From 9fa40314fcfd19d2e09459faeb480d213af56324 Mon Sep 17 00:00:00 2001 From: Adam Cozzette Date: Wed, 8 Mar 2017 11:25:48 -0800 Subject: [PATCH] Ruby: wrap calls to memcpy so that gem is compatible with pre-2.14 glibc This commit adds a __wrap_memcpy function and a linker flag to use that in place of memcpy for our Ruby gem C extension. This allows us to always use the 2.2.5 version of memcpy, making it possible to use the gem on distributions with pre-2.14 versions of glibc. Before this change: $ objdump -T protobuf_c.so | grep memcpy 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.3.4 __memcpy_chk 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.14 memcpy After: $ objdump -T protobuf_c.so | grep memcpy 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.2.5 memcpy 0000000000000000 DF *UND* 0000000000000000 GLIBC_2.3.4 __memcpy_chk 0000000000042450 g DF .text 0000000000000005 Base __wrap_memcpy This is based on gRPC's solution to a similar problem: https://github.com/grpc/grpc/blob/5098508d2d41a116113f7e333c516cd9ef34a943/src/core/lib/support/wrap_memcpy.c This fixes issue #2783. --- Makefile.am | 1 + ruby/ext/google/protobuf_c/extconf.rb | 9 ++++- ruby/ext/google/protobuf_c/wrap_memcpy.c | 51 ++++++++++++++++++++++++ 3 files changed, 60 insertions(+), 1 deletion(-) create mode 100644 ruby/ext/google/protobuf_c/wrap_memcpy.c diff --git a/Makefile.am b/Makefile.am index c8f7f6965d..3222417fac 100644 --- a/Makefile.am +++ b/Makefile.am @@ -795,6 +795,7 @@ ruby_EXTRA_DIST= \ ruby/ext/google/protobuf_c/storage.c \ ruby/ext/google/protobuf_c/upb.c \ ruby/ext/google/protobuf_c/upb.h \ + ruby/ext/google/protobuf_c/wrap_memcpy.c \ ruby/google-protobuf.gemspec \ ruby/lib/google/protobuf/message_exts.rb \ ruby/lib/google/protobuf/repeated_field.rb \ diff --git a/ruby/ext/google/protobuf_c/extconf.rb b/ruby/ext/google/protobuf_c/extconf.rb index b368dcc6c7..0886e60708 100644 --- a/ruby/ext/google/protobuf_c/extconf.rb +++ b/ruby/ext/google/protobuf_c/extconf.rb @@ -4,7 +4,14 @@ require 'mkmf' $CFLAGS += " -std=c99 -O3 -DNDEBUG" + +if RUBY_PLATFORM =~ /linux/ + # Instruct the linker to point memcpy calls at our __wrap_memcpy wrapper. + $LDFLAGS += " -Wl,-wrap,memcpy" +end + $objs = ["protobuf.o", "defs.o", "storage.o", "message.o", - "repeated_field.o", "map.o", "encode_decode.o", "upb.o"] + "repeated_field.o", "map.o", "encode_decode.o", "upb.o", + "wrap_memcpy.o"] create_makefile("google/protobuf_c") diff --git a/ruby/ext/google/protobuf_c/wrap_memcpy.c b/ruby/ext/google/protobuf_c/wrap_memcpy.c new file mode 100644 index 0000000000..158952a8b7 --- /dev/null +++ b/ruby/ext/google/protobuf_c/wrap_memcpy.c @@ -0,0 +1,51 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2017 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// 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 Google Inc. 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 + +// On x86-64 Linux, we link against the 2.2.5 version of memcpy so that we +// avoid depending on the 2.14 version of the symbol. This way, distributions +// that are using pre-2.14 versions of glibc can successfully use the gem we +// distribute (https://github.com/google/protobuf/issues/2783). +// +// This wrapper is enabled by passing the linker flags -Wl,-wrap,memcpy in +// extconf.rb. +#ifdef __linux__ +#ifdef __x86_64__ +__asm__(".symver memcpy,memcpy@GLIBC_2.2.5"); +void *__wrap_memcpy(void *dest, const void *src, size_t n) { + return memcpy(dest, src, n); +} +#else +void *__wrap_memcpy(void *dest, const void *src, size_t n) { + return memmove(dest, src, n); +} +#endif +#endif