Add tracemem support

Also, replace tst.three_arg.sh with tst.tracemem.d:
- to avoid the problematic profile probe (fires irregularly)
- for cleaner post processing
- to check both 2-arg and 3-arg results

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

libdtrace/dt_cg.c

@@ -1996,8 +1996,49 @@ dt_cg_act_trace(dt_pcb_t *pcb, dt_node_t *dnp, dtrace_actkind_t kind)
 static void
 dt_cg_act_tracemem(dt_pcb_t *pcb, dt_node_t *dnp, dtrace_actkind_t kind)
 {
-	dnerror(dnp, D_UNKNOWN, "tracemem() is not implemented (yet)\n");
-	/* FIXME: Needs implementation */
+	char		n[DT_TYPE_NAMELEN];
+	dt_node_t	*addr = dnp->dn_args;
+	dt_node_t	*nsiz = addr->dn_list;
+	dt_node_t	*dsiz = nsiz->dn_list;
+	dtrace_hdl_t	*dtp = pcb->pcb_hdl;
+	dt_irlist_t	*dlp = &pcb->pcb_ir;
+	dt_regset_t	*drp = pcb->pcb_regs;
+	uint_t		off;
+
+	if (dt_node_is_integer(addr) == 0 && dt_node_is_pointer(addr) == 0)
+		dnerror(addr, D_TRACEMEM_ADDR,
+		    "tracemem( ) argument #1 is incompatible with prototype:\n"
+		    "\tprototype: pointer or integer\n"
+		    "\t argument: %s\n", dt_node_type_name(addr, n, sizeof(n)));
+
+	if (dt_node_is_posconst(nsiz) == 0)
+		dnerror(nsiz, D_TRACEMEM_SIZE,
+		    "tracemem( ) argument #2 must be a non-zero positive integral constant expression\n");
+
+	dt_cg_node(addr, dlp, drp);
+	dt_cg_node(nsiz, dlp, drp);
+
+	off = dt_rec_add(dtp, dt_cg_fill_gap, DTRACEACT_TRACEMEM, nsiz->dn_value, 1, NULL,
+	    dsiz ? DTRACE_TRACEMEM_DYNAMIC : DTRACE_TRACEMEM_STATIC);
+
+	if (dsiz != NULL)
+		dt_cg_store_val(pcb, dsiz, DTRACEACT_TRACEMEM, NULL,
+		    dsiz->dn_flags & DT_NF_SIGNED ? DTRACE_TRACEMEM_SSIZE : DTRACE_TRACEMEM_SIZE);
+
+	if (dt_regset_xalloc_args(drp) == -1)
+		longjmp(yypcb->pcb_jmpbuf, EDT_NOREG);
+
+	emit(dlp, BPF_MOV_REG(BPF_REG_1, BPF_REG_9));
+	emit(dlp, BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, off));
+	emit(dlp, BPF_MOV_REG(BPF_REG_2, nsiz->dn_reg));
+	dt_regset_free(drp, nsiz->dn_reg);
+	emit(dlp, BPF_MOV_REG(BPF_REG_3, addr->dn_reg));
+	dt_regset_free(drp, addr->dn_reg);
+
+	dt_regset_xalloc(drp, BPF_REG_0);
+	emit(dlp, BPF_CALL_HELPER(BPF_FUNC_probe_read));
+	dt_regset_free_args(drp);
+	dt_regset_free(drp, BPF_REG_0);
 }
 
 static void

libdtrace/dt_consume.c

@@ -1005,7 +1005,6 @@ dt_print_bytes(dtrace_hdl_t *dtp, FILE *fp, caddr_t addr,
 	return dt_print_rawbytes(dtp, fp, addr, nbytes);
 }
 
-#ifdef FIXME
 static int
 dt_print_tracemem(dtrace_hdl_t *dtp, FILE *fp, const dtrace_recdesc_t *rec,
     uint_t nrecs, const caddr_t buf)
@@ -1053,7 +1052,6 @@ dt_print_tracemem(dtrace_hdl_t *dtp, FILE *fp, const dtrace_recdesc_t *rec,
 
 	return nconsumed;
 }
-#endif
 
 int
 dt_print_stack(dtrace_hdl_t *dtp, FILE *fp, const char *format,
@@ -2471,6 +2469,17 @@ dt_consume_one_probe(dtrace_hdl_t *dtp, FILE *fp, char *data, uint32_t size,
 			if (dt_print_umod(dtp, fp, NULL, recdata) < 0)
 				return -1;
 			continue;
+		case DTRACEACT_TRACEMEM: {
+			int nrecs;
+
+			nrecs = epd->dtdd_nrecs - i;
+			n = dt_print_tracemem(dtp, fp, rec, nrecs, data);
+			if (n < 0)
+				return -1;
+
+			i += n - 1;
+			continue;
+		}
 		case DTRACEACT_PRINTF:
 			func = dtrace_fprintf;
 			break;

test/unittest/tracemem/err.D_TRACEMEM_ADDR.badaddr.d

@@ -1,10 +1,10 @@
 /*
  * Oracle Linux DTrace.
- * Copyright (c) 2006, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2023, 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.
  */
-/* @@xfail: dtv2 */
+
 /*
  * ASSERTION:
  *  Test tracemem() with an invalid address argument.

