Add support for copyinto() subroutine

The copyinto() subroutine is a near-identical copy of bcopy() other
than that the arguments are ordered differently, and it reads from
userspace addresses rather than kernel addresses.  A new function is
added to implement the shared functionality (dt_cg_subr_bcopy_impl).

Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Eugene Loh <eugene.loh@oracle.com>

libdtrace/dt_cg.c

@@ -4223,37 +4223,43 @@ dt_cg_subr_alloca(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 }
 
 static void
-dt_cg_subr_bcopy(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
+dt_cg_subr_bcopy_impl(dt_node_t *dnp, dt_node_t *dst, dt_node_t *src,
+		      dt_node_t *size, dt_irlist_t *dlp, dt_regset_t *drp)
 {
-	dt_node_t	*src = dnp->dn_args;
-	dt_node_t	*dst = src->dn_list;
-	dt_node_t	*size = dst->dn_list;
-	int		maxsize = yypcb->pcb_hdl->dt_options[DTRACEOPT_SCRATCHSIZE] - 8;
+	dtrace_hdl_t	*dtp = yypcb->pcb_hdl;
+	int		maxsize = dtp->dt_options[DTRACEOPT_SCRATCHSIZE] - 8;
 	uint_t		lbl_badsize = dt_irlist_label(dlp);
 	uint_t		lbl_ok = dt_irlist_label(dlp);
+	int		is_bcopy = dnp->dn_ident->di_id == DIF_SUBR_BCOPY;
 
-	TRACE_REGSET("    subr-bcopy:Begin");
+	TRACE_REGSET("      subr-bcopy-impl:Begin");
+
+	/* Validate the size for the copy operation. */
+	dt_cg_node(size, dlp, drp);
 
+	emit(dlp,  BPF_BRANCH_IMM(BPF_JSLT, size->dn_reg, 0, lbl_badsize));
+	emit(dlp,  BPF_BRANCH_IMM(BPF_JGT, size->dn_reg, maxsize, lbl_badsize));
+
+	/* Validate the source pointer. */
 	dt_cg_node(src, dlp, drp);
 	if (src->dn_flags & DT_NF_ALLOCA)
 		dnerror(src, D_PROTO_ARG,
-			"bcopy( ) argument #1 is incompatible with prototype:\n"
+			"%s( ) argument #1 is incompatible with prototype:\n"
 			"\tprototype: non-alloca pointer\n"
-			"\t argument: alloca pointer\n");
+			"\t argument: alloca pointer\n",
+			is_bcopy ? "bcopy" : "copyinto");
 	dt_cg_check_notnull(dlp, drp, src->dn_reg);
 
+	/* Validate the destination pointer. */
 	dt_cg_node(dst, dlp, drp);
 	if (!(dst->dn_flags & DT_NF_ALLOCA))
 		dnerror(dst, D_PROTO_ARG,
-			"bcopy( ) argument #2 is incompatible with prototype:\n"
+			"%s( ) argument #%d is incompatible with prototype:\n"
 			"\tprototype: alloca pointer\n"
-			"\t argument: non-alloca pointer\n");
+			"\t argument: non-alloca pointer\n",
+			is_bcopy ? "bcopy" : "copyinto", is_bcopy ? 2 : 3);
 	/* The dst will be NULL-checked in the alloca access check below. */
 
-	dt_cg_node(size, dlp, drp);
-	emit(dlp,  BPF_BRANCH_IMM(BPF_JSLT, size->dn_reg, 0, lbl_badsize));
-	emit(dlp,  BPF_BRANCH_IMM(BPF_JGT, size->dn_reg, maxsize, lbl_badsize));
-
 	dt_cg_alloca_access_check(dlp, drp, dst->dn_reg,
 				  DT_ISREG, size->dn_reg);
 	dt_cg_alloca_ptr(dlp, drp, dst->dn_reg, dst->dn_reg);
@@ -4265,7 +4271,9 @@ dt_cg_subr_bcopy(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 	emit(dlp,  BPF_MOV_REG(BPF_REG_2, size->dn_reg));
 	emit(dlp,  BPF_MOV_REG(BPF_REG_3, src->dn_reg));
 	dt_regset_xalloc(drp, BPF_REG_0);
-	emit(dlp,  BPF_CALL_HELPER(BPF_FUNC_probe_read));
+	emit(dlp,  BPF_CALL_HELPER(dtp->dt_bpfhelper[
+					is_bcopy ? BPF_FUNC_probe_read_kernel
+						 : BPF_FUNC_probe_read_user]));
 
 	/*
 	 * At this point the dst is validated, so any problem must be with
@@ -4285,6 +4293,20 @@ dt_cg_subr_bcopy(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 	dt_regset_free(drp, dst->dn_reg);
 	dt_regset_free(drp, size->dn_reg);
 
