Re: [gentoo-portage-dev] [PATCH] econf: update configure/config.{sub,guess} atomically to avoid races

[Brian Dolbec <dolsen@gentoo.org>]

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On Tue, 2013-12-17 at 18:28 -0500, Mike Frysinger wrote:
> Use $BASHPID which will be unique even in subshells.
> 
> URL: https://bugs.gentoo.org/487478
> ---
>  bin/phase-helpers.sh | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/bin/phase-helpers.sh b/bin/phase-helpers.sh
> index ec48c94..1a7ae03 100644
> --- a/bin/phase-helpers.sh
> +++ b/bin/phase-helpers.sh
> @@ -469,6 +469,7 @@ unpack() {
>  
>  econf() {
>  	local x
> +	local pid=${BASHPID}
>  
>  	if ! ___eapi_has_prefix_variables; then
>  		local EPREFIX=
> @@ -501,18 +502,22 @@ econf() {
>  		if [[ -n $CONFIG_SHELL && \
>  			"$(head -n1 "$ECONF_SOURCE/configure")" =~ ^'#!'[[:space:]]*/bin/sh([[:space:]]|$) ]] ; then
>  			# preserve timestamp, see bug #440304
> -			touch -r "$ECONF_SOURCE/configure" "$ECONF_SOURCE/configure._portage_tmp_.$$" || die
> -			sed -e "1s:^#![[:space:]]*/bin/sh:#!$CONFIG_SHELL:" -i "$ECONF_SOURCE/configure" || \
> -				die "Substition of shebang in '$ECONF_SOURCE/configure' failed"
> -			touch -r "$ECONF_SOURCE/configure._portage_tmp_.$$" "$ECONF_SOURCE/configure" || die
> -			rm -f "$ECONF_SOURCE/configure._portage_tmp_.$$"
> +			touch -r "${ECONF_SOURCE}/configure" "${ECONF_SOURCE}/configure._portage_tmp_.${pid}" || die
> +			sed -i \
> +				-e "1s:^#![[:space:]]*/bin/sh:#!$CONFIG_SHELL:" \
> +				"${ECONF_SOURCE}/configure" \
> +				|| die "Substition of shebang in '${ECONF_SOURCE}/configure' failed"
> +			touch -r "${ECONF_SOURCE}/configure._portage_tmp_.${pid}" "${ECONF_SOURCE}/configure" || die
> +			rm -f "${ECONF_SOURCE}/configure._portage_tmp_.${pid}"
>  		fi
>  		if [ -e "${EPREFIX}"/usr/share/gnuconfig/ ]; then
>  			find "${WORKDIR}" -type f '(' \
>  			-name config.guess -o -name config.sub ')' -print0 | \
>  			while read -r -d $'\0' x ; do
>  				__vecho " * econf: updating ${x/${WORKDIR}\/} with ${EPREFIX}/usr/share/gnuconfig/${x##*/}"
> -				cp -f "${EPREFIX}"/usr/share/gnuconfig/"${x##*/}" "${x}"
> +				# Make sure we do this atomically incase we're run in parallel. #487478
> +				cp -f "${EPREFIX}"/usr/share/gnuconfig/"${x##*/}" "${x}.${pid}"
> +				mv -f "${x}.${pid}" "${x}"
>  			done
>  		fi
>  


Sorry, my bash skills are not enough to review this stuff. Others will
have to reply :)
-- 
Brian Dolbec <dolsen@gentoo.org>

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