ebuild.sh: sandbox write to ${PORTAGE_TMPDIR}/portage (bug 673738)

In ebuild.sh, grant sandbox write access directly to
${PORTAGE_TMPDIR}/portage, since write access to ${PORTAGE_TMPDIR}
itself is not needed. Also, remove the _check_temp_dir symlink
check from bug 378403, since a symlink is permissible if write
access is granted directly to ${PORTAGE_TMPDIR}/portage.

Bug: https://bugs.gentoo.org/673738
Bug: https://bugs.gentoo.org/378403
Signed-off-by: Zac Medico <zmedico@gentoo.org>

2 files changed, 4 insertions, 27 deletions

diff --git a/bin/ebuild.sh b/bin/ebuild.sh
index 00524d019..978643af7 100755
--- a/bin/ebuild.sh
+++ b/bin/ebuild.sh
@@ -161,8 +161,8 @@ addwrite()   { __sb_append_var WRITE   "$@" ; }
 adddeny()    { __sb_append_var DENY    "$@" ; }
 addpredict() { __sb_append_var PREDICT "$@" ; }
 
-addwrite "${PORTAGE_TMPDIR}"
-addread "/:${PORTAGE_TMPDIR}"
+addwrite "${PORTAGE_TMPDIR}/portage"
+addread "/:${PORTAGE_TMPDIR}/portage"
 [[ -n ${PORTAGE_GPG_DIR} ]] && addpredict "${PORTAGE_GPG_DIR}"
 
 # Avoid sandbox violations in temporary directories.
diff --git a/lib/portage/package/ebuild/doebuild.py b/lib/portage/package/ebuild/doebuild.py
index 2dd458835..baebb9a27 100644
--- a/lib/portage/package/ebuild/doebuild.py
+++ b/lib/portage/package/ebuild/doebuild.py
@@ -82,6 +82,7 @@ from portage.util import ( apply_recursive_permissions,
 from portage.util.cpuinfo import get_cpu_count
 from portage.util.lafilefixer import rewrite_lafile
 from portage.util.compression_probe import _compressors
+from portage.util.path import first_existing
 from portage.util.socks5 import get_socks5_proxy
 from portage.versions import _pkgsplit
 from _emerge.BinpkgEnvExtractor import BinpkgEnvExtractor
@@ -1296,31 +1297,7 @@ def _check_temp_dir(settings):
 	# as some people use a separate PORTAGE_TMPDIR mount
 	# we prefer that as the checks below would otherwise be pointless
 	# for those people.
-	tmpdir = os.path.realpath(settings["PORTAGE_TMPDIR"])
-	if os.path.exists(os.path.join(tmpdir, "portage")):
-		checkdir = os.path.realpath(os.path.join(tmpdir, "portage"))
-		if ("sandbox" in settings.features or
-			"usersandox" in settings.features) and \
-			not checkdir.startswith(tmpdir + os.sep):
-			msg = _("The 'portage' subdirectory of the directory "
-			"referenced by the PORTAGE_TMPDIR