+	TRACE_REGSET("      subr-bcopy-impl:End  ");
+}
+
+static void
+dt_cg_subr_bcopy(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
+{
+	dt_node_t	*src = dnp->dn_args;
+	dt_node_t	*dst = src->dn_list;
+	dt_node_t	*size = dst->dn_list;
+
+	TRACE_REGSET("    subr-bcopy:Begin");
+
+	dt_cg_subr_bcopy_impl(dnp, dst, src, size, dlp, drp);
+
 	TRACE_REGSET("    subr-bcopy:End  ");
 }
 
@@ -4339,6 +4361,20 @@ dt_cg_subr_copyin(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 	TRACE_REGSET("    subr-copyin:End  ");
 }
 
+static void
+dt_cg_subr_copyinto(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
+{
+	dt_node_t	*src = dnp->dn_args;
+	dt_node_t	*size = src->dn_list;
+	dt_node_t	*dst = size->dn_list;
+
+	TRACE_REGSET("    subr-copyinto:Begin");
+
+	dt_cg_subr_bcopy_impl(dnp, dst, src, size, dlp, drp);
+
+	TRACE_REGSET("    subr-copyinto:End  ");
+}
+
 static void
 dt_cg_subr_strchr(dt_node_t *dnp, dt_irlist_t *dlp, dt_regset_t *drp)
 {
@@ -4819,7 +4855,7 @@ static dt_cg_subr_f *_dt_cg_subr[DIF_SUBR_MAX + 1] = {
 	[DIF_SUBR_COPYOUTSTR]		= NULL,
 	[DIF_SUBR_ALLOCA]		= &dt_cg_subr_alloca,
 	[DIF_SUBR_BCOPY]		= &dt_cg_subr_bcopy,
-	[DIF_SUBR_COPYINTO]		= NULL,
+	[DIF_SUBR_COPYINTO]		= &dt_cg_subr_copyinto,
 	[DIF_SUBR_MSGDSIZE]		= NULL,
 	[DIF_SUBR_MSGSIZE]		= NULL,
 	[DIF_SUBR_GETMAJOR]		= &dt_cg_subr_getmajor,

test/unittest/funcs/copyinto/err.D_PROTO_ARG.non_alloca_arg3-2.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Argument 3 for copyinto() must be an alloca() pointer.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto(1, 2, &`max_pfn);
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_ARG.non_alloca_arg3.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Argument 3 for copyinto() must be an alloca() pointer.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto(1, 2, "");
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_ARG.non_ptr_arg3.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Argument 3 for copyinto() must be a pointer.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto(1, 2, 3);
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_ARG.non_scalar_arg1.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Argument 1 for copyinto() must be a scalar.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto("1", 2, 3);
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_ARG.non_scalar_arg2.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Argument 2 for copyinto() must be a scalar.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto(1, "2", 3);
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_LEN.missing_arg.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Arguments are required for copyinto().
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto();
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_LEN.too_few_args.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Three arguments are required for copyinto().
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyinto(1, 2);
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.D_PROTO_LEN.too_many_args.d

@@ -0,0 +1,23 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Exactly three Arguments are required for copyinto().
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	copyin(1, 2, 3, 4);
+	exit(1);
+}
+
+ERROR
+{
+	exit(0);
+}

test/unittest/funcs/copyinto/err.badaddr.d

@@ -0,0 +1,24 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: Using copyinto() with an invalid source address reports a fault.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	ptr = (char *)alloca(256);
+	copyinto(0x1234, 8, ptr);
+	exit(0);
+}
+
+ERROR
+{
+	exit(1);
+}

test/unittest/funcs/copyinto/err.badaddr.r

@@ -0,0 +1,6 @@
+                   FUNCTION:NAME
+                          :ERROR 
+
+-- @@stderr --
+dtrace: script 'test/unittest/funcs/copyinto/err.badaddr.d' matched 2 probes
+dtrace: error on enabled probe ID 3 (ID 1: dtrace:::BEGIN): invalid address ({ptr}) in action #1 at BPF pc NNN

test/unittest/funcs/copyinto/err.badsize.d

@@ -0,0 +1,24 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Licensed under the Universal Permissive License v 1.0 as shown at
+ * http://oss.oracle.com/licenses/upl.
+ */
+
+/*
+ * ASSERTION: The copyinto() size must not exceed the allocated space.
+ *
+ * SECTION: Actions and Subroutines/copyinto()
+ */
+
+BEGIN
+{
+	ptr = (char *)alloca(64);
+	copyinto(curthread->mm->env_start, 65, ptr);
+	exit(0);
+}
+
+ERROR
+{
+	exit(1);
+}

test/unittest/funcs/copyinto/err.badsize.r

@@ -0,0 +1,6 @@
+                   FUNCTION:NAME
+                          :ERROR 
+
+-- @@stderr --
+dtrace: script 'test/unittest/funcs/copyinto/err.badsize.d' matched 2 probes
+dtrace: error on enabled probe ID 3 (ID 1: dtrace:::BEGIN): invalid size ({ptr}) in action #1 at BPF pc NNN