From 1bec2f5bfae922cc163cecb43c868e8e8ee3a66d Mon Sep 17 00:00:00 2001
From: "Kevin P. Fleming" <kpfleming@digium.com>
Date: Thu, 22 Feb 2007 02:36:00 +0000
Subject: [PATCH] give embedded modules a helping hand by backing up and
restoring their global variables when they are loaded and unloaded
git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@56092 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
Makefile.moddir_rules | 12 ++---
Makefile.rules | 28 ++++++++++++
build_tools/make_linker_eo_script | 27 ++++++++++++
include/asterisk/module.h | 73 +++++++++++++++++++++++++++++++
main/loader.c | 8 ++++
5 files changed, 143 insertions(+), 5 deletions(-)
create mode 100755 build_tools/make_linker_eo_script
diff --git a/Makefile.moddir_rules b/Makefile.moddir_rules
index c614c2ab55..d2dafe3294 100644
--- a/Makefile.moddir_rules
+++ b/Makefile.moddir_rules
@@ -34,11 +34,13 @@ $(LOADABLE_MODS:%=%.so): ASTCFLAGS+=-fPIC
$(LOADABLE_MODS:%=%.so): LIBS+=$(foreach dep,$(MENUSELECT_DEPENDS_$*),$(value $(dep)_LIB))
$(LOADABLE_MODS:%=%.so): ASTLDFLAGS+=$(foreach dep,$(MENUSELECT_DEPENDS_$*),$(value $(dep)_LDFLAGS))
+$(EMBEDDED_MODS:%=%.o): ASTCFLAGS+=-DEMBEDDED_MODULE=$*
+
$(addsuffix .so,$(filter $(LOADABLE_MODS),$(C_MODS))): %.so: %.o
$(addsuffix .so,$(filter $(LOADABLE_MODS),$(CC_MODS))): %.so: %.oo
-modules.link: $(addsuffix .o,$(filter $(EMBEDDED_MODS),$(C_MODS)))
-modules.link: $(addsuffix .oo,$(filter $(EMBEDDED_MODS),$(CC_MODS)))
+modules.link: $(addsuffix .eo,$(filter $(EMBEDDED_MODS),$(C_MODS)))
+modules.link: $(addsuffix .eoo,$(filter $(EMBEDDED_MODS),$(CC_MODS)))
.PHONY: clean uninstall _all
@@ -64,11 +66,11 @@ endif
modules.link:
@rm -f $@
- @for file in $(patsubst %,$(SUBDIR)/%,$(filter %.o,$^)); do echo "INPUT (../$${file})" >> $@; done
- @for file in $(patsubst %,$(SUBDIR)/%,$(filter-out %.o,$^)); do echo "INPUT (../$${file})" >> $@; done
+ @for file in $(patsubst %,$(SUBDIR)/%,$(filter %.eo %.eoo,$^)); do echo "INPUT (../$${file})" >> $@; done
+ @for file in $(patsubst %,$(SUBDIR)/%,$(filter-out %.eo %.eoo,$^)); do echo "INPUT (../$${file})" >> $@; done
clean::
- rm -f *.so *.o *.oo
+ rm -f *.so *.o *.oo *.eo *.eoo
rm -f .*.o.d .*.oo.d
rm -f modules.link
diff --git a/Makefile.rules b/Makefile.rules
index 9d20c5a914..e847c3af33 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -44,6 +44,22 @@ else
$(CMD_PREFIX) $(CC) -o $@ -c $< $(PTHREAD_CFLAGS) $(ASTCFLAGS)
endif
+%.o: %.i
+ $(ECHO_PREFIX) echo " [CC] $< -> $@"
+ifeq ($(AST_DEVMODE),yes)
+ $(CMD_PREFIX) $(CC) -o $@ -c $< $(PTHREAD_CFLAGS) $(ASTCFLAGS) -MMD -MT $@ -MF .$(subst /,_,$@).d -MP
+else
+ $(CMD_PREFIX) $(CC) -o $@ -c $< $(PTHREAD_CFLAGS) $(ASTCFLAGS)
+endif
+
+%.i: %.c
+ $(ECHO_PREFIX) echo " [CC] $< -> $@"
+ifeq ($(AST_DEVMODE),yes)
+ $(CMD_PREFIX) $(CC) -o $@ -E $< $(PTHREAD_CFLAGS) $(ASTCFLAGS) -MMD -MT $@ -MF .$(subst /,_,$@).d -MP
+else
+ $(CMD_PREFIX) $(CC) -o $@ -E $< $(PTHREAD_CFLAGS) $(ASTCFLAGS)
+endif
+
%.o: %.s
$(ECHO_PREFIX) echo " [AS] $< -> $@"
ifeq ($(AST_DEVMODE),yes)
@@ -76,6 +92,18 @@ endif
$(ECHO_PREFIX) echo " [LDXX] $^ -> $@"
$(CMD_PREFIX) $(CXX) $(STATIC_BUILD) -o $@ $(PTHREAD_CFLAGS) $(ASTLDFLAGS) $(SOLINK) $^ $(PTHREAD_LIBS) $(LIBS)
+%.eo: %.o
+ $(ECHO_PREFIX) echo " [EMBED] $< -> $@"
+ $(CMD_PREFIX) $(ASTTOPDIR)/build_tools/make_linker_eo_script $* > .$@.ld
+ $(CMD_PREFIX) $(LD) -r -T .$@.ld -o $@ $<
+ $(CMD_PREFIX) rm -f .$@.ld
+
+%.eoo: %.o
+ $(ECHO_PREFIX) echo " [EMBED] $< -> $@"
+ $(CMD_PREFIX) $(ASTTOPDIR)/build_tools/make_linker_eo_script $* > .$@.ld
+ $(CMD_PREFIX) $(LD) -r -T .$@.ld -o $@ $<
+ $(CMD_PREFIX) rm -f .$@.ld
+
%: %.o
$(ECHO_PREFIX) echo " [LD] $^ -> $@"
$(CMD_PREFIX) $(CXX) $(STATIC_BUILD) -o $@ $(PTHREAD_CFLAGS) $(ASTLDFLAGS) $^ $(PTHREAD_LIBS) $(LIBS)
diff --git a/build_tools/make_linker_eo_script b/build_tools/make_linker_eo_script
new file mode 100755
index 0000000000..39456c058a
--- /dev/null
+++ b/build_tools/make_linker_eo_script
@@ -0,0 +1,27 @@
+#!/bin/sh
+
+cat << EOF
+SECTIONS {
+.text : { *(.text) }
+.data : { __${1}_data_start = . ; *(.data) __${1}_data_end = . ;}
+.rodata : { *(.rodata*) }
+.bss : { __${1}_bss_start = . ; *(.bss) __${1}_bss_end = . ;}
+.debug_abbrev : { *(.debug_abbrev) }
+.debug_info : { *(.debug_info) }
+.debug_line : { *(.debug_line) }
+.debug_macinfo : { *(.debug_macinfo) }
+.dtors : { *(.dtors) }
+.ctors : { *(.ctors) }
+.data.rel.local : { *(.data.rel.local) }
+.data.rel.ro.local : { *(.data.rel.ro.local) }
+.debug_frame : { *(.debug_frame) }
+.eh_frame : { *(.eh_frame) }
+.debug_loc : { *(.debug_loc) }
+.debug_pubname : { *(.debug_pubname) }
+.debug_aranges : { *(.debug_aranges) }
+.debug_ranges : { *(.debug_ranges) }
+.debug_str : { *(.debug_str) }
+.comment : { *(.comment) }
+.note.GNU-stack : { *(.note.GNU-stack) }
+}
+EOF
diff --git a/include/asterisk/module.h b/include/asterisk/module.h
index 9d51488d13..4ced03fa98 100644
--- a/include/asterisk/module.h
+++ b/include/asterisk/module.h
@@ -192,6 +192,8 @@ struct ast_module_info {
enum ast_module_load_result (*load)(void); /* register stuff etc. Optional. */
int (*reload)(void); /* config etc. Optional. */
int (*unload)(void); /* unload. called with the module locked */
+ int (*backup_globals)(void); /* for embedded modules, backup global data */
+ void (*restore_globals)(void); /* for embedded modules, restore global data */
const char *name; /* name of the module for loader reference and CLI commands */
const char *description; /* user friendly description of the module. */
@@ -253,8 +255,54 @@ void ast_module_unref(struct ast_module *);
and populated at the end of the module's source file... */
const static __attribute__((unused)) struct ast_module_info *ast_module_info;
+#if defined(EMBEDDED_MODULE)
+
+#define make_var_sub(mod, type) __ ## mod ## _ ## type
+#define make_var(mod, type) make_var_sub(mod, type)
+
+extern void make_var(EMBEDDED_MODULE, bss_start);
+extern void make_var(EMBEDDED_MODULE, bss_end);
+extern void make_var(EMBEDDED_MODULE, data_start);
+extern void make_var(EMBEDDED_MODULE, data_end);
+
+static void * __attribute__((section(".embed_module"))) __global_backup;
+
+static int __backup_globals(void)
+{
+ size_t data_size = & make_var(EMBEDDED_MODULE, data_end) - & make_var(EMBEDDED_MODULE, data_start);
+
+ if (__global_backup)
+ return 0;
+
+ if (!data_size)
+ return 0;
+
+ if (!(__global_backup = ast_malloc(data_size)))
+ return -1;
+
+ memcpy(__global_backup, & make_var(EMBEDDED_MODULE, data_start), data_size);
+
+ return 0;
+}
+
+static void __restore_globals(void)
+{
+ size_t data_size = & make_var(EMBEDDED_MODULE, data_end) - & make_var(EMBEDDED_MODULE, data_start);
+ size_t bss_size = & make_var(EMBEDDED_MODULE, bss_end) - & make_var(EMBEDDED_MODULE, bss_start);
+
+ if (bss_size)
+ memset(& make_var(EMBEDDED_MODULE, bss_start), 0, bss_size);
+
+ if (!data_size || !__global_backup)
+ return;
+
+ memcpy(& make_var(EMBEDDED_MODULE, data_start), __global_backup, data_size);
+}
+
#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...) \
static struct ast_module_info __mod_info = { \
+ .backup_globals = __backup_globals, \
+ .restore_globals = __restore_globals, \
.name = AST_MODULE, \
.flags = flags_to_set, \
.description = desc, \
@@ -271,6 +319,31 @@ const static __attribute__((unused)) struct ast_module_info *ast_module_info;
} \
const static struct ast_module_info *ast_module_info = &__mod_info
+#undef make_var
+#undef make_var_sub
+
+#else /* !defined(EMBEDDED_MODULE) */
+
+#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...) \
+ static struct ast_module_info __mod_info = { \
+ .name = AST_MODULE, \
+ .flags = flags_to_set, \
+ .description = desc, \
+ .key = keystr, \
+ fields \
+ }; \
+ static void __attribute__ ((constructor)) __reg_module(void) \
+ { \
+ ast_module_register(&__mod_info); \
+ } \
+ static void __attribute__ ((destructor)) __unreg_module(void) \
+ { \
+ ast_module_unregister(&__mod_info); \
+ } \
+ const static struct ast_module_info *ast_module_info = &__mod_info
+
+#endif /* !defined(EMBEDDED_MODULE) */
+
#define AST_MODULE_INFO_STANDARD(keystr, desc) \
AST_MODULE_INFO(keystr, AST_MODFLAG_DEFAULT, desc, \
.load = load_module, \
diff --git a/main/loader.c b/main/loader.c
index 65c95ecc68..4516b37790 100644
--- a/main/loader.c
+++ b/main/loader.c
@@ -483,6 +483,9 @@ int ast_unload_resource(const char *resource_name, enum ast_module_unload_mode f
if (!error)
ast_update_use_count();
+ if (!error && !mod->lib)
+ mod->info->restore_globals();
+
return res;
}
@@ -627,6 +630,11 @@ static enum ast_module_load_result load_resource(const char *resource_name, unsi
return AST_MODULE_LOAD_DECLINE;
}
+ if (!mod->lib && mod->info->backup_globals()) {
+ ast_log(LOG_WARNING, "Module '%s' was unable to backup its global data.\n", resource_name);
+ return AST_MODULE_LOAD_DECLINE;
+ }
+
ast_clear_flag(mod, FLAG_DECLINED);
if (mod->info->load)
--
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