alloca: new faults

We'll use DTRACEFLT_BADSIZE to distinguish in error messages between
out-of-bounds errors in bcopy and the like, and size-too-large errors.
(Without this, it's hard to tell if a, say, 0x12 in the fault value
is a nearly-NULL pointer or a wrong size.)

We'll use DTRACEFLT_INTERR to indicate can-never-happen errors where we
have tested the actual condition already (and emitted a proper error)
followed by a check to placate the verifier (which will always succeed
if the actual condition check failed).  The latter failure happening at
runtime always indicates a bug in DTrace, not in the user's code, so
indicate as much.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>

include/dtrace/faults_defines.h

@@ -32,6 +32,8 @@
 #define DTRACEFLT_UPRIV			7	/* Illegal user access */
 #define DTRACEFLT_TUPOFLOW		8	/* Tuple stack overflow */
 #define DTRACEFLT_BADSTACK		9	/* Bad stack */
+#define DTRACEFLT_BADSIZE		10	/* Bad size */
+#define DTRACEFLT_INTERR		11	/* Internal error */
 
 #define DTRACEFLT_LIBRARY		1000	/* Library-level fault */
 

libdtrace/dt_error.c

@@ -206,6 +206,8 @@ dtrace_faultstr(dtrace_hdl_t *dtp, int fault)
 		{ DTRACEFLT_UPRIV,	"invalid user access" },
 		{ DTRACEFLT_TUPOFLOW,	"tuple stack overflow" },
 		{ DTRACEFLT_BADSTACK,	"bad stack" },
+		{ DTRACEFLT_BADSIZE,	"invalid size" },
+		{ DTRACEFLT_INTERR,	"internal error" },
 		{ DTRACEFLT_LIBRARY,	"library-level fault" },
 		{ 0,			NULL }
 	};

libdtrace/dt_handle.c

@@ -181,6 +181,7 @@ dt_handle_err(dtrace_hdl_t *dtp, dtrace_probedata_t *data)
 	case DTRACEFLT_BADADDR:
 	case DTRACEFLT_BADALIGN:
 	case DTRACEFLT_BADSTACK:
+	case DTRACEFLT_BADSIZE:
 		sprintf(details, " (0x%llx)", (u_longlong_t)err.dteda_addr);
 		break;