[DTrace-devel] [PATCH] Add 'id' builtin D variable and a test for it
David Mc Lean
david.mclean at oracle.com
Wed Sep 16 22:08:32 PDT 2020
Signed-off-by: David Mc Lean <david.mclean at oracle.com>
---
bpf/get_bvar.c | 2 ++
libdtrace/dt_bpf.h | 1 +
libdtrace/dt_cc.c | 5 ++-
libdtrace/dt_cg.c | 6 ++++
libdtrace/dt_dctx.h | 2 ++
libdtrace/dt_dlibs.c | 1 +
test/unittest/variables/bvar/tst.id.sh | 59 ++++++++++++++++++++++++++++++++++
7 files changed, 75 insertions(+), 1 deletion(-)
create mode 100755 test/unittest/variables/bvar/tst.id.sh
diff --git a/bpf/get_bvar.c b/bpf/get_bvar.c
index 9f09108..52ec186 100644
--- a/bpf/get_bvar.c
+++ b/bpf/get_bvar.c
@@ -27,6 +27,8 @@ noinline uint64_t dt_get_bvar(dt_mstate_t *mst, uint32_t id)
return mst->tstamp;
case DIF_VAR_EPID:
return mst->epid;
+ case DIF_VAR_ID:
+ return mst->prid;
case DIF_VAR_ARG0: case DIF_VAR_ARG1: case DIF_VAR_ARG2:
case DIF_VAR_ARG3: case DIF_VAR_ARG4: case DIF_VAR_ARG5:
case DIF_VAR_ARG6: case DIF_VAR_ARG7: case DIF_VAR_ARG8:
diff --git a/libdtrace/dt_bpf.h b/libdtrace/dt_bpf.h
index c4a4a99..7a7fe87 100644
--- a/libdtrace/dt_bpf.h
+++ b/libdtrace/dt_bpf.h
@@ -17,6 +17,7 @@ extern "C" {
#define DT_CONST_EPID 1
#define DT_CONST_ARGC 2
+#define DT_CONST_PRID 3
extern int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
int group_fd, unsigned long flags);
diff --git a/libdtrace/dt_cc.c b/libdtrace/dt_cc.c
index f29a21f..ceea19c 100644
--- a/libdtrace/dt_cc.c
+++ b/libdtrace/dt_cc.c
@@ -2412,7 +2412,10 @@ dt_link_construct(dtrace_hdl_t *dtp, const dt_probe_t *prp, dtrace_difo_t *dp,
case DT_IDENT_SCALAR: /* constant */
switch (idp->di_id) {
case DT_CONST_EPID:
- nrp->dofr_data = epid; /* set vakue */
+ nrp->dofr_data = epid;
+ break;
+ case DT_CONST_PRID:
+ nrp->dofr_data = prp->desc->id;
break;
case DT_CONST_ARGC:
nrp->dofr_data = 0; /* FIXME */
diff --git a/libdtrace/dt_cg.c b/libdtrace/dt_cg.c
index 0d3463c..14e543b 100644
--- a/libdtrace/dt_cg.c
+++ b/libdtrace/dt_cg.c
@@ -175,9 +175,11 @@ dt_cg_prologue(dt_pcb_t *pcb, dt_node_t *pred)
{
dt_irlist_t *dlp = &pcb->pcb_ir;
dt_ident_t *epid = dt_dlib_get_var(pcb->pcb_hdl, "EPID");
+ dt_ident_t *prid = dt_dlib_get_var(pcb->pcb_hdl, "PRID");
struct bpf_insn instr;
assert(epid != NULL);
+ assert(prid != NULL);
/*
* void dt_program(dt_dctx_t *dctx)
@@ -206,6 +208,7 @@ dt_cg_prologue(dt_pcb_t *pcb, dt_node_t *pred)
* // stdw [%r0 + DMST_FAULT], 0
* dctx->mst->tstamp = 0; // stdw [%r0 + DMST_TSTAMP], 0
* dctx->mst->epid = EPID; // stw [%r0 + DMST_EPID], EPID
+ * dctx->mst->prid = PRID; // stw [%r0 + DMST_PRID], PRID
* *((uint32_t *)&buf[0]) = EPID;
* // stw [%r9 + 0], EPID
*/
@@ -218,6 +221,9 @@ dt_cg_prologue(dt_pcb_t *pcb, dt_node_t *pred)
instr = BPF_STORE_IMM(BPF_W, BPF_REG_0, DMST_EPID, -1);
dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
