From 2e568375ea3410a67ed4d7cb18a2cabd4ece0580 Mon Sep 17 00:00:00 2001
From: Barnabas Debreczeni <keo@users.noreply.github.com>
Date: Sat, 5 Mar 2016 15:21:22 +0100
Subject: [PATCH] Gitian: fix check-symbols for armhf builds
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amrhf builds leak Boost symbols, so @laanwj’s linker script hack was
added back to armhf builds.

Also added ld-linux-armhf.so.3 to the list of allowed libraries in
symbol-check.py.
---
 contrib/devtools/symbol-check.py                 |  1 +
 .../gitian-descriptors/gitian-linux-armhf.yml    | 16 ++++++++++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/contrib/devtools/symbol-check.py b/contrib/devtools/symbol-check.py
index 4ad5136f79e..7ea6b5c97c3 100755
--- a/contrib/devtools/symbol-check.py
+++ b/contrib/devtools/symbol-check.py
@@ -62,6 +62,7 @@ ALLOWED_LIBRARIES = {
 'librt.so.1', # real-time (clock)
 'ld-linux-x86-64.so.2', # 64-bit dynamic linker
 'ld-linux.so.2', # 32-bit dynamic linker
+'ld-linux-armhf.so.3', # 32-bit armhf dynamic linker
 # bitcoin-qt only
 'libX11-xcb.so.1', # part of X11
 'libX11.so.6', # part of X11
diff --git a/contrib/gitian-descriptors/gitian-linux-armhf.yml b/contrib/gitian-descriptors/gitian-linux-armhf.yml
index c47b9f5571f..020e2c2dff6 100644
--- a/contrib/gitian-descriptors/gitian-linux-armhf.yml
+++ b/contrib/gitian-descriptors/gitian-linux-armhf.yml
@@ -23,9 +23,20 @@ remotes:
   "dir": "bitcoin"
 files: []
 script: |
+  # Avoid exporting *any* symbols from the executable
+  # This avoids conflicts between the libraries statically linked into bitcoin and any
+  # libraries we may link dynamically (such as Qt and OpenSSL, see issue #4094).
+  # It also avoids start-up overhead to not export any unnecessary symbols.
+  # To do this, build a linker script that marks all symbols as local.
+  LINKER_SCRIPT=$HOME/build/linker_version_script
+  echo '
+  {
+    local: *;
+  };' > $LINKER_SCRIPT
   WRAP_DIR=$HOME/wrapped
   HOSTS="arm-linux-gnueabihf"
-  CONFIGFLAGS="--enable-glibc-back-compat --enable-reduce-exports LDFLAGS=-static-libstdc++"
+  CONFIGFLAGS="--enable-glibc-back-compat --enable-reduce-exports"
+  CONFIGLDFLAGS="-static-libstdc++ -Wl,--version-script=$LINKER_SCRIPT"
   FAKETIME_HOST_PROGS=""
   FAKETIME_PROGS="date ar ranlib nm strip"
 
@@ -95,9 +106,10 @@ script: |
     mkdir -p ${INSTALLPATH}
     tar --strip-components=1 -xf ../$SOURCEDIST
 
-    ./configure --prefix=${BASEPREFIX}/${i} --bindir=${INSTALLPATH}/bin --includedir=${INSTALLPATH}/include --libdir=${INSTALLPATH}/lib --disable-ccache --disable-maintainer-mode --disable-dependency-tracking ${CONFIGFLAGS}
+    ./configure --prefix=${BASEPREFIX}/${i} --bindir=${INSTALLPATH}/bin --includedir=${INSTALLPATH}/include --libdir=${INSTALLPATH}/lib --disable-ccache --disable-maintainer-mode --disable-dependency-tracking ${CONFIGFLAGS} LDFLAGS="${CONFIGLDFLAGS}"
     make ${MAKEOPTS}
     make ${MAKEOPTS} -C src check-security
+    make ${MAKEOPTS} -C src check-symbols
     make install-strip
     cd installed
     find . -name "lib*.la" -delete