test/unittest/tracemem/err.D_TRACEMEM_SIZE.negsize.d

@@ -1,10 +1,10 @@
 /*
  * Oracle Linux DTrace.
- * Copyright (c) 2006, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2023, 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.
  */
-/* @@xfail: dtv2 */
+
 /*
  * ASSERTION:
  *  Test tracemem() with a negative size argument.

test/unittest/tracemem/err.D_TRACEMEM_SIZE.zerosize.d

@@ -1,10 +1,10 @@
 /*
  * Oracle Linux DTrace.
- * Copyright (c) 2006, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2023, 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.
  */
-/* @@xfail: dtv2 */
+
 /*
  * ASSERTION:
  *  Test tracemem() with a zero size argument.

test/unittest/tracemem/tst.init_task.d

@@ -1,10 +1,10 @@
 /*
  * Oracle Linux DTrace.
- * Copyright (c) 2006, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2023, 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.
  */
-/* @@xfail: dtv2 - requires tracemem() */
+
 
 /*
  * ASSERTION:

test/unittest/tracemem/tst.tracemem.d

@@ -0,0 +1,65 @@
+/*
+ * Oracle Linux DTrace.
+ * Copyright (c) 2023, 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: Results for tracemem() are correct.
+ *
+ * SECTION: Actions and Subroutines/tracemem()
+ */
+
+#pragma D option quiet
+
+long long *p;
+
+BEGIN {
+	/* pick some pointer to kernel memory */
+	p = (long long *) curthread;
+
+	/* dump memory at this pointer */
+	printf("%16.16x %16.16x\n", p[ 0], p[ 1]);
+	printf("%16.16x %16.16x\n", p[ 2], p[ 3]);
+	printf("%16.16x %16.16x\n", p[ 4], p[ 5]);
+	printf("%16.16x %16.16x\n", p[ 6], p[ 7]);
+	printf("%16.16x %16.16x\n", p[ 8], p[ 9]);
+	printf("%16.16x %16.16x\n", p[10], p[11]);
+	printf("%16.16x %16.16x\n", p[12], p[13]);
+	printf("%16.16x %16.16x\n", p[14], p[15]);
+	printf("%16.16x %16.16x\n", p[16], p[17]);
+	printf("%16.16x %16.16x\n", p[18], p[19]);
+	printf("%16.16x %16.16x\n", p[20], p[21]);
+	printf("%16.16x %16.16x\n", p[22], p[23]);
+	printf("%16.16x %16.16x\n", p[24], p[25]);
+	printf("%16.16x %16.16x\n", p[26], p[27]);
+	printf("%16.16x %16.16x\n", p[28], p[29]);
+	printf("%16.16x %16.16x\n", p[30], p[31]);
+
+	/* try tracemem() with this same pointer but various sizes */
+
+	tracemem(p, 256);	/* 256 bytes */
+
+	tracemem(p, 256,  -1);	/* 256 bytes (arg2 < 0) */
+
+	tracemem(p, 256,   0);	/*   0 bytes */
+
+	tracemem(p, 256,  32);	/*  32 bytes */
+
+	tracemem(p, 256,  64);	/*  64 bytes */
+
+	tracemem(p, 256, 128);	/* 128 bytes */
+
+	tracemem(p, 256, 256);	/* 256 bytes */
+
+	tracemem(p, 256, 320);	/* 256 bytes (arg1 <= arg2) */
+
+	tracemem(p, 256, (unsigned char) 0x80);
+				/* 128 bytes */
+
+	tracemem(p, 256, (signed char) 0x80);
+				/* 256 bytes (arg2 < 0) */
+
+	exit(0);
+}

test/unittest/tracemem/tst.tracemem.r

@@ -0,0 +1,9 @@
+256 bytes
+256 bytes
+32 bytes
+64 bytes
+128 bytes
+256 bytes
+256 bytes
+128 bytes
+256 bytes

test/unittest/tracemem/tst.tracemem.r.p

@@ -0,0 +1,30 @@
+#!/usr/bin/gawk -f
+
+# read data against which we will check tracemem() results
+BEGIN {
+        n = 0;    # count check results
+        m = 0;    # count tracemem() results
+}
+NF == 2 {
+        check[n] = $1; n++;
+        check[n] = $2; n++;
+        next;
+}
+
+# if we have a blank line, report number of bytes compared, if any
+NF == 0 && m > 0 { print 8 * m, "bytes" }
+
+# restart counting tracemem() output
+NF == 0 { m = 0; next; }
+
+# comparison function
+function mycomp(expect, actual) {
+        if ( expect != actual )
+                print "ERROR: expect", expect, "actual", actual;
+}
+
+# tracemem output has two sets of 8 bytes each; reverse bytes for comparison
+/:/ {
+        mycomp( check[m++], $9$8$7$6$5$4$3$2);
+        mycomp( check[m++], $17$16$15$14$13$12$11$10);
+}

test/unittest/types/tst.complex.d

@@ -1,10 +1,9 @@
 /*
  * Oracle Linux DTrace.
- * Copyright (c) 2006, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2023, 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.
  */
-/* @@xfail: dtv2 - requires tracemem() */
 
 /*
  * ASSERTION: