On Tue, Apr 17, 2018 at 12:39:27PM -0400, Steven Rostedt wrote:
> > > names, they do not match the default compare algorithm. As this was a
> > > problem for power pc, the algorithm can be overwritten by the
> > > architecture.
> > > The solution is to have x86 have its own algorithm to do the compare and
> > > this brings back the system call trace events.
> >
> > this lets me wonder *which* syscall "function" should be included in this
> > directory. Is it really the stub (__x64_sys_waitid, for example), or better
> > the sign-extending C function (__se_sys_waitid) which then calls an
> > internal helper (__do_sys_waitid). An additional advantage:
> > __se_sys_waitid would be available on x86 and, AFAICS, on all other archs.
>
> It should include anything that uses the "SYSCALL_DEFINE#()" macros.
Well, that's not a 1:1, but a 1:several translation... SYSCALL_DEFINEx()
[SYSCALL_DEFINE0() is special] expands to
__do_sys_waitid # inlined helper doing actual work
__se_sys_waitid # C func calling inlined helper
on all architectures, with most (!= 64-bit x86) also having
sys_waitid # alias to __se_sys_waitid()
On 64-bit x86, it does not only extend to the two functions mentioned above,
but also to one or two stubs (depending on the configuration), namely
__x64_sys_waitid # x64 64-bit-ptregs -> C stub
__ia32_sys_waitid # ia32 32-bit-ptregs -> C stub
Thanks,
Dominik
