[PowerPC] print debugging information on trap signal

[alfredo]

Summary

Add support for sysctl 'machdep.uprintf_signal' that prints debugging information on trap signal, as used in other platforms.

User can enable it with "sysctl -w machdep.uprintf_signal=1"

[luporl]

Looks good, very similar to amd64 code.
But if you want to make it equivalent to amd64 code, you could also print SP, PC (that would be frame->fixreg[1] and frame->srr0, I think) and the word (or maybe the first 2 words) at frame->srr0.

[alfredo]

added frame->srr0, frame->srr1 and frame->fixreg[1] to output

[bdragon]

sys/powerpc/powerpc/trap.c

500

This will fail to build on ppc32.

Building /usr/obj/usr/src/powerpc.powerpc/sys/GENERIC/modules/usr/src/sys/modules/usb/urndis/if_urndis.ko.full
--- trap.o ---
/usr/src/sys/powerpc/powerpc/trap.c:501:43: error: format specifies type 'unsigned long' but the argument has type 'register_t' (aka 'int') [-Werror,-Wformat]
                        p->p_pid, p->p_comm, sig, ucode, type, addr,
                                                               ^~~~
/usr/src/sys/powerpc/powerpc/trap.c:502:4: error: format specifies type 'unsigned long' but the argument has type 'register_t' (aka 'int') [-Werror,-Wformat]
                        frame->fixreg[1], frame->srr0, frame->srr1);
                        ^~~~~~~~~~~~~~~~
/usr/src/sys/powerpc/powerpc/trap.c:502:22: error: format specifies type 'unsigned long' but the argument has type 'register_t' (aka 'int') [-Werror,-Wformat]
                        frame->fixreg[1], frame->srr0, frame->srr1);
                                          ^~~~~~~~~~~
/usr/src/sys/powerpc/powerpc/trap.c:502:35: error: format specifies type 'unsigned long' but the argument has type 'register_t' (aka 'int') [-Werror,-Wformat]
                        frame->fixreg[1], frame->srr0, frame->srr1);
                                                       ^~~~~~~~~~~

Need to cast the registers to unsigned long.

505

Extra newline.

[alfredo]

cast to u_long fixing build on 32 bit

[alfredo]

remove extra new line

[alfredo]

@bdragon thank you for pointing out the 32 bit build issue!