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[Qemu-devel] [PATCH v9 5/8] module: implement module loading
From: |
Fam Zheng |
Subject: |
[Qemu-devel] [PATCH v9 5/8] module: implement module loading |
Date: |
Fri, 13 Sep 2013 17:59:13 +0800 |
Added three types of modules:
typedef enum {
MODULE_LOAD_BLOCK = 0,
MODULE_LOAD_UI,
MODULE_LOAD_NET,
MODULE_LOAD_MAX,
} module_load_type;
and their loading function:
void module_load(module_load_type).
which loads whitelisted ".so" files in a subdir under configured
${MODDIR}, e.g. "/usr/lib/qemu/block". Modules of each type should be
loaded in respective subsystem initialization code.
The init function of dynamic module is no longer with
__attribute__((constructor)) as static linked version, and need to be
explicitly called once loaded. The function name is mangled with per
configure fingerprint as:
init_$(date +%s$$$RANDOM)
Which is known to module_load function, and the loading fails if this
symbol is not there. With this, modules built from a different
tree/version/configure will not be loaded.
The module loading code requires gmodule-2.0.
Configure option "--enable-modules=L" can be used to restrict qemu to
only build/load some whitelisted modules.
Signed-off-by: Fam Zheng <address@hidden>
---
Makefile | 3 +++
block.c | 1 +
configure | 43 ++++++++++++++++++++++--------
include/qemu/module.h | 23 ++++++++++++++++
rules.mak | 9 +++++--
scripts/create_config | 21 +++++++++++++++
util/module.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++
vl.c | 2 ++
8 files changed, 163 insertions(+), 13 deletions(-)
diff --git a/Makefile b/Makefile
index ef76967..766b309 100644
--- a/Makefile
+++ b/Makefile
@@ -196,6 +196,9 @@ Makefile: $(version-obj-y) $(version-lobj-y)
libqemustub.a: $(stub-obj-y)
libqemuutil.a: $(util-obj-y) qapi-types.o qapi-visit.o
+default-whitelist = $(foreach o,$(modules-m),"$(notdir $(basename $o))",) NULL
+util/module.o-cflags = -D'CONFIG_MODULE_WHITELIST=$(default-whitelist)'
+
######################################################################
qemu-img.o: qemu-img-cmds.h
diff --git a/block.c b/block.c
index 26639e8..16ceaaf 100644
--- a/block.c
+++ b/block.c
@@ -4008,6 +4008,7 @@ BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs,
void bdrv_init(void)
{
+ module_load(MODULE_LOAD_BLOCK);
module_call_init(MODULE_INIT_BLOCK);
}
diff --git a/configure b/configure
index 5bc7256..05aa964 100755
--- a/configure
+++ b/configure
@@ -199,6 +199,7 @@ datadir="\${prefix}/share"
qemu_docdir="\${prefix}/share/doc/qemu"
bindir="\${prefix}/bin"
libdir="\${prefix}/lib"
+moddir="\${prefix}/lib/qemu"
libexecdir="\${prefix}/libexec"
includedir="\${prefix}/include"
sysconfdir="\${prefix}/etc"
@@ -651,7 +652,9 @@ for opt do
;;
--disable-debug-info)
;;
- --enable-modules) modules="yes"
+ --enable-modules|--enable-modules=*)
+ modules="yes"
+ module_list=`echo "$optarg" | sed -e 's/,/ /g'`
;;
--cpu=*)
;;
@@ -676,6 +679,8 @@ for opt do
;;
--libdir=*) libdir="$optarg"
;;
+ --moddir=*) moddir="$optarg"
+ ;;
--libexecdir=*) libexecdir="$optarg"
;;
--includedir=*) includedir="$optarg"
@@ -1052,10 +1057,13 @@ echo " --datadir=PATH install firmware in
PATH$confsuffix"
echo " --docdir=PATH install documentation in PATH$confsuffix"
echo " --bindir=PATH install binaries in PATH"
echo " --libdir=PATH install libraries in PATH"
+echo " --moddir=PATH install modules in PATH"
echo " --sysconfdir=PATH install config in PATH$confsuffix"
echo " --localstatedir=PATH install local state in PATH (set at runtime
on win32)"
echo " --with-confsuffix=SUFFIX suffix for QEMU data inside datadir and
sysconfdir [$confsuffix]"
-echo " --enable-modules enable modules support"
+echo " --enable-modules enable modules support and whitelist all
modules"
+echo " --enable-modules=L enable modules and provide a whitelist"
+echo " Available modules: curl iscsi gluster ssh rbd"
echo " --enable-debug-tcg enable TCG debugging"
echo " --disable-debug-tcg disable TCG debugging (default)"
echo " --enable-debug-info enable debugging information (default)"
@@ -2256,15 +2264,19 @@ 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"
-fi
+
+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 required to compile QEMU"
+ fi
+done
+
##########################################
