I certainly have no objection in principle. I doubt that any x86 userland apps expect certain si_code values for SIGTRAP now, since the existing values are not of any real use. (Signal handlers get the thread.trap_no and thread.error_code values from hardware to guess from, and debuggers via ptrace get the hardware %db6 value to guess from.) I do have a few comments. If you're doing it, I think you should do the do_int3 case too, so every machine-generated SIGTRAP has a meaningful si_code value. The only use of send_sigtrap is for do_debug (and for faking that do_debug happened in the syscall_trace_leave case). You should consolidate all the uses in both 32 and 64 to use send_sigtrap uniformly, change its signature as needed. I'm inclined to consolidate the si_code logic there, and just pass it the hardware bits or let it get them from the thread_struct (trap_nr, error_code, debugreg6). About that si_code logic based on %db6. There are some funny "sticky" properties to how that register gets set in hardware. Even reading the hardware manuals doesn't always make it plain what to expect. I wouldn't want to testify that the patch's logic is correct in distinguishing which event really just happened. (I'm not sure, but I think it may also be possible to have a single do_debug trap for both a single-step trap and a hardware breakpoint trap generated by the same instruction.) I know that Alan Stern figured out a lot of the magic empirically a while back. That deserves a careful double-checking if we are now trying to make si_code tell a clear and reliable story. Thanks, Roland -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
