers.  */
       set_gdbarch_convert_from_func_ptr_addr (gdbarch,
         rs6000_convert_from_func_ptr_addr);

the attached patch changes things to select all of:

       set_gdbarch_frameless_function_invocation (gdbarch,
         ppc_linux_frameless_function_invocation);
       set_gdbarch_frame_chain (gdbarch, ppc_linux_frame_chain);
       set_gdbarch_frame_saved_pc (gdbarch, ppc_linux_frame_saved_pc);

       set_gdbarch_frame_init_saved_regs (gdbarch,
                                          ppc_linux_frame_init_saved_regs);
       set_gdbarch_init_extra_frame_info (gdbarch,
                                          ppc_linux_init_extra_frame_info);

       set_gdbarch_memory_remove_breakpoint (gdbarch,
 
ppc_linux_memory_remove_breakpoint);
       set_solib_svr4_fetch_link_map_offsets
         (gdbarch, ppc_linux_svr4_fetch_link_map_offsets);

when svr4_abi.  It certainly improves things (fails went from 136 -> 80) 
  but I'm not 100% certain if this is correct for all the above - I 
suspect it is overkill :-/

Andrew