# pixman support probe
@@ -3557,6 +3569,7 @@ 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 $moddir`"
echo "libexec directory `eval echo $libexecdir`"
echo "include directory `eval echo $includedir`"
echo "config directory `eval echo $sysconfdir`"
@@ -3581,6 +3594,9 @@ if test "$slirp" = "yes" ; then
echo "smbd $smbd"
fi
echo "module support $modules"
+if test -n "$module_list"; then
+ echo "module whitelist $module_list"
+fi
echo "host CPU $cpu"
echo "host big endian $bigendian"
echo "target list $target_list"
@@ -3680,6 +3696,7 @@ echo all: >> $config_host_mak
echo "prefix=$prefix" >> $config_host_mak
echo "bindir=$bindir" >> $config_host_mak
echo "libdir=$libdir" >> $config_host_mak
+echo "moddir=$moddir" >> $config_host_mak
echo "libexecdir=$libexecdir" >> $config_host_mak
echo "includedir=$includedir" >> $config_host_mak
echo "mandir=$mandir" >> $config_host_mak
@@ -3698,8 +3715,12 @@ echo "libs_softmmu=$libs_softmmu" >> $config_host_mak
echo "ARCH=$ARCH" >> $config_host_mak
+echo "CONFIG_FINGERPRINT=$(date +%s$$$RANDOM)" >> $config_host_mak
if test "$modules" = "yes"; then
echo "CONFIG_MODULES=y" >> $config_host_mak
+ if test -n "$module_list"; then
+ echo "CONFIG_MODULE_WHITELIST=$module_list" >> $config_host_mak
+ fi
fi
case "$cpu" in
arm|i386|x86_64|x32|ppc|aarch64)
diff --git a/include/qemu/module.h b/include/qemu/module.h
index c4ccd57..6458d8f 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -14,11 +14,25 @@
#ifndef QEMU_MODULE_H
#define QEMU_MODULE_H
+#ifdef BUILD_DSO
+
+/* For error message, this function is an identification of qemu module */
+void qemu_module_do_init(void (*init)(void));
+
+/* To restrict loading of arbitrary DSO, The init function name is changed per
+ * "./configure" to refuse unknown DSO file */
+void DSO_INIT_FUN(void);
+
+#define module_init(function, type) \
+void qemu_module_do_init(void (*init)(void)) { init(); } \
+void DSO_INIT_FUN(void) { qemu_module_do_init(function); }
+#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) { \
register_module_init(function, type); \
}
+#endif
typedef enum {
MODULE_INIT_BLOCK,
@@ -37,4 +51,13 @@ void register_module_init(void (*fn)(void), module_init_type
type);
void module_call_init(module_init_type type);
+typedef enum {
+ MODULE_LOAD_BLOCK = 0,
+ MODULE_LOAD_UI,
+ MODULE_LOAD_NET,
+ MODULE_LOAD_MAX,
+} module_load_type;
+
+void module_load(module_load_type type);
+
#endif
diff --git a/rules.mak b/rules.mak
index 43a502e..e5529da 100644
--- a/rules.mak
+++ b/rules.mak
@@ -62,7 +62,7 @@ endif
%.o: %.dtrace
$(call quiet-command,dtrace -o $@ -G -s $<, " GEN $(TARGET_DIR)$@")
-%$(DSOSUF): QEMU_CFLAGS += -fPIC
+%$(DSOSUF): QEMU_CFLAGS += -fPIC -DBUILD_DSO
%$(DSOSUF): LDFLAGS += $(LDFLAGS_SHARED)
%$(DSOSUF): %.mo libqemustub.a
$(call LINK,$^)
@@ -165,13 +165,18 @@ $(if $(nested-dirs),
$(call unnest-vars-1))
endef
+is-whitelisted = $(if $(CONFIG_MODULE_WHITELIST),$(strip \
+ $(filter $(CONFIG_MODULE_WHITELIST),$(basename $(notdir $1)))),\
+ yes)
define add-modules
$(foreach o,$(filter %.o,$($1)),
$(eval $(patsubst %.o,%.mo,$o): $o) \
$(eval $(patsubst %.o,%.mo,$o)-objs := $o))
$(foreach o,$(filter %.mo,$($1)),$(eval \
$o: $($o-objs)))
-$(eval modules-m += $(patsubst %.o,%.mo,$($1)))
+$(eval t := $(patsubst %.o,%.mo,$($1)))
+$(foreach o,$t,$(if $(call is-whitelisted,$o),$(eval \
+ modules-m += $o)))
endef
define unnest-vars
diff --git a/scripts/create_config b/scripts/create_config
index b1adbf5..ab430c7 100755
--- a/scripts/create_config
+++ b/scripts/create_config
@@ -26,6 +26,24 @@ case $line in
# save for the next definitions
prefix=${line#*=}
;;
+ moddir=*)
+ eval "moddir=\"${line#*=}\""
+ echo "#define CONFIG_MODDIR \"$moddir\""
+ ;;
+ CONFIG_FINGERPRINT=*)
+ echo "#define DSO_INIT_FUN init_${line#*=}"
+ echo "#define DSO_INIT_FUN_STR \"init_${line#*=}\""
+ ;;
+ CONFIG_MODULES=*)
+ echo "#define CONFIG_MODULES \"${line#*=}\""
+ ;;
+ CONFIG_MODULE_WHITELIST=*)
+ echo "#define CONFIG_MODULE_WHITELIST\\"
+ for mod in ${line#*=}; do
+ echo " \"${mod}\",\\"
+ done
+ echo " NULL"
+ ;;
CONFIG_AUDIO_DRIVERS=*)
drivers=${line#*=}
echo "#define CONFIG_AUDIO_DRIVERS \\"
@@ -104,6 +122,9 @@ 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..1f38311 100644
--- a/util/module.c
+++ b/util/module.c
@@ -13,6 +13,7 @@
* GNU GPL, version 2 or (at your option) any later version.