dlp->dl_last->di_extern = epid;
+ instr = BPF_STORE_IMM(BPF_W, BPF_REG_0, DMST_PRID, -1);
+ dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
+ dlp->dl_last->di_extern = prid;
instr = BPF_STORE_IMM(BPF_W, BPF_REG_9, 0, -1);
dt_irlist_append(dlp, dt_cg_node_alloc(DT_LBL_NONE, instr));
dlp->dl_last->di_extern = epid;
diff --git a/libdtrace/dt_dctx.h b/libdtrace/dt_dctx.h
index 79ef710..48b1470 100644
--- a/libdtrace/dt_dctx.h
+++ b/libdtrace/dt_dctx.h
@@ -15,6 +15,7 @@
*/
typedef struct dt_mstate {
uint32_t epid; /* Enabled probe ID */
+ uint32_t prid; /* Probe ID */
uint32_t tag; /* Tag (for future use) */
uint64_t fault; /* DTrace fault flags */
uint64_t tstamp; /* cached timestamp value */
@@ -45,6 +46,7 @@ typedef struct dt_dctx {
#define DCTX_FP(off) (-(ushort_t)DCTX_SIZE + (ushort_t)(off))
#define DMST_EPID offsetof(dt_mstate_t, epid)
+#define DMST_PRID offsetof(dt_mstate_t, prid)
#define DMST_TAG offsetof(dt_mstate_t, tag)
#define DMST_FAULT offsetof(dt_mstate_t, fault)
#define DMST_TSTAMP offsetof(dt_mstate_t, tstamp)
diff --git a/libdtrace/dt_dlibs.c b/libdtrace/dt_dlibs.c
index 83eb4a1..2875364 100644
--- a/libdtrace/dt_dlibs.c
+++ b/libdtrace/dt_dlibs.c
@@ -69,6 +69,7 @@ static const dt_ident_t dt_bpf_symbols[] = {
DT_BPF_SYMBOL(tvars, DT_IDENT_PTR),
/* BPF internal identifiers */
DT_BPF_SYMBOL_ID(EPID, DT_IDENT_SCALAR, DT_CONST_EPID),
+ DT_BPF_SYMBOL_ID(PRID, DT_IDENT_SCALAR, DT_CONST_PRID),
DT_BPF_SYMBOL_ID(ARGC, DT_IDENT_SCALAR, DT_CONST_ARGC),
/* End-of-list marker */
{ NULL, }
diff --git a/test/unittest/variables/bvar/tst.id.sh b/test/unittest/variables/bvar/tst.id.sh
new file mode 100755
index 0000000..c34679f
--- /dev/null
+++ b/test/unittest/variables/bvar/tst.id.sh
@@ -0,0 +1,59 @@
+#!/bin/bash
+#
+# Oracle Linux DTrace.
+# Copyright (c) 2020, 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 id built-in variable matches the ID.
+#
+# SECTION: Variables/Built-in Variables/id
+#
+##
+
+dtrace=$1
+
+# Testing turns off default ID output.
+# For this test, however, we want that ID output.
+unset _DTRACE_TESTING
+
+# Feed DTrace output into awk script to process results.
+$dtrace $dt_flags -n '
+profile-3 {
+ trace(id);
+}
+
+tick-2 {
+ exit(0);
+}
+' | awk '
+BEGIN {
+ nevents = 0;
+ nerrors = 0;
+ ID = -1;
+}
+
+{ print }
+
+$3 == ":profile-3" {
+ nevents++;
+ if (NF != 4) { nerrors++; print; print "ERROR: not 4 fields" };
+ if ($2 != $4) { nerrors++; print; print "ERROR: ID and id differ" };
+ if (ID == -1) { ID = $2 };
+ if (ID != $2) { nerrors++; print; print "ERROR: probe ID changed" };
+}
+
+END {
+ if (nevents == 0) { print "NO EVENTS"; exit(1) };
+ if (nerrors != 0) { print "FOUND ERRORS"; exit(1) };
+ print "success";
+ exit(0);
+}
+'
+
+exit $?
+
--
1.8.3.1
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