From 72d751cba9cda9ce3ae46d5e6ab962d2f675e970 Mon Sep 17 00:00:00 2001 From: Jo-Philipp Wich Date: Tue, 10 Jan 2017 11:37:47 +0100 Subject: [PATCH] build: rework library bundling Rework the bundle-libraries.sh implementation to use a more robust approach for executing host binaries through the shipped ELF loader and libraries. The previous approach relied on symlinks pointing to a wrapper script which caused various issues, especially with multicall binaries as the original argv[0] name was not preserved through the ld.so invocation. Another down- side was the fact that the actual binaries got moved into another directory which caused executables to fail looking up resources with paths relative to the executable location. The new library wrapper implements the following improvements: - Instead of symlinks pointing to a common wrapper, each ELF executable is now replaced by a unqiue shell script which retains the original program name getting called - Instead of letting ld.so invoke the ELF executable directly, launch the final ELF binary through a helper program which fixes up the argv[0] argument for the target program - Support sharing a common location for the bundled libraries instead of having one copy in each directory containing wrapped binaries Finally modify the SDK build to wrap the staging_dir and toolchain binaries which allows to use the SDK on systems with a different glibc version. Signed-off-by: Jo-Philipp Wich --- scripts/bundle-libraries.sh | 102 +++++++++++++++++++++++++---------- target/imagebuilder/Makefile | 12 +++-- target/sdk/Makefile | 4 ++ 3 files changed, 87 insertions(+), 31 deletions(-) diff --git a/scripts/bundle-libraries.sh b/scripts/bundle-libraries.sh index aba1cd6268..dfc2b85a47 100755 --- a/scripts/bundle-libraries.sh +++ b/scripts/bundle-libraries.sh @@ -2,7 +2,7 @@ # # Script to install host system binaries along with required libraries. # -# Copyright (C) 2012-2013 Jo-Philipp Wich +# Copyright (C) 2012-2017 Jo-Philipp Wich # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -27,6 +27,13 @@ _cp() { } } +_mv() { + mv ${VERBOSE:+-v} "$1" "$2" || { + echo "mv($1 $2) failed" >&2 + exit 1 + } +} + _md() { mkdir ${VERBOSE:+-v} -p "$1" || { echo "mkdir($1) failed" >&2 @@ -41,6 +48,52 @@ _ln() { } } +_relpath() { + local base="$(readlink -f "$1")" + local dest="$(readlink -f "$2")" + local up + + [ -d "$base" ] || base="${base%/*}" + [ -d "$dest" ] || dest="${dest%/*}" + + while true; do + case "$base" + in "$dest"/*) + echo "$up/${base#$dest/}" + break + ;; + *) + dest="${dest%/*}" + up="${up:+$up/}.." + ;; + esac + done +} + +_wrapper() { + cat <<-EOT | ${CC:-gcc} -x c -o "$1" - + #include + #include + + int main(int argc, char **argv) { + const char *self = argv[0]; + const char *target = argv[1]; + + if (argc < 3) { + fprintf(stderr, "Usage: %s executable arg0 [args...]\n", self); + return 1; + } + + return execv(target, argv + 2); + } + EOT + + [ -x "$1" ] || { + echo "compiling wrapper failed" >&2 + exit 5 + } +} + for LDD in ${PATH//://ldd }/ldd; do "$LDD" --version >/dev/null 2>/dev/null && break LDD="" @@ -49,29 +102,31 @@ done [ -n "$LDD" -a -x "$LDD" ] || LDD= for BIN in "$@"; do - [ -n "$BIN" -a -x "$BIN" -a -n "$DIR" ] || { + [ -n "$BIN" -a -n "$DIR" ] || { echo "Usage: $0 ..." >&2 exit 1 } - [ ! -d "$DIR/bundled/lib" ] && { - _md "$DIR/bundled/lib" - _md "$DIR/bundled/usr" - _ln "../lib" "$DIR/bundled/usr/lib" + [ ! -d "$DIR/lib" ] && { + _md "$DIR/lib" + _md "$DIR/usr" + _ln "../lib" "$DIR/usr/lib" + } + + [ ! -x "$DIR/lib/runas" ] && { + _wrapper "$DIR/lib/runas" } LDSO="" - echo "Bundling ${BIN##*/}" - [ -n "$LDD" ] && { + [ -n "$LDD" ] && [ -x "$BIN" ] && file "$BIN" | grep -sqE "ELF.