usdt: common infrastructure

USDT will include a daemon that implements a CUSE device that programs
containing USDT probes issue ioctl()s to.  This daemon needs to create
uprobes, and this needs to use libproc to extract information about the
processes (like mapping addresses, etc).  This is something the rest of
DTrace can already do: so split out infrastructure needed by libproc and
infrastructure needed to create uprobes into a new libcommon (static)
library that the daemon can use.  Make tiny adjustments to libproc and
triggers that use it so that libproc can stand independent of libdtrace
(it was very nearly there already: only one debugging statement change
and a move of dt_list into the common library is needed).

A future commit will adjust DTrace to use this library to create uprobes
too.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Reviewed-by: Kris Van Hees <kris.van.hees@oracle.com>

libcommon/Build

@@ -0,0 +1,13 @@
+# 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.
+
+BUILDLIBS += libcommon
+LIBS += libcommon
+
+libcommon_TARGET = libcommon
+libcommon_DIR := $(current-dir)
+libcommon_CPPFLAGS := -Ilibcommon -Ilibproc
+libcommon_SOURCES = dt_list.c
+libcommon_LIBSOURCES = libcommon

libcommon/GNUmakefile

@@ -0,0 +1,5 @@
+%:
+	$(MAKE) -C .. $@
+
+all::
+	$(MAKE) -C .. all

libdtrace/Build

@@ -4,7 +4,7 @@
 # http://oss.oracle.com/licenses/upl.
 
 BUILDLIBS += libdtrace-build
-libdtrace-build_CPPFLAGS = -Ilibdtrace -Ilibproc -Iuts/intel -Ilibdtrace/$(ARCHINC) \
+libdtrace-build_CPPFLAGS = -Ilibdtrace -Ilibproc -Ilibcommon -Iuts/intel -Ilibdtrace/$(ARCHINC) \
                            -DDTRACE_LIBDIR="\"$(LIBDIR)/dtrace\"" -DDTRACE_USER_UID=$(USER_UID) \
                            -DUNPRIV_UID=$(UNPRIV_UID) -DDUMPCAP_GROUP=\"$(DUMPCAP_GROUP)\" \
                            -DUNPRIV_HOME=\"$(UNPRIV_HOME)\"
@@ -32,7 +32,6 @@ libdtrace-build_SOURCES = dt_aggregate.c \
 			  dt_lex.c \
 			  dt_link.c \
 			  dt_kernel_module.c \
-			  dt_list.c \
 			  dt_map.c \
 			  dt_module.c \
 			  dt_open.c \
@@ -77,7 +76,7 @@ endif
 libdtrace_VERSION := 2.0.0
 libdtrace_SONAME := libdtrace.so.2
 libdtrace_VERSCRIPT := libdtrace.ver
-libdtrace_LIBSOURCES := libdtrace-build libproc libport
+libdtrace_LIBSOURCES := libdtrace-build libproc libport libcommon
 libdtrace_SECONDARY := libproc libport
 
 # Disable certain warnings for these files

libproc/Build

@@ -4,10 +4,13 @@
 # http://oss.oracle.com/licenses/upl.
 
 BUILDLIBS += libproc
-libproc_CPPFLAGS = -Ilibproc -Ilibdtrace -I$(objdir) -Iuts/intel -Ilibproc/$(ARCHINC)
+LIBS += libproc
+libproc_CPPFLAGS = -Ilibproc -Ilibdtrace -Ilibcommon -I$(objdir) -Iuts/intel -Ilibproc/$(ARCHINC)
 libproc_TARGET = libproc
 libproc_DIR := $(current-dir)
 libproc_SOURCES = Pcontrol.c elfish.c elfish_64.c elfish_32.c Psymtab.c rtld_db.c rtld_offsets.c wrap.c isadep_dispatch.c $(ARCHINC)/isadep.c
+libproc_LIBSOURCES := libproc libcommon
+libproc_SECONDARY := libcommon
 libproc_SRCDEPS := $(objdir)/rtld_offsets.stamp
 
 rtld_offsets.c_CFLAGS := -Wno-prio-ctor-dtor

libproc/Pcontrol.c

@@ -1,6 +1,6 @@
 /*
  * Oracle Linux DTrace.
- * Copyright (c) 2010, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 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.
  */
@@ -352,7 +352,7 @@ Pgrab(pid_t pid, int noninvasiveness, int already_ptraced, void *wrap_arg,
 	 * it to definite noninvasiveness.
 	 */
 	if (*perr || noninvasiveness > 1) {
-		dt_dprintf("%i: grabbing noninvasively.\n", P->pid);
+		_dprintf("%i: grabbing noninvasively.\n", P->pid);
 		P->noninvasive = TRUE;
 	}
 

test/triggers/Build

@@ -133,17 +133,17 @@ visible-constructor-32_LDFLAGS := -s
 libproc-pldd_CFLAGS := -Ilibproc -Ilibdtrace
 libproc-pldd_NOCFLAGS :=
 libproc-pldd_NOLDFLAGS :=
-libproc-pldd_DEPS := build-libproc.a build-libdtrace.a libport.a
-libproc-pldd_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/build-libport.a $(libdtrace_LIBS)
+libproc-pldd_DEPS := build-libproc.a build-libdtrace.a libcommon.a libport.a
+libproc-pldd_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/build-libcommon.a $(objdir)/build-libport.a $(libdtrace_LIBS)
 
 # Technically libproc-dlmlib is not a dependency of libproc-consistency, but in
 # practice the tests never call it with anything else, so it's needed whenever
 # libproc-consistency is.
 libproc-consistency_CFLAGS := -Ilibproc -Ilibdtrace
 libproc-consistency_NOCFLAGS :=
 libproc-consistency_NOLDFLAGS :=
-libproc-consistency_DEPS := build-libproc.a build-libdtrace.a libport.a libproc-dlmlib.so
-libproc-consistency_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/build-libport.a $(libdtrace_LIBS)
+libproc-consistency_DEPS := build-libproc.a build-libdtrace.a libcommon.a libport.a libproc-dlmlib.so
+libproc-consistency_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/libcommon.a $(objdir)/build-libport.a $(libdtrace_LIBS)
 
 # The lookup victim also needs to have an rpath baked into it, since when
 # testing in --use-installed mode, there is no LD_LIBRARY_PATH pointing into
@@ -157,15 +157,15 @@ libproc-lookup-by-name_CFLAGS := -Ilibproc -Ilibdtrace
 libproc-lookup-by-name_LDFLAGS := -Bdynamic
 libproc-lookup-by-name_NOCFLAGS :=
 libproc-lookup-by-name_NOLDFLAGS :=
-libproc-lookup-by-name_DEPS := build-libproc.a build-libdtrace.a libport.a
-libproc-lookup-by-name_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/build-libport.a $(libdtrace_LIBS)
+libproc-lookup-by-name_DEPS := build-libproc.a build-libdtrace.a libcommon.a libport.a
+libproc-lookup-by-name_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/libcommon.a $(objdir)/build-libport.a $(libdtrace_LIBS)
 
 libproc-execing-bkpts_CFLAGS := -Ilibproc -Ilibdtrace
 libproc-execing-bkpts_LDFLAGS :=
 libproc-execing-bkpts_NOCFLAGS :=
 libproc-execing-bkpts_NOLDFLAGS :=
-libproc-execing-bkpts_DEPS := build-libproc.a build-libdtrace.a libport.a
-libproc-execing-bkpts_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/build-libport.a $(libdtrace_LIBS)
+libproc-execing-bkpts_DEPS := build-libproc.a build-libdtrace.a libcommon.a libport.a
+libproc-execing-bkpts_LIBS := $(objdir)/build-libproc.a $(objdir)/build-libdtrace.a $(objdir)/libcommon.a $(objdir)/build-libport.a $(libdtrace_LIBS)
 
 # We need multiple versions of libproc-sleeper with different combinations
 # of flags.

test/utils/Build

@@ -1,5 +1,5 @@
 # Oracle Linux DTrace.
-# Copyright (c) 2011, 2021, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 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.
 
@@ -11,7 +11,7 @@ $(1)_DIR := $(current-dir)
 $(1)_TARGET = $(1)
 $(1)_SOURCES = $(1).c
 $(1)_POST := link-test-util
-$(1)_CFLAGS := -Ilibdtrace -Ilibproc
+$(1)_CFLAGS := -Ilibdtrace -Ilibproc -Ilibcommon
 $(1)_NOCFLAGS := --coverage
 $(1)_NOLDFLAGS := --coverage
 $(1)_DEPS = libdtrace.so