[DTrace-devel] [PATCH 08/10 REVIEWED] Add disassembler annotations for assoc arrays
Kris Van Hees
kris.van.hees at oracle.com
Fri Mar 18 19:04:46 UTC 2022
Signed-off-by: Kris Van Hees <kris.van.hees at oracle.com>
Reviewed-by: Eugene Loh <eugene.loh at oracle.com>
---
libdtrace/dt_dis.c | 29 ++++++++++++++++++++++
test/unittest/disasm/tst.ann-gvar-assoc.r | 2 ++
test/unittest/disasm/tst.ann-gvar-assoc.sh | 22 ++++++++++++++++
test/unittest/disasm/tst.ann-tvar-assoc.r | 2 ++
test/unittest/disasm/tst.ann-tvar-assoc.sh | 22 ++++++++++++++++
5 files changed, 77 insertions(+)
create mode 100644 test/unittest/disasm/tst.ann-gvar-assoc.r
create mode 100755 test/unittest/disasm/tst.ann-gvar-assoc.sh
create mode 100644 test/unittest/disasm/tst.ann-tvar-assoc.r
create mode 100755 test/unittest/disasm/tst.ann-tvar-assoc.sh
diff --git a/libdtrace/dt_dis.c b/libdtrace/dt_dis.c
index e7d7194f..7d5e5d54 100644
--- a/libdtrace/dt_dis.c
+++ b/libdtrace/dt_dis.c
@@ -357,6 +357,35 @@ dt_dis_bpf_args(const dtrace_difo_t *dp, const char *fn,
dt_dis_varname_id(dp, in->imm + DIF_VAR_OTHER_UBASE,
DIFV_SCOPE_THREAD, addr));
return buf;
+ } else if (strcmp(fn, "dt_get_assoc") == 0) {
+ uint_t varid;
+
+ /*
+ * We know that the previous four instructions exist and
+ * move the variable id to a register in the first instruction
+ * of that seqeuence (because we wrote the code generator to
+ * emit the instructions in this exact order.)
+ */
+ in -= 4;
+ varid = in->imm + DIF_VAR_OTHER_UBASE;
+
+ /*
+ * Four instructions prior to this there will be a STORE (TLS
+ * associative array) or a STORE_IMM (global associative array).
+ */
+ in -= 4;
+ if (in->code == (BPF_STX | BPF_MEM | BPF_DW))
+ snprintf(buf, len, "self->%s[]",
+ dt_dis_varname_id(dp, varid, DIFV_SCOPE_THREAD,
+ addr));
+ else if (in->code == (BPF_ST | BPF_MEM | BPF_DW))
+ snprintf(buf, len, "%s[]",
+ dt_dis_varname_id(dp, varid, DIFV_SCOPE_GLOBAL,
+ addr));
+ else
+ snprintf(buf, len, "???[]");
+
+ return buf;
}
return NULL;
diff --git a/test/unittest/disasm/tst.ann-gvar-assoc.r b/test/unittest/disasm/tst.ann-gvar-assoc.r
new file mode 100644
index 00000000..f7563a51
--- /dev/null
+++ b/test/unittest/disasm/tst.ann-gvar-assoc.r
@@ -0,0 +1,2 @@
+85 0 1 0000 ffffffff call dt_get_assoc ! st[]
+85 0 1 0000 ffffffff call dt_get_assoc ! ld[]
diff --git a/test/unittest/disasm/tst.ann-gvar-assoc.sh b/test/unittest/disasm/tst.ann-gvar-assoc.sh
new file mode 100755
index 00000000..6690967d
--- /dev/null
+++ b/test/unittest/disasm/tst.ann-gvar-assoc.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+#
+# 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.
+#
+
+dtrace=$1
+
+$dtrace $dt_flags -Sen '
+int st[int], ld[int];
+
+BEGIN
+{
+ st[2] = 42;
+ trace(ld[5]);
+ exit(0);
+}
+' 2>&1 | awk '/ call dt_get_assoc/ { sub(/^[^:]+: /, ""); print; }'
+
+exit $?
diff --git a/test/unittest/disasm/tst.ann-tvar-assoc.r b/test/unittest/disasm/tst.ann-tvar-assoc.r
new file mode 100644
index 00000000..573c93e2
--- /dev/null
+++ b/test/unittest/disasm/tst.ann-tvar-assoc.r
@@ -0,0 +1,2 @@
+85 0 1 0000 ffffffff call dt_get_assoc ! self->st[]
+85 0 1 0000 ffffffff call dt_get_assoc ! self->ld[]
diff --git a/test/unittest/disasm/tst.ann-tvar-assoc.sh b/test/unittest/disasm/tst.ann-tvar-assoc.sh
new file mode 100755
index 00000000..354d8fbe
--- /dev/null
+++ b/test/unittest/disasm/tst.ann-tvar-assoc.sh
@@ -0,0 +1,22 @@
+#!/bin/bash
+#
+# 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.
+#
+
+dtrace=$1
+
+$dtrace $dt_flags -Sen '
+self int st[int], ld[int];
+
+BEGIN
+{
+ self->st[2] = 42;
+ trace(self->ld[5]);
+ exit(0);
+}
+' 2>&1 | awk '/ call dt_get_assoc/ { sub(/^[^:]+: /, ""); print; }'
+
+exit $?
--
2.34.1
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