From 166a743c53fa6cde255c5e0e3bb34d4a7c54d0bf Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Mon, 2 Feb 2015 12:40:19 -0500 Subject: [PATCH] compat: add infrastructure to support symbol versioning Add initial pass header files to support symbol versioning. Signed-off-by: Neil Horman Acked-by: Sergio Gonzalez Monroy --- lib/Makefile | 1 + lib/librte_compat/Makefile | 38 +++++++++++ lib/librte_compat/rte_compat.h | 114 +++++++++++++++++++++++++++++++++ mk/rte.lib.mk | 4 ++ 4 files changed, 157 insertions(+) create mode 100644 lib/librte_compat/Makefile create mode 100644 lib/librte_compat/rte_compat.h diff --git a/lib/Makefile b/lib/Makefile index 0ffc9825c5..d617d814a4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -31,6 +31,7 @@ include $(RTE_SDK)/mk/rte.vars.mk +DIRS-y += librte_compat DIRS-$(CONFIG_RTE_LIBRTE_EAL) += librte_eal DIRS-$(CONFIG_RTE_LIBRTE_MALLOC) += librte_malloc DIRS-$(CONFIG_RTE_LIBRTE_RING) += librte_ring diff --git a/lib/librte_compat/Makefile b/lib/librte_compat/Makefile new file mode 100644 index 0000000000..0bab870bb5 --- /dev/null +++ b/lib/librte_compat/Makefile @@ -0,0 +1,38 @@ +# BSD LICENSE +# +# Copyright(c) 2013 Neil Horman +# 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. +# * Neither the name of Intel Corporation nor the names of its +# contributors may be used to endorse or promote products derived +# from this software without specific prior written permission. +# +# 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. + +include $(RTE_SDK)/mk/rte.vars.mk + + +# install includes +SYMLINK-y-include := rte_compat.h + +include $(RTE_SDK)/mk/rte.install.mk diff --git a/lib/librte_compat/rte_compat.h b/lib/librte_compat/rte_compat.h new file mode 100644 index 0000000000..3a0fd2d352 --- /dev/null +++ b/lib/librte_compat/rte_compat.h @@ -0,0 +1,114 @@ +/*- + * BSD LICENSE + * + * Copyright(c) 2015 Neil Horman . + * 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. + */ + +#ifndef _RTE_COMPAT_H_ +#define _RTE_COMPAT_H_ +#include + +#ifdef RTE_BUILD_SHARED_LIB + +/* + * Provides backwards compatibility when updating exported functions. + * When a symol is exported from a library to provide an API, it also provides a + * calling convention (ABI) that is embodied in its name, return type, + * arguments, etc. On occasion that function may need to change to accommodate + * new functionality, behavior, etc. When that occurs, it is desireable to + * allow for backwards compatibility for a time with older binaries that are + * dynamically linked to the dpdk. To support that, the __vsym and + * VERSION_SYMBOL macros are created. They, in conjunction with the + * _version.map file for a given library allow for multiple versions of + * a symbol to exist in a shared library so that older binaries need not be + * immediately recompiled. Their use is outlined in the following example: + * Assumptions: DPDK 2.(X) contains a function int foo(char *string) + * DPDK 2.(X+1) needs to change foo to be int foo(int index) + * + * To accomplish this: + * 1) Edit lib//library_version.map to add a DPDK_2.(X+1) node, in which + * foo is exported as a global symbol. + * + * 2) rename the existing function int foo(char *string) to + * int __vsym foo_v20(char *string) + * + * 3) Add this macro immediately below the function + * VERSION_SYMBOL(foo, _v20, 2.0); + * + * 4) Implement a new version of foo. + * char foo(int value, int otherval) { ...} + * + * 5) Mark the newest version as the default version + * BIND_DEFAULT_SYMBOL(foo, 2.1); + * + */ + +/* + * Macro Parameters: + * b - function base name + * e - function version extension, to be concatenated with base name + * n - function symbol version string to be applied + */ + +/* + * VERSION_SYMBOL + * Creates a symbol version table entry binding symbol @DPDK_ to the internal + * function name _ + */ +#define VERSION_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", "RTE_STR(b)"@DPDK_"RTE_STR(n)) + +/* + * BASE_SYMBOL + * Creates a symbol version table entry binding unversioned symbol + * to the internal function _ + */ +#define BASE_SYMBOL(b, e) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", "RTE_STR(b)"@") + +/* + * BNID_DEFAULT_SYMBOL + * Creates a symbol version entry instructing the linker to bind references to + * symbol to the internal symbol _ + */ +#define BIND_DEFAULT_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", "RTE_STR(b)"@@DPDK_"RTE_STR(n)) +#define __vsym __attribute__((used)) + +#else +/* + * No symbol versioning in use + */ +#define VERSION_SYMBOL(b, e, v) +#define __vsym +#define BASE_SYMBOL(b, n) +#define BIND_DEFAULT_SYMBOL(b, v) + +/* + * RTE_BUILD_SHARED_LIB=n + */ +#endif + + +#endif /* _RTE_COMPAT_H_ */ diff --git a/mk/rte.lib.mk b/mk/rte.lib.mk index 81bf8e13c1..1d3b64628b 100644 --- a/mk/rte.lib.mk +++ b/mk/rte.lib.mk @@ -40,8 +40,12 @@ VPATH += $(SRCDIR) ifeq ($(RTE_BUILD_SHARED_LIB),y) LIB := $(patsubst %.a,%.so,$(LIB)) + +CPU_LDFLAGS += --version-script=$(SRCDIR)/$(EXPORT_MAP) + endif + _BUILD = $(LIB) _INSTALL = $(INSTALL-FILES-y) $(SYMLINK-FILES-y) $(RTE_OUTPUT)/lib/$(LIB) _CLEAN = doclean -- 2.20.1