*/
+#include <gmodule.h>
#include "qemu-common.h"
#include "qemu/queue.h"
#include "qemu/module.h"
@@ -79,3 +80,76 @@ void module_call_init(module_init_type type)
e->init();
}
}
+
+#ifdef CONFIG_MODULES
+static void module_load_file(const char *fname)
+{
+ GModule *g_module;
+ void (*init_fun)(void);
+ const char *dsosuf = HOST_DSOSUF;
+ int len = strlen(fname);
+ int suf_len = strlen(dsosuf);
+
+ if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
+ /* wrong suffix */
+ return;
+ }
+ g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
+ if (!g_module) {
+ fprintf(stderr, "Failed to open module file %s\n",
+ g_module_error());
+ return;
+ }
+ if (!g_module_symbol(g_module, DSO_INIT_FUN_STR, (gpointer *)&init_fun)) {
+ 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_do_init",
+ (gpointer *)&init_fun)) {
+ fprintf(stderr,
+ "Note: only modules from the same build can be loaded.\n");
+ }
+ g_module_close(g_module);
+ return;
+ }
+ init_fun();
+}
+#endif
+
+void module_load(module_load_type type)
+{
+#ifdef CONFIG_MODULES
+ const char *path;
+ char *fname = NULL;
+ const char **mp;
+ const char *module_whitelist[] = {
+ CONFIG_MODULE_WHITELIST
+ };
+
+ if (!g_module_supported()) {
+ return;
+ }
+
+ switch (type) {
+ case MODULE_LOAD_BLOCK:
+ path = CONFIG_MODDIR "/block/";
+ break;
+ case MODULE_LOAD_UI:
+ path = CONFIG_MODDIR "/ui/";
+ break;
+ case MODULE_LOAD_NET:
+ path = CONFIG_MODDIR "/net/";
+ break;
+ default:
+ return;
+ }
+
+ for (mp = &module_whitelist[0]; *mp; mp++) {
+ fname = g_strdup_printf("%s%s" HOST_DSOSUF, path, *mp);
+ module_load_file(fname);
+ g_free(fname);
+ }
+
+#endif
+}
diff --git a/vl.c b/vl.c
index b4b119a..659e53a 100644
--- a/vl.c
+++ b/vl.c
@@ -2940,6 +2940,8 @@ int main(int argc, char **argv, char **envp)
#endif
}
+ module_load(MODULE_LOAD_UI);
+ module_load(MODULE_LOAD_NET);
module_call_init(MODULE_INIT_QOM);
qemu_add_opts(&qemu_drive_opts);
--
1.8.3.1
- [Qemu-devel] [PATCH v9 0/8] Shared Library Module Support, Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 1/8] ui/Makefile.objs: delete unnecessary cocoa.o dependency, Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 2/8] make.rule: fix $(obj) to a real relative path, Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 3/8] rule.mak: allow per object cflags and libs, Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 4/8] build-sys: introduce common-obj-m and block-obj-m for DSO, Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 6/8] Makefile: install modules with "make install", Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 5/8] module: implement module loading,
Fam Zheng <=
- [Qemu-devel] [PATCH v9 7/8] .gitignore: ignore module related files (dll, so, mo), Fam Zheng, 2013/09/13
- [Qemu-devel] [PATCH v9 8/8] block: convert block drivers linked with libs to modules, Fam Zheng, 2013/09/13
- Re: [Qemu-devel] [PATCH v9 0/8] Shared Library Module Support, Peter Maydell, 2013/09/13