Integration DTrace problems

[Mark Johnston]

On Sun, Oct 20, 2013 at 07:52:16PM -0400, Mark Johnston 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
> 
> ...
> 
> 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).

This comment can be ignored - I had forgotten that the argN variables
are always 64 bits wide and so may give incorrect results when trying to
print a 32-bit function argument. Switching to args[N] gives me correct
results. So with r256822, argument fetching seems to be working properly
with USDT and PID probes. :)

-Mark

> 
> > * 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;