powerpc/64: Make sys_switch_endian() traceable

[Michael Ellerman]

On Tue, 2019-01-15 at 06:37:36 UTC, Michael Ellerman wrote:
> We weren't using SYSCALL_DEFINE for sys_switch_endian(), which means
> it wasn't able to be traced by CONFIG_FTRACE_SYSCALLS.
> 
> By using the macro we create the right metadata and the syscall is
> visible. eg:
> 
>   # cd /sys/kernel/debug/tracing
>   # echo 1 | tee events/syscalls/sys_*_switch_endian/enable
>   # ~/switch_endian_test
>   # cat trace
>   ...
>   switch_endian_t-3604  [009] ....   315.175164: sys_switch_endian()
>   switch_endian_t-3604  [009] ....   315.175167: sys_switch_endian -> 0x5555aaaa5555aaaa
>   switch_endian_t-3604  [009] ....   315.175169: sys_switch_endian()
>   switch_endian_t-3604  [009] ....   315.175169: sys_switch_endian -> 0x5555aaaa5555aaaa
> 
> Fixes: 529d235a0e19 ("powerpc: Add a proper syscall for switching endianness")
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/81dac817786263bb44cd5a200a07eff3

cheers