From: Paolo Bonzini <pbonzini@redhat.com>
To: Fam Zheng <famz@redhat.com>
Cc: kwolf@redhat.com, peter.maydell@linaro.org, alex@alex.org.uk,
mjt@tls.msk.ru, qemu-devel@nongnu.org, vilanova@ac.upc.edu,
stefanha@redhat.com, xiawenc@linux.vnet.ibm.com, rth@twiddle.net
Subject: Re: [Qemu-devel] [PATCH v12 5/8] module: implement module loading
Date: Thu, 10 Oct 2013 14:16:15 +0200 [thread overview]
Message-ID: <52569A8F.8080501@redhat.com> (raw)
In-Reply-To: <1381404376-28156-6-git-send-email-famz@redhat.com>
Il 10/10/2013 13:26, Fam Zheng ha scritto:
> 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_$(date +%s$$$RANDOM)
>
> With this, modules built from a different tree/version/configure will
> not be loaded.
>
> The module loading code requires gmodule-2.0.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
> Makefile | 3 ++
> configure | 32 ++++++++++-----
> include/qemu/module.h | 12 ++++++
> module-common.c | 10 +++++
> rules.mak | 7 ++--
> scripts/create_config | 14 +++++++
> util/module.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++-
> 7 files changed, 170 insertions(+), 15 deletions(-)
> create mode 100644 module-common.c
>
> diff --git a/Makefile b/Makefile
> index a8488d6..51de298 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
>
> +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 7b8771a..dd901ab 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"
> @@ -660,7 +661,8 @@ for opt do
> ;;
> --disable-debug-info)
> ;;
> - --enable-modules) modules="yes"
> + --enable-modules)
> + modules="yes"
> ;;
> --cpu=*)
> ;;
> @@ -685,6 +687,8 @@ for opt do
> ;;
> --libdir=*) libdir="$optarg"
> ;;
> + --moddir=*) moddir="$optarg"
> + ;;
> --libexecdir=*) libexecdir="$optarg"
> ;;
> --includedir=*) includedir="$optarg"
> @@ -1084,6 +1088,7 @@ 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"
Is moddir needed? It should always be LIBDIR/qemu.
Paolo
> 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]"
> @@ -2291,15 +2296,19 @@ 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
> @@ -3660,6 +3669,7 @@ 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`"
> @@ -3786,6 +3796,7 @@ 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
> @@ -3804,6 +3815,7 @@ echo "libs_softmmu=$libs_softmmu" >> $config_host_mak
>
> echo "ARCH=$ARCH" >> $config_host_mak
>
> +echo "CONFIG_STAMP=$(date +%s$$$RANDOM)" >> $config_host_mak
> if test "$modules" = "yes"; then
> echo "CONFIG_MODULES=y" >> $config_host_mak
> fi
> diff --git a/include/qemu/module.h b/include/qemu/module.h
> index c4ccd57..47b7f1d 100644
> --- a/include/qemu/module.h
> +++ b/include/qemu/module.h
> @@ -14,11 +14,22 @@
> #ifndef QEMU_MODULE_H
> #define QEMU_MODULE_H
>
> +#ifdef BUILD_DSO
> +void DSO_STAMP_FUN(void);
> +/* For error message, this function is an identification of qemu module */
> +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) { \
> register_module_init(function, type); \
> }
> +#endif
>
> typedef enum {
> MODULE_INIT_BLOCK,
> @@ -34,6 +45,7 @@ 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 2ff2f16..b0ccfcd 100644
> --- a/rules.mak
> +++ b/rules.mak
> @@ -69,9 +69,9 @@ 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
> +%$(DSOSUF): %.mo libqemustub.a module-common.o
> $(call LINK,$^)
>
> .PHONY: modules
> @@ -178,7 +178,8 @@ $(foreach o,$(filter %.o,$($1)),
> $(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,$t,$(eval modules-m += $o)))
> endef
>
> define unnest-vars
> diff --git a/scripts/create_config b/scripts/create_config
> index b1adbf5..d7ba61d 100755
> --- a/scripts/create_config
