Re: [S390] ftrace: update system call tracer support

[Ingo Molnar <mingo@elte.hu>]

* Martin Schwidefsky <schwidefsky@de.ibm.com> wrote:

> On Tue, 18 Aug 2009 10:51:10 +0200
> Ingo Molnar <mingo@elte.hu> wrote:
> 
> > 
> > * Ingo Molnar <mingo@elte.hu> wrote:
> > 
> > > * Paul Mundt <lethal@linux-sh.org> wrote:
> > > 
> > > > [ Adding to Cc everyone that now has a broken tree thanks to this .. ]
> > > > 
> > > > On Wed, Aug 12, 2009 at 11:11:33AM +0200, Ingo Molnar wrote:
> > > > > * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > > > > > This pull request integrate one cleanup/fix for ftrace and an 
> > > > > > update for syscall tracing: the migration from old-style tracer to 
> > > > > > individual tracepoints/trace_events and the support for perf 
> > > > > > counter.
> > > > > > 
> > > > > > I've tested it with success either with ftrace (every syscall 
> > > > > > tracepoints enabled at the same time without problems) and with 
> > > > > > perfcounter.
> > > > > > 
> > > > > > May be one drawback: it creates so much trace events that the 
> > > > > > ftrace selftests can take some time :-)
> > > > > 
> > > > > Pulled, thanks a lot!
> > > > 
> > > > And this has now subsequently broken every single SH and S390 
> > > > configuration, [...]
> > > 
> > > I test SH cross-builds regularly. I just checked the SH defconfig 
> > > and it builds just fine here:
> > > 
> > > $ make -j32 CROSS_COMPILE=sh3-linux- ARCH=sh vmlinux
> > 
> > The s390 build indeed broke. (This got masked by the s390 toolchain 
> > i'm using not having been able to build Linus's tree - i fixed 
> > that.)
> > 
> > Could you try the fix below? It does the trick here.
> > 
> > Martin, Heiko - does the fix look good to you? regs->gprs[2] seems 
> > to be the register used for both the syscall number (enter 
> > callback) and for the return code (exit callback).
> 
> Correct, for do_syscall_trace_{enter,exit} the code in entry.S 
> stores the system call number in regs->gprs[2]. The fix is fine. 
> Thanks Ingo.

Thanks, i've added your Acked-by to the commit. I suspect you dont 
want to pull tracing infrastructure changes into the S390 tree, so 
keeping this fix in the tracing tree would be the best option?

	Ingo