[Buildroot] [RFC PATCH 2/9] support/scripts: add fix-rpath script to sanitize the rpath

[Arnout Vandecappelle]

 Hi Wolfgang,

 I realize that this patch is going to be dropped because it is going to be done
directly from the makefiles, but I have some hopefully useful comments still.

 First of all: make sure the original author is explicitly in Cc. git send-email
normally does that automatically so I'm surprised Samuel isn't there.

On 03-03-17 15:18, Wolfgang Grandegger wrote:
> From: Samuel Martin <s.martin49 at gmail.com>
> 
> This commit introduces a fix-rpath script able to scan a tree,
> detect ELF files, check their RPATH and fix it in a proper way.
> The RPATH fixup is done by the patchelf utility using the option
> "--make-rpath-relative".
> 
> Signed-off-by: Samuel Martin <s.martin49 at gmail.com>
> Signed-off-by: Wolfgang Grandegger <wg at grandegger.com>
> ---
>  support/scripts/fix-rpath | 106 ++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 106 insertions(+)
>  create mode 100755 support/scripts/fix-rpath
> 
> diff --git a/support/scripts/fix-rpath b/support/scripts/fix-rpath
> new file mode 100755
> index 0000000..bde2c17
> --- /dev/null
> +++ b/support/scripts/fix-rpath
> @@ -0,0 +1,106 @@
> +#!/usr/bin/env bash
> +
> +# Copyright (C) 2016 Samuel Martin <s.martin49 at gmail.com>
> +#
> +# 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
> +# the Free Software Foundation; either version 2 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> +# General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write to the Free Software
> +# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> +
> +#set -e
> +#set -v

 Don't include debugging cruft in the final patch.

> +
> +usage() {
> +  cat <<EOF >&2
> +Usage:  ${0} TREE_KIND TREE_ROOT
> +
> +Description:
> +
> +        This script scans a tree and sanitize ELF files' RPATH found in there.
> +
> +        Sanitization behaves the same whatever the kindd of the processed tree, but
> +        the resulting RPATH differs.
> +
> +        Sanitization action:
> +        - remove RPATH pointing outside of the tree
> +        - for RPATH pointing in the tree:
> +          - if they point to standard location (/lib, /usr/lib): remove them
> +          - otherwise: make them relative using \$ORIGIN
> +
> +        For the target tree:
> +        - scan the whole tree for sanitization
> +
> +        For the staging tree :
> +        - scan the whole tree for sanitization
> +
> +        For the host tree:
> +        - skip the staging tree for sanitization
> +        - add \$HOST_DIR/{lib,usr/lib} to RPATH (as relative pathes)
> +
> +Arguments:
> +
> +        TREE_KIND   Kind of tree to be processed.
> +                    Allowed values: host, target, staging
> +
> +        TREE_ROOT   Path to the root of the tree to be scaned
> +
> +Environment:
> +
> +        PATCHELF        patchelf program to use
> +                        (default: patchelf)
> +EOF
> +}
> +
> +: ${PATCHELF:=patchelf}
> +
> +main() {
> +    local tree="${1}"
> +    local basedir="$(readlink -f "${2}")"
> +
> +    local find_args=( "${basedir}" )
> +    local sanitize_extra_args=( )
> +
> +    case "${tree}" in
> +        host)
> +            # do not process the sysroot (only contains target binaries)
> +            find_args+=( "-name" "sysroot" "-prune" "-o" )

 I believe we should specify a full path here. If there is any other directory
in the tree that happens to be called 'sysroot' for whatever reason, it
shouldn't be pruned. When this is done directly from make, it's pretty easy:
-path $(STAGING_DIR) -prune


> +
> +            # do not process the external toolchain installation directory to
> +            # to avoid breaking it.
> +            find_args+=( "-path" "*/opt/ext-toolchain" "-prune" "-o" )

 Same here: $(TOOLCHAIN_EXTERNAL_DOWNLOAD_INSTALL_DIR) which has the full path.


 Regards,
 Arnout

> +
> +            ;;
> +        staging|target)
> +            # discard ${hostdir}/lib and ${hostdir}/usr/lib
> +            sanitize_extra_args+=( "--no-standard-lib-dirs" )
> +
> +            ;;
> +        *)
> +            usage
> +            exit 1
> +            ;;
> +    esac
> +
> +    find_args+=( "-type" "f" "-print" )
> +
> +    while read file ; do
> +        # some files are not writable
> +        chmod u+w $file
> +        # call patchelf for each regular file; error will silently be ignored.
> +        ${PATCHELF} --debug --make-rpath-relative "${basedir}" ${sanitize_extra_args[@]} "${file}" >> /dev/null 2>&1
> +    done < <(find ${find_args[@]})
> +
> +    # ignore errors
> +    return 0
> +}
> +
> +main ${@}
> 

-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
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