Integration DTrace problems

[Mark Johnston]

On Sun, Oct 20, 2013 at 09:29:06PM -0500, Adam Leventhal wrote:
> Hey Mark,
> 
> I'd go so far as to suggest you remove the #ifdef sun stuff and just
> have your new logic replace what was there. As the original author of
> that code (I think), it is more kludgy than clever in retrospect -- as
> so many things are...

Fair enough. I removed the #ifdefs and committed the change as r256822.
Thanks!

-Mark

> 
> Thanks.
> 
> Adam
> 
> On Sun, Oct 20, 2013 at 6:52 PM, Mark Johnston <markj at freebsd.org> wrote:
> > On Wed, Oct 09, 2013 at 01:54:14AM +0400, Veniamin Gvozdikov wrote:
> >> Hello,
> >>
> >> I have problems with integration DTrace:
> >>
> >> * Wildcard bug
> >> * USDT at runtime works only with probes with arguments less than 5
> >
> > The patch below should partly address this issue (which exists for the
> > pid provider too). On amd64, the first six arguments are taken out of the
> > trap frame with (roughly) the following line:
> >
> >     val = regs->r_rdi[argno]
> >
> > where 0 <= argno <= 5 is the argument index. This works when the six
> > argument registers correspond to consecutive of struct reg, which is not
> > the case on FreeBSD. This bug only comes up when argno == 5 though,
> > since the first _five_ arguments are passed directly to dtrace_probe() by
> > the fasttrap trap handler.
> >
> > Arguments of index > 5 come from the stack and may still be incorrect
> > with this patch. I'm not yet sure what the problem is - if the arguments
> > are (4-byte) ints, some of the values are wrong, but when I change the
> > types to long, the values are correct (up to arg9 at least).
> >
> >> * USDT depended by base src because need dtrace.h although It exists on OSX and Oracle Linux
> >> * Bug with providers position in D file with multi link dtrace objects
> >> * Bug with not used probes when all providers unavailable if doesn't use in code
> >> * Inconvenient toolchains (need to see DTrace on OSX)
> >>
> >> For more details go to link http://zlonet.ru/page/dtrace-integration-features/ .
> >>
> >>
> >> Any idea?
> >
> > diff --git a/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c b/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
> > index 65991af..8afc45a 100644
> > --- a/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
> > +++ b/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
> > @@ -271,8 +271,26 @@ fasttrap_anarg(struct reg *rp, int function_entry, int argno)
> >                  * In 64-bit mode, the first six arguments are stored in
> >                  * registers.
> >                  */
> > -               if (argno < 6)
> > +               if (argno < 6) {
> > +#if !defined(sun)
> > +                       switch (argno) {
> > +                       case 0:
> > +                               return (rp->r_rdi);
> > +                       case 1:
> > +                               return (rp->r_rsi);
> > +                       case 2:
> > +                               return (rp->r_rdx);
> > +                       case 3:
> > +                               return (rp->r_rcx);
> > +                       case 4:
> > +                               return (rp->r_r8);
> > +                       case 5:
> > +                               return (rp->r_r9);
> > +                       }
> > +#else
> >                         return ((&rp->r_rdi)[argno]);
> > +#endif
> > +               }
> >
> >                 stack = (uintptr_t *)rp->r_rsp;
> >                 DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
> > diff --git a/sys/cddl/dev/dtrace/amd64/dtrace_isa.c b/sys/cddl/dev/dtrace/amd64/dtrace_isa.c
> > index 34d6f33..b82b77f 100644
> > --- a/sys/cddl/dev/dtrace/amd64/dtrace_isa.c
> > +++ b/sys/cddl/dev/dtrace/amd64/dtrace_isa.c
> > @@ -367,7 +367,31 @@ dtrace_getarg(int arg, int aframes)
> >                             sizeof (uintptr_t));
> >
> >                         if (arg <= inreg) {
> > +#if !defined(sun)
> > +                               switch (arg) {
> > +                               case 0:
> > +                                       stack = (uintptr_t *)&rp->r_rdi;
> > +                                       break;
> > +                               case 1:
> > +                                       stack = (uintptr_t *)&rp->r_rsi;
> > +                                       break;
> > +                               case 2:
> > +                                       stack = (uintptr_t *)&rp->r_rdx;
> > +                                       break;
> > +                               case 3:
> > +                                       stack = (uintptr_t *)&rp->r_rcx;
> > +                                       break;
> > +                               case 4:
> > +                                       stack = (uintptr_t *)&rp->r_r8;
> > +                                       break;
> > +                               case 5:
> > +                                       stack = (uintptr_t *)&rp->r_r9;
> > +                                       break;
> > +                               }
> > +                               arg = 0;
> > +#else
> >                                 stack = (uintptr_t *)&rp->r_rdi;
> > +#endif
> >                         } else {
> >                                 stack = (uintptr_t *)(rp->r_rsp);
> >                                 arg -= inreg;
> > _______________________________________________
> > freebsd-dtrace at freebsd.org mailing list
> > https://lists.freebsd.org/mailman/listinfo/freebsd-dtrace
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> 
> 
> 
> -- 
> Adam Leventhal
> CTO, Delphix
> http://blog.delphix.com/ahl