PSARC 2008/302 DTrace IP Provider

6640019 DTrace IP Provider
6655707 sdt arguments are off-by-one past the 5th
6667364 /usr/demo/dtrace/index.html: URLs to dtrace guide chapters wrong

--HG--
rename : usr/src/lib/libdtrace/common/net.d => deleted_files/usr/src/lib/libdtrace/common/net.d

1 files changed, 73 insertions, 2 deletions

diff --git a/usr/src/uts/intel/dtrace/sdt.c b/usr/src/uts/intel/dtrace/sdt.c
index aa31d84d14..55724b3d89 100644
--- a/usr/src/uts/intel/dtrace/sdt.c
+++ b/usr/src/uts/intel/dtrace/sdt.c
@@ -19,7 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -33,6 +33,11 @@
 #include <sys/conf.h>
 #include <vm/seg_kmem.h>
 #include <sys/stack.h>
+#include <sys/frame.h>
+#include <sys/dtrace_impl.h>
+#include <sys/cmn_err.h>
+#include <sys/sysmacros.h>
+#include <sys/privregs.h>
 #include <sys/sdt_impl.h>
 
 #define	SDT_PATCHVAL	0xf0
@@ -289,6 +294,72 @@ err:
 	;
 }
 
+/*ARGSUSED*/
+uint64_t
+sdt_getarg(void *arg, dtrace_id_t id, void *parg, int argno, int aframes)
+{
+	uintptr_t val;
+	struct frame *fp = (struct frame *)dtrace_getfp();
+	uintptr_t *stack;
+	int i;
+#if defined(__amd64)
+	/*
+	 * A total of 6 arguments are passed via registers; any argument with
+	 * index of 5 or lower is therefore in a register.
+	 */
+	int inreg = 5;
+#endif
+
+	for (i = 1; i <= aframes; i++) {
+		fp = (struct frame *)(fp->fr_savfp);
+
+		if (fp->fr_savpc == (pc_t)dtrace_invop_callsite) {
+#if !defined(__amd64)
+			/*
+			 * If we pass through the invalid op handler, we will
+			 * use the pointer that it passed to the stack as the
+			 * second argument to dtrace_invop() as the pointer to
+			 * the stack.  When using this stack, we must step
+			 * beyond the EIP/RIP that was pushed when the trap was
+			 * taken -- hence the "+ 1" below.
+			 */
+			stack = ((uintptr_t **)&fp[1])[1];
+#else
+			/*
+			 * In the case of amd64, we will use the pointer to the
+			 * regs structure that was pushed when we took the
+			 * trap.  To get this structure, we must increment
+			 * beyond the frame structure, and then again beyond
+			 * the calling RIP stored in dtrace_invop().  If the
+			 * argument that we're seeking is passed on the stack,
+			 * we'll pull the true stack pointer out of the saved
+			 * registers and decrement our argument by the number
+			 * of arguments passed in registers; if the argument
+			 * we're seeking is passed in regsiters, we can just
+			 * load it directly.
+			 */
+			struct regs *rp = (struct regs *)((uintptr_t)&fp[1] +
+			    sizeof (uintptr_t));
+
+			if (argno <= inreg) {
+				stack = (uintptr_t *)&rp->r_rdi;
+			} else {
+				stack = (uintptr_t *)(rp->r_rsp);
+				argno -= inreg;
+			}
+#endif
+			goto load;
+		}
+	}
+
+load:
+	DTRACE_CPUFLAG_SET(CPU_DTRACE_NOFAULT);
+	val = stack[argno];
+	DTRACE_CPUFLAG_CLEAR(CPU_DTRACE_NOFAULT);
+
+	return (val);
+}
+
 static dtrace_pops_t sdt_pops = {
 	NULL,
 	sdt_provide_module,
@@ -297,7 +368,7 @@ static dtrace_pops_t sdt_pops = {
 	NULL,
 	NULL,
 	sdt_getargdesc,
-	NULL,
+	sdt_getarg,
 	NULL,
 	sdt_destroy
 };