*executable" && { for token in $("$LDD" "$BIN" 2>/dev/null); do case "$token" in */*.so*) case "$token" in *ld-*.so*) LDSO="${token##*/}" ;; - *) echo " * lib: ${token##*/}" ;; esac - dest="$DIR/bundled/lib/${token##*/}" + dest="$DIR/lib/${token##*/}" ddir="${dest%/*}" [ -f "$token" -a ! -f "$dest" ] && { @@ -82,29 +137,22 @@ for BIN in "$@"; do done } - _md "$DIR" - # is a dynamically linked executable if [ -n "$LDSO" ]; then - _cp "$BIN" "$DIR/bundled/${BIN##*/}" + echo "Bundling ${BIN##*/}" + RUNDIR="$(readlink -f "$BIN")"; RUNDIR="${RUNDIR%/*}" RUN="${LDSO#ld-}"; RUN="run-${RUN%%.so*}.sh" + REL="$(_relpath "$DIR/lib" "$BIN")" - [ -x "$DIR/bundled/$RUN" ] || { - cat <<-EOF > "$DIR/bundled/$RUN" - #!/usr/bin/env bash - dir="\$(dirname "\$0")" - bin="\$(basename "\$0")" - exec -a "\$0" "\$dir/bundled/lib/$LDSO" --library-path "\$dir/bundled/lib" "\$dir/bundled/\$bin" "\$@" - EOF - chmod ${VERBOSE:+-v} 0755 "$DIR/bundled/$RUN" - } + _mv "$BIN" "$RUNDIR/.${BIN##*/}.bin" - _ln "./bundled/$RUN" "$DIR/${BIN##*/}" + cat <<-EOF > "$BIN" + #!/usr/bin/env bash + dir="\$(dirname "\$0")" + exec "\$dir/${REL:+$REL/}$LDSO" --library-path "\$dir/${REL:+$REL/}" "\$dir/${REL:+$REL/}runas" "\$dir/.${BIN##*/}.bin" "\$0" "\$@" + EOF - # is a static executable or non-elf binary - else - [ -n "$LDD" ] && echo " * not dynamically linked" - _cp "$BIN" "$DIR/${BIN##*/}" + chmod ${VERBOSE:+-v} 0755 "$BIN" fi done diff --git a/target/imagebuilder/Makefile b/target/imagebuilder/Makefile index b43662b6ac..8a7c2093b9 100644 --- a/target/imagebuilder/Makefile +++ b/target/imagebuilder/Makefile @@ -66,16 +66,20 @@ endif $(PKG_BUILD_DIR)/target/linux/*/patches{,-*} -cp $(KERNEL_BUILD_DIR)/* $(IB_KDIR)/ # don't copy subdirectories here -cp $(LINUX_DIR)/.config $(IB_LDIR)/ - -$(SCRIPT_DIR)/bundle-libraries.sh $(IB_LDIR)/scripts/dtc \ - $(LINUX_DIR)/scripts/dtc/dtc + if [ -x $(LINUX_DIR)/scripts/dtc/dtc ]; then \ + $(INSTALL_DIR) $(IB_LDIR)/scripts/dtc; \ + $(INSTALL_BIN) $(LINUX_DIR)/scripts/dtc/dtc $(IB_LDIR)/scripts/dtc/dtc; \ + fi if [ -d $(LINUX_DIR)/arch/$(ARCH)/boot/dts ]; then \ $(CP) $(LINUX_DIR)/arch/$(ARCH)/boot/dts/* $(IB_DTSDIR); \ fi $(SED) 's,^# REVISION:=.*,REVISION:=$(REVISION),g' $(PKG_BUILD_DIR)/include/version.mk find $(PKG_BUILD_DIR) -name CVS -o -name .git -o -name .svn \ | $(XARGS) rm -rf - find $(STAGING_DIR_HOST)/bin -maxdepth 1 -type f -perm -u=x \ - | $(XARGS) $(SCRIPT_DIR)/bundle-libraries.sh $(PKG_BUILD_DIR)/staging_dir/host/bin/ + $(INSTALL_DIR) $(PKG_BUILD_DIR)/staging_dir/host/bin + $(CP) $(STAGING_DIR_HOST)/bin/* $(PKG_BUILD_DIR)/staging_dir/host/bin/ + (cd $(PKG_BUILD_DIR); find staging_dir/host/bin/ $(IB_LDIR)/scripts/dtc/ -type f | \ + $(XARGS) $(SCRIPT_DIR)/bundle-libraries.sh $(PKG_BUILD_DIR)/staging_dir/host) STRIP=sstrip $(SCRIPT_DIR)/rstrip.sh $(PKG_BUILD_DIR)/staging_dir/host/bin/ $(TAR) -cf - -C $(BUILD_DIR) $(IB_NAME) | xz -zc -7e > $@ diff --git a/target/sdk/Makefile b/target/sdk/Makefile index de77d1a31a..c1eca736b0 100644 --- a/target/sdk/Makefile +++ b/target/sdk/Makefile @@ -76,6 +76,10 @@ $(BIN_DIR)/$(SDK_NAME).tar.xz: clean $(SDK_DIRS) $(KERNEL_FILES) | \ $(TAR) -xf - -C $(SDK_BUILD_DIR) + (cd $(SDK_BUILD_DIR); find $(STAGING_SUBDIR_HOST)/bin $(STAGING_SUBDIR_HOST)/usr/bin \ + $(STAGING_SUBDIR_TOOLCHAIN)/bin $(STAGING_SUBDIR_TOOLCHAIN)/*/bin $(STAGING_SUBDIR_TOOLCHAIN)/libexec \ + -type f | $(XARGS) $(SCRIPT_DIR)/bundle-libraries.sh $(SDK_BUILD_DIR)/$(STAGING_SUBDIR_HOST)) + @-( \ find \ $(SDK_BUILD_DIR)/$(STAGING_SUBDIR_HOST)/bin \ -- 2.30.2