> +++ b/scripts/create_config
> @@ -26,6 +26,17 @@ case $line in
> # save for the next definitions
> prefix=${line#*=}
> ;;
> + moddir=*)
> + eval "moddir=\"${line#*=}\""
> + echo "#define CONFIG_MODDIR \"$moddir\""
> + ;;
> + CONFIG_STAMP=*)
> + echo "#define DSO_STAMP_FUN qemu_stamp_${line#*=}"
> + echo "#define DSO_STAMP_FUN_STR \"qemu_stamp_${line#*=}\""
> + ;;
> + CONFIG_MODULES=*)
> + echo "#define CONFIG_MODULES \"${line#*=}\""
> + ;;
> CONFIG_AUDIO_DRIVERS=*)
> drivers=${line#*=}
> echo "#define CONFIG_AUDIO_DRIVERS \\"
> @@ -104,6 +115,9 @@ 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..c4115be 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"
> @@ -21,13 +22,16 @@ 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 +44,8 @@ static void init_types(void)
> QTAILQ_INIT(&init_type_list[i]);
> }
>
> + QTAILQ_INIT(&dso_init_list);
> +
> inited = 1;
> }
>
> @@ -48,7 +54,7 @@ static ModuleTypeList *find_type(module_init_type type)
> {
> ModuleTypeList *l;
>
> - init_types();
> + init_lists();
>
> l = &init_type_list[type];
>
> @@ -62,20 +68,117 @@ 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 void 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;
> +
> + if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
> + /* wrong suffix */
> + return;
> + }
> + if (access(fname, F_OK)) {
> + return;
> + }
> +
> + 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 load module: %s\n",
> + g_module_error());
> + return;
> + }
> + 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);
> + } else {
> + QTAILQ_FOREACH(e, &dso_init_list, node) {
> + register_module_init(e->init, e->type);
> + }
> + }
> +
> + QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
> + QTAILQ_REMOVE(&dso_init_list, e, node);
> + g_free(e);
> + }
> +}
> +#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
> + };
> +
> + if (!g_module_supported()) {
> + return;
> + }
> +
> + switch (type) {
> + case MODULE_INIT_BLOCK:
> + mp = block_modules;
> + break;
> + /* no other types have dynamic modules for now*/
> + default:
> + return;
> + }
> +
> + for ( ; *mp; mp++) {
> + fname = g_strdup_printf("%s/%s%s", CONFIG_MODDIR, *mp, HOST_DSOSUF);
> + module_load_file(fname);
> + g_free(fname);
> + }
> +
> +#endif
> +}
>
next prev parent reply other threads:[~2013-10-10 12:16 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-10 11:26 [Qemu-devel] [PATCH v12 0/8] Shared Library Module Support Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 1/8] ui/Makefile.objs: delete unnecessary cocoa.o dependency Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 2/8] make.rule: fix $(obj) to a real relative path Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 3/8] rule.mak: allow per object cflags and libs Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 4/8] build-sys: introduce common-obj-m and block-obj-m for DSO Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 5/8] module: implement module loading Fam Zheng
2013-10-10 12:16 ` Paolo Bonzini [this message]
2013-10-10 12:34 ` Fam Zheng
2013-10-10 13:40 ` Paolo Bonzini
2013-10-11 1:10 ` Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 6/8] Makefile: install modules with "make install" Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 7/8] .gitignore: ignore module related files (dll, so, mo) Fam Zheng
2013-10-10 11:26 ` [Qemu-devel] [PATCH v12 8/8] block: convert block drivers linked with libs to modules Fam Zheng
2013-10-10 12:19 ` [Qemu-devel] [PATCH v12 0/8] Shared Library Module Support Paolo Bonzini
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