From: David 'Digit' Turner Date: Fri, 18 Jun 2010 21:47:22 +0000 (-0700) Subject: Allow static C++ destructors to be properly called on dlclose(). X-Git-Tag: android-x86-4.4-r1~1143^2~8^2~39 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=6a9b888d;p=android-x86%2Fbionic.git Allow static C++ destructors to be properly called on dlclose(). With this patch, _and_ an upcoming build/ patch, the destruction of static C++ objects contained in shared libraries will happen properly when dlclose() is called. Note that this change introduces crtbegin_so.S and crtend_so.S which are currently ignored by the build system. + move definition of __dso_handle to the right place (before that, all shared libraries used the __dso_handle global variable from the C library). Note that we keep a 'weak' __dso_handle in aeabi.c to avoid breaking the build until the next patch to build/core/combo/ appears. We will be able to remove that later. + move bionic/aeabi.c to arch-arm/bionic/ (its proper location) Change-Id: Ie771aa204e3acbdf02fd30ebd4150373a1398f39 NOTE: The NDK will need to be modified to enable this feature in the shared libraries that are generated through it. --- diff --git a/libc/Android.mk b/libc/Android.mk index 79c89ed1e..6b2334e70 100644 --- a/libc/Android.mk +++ b/libc/Android.mk @@ -317,7 +317,6 @@ libc_common_src_files := \ # ========================================================= ifeq ($(TARGET_ARCH),arm) libc_common_src_files += \ - bionic/eabi.c \ bionic/bionic_clone.c \ arch-arm/bionic/__get_pc.S \ arch-arm/bionic/__get_sp.S \ @@ -325,6 +324,7 @@ libc_common_src_files += \ arch-arm/bionic/_setjmp.S \ arch-arm/bionic/atomics_arm.S \ arch-arm/bionic/clone.S \ + arch-arm/bionic/eabi.c \ arch-arm/bionic/ffs.S \ arch-arm/bionic/kill.S \ arch-arm/bionic/libgcc_compat.c \ @@ -421,7 +421,6 @@ libc_common_src_files += \ string/strncmp.c \ string/memcmp.c \ string/strlen.c \ - bionic/eabi.c \ bionic/pthread.c \ bionic/pthread-rwlocks.c \ bionic/pthread-timers.c \ @@ -490,6 +489,10 @@ else libc_common_cflags += -DANDROID_SMP=0 endif +# Needed to access private/__dso_handle.S from +# crtbegin_xxx.S and crtend_xxx.S +# +libc_crt_target_cflags += -I$(LOCAL_PATH)/private # Define some common includes # ======================================================== @@ -504,10 +507,17 @@ libc_common_c_includes := \ # executables) # ========================================================================== -ifeq ($(TARGET_ARCH),x86) -# we only need begin_so/end_so for x86, since it needs an appropriate .init -# section in the shared library with a function to call all the entries in -# .ctors section. ARM uses init_array, and does not need the function. +ifneq ($(filter arm x86,$(TARGET_ARCH)),) +# ARM and x86 need crtbegin_so/crtend_so. +# +# For x86, the .init section must point to a function that calls all +# entries in the .ctors section. (on ARM this is done through the +# .init_array section instead). +# +# For both platforms, the .fini_array section must point to a function +# that will call __cxa_finalize(&__dso_handle) in order to ensure that +# static C++ destructors are properly called on dlclose(). +# GEN := $(TARGET_OUT_STATIC_LIBRARIES)/crtbegin_so.o $(GEN): $(LOCAL_PATH)/arch-$(TARGET_ARCH)/bionic/crtbegin_so.S @mkdir -p $(dir $@) diff --git a/libc/arch-arm/bionic/crtbegin_dynamic.S b/libc/arch-arm/bionic/crtbegin_dynamic.S index e26592317..d18e715f5 100644 --- a/libc/arch-arm/bionic/crtbegin_dynamic.S +++ b/libc/arch-arm/bionic/crtbegin_dynamic.S @@ -31,7 +31,7 @@ .globl _start # this is the small startup code that is first run when -# any executable that is statically-linked with Bionic +# any executable that is dynamically-linked with Bionic # runs. # # it's purpose is to call __libc_init with appropriate @@ -63,13 +63,7 @@ _start: .long __INIT_ARRAY__ .long __FINI_ARRAY__ .long __CTOR_LIST__ - -# the .ctors section contains a list of pointers to "constructor" -# functions that need to be called in order during C library initialization, -# just before the program is being run. This is a C++ requirement -# -# the last entry shall be 0, and is defined in crtend.S -# + .section .preinit_array, "aw" .globl __PREINIT_ARRAY__ __PREINIT_ARRAY__: @@ -90,3 +84,4 @@ __FINI_ARRAY__: __CTOR_LIST__: .long -1 +#include "__dso_handle.S" diff --git a/libc/arch-arm/bionic/crtbegin_so.S b/libc/arch-arm/bionic/crtbegin_so.S new file mode 100644 index 000000000..bb6b3e2c3 --- /dev/null +++ b/libc/arch-arm/bionic/crtbegin_so.S @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +# Implement static C++ destructors when the shared +# library is unloaded through dlclose(). +# +# A call to this function must be the first entry +# in the .fini_array. See 3.3.5.3.C of C++ ABI +# standard. +# +__on_dlclose: + adr r0, 0f + ldr r0, [r0] + b __cxa_finalize + +0: + .long __dso_handle + + .section .init_array, "aw" + .globl __INIT_ARRAY__ +__INIT_ARRAY__: + .long -1 + + .section .fini_array, "aw" + .globl __FINI_ARRAY__ +__FINI_ARRAY__: + .long -1 + .long __on_dlclose + +#include "__dso_handle.S" diff --git a/libc/arch-arm/bionic/crtbegin_static.S b/libc/arch-arm/bionic/crtbegin_static.S index e26592317..6f9cf25dd 100644 --- a/libc/arch-arm/bionic/crtbegin_static.S +++ b/libc/arch-arm/bionic/crtbegin_static.S @@ -63,13 +63,7 @@ _start: .long __INIT_ARRAY__ .long __FINI_ARRAY__ .long __CTOR_LIST__ - -# the .ctors section contains a list of pointers to "constructor" -# functions that need to be called in order during C library initialization, -# just before the program is being run. This is a C++ requirement -# -# the last entry shall be 0, and is defined in crtend.S -# + .section .preinit_array, "aw" .globl __PREINIT_ARRAY__ __PREINIT_ARRAY__: @@ -90,3 +84,5 @@ __FINI_ARRAY__: __CTOR_LIST__: .long -1 + +#include "__dso_handle.S" diff --git a/libc/arch-arm/bionic/crtend_so.S b/libc/arch-arm/bionic/crtend_so.S new file mode 100644 index 000000000..a1281c402 --- /dev/null +++ b/libc/arch-arm/bionic/crtend_so.S @@ -0,0 +1,38 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* This is the same than crtend.S except that a shared library + * cannot have a .preinit_array + */ + + .section .init_array, "aw" + .long 0 + + .section .fini_array, "aw" + .long 0 + diff --git a/libc/bionic/eabi.c b/libc/arch-arm/bionic/eabi.c similarity index 83% rename from libc/bionic/eabi.c rename to libc/arch-arm/bionic/eabi.c index a5f662746..3f26f2b45 100644 --- a/libc/bionic/eabi.c +++ b/libc/arch-arm/bionic/eabi.c @@ -30,7 +30,21 @@ extern int __cxa_atexit(void (*)(void*), void*, void* ); -void* __dso_handle = 0; +/* Temporary hack: this variable should not be part of the C library + * itself, but placed in the .bss section of each executable or + * shared library instead. + * + * We keep it here temporarily until the build system has been + * modified properly to use crtbegin_so.S and crtend_so.S when + * generating shared libraries. + * + * It must be a 'weak' symbol to avoid conflicts with the definitions + * that have been moved to crtbegin_static.S and crtbegin_dynamic.S + * + * For the record, it is used for static C++ object construction + * and destruction. See http://www.codesourcery.com/public/cxx-abi/abi.html#dso-dtor + */ +void* __attribute__((weak)) __dso_handle; /* The "C++ ABI for ARM" document states that static C++ constructors, * which are called from the .init_array, should manually call diff --git a/libc/arch-sh/bionic/crtbegin_dynamic.S b/libc/arch-sh/bionic/crtbegin_dynamic.S index dc485dda5..daf6c8b5b 100644 --- a/libc/arch-sh/bionic/crtbegin_dynamic.S +++ b/libc/arch-sh/bionic/crtbegin_dynamic.S @@ -1,5 +1,5 @@ /* - * Copyright (C) 2009 The Android Open Source Project + * Copyright (C) 2009-2010 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -31,7 +31,7 @@ .globl _start # this is the small startup code that is first run when -# any executable that is statically-linked with Bionic +# any executable that is dynamically-linked with Bionic # runs. # # it's purpose is to call __libc_init with appropriate @@ -93,3 +93,5 @@ __FINI_ARRAY__: .globl __CTOR_LIST__ __CTOR_LIST__: .long -1 + +#include "__dso_handle.S" diff --git a/libc/arch-sh/bionic/crtbegin_static.S b/libc/arch-sh/bionic/crtbegin_static.S index 97db1e45a..1d3fdf839 100644 --- a/libc/arch-sh/bionic/crtbegin_static.S +++ b/libc/arch-sh/bionic/crtbegin_static.S @@ -1,5 +1,5 @@ /* - * Copyright (C) 2009 The Android Open Source Project + * Copyright (C) 2009-2010 The Android Open Source Project * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -68,12 +68,6 @@ _start: .long __FINI_ARRAY__ .long __CTOR_LIST__ -# the .ctors section contains a list of pointers to "constructor" -# functions that need to be called in order during C library initialization, -# just before the program is being run. This is a C++ requirement -# -# the last entry shall be 0, and is defined in crtend.S -# .section .preinit_array, "aw" .globl __PREINIT_ARRAY__ __PREINIT_ARRAY__: @@ -94,3 +88,4 @@ __FINI_ARRAY__: __CTOR_LIST__: .long -1 +#include "__dso_handle.S" diff --git a/libc/arch-x86/bionic/crtbegin_dynamic.S b/libc/arch-x86/bionic/crtbegin_dynamic.S index 3b47b18ef..88e7e6a0a 100644 --- a/libc/arch-x86/bionic/crtbegin_dynamic.S +++ b/libc/arch-x86/bionic/crtbegin_dynamic.S @@ -30,7 +30,7 @@ .globl _start # this is the small startup code that is first run when -# any executable that is statically-linked with Bionic +# any executable that is dynamically-linked with Bionic # runs. # # it's purpose is to call __libc_init with appropriate @@ -94,3 +94,4 @@ __FINI_ARRAY__: __CTOR_LIST__: .long -1 +#include "__dso_handle.S" diff --git a/libc/arch-x86/bionic/crtbegin_so.S b/libc/arch-x86/bionic/crtbegin_so.S index d49e9df83..d879feff0 100644 --- a/libc/arch-x86/bionic/crtbegin_so.S +++ b/libc/arch-x86/bionic/crtbegin_so.S @@ -1,3 +1,10 @@ +# This function is to be called when the shared library +# is unloaded through dlclose() +_on_dlclose: + lea __dso_handle, %eax + call __cxa_finalize + ret + /* we put the _init() function here in case the user files for the shared * libs want to drop things into .init section. * We then will call our ctors from crtend_so.o */ @@ -20,6 +27,7 @@ __INIT_ARRAY__: .globl __FINI_ARRAY__ __FINI_ARRAY__: .long -1 + .long _on_dlclose .section .ctors, "aw" .align 4 @@ -27,3 +35,5 @@ __FINI_ARRAY__: .globl __CTOR_LIST__ __CTOR_LIST__: .long -1 + +#include "__dso_handle.S" diff --git a/libc/arch-x86/bionic/crtbegin_static.S b/libc/arch-x86/bionic/crtbegin_static.S index eb4acee8f..3f8446ec7 100644 --- a/libc/arch-x86/bionic/crtbegin_static.S +++ b/libc/arch-x86/bionic/crtbegin_static.S @@ -67,12 +67,6 @@ _start: .long __FINI_ARRAY__ .long __CTOR_LIST__ -# the .ctors section contains a list of pointers to "constructor" -# functions that need to be called in order during C library initialization, -# just before the program is being run. This is a C++ requirement -# -# the last entry shall be 0, and is defined in crtend.S -# .section .preinit_array, "aw" .globl __PREINIT_ARRAY__ __PREINIT_ARRAY__: @@ -93,3 +87,4 @@ __FINI_ARRAY__: __CTOR_LIST__: .long -1 +#include "__dso_handle.S" diff --git a/libc/private/__dso_handle.S b/libc/private/__dso_handle.S new file mode 100644 index 000000000..fcebab642 --- /dev/null +++ b/libc/private/__dso_handle.S @@ -0,0 +1,37 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +# The __dso_handle global variable is used by static +# C++ constructors and destructors in the binary. +# See http://www.codesourcery.com/public/cxx-abi/abi.html#dso-dtor +# + .section .bss + .align 4 + .globl __dso_handle +__dso_handle: + .long 0