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[Qemu-devel] [PULL 07/12] module: implement module loading
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 07/12] module: implement module loading |
Date: |
Mon, 17 Feb 2014 18:35:54 +0100 |
From: Fam Zheng <address@hidden>
This patch adds loading, stamp checking and initialization of modules.
The init function of dynamic module is no longer directly called as
__attribute__((constructor)) in static linked version, it is called
only after passed the checking of presense of stamp symbol:
qemu_stamp_$RELEASEHASH
where $RELEASEHASH is generated by hashing version strings and content
of configure script.
With this, modules built from a different tree/version/configure will
not be loaded.
The module loading code requires gmodule-2.0.
Modules are searched under
- CONFIG_MODDIR
- executable folder (to allow running qemu-{img,io} in the build
directory)
- ../ of executable folder (to allow running system emulator in the
build directory)
Modules are linked under their subdir respectively, then copied to top
level of build directory for above convinience, e.g.:
$(BUILD_DIR)/block/curl.so -> $(BUILD_DIR)/block-curl.so
Signed-off-by: Paolo Bonzini <address@hidden>
Signed-off-by: Fam Zheng <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
Makefile | 3 +
configure | 42 +++++++++++---
include/qemu/module.h | 23 ++++++++-
module-common.c | 10 ++++
rules.mak | 3 +
scripts/create_config | 3 +
util/module.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++++-
7 files changed, 217 insertions(+), 12 deletions(-)
create mode 100644 module-common.c
diff --git a/Makefile b/Makefile
index 9d53117..07d1ed7 100644
--- a/Makefile
+++ b/Makefile
@@ -201,6 +201,9 @@ Makefile: $(version-obj-y) $(version-lobj-y)
libqemustub.a: $(stub-obj-y)
libqemuutil.a: $(util-obj-y) qapi-types.o qapi-visit.o
+block-modules = $(foreach o,$(block-obj-m),"$(basename $(subst /,-,$o))",) NULL
+util/module.o-cflags = -D'CONFIG_BLOCK_MODULES=$(block-modules)'
+
######################################################################
qemu-img.o: qemu-img-cmds.h
diff --git a/configure b/configure
index 14f4501..bd21db9 100755
--- a/configure
+++ b/configure
@@ -1132,7 +1132,7 @@ Advanced options (experts only):
--libdir=PATH install libraries in PATH
--sysconfdir=PATH install config in PATH$confsuffix
--localstatedir=PATH install local state in PATH (set at runtime on
win32)
- --with-confsuffix=SUFFIX suffix for QEMU data inside datadir and sysconfdir
[$confsuffix]
+ --with-confsuffix=SUFFIX suffix for QEMU data inside
datadir/libdir/sysconfdir [$confsuffix]
--enable-modules enable modules support
--enable-debug-tcg enable TCG debugging
--disable-debug-tcg disable TCG debugging (default)
@@ -2348,14 +2348,32 @@ if test "$mingw32" = yes; then
else
glib_req_ver=2.12
fi
-if $pkg_config --atleast-version=$glib_req_ver gthread-2.0; then
- glib_cflags=`$pkg_config --cflags gthread-2.0`
- glib_libs=`$pkg_config --libs gthread-2.0`
- CFLAGS="$glib_cflags $CFLAGS"
- LIBS="$glib_libs $LIBS"
- libs_qga="$glib_libs $libs_qga"
-else
- error_exit "glib-$glib_req_ver required to compile QEMU"
+
+for i in gthread-2.0 gmodule-2.0; do
+ if $pkg_config --atleast-version=$glib_req_ver $i; then
+ glib_cflags=`$pkg_config --cflags $i`
+ glib_libs=`$pkg_config --libs $i`
+ CFLAGS="$glib_cflags $CFLAGS"
+ LIBS="$glib_libs $LIBS"
+ libs_qga="$glib_libs $libs_qga"
+ else
+ error_exit "glib-$glib_req_ver $i is required to compile QEMU"
+ fi
+done
+
+##########################################
+# SHA command probe for modules
+if test "$modules" = yes; then
+ shacmd_probe="sha1sum sha1 shasum"
+ for c in $shacmd_probe; do
+ if which $c &>/dev/null; then
+ shacmd="$c"
+ break
+ fi
+ done
+ if test "$shacmd" = ""; then
+ error_exit "one of the checksum commands is required to enable
modules: $shacmd_probe"
+ fi
fi
##########################################
@@ -3633,6 +3651,7 @@ if test "$mingw32" = "yes" ; then
fi
qemu_confdir=$sysconfdir$confsuffix
+qemu_moddir=$libdir$confsuffix
qemu_datadir=$datadir$confsuffix
qemu_localedir="$datadir/locale"
@@ -3723,6 +3742,7 @@ echo "Install prefix $prefix"
echo "BIOS directory `eval echo $qemu_datadir`"
echo "binary directory `eval echo $bindir`"
echo "library directory `eval echo $libdir`"
+echo "module directory `eval echo $qemu_moddir`"
echo "libexec directory `eval echo $libexecdir`"
echo "include directory `eval echo $includedir`"
echo "config directory `eval echo $sysconfdir`"
@@ -3861,6 +3881,7 @@ echo "sysconfdir=$sysconfdir" >> $config_host_mak
echo "qemu_confdir=$qemu_confdir" >> $config_host_mak
echo "qemu_datadir=$qemu_datadir" >> $config_host_mak
echo "qemu_docdir=$qemu_docdir" >> $config_host_mak
+echo "qemu_moddir=$qemu_moddir" >> $config_host_mak
if test "$mingw32" = "no" ; then
echo "qemu_localstatedir=$local_statedir" >> $config_host_mak
fi
@@ -3994,6 +4015,9 @@ if [ "$docs" = "yes" ] ; then
echo "BUILD_DOCS=yes" >> $config_host_mak
fi
if test "$modules" = "yes"; then
+ # $shacmd can generate a hash started with digit, which the compiler doesn't
+ # like as an symbol. So prefix it with an underscore
+ echo "CONFIG_STAMP=_`(echo $qemu_version; echo $pkgversion; cat $0) |
$shacmd - | cut -f1 -d\ `" >> $config_host_mak
echo "CONFIG_MODULES=y" >> $config_host_mak
fi
if test "$sdl" = "yes" ; then
diff --git a/include/qemu/module.h b/include/qemu/module.h
index c4ccd57..72d9498 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -14,11 +14,31 @@
#ifndef QEMU_MODULE_H
#define QEMU_MODULE_H
+#include "qemu/osdep.h"
+
+#define DSO_STAMP_FUN glue(qemu_stamp, CONFIG_STAMP)
+#define DSO_STAMP_FUN_STR stringify(DSO_STAMP_FUN)
+
+#ifdef BUILD_DSO
+void DSO_STAMP_FUN(void);
+/* This is a dummy symbol to identify a loaded DSO as a QEMU module, so we can
+ * distinguish "version mismatch" from "not a QEMU module", when the stamp
+ * check fails during module loading */
+void qemu_module_dummy(void);
+
+#define module_init(function, type) \
+static void __attribute__((constructor)) do_qemu_init_ ## function(void) \
+{ \
+ register_dso_module_init(function, type); \
+}
+#else
/* This should not be used directly. Use block_init etc. instead. */
#define module_init(function, type) \
-static void __attribute__((constructor)) do_qemu_init_ ## function(void) { \
+static void __attribute__((constructor)) do_qemu_init_ ## function(void) \
+{ \
register_module_init(function, type); \
}
+#endif
typedef enum {
MODULE_INIT_BLOCK,
@@ -34,6 +54,7 @@ typedef enum {
#define type_init(function) module_init(function, MODULE_INIT_QOM)
void register_module_init(void (*fn)(void), module_init_type type);
+void register_dso_module_init(void (*fn)(void), module_init_type type);
void module_call_init(module_init_type type);
diff --git a/module-common.c b/module-common.c
new file mode 100644
index 0000000..50c6750
--- /dev/null
+++ b/module-common.c
@@ -0,0 +1,10 @@
+#include "config-host.h"
+#include "qemu/module.h"
+
+void qemu_module_dummy(void)
+{
+}
+
+void DSO_STAMP_FUN(void)
+{
+}
diff --git a/rules.mak b/rules.mak
index 55db767..a4d88e6 100644
--- a/rules.mak
+++ b/rules.mak
@@ -74,6 +74,8 @@ DSO_CFLAGS := -fPIC -DBUILD_DSO
%$(DSOSUF): LDFLAGS += $(LDFLAGS_SHARED)
%$(DSOSUF): %.mo libqemustub.a
$(call LINK,$^)
+ @# Copy to build root so modules can be loaded when program started
without install
+ $(if $(findstring /,$@),$(call quiet-command,cp $@ $(subst /,-,$@), "
CP $(subst /,-,$@)"))
.PHONY: modules
modules:
@@ -203,6 +205,7 @@ $(foreach o,$(filter %.o,$($1)),
$(eval $(patsubst %.o,%.mo,$o): $o) \
$(eval $(patsubst %.o,%.mo,$o)-objs := $o))
$(foreach o,$(filter-out $(modules-m), $(patsubst %.o,%.mo,$($1))), \
+ $(eval $o-objs += module-common.o)
$(eval $o: $($o-objs))
$(eval modules-objs-m += $($o-objs))
$(eval modules-m += $o)
diff --git a/scripts/create_config b/scripts/create_config
index 06f5316..546f889 100755
--- a/scripts/create_config
+++ b/scripts/create_config
@@ -108,6 +108,9 @@ case $line in
value=${line#*=}
echo "#define $name $value"
;;
+ DSOSUF=*)
+ echo "#define HOST_DSOSUF \"${line#*=}\""
+ ;;
esac
done # read
diff --git a/util/module.c b/util/module.c
index 7acc33d..42bc373 100644
--- a/util/module.c
+++ b/util/module.c
@@ -13,6 +13,8 @@
* GNU GPL, version 2 or (at your option) any later version.
*/
+#include <stdlib.h>
+#include <gmodule.h>
#include "qemu-common.h"
#include "qemu/queue.h"
#include "qemu/module.h"
@@ -21,13 +23,16 @@ typedef struct ModuleEntry
{
void (*init)(void);
QTAILQ_ENTRY(ModuleEntry) node;
+ module_init_type type;
} ModuleEntry;
typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;
static ModuleTypeList init_type_list[MODULE_INIT_MAX];
-static void init_types(void)
+static ModuleTypeList dso_init_list;
+
+static void init_lists(void)
{
static int inited;
int i;
@@ -40,6 +45,8 @@ static void init_types(void)
QTAILQ_INIT(&init_type_list[i]);
}
+ QTAILQ_INIT(&dso_init_list);
+
inited = 1;
}
@@ -48,7 +55,7 @@ static ModuleTypeList *find_type(module_init_type type)
{
ModuleTypeList *l;
- init_types();
+ init_lists();
l = &init_type_list[type];
@@ -62,20 +69,154 @@ void register_module_init(void (*fn)(void),
module_init_type type)
e = g_malloc0(sizeof(*e));
e->init = fn;
+ e->type = type;
l = find_type(type);
QTAILQ_INSERT_TAIL(l, e, node);
}
+void register_dso_module_init(void (*fn)(void), module_init_type type)
+{
+ ModuleEntry *e;
+
+ init_lists();
+
+ e = g_malloc0(sizeof(*e));
+ e->init = fn;
+ e->type = type;
+
+ QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
+}
+
+static void module_load(module_init_type type);
+
void module_call_init(module_init_type type)
{
ModuleTypeList *l;
ModuleEntry *e;
+ module_load(type);
l = find_type(type);
QTAILQ_FOREACH(e, l, node) {
e->init();
}
}
+
+#ifdef CONFIG_MODULES
+static int module_load_file(const char *fname)
+{
+ GModule *g_module;
+ void (*sym)(void);
+ const char *dsosuf = HOST_DSOSUF;
+ int len = strlen(fname);
+ int suf_len = strlen(dsosuf);
+ ModuleEntry *e, *next;
+ int ret;
+
+ if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
+ /* wrong suffix */
+ ret = -EINVAL;
+ goto out;
+ }
+ if (access(fname, F_OK)) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ assert(QTAILQ_EMPTY(&dso_init_list));
+
+ g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
+ if (!g_module) {
+ fprintf(stderr, "Failed to open module: %s\n",
+ g_module_error());
+ ret = -EINVAL;
+ goto out;
+ }
+ if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
+ fprintf(stderr, "Failed to initialize module: %s\n",
+ fname);
+ /* Print some info if this is a QEMU module (but from different build),
+ * this will make debugging user problems easier. */
+ if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) {
+ fprintf(stderr,
+ "Note: only modules from the same build can be loaded.\n");
+ }
+ g_module_close(g_module);
+ ret = -EINVAL;
+ } else {
+ QTAILQ_FOREACH(e, &dso_init_list, node) {
+ register_module_init(e->init, e->type);
+ }
+ ret = 0;
+ }
+
+ QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
+ QTAILQ_REMOVE(&dso_init_list, e, node);
+ g_free(e);
+ }
+out:
+ return ret;
+}
+#endif
+
+void module_load(module_init_type type)
+{
+#ifdef CONFIG_MODULES
+ char *fname = NULL;
+ const char **mp;
+ static const char *block_modules[] = {
+ CONFIG_BLOCK_MODULES
+ };
+ char *exec_dir;
+ char *dirs[3];
+ int i = 0;
+ int ret;
+
+ if (!g_module_supported()) {
+ fprintf(stderr, "Module is not supported by system.\n");
+ return;
+ }
+
+ switch (type) {
+ case MODULE_INIT_BLOCK:
+ mp = block_modules;
+ break;
+ default:
+ /* no other types have dynamic modules for now*/
+ return;
+ }
+
+ exec_dir = qemu_get_exec_dir();
+ dirs[i++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR);
+ dirs[i++] = g_strdup_printf("%s/..", exec_dir ? : "");
+ dirs[i++] = g_strdup_printf("%s", exec_dir ? : "");
+ assert(i == ARRAY_SIZE(dirs));
+ g_free(exec_dir);
+ exec_dir = NULL;
+
+ for ( ; *mp; mp++) {
+ for (i = 0; i < ARRAY_SIZE(dirs); i++) {
+ fname = g_strdup_printf("%s/%s%s", dirs[i], *mp, HOST_DSOSUF);
+ ret = module_load_file(fname);
+ /* Try loading until loaded a module file */
+ if (!ret) {
+ break;
+ }
+ g_free(fname);
+ fname = NULL;
+ }
+ if (ret == -ENOENT) {
+ fprintf(stderr, "Can't find module: %s\n", *mp);
+ }
+
+ g_free(fname);
+ }
+
+ for (i = 0; i < ARRAY_SIZE(dirs); i++) {
+ g_free(dirs[i]);
+ }
+
+#endif
+}
--
1.7.1
- [Qemu-devel] [PULL 00/12] Build system changes for 2014-02-17, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 02/12] rules.mak: fix $(obj) to a real relative path, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 11/12] configure: Disable libtool if -fPIE does not work with it (bug #1257099), Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 01/12] util: Split out exec_dir from os_find_datadir, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 03/12] rules.mak: allow per object cflags and libs, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 05/12] darwin: do not use -mdynamic-no-pic, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 04/12] block: use per-object cflags and libs, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 06/12] rules.mak: introduce DSO rules, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 07/12] module: implement module loading,
Paolo Bonzini <=
- [Qemu-devel] [PULL 08/12] Makefile: install modules with "make install", Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 09/12] Makefile: introduce common-obj-m and block-obj-m for DSO, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 10/12] block: convert block drivers linked with libs to modules, Paolo Bonzini, 2014/02/17
- [Qemu-devel] [PULL 12/12] build: softmmu targets do not have a "main.o" file, Paolo Bonzini, 2014/02/17
- Re: [Qemu-devel] [PULL 00/12] Build system changes for 2014-02-17, Peter Maydell, 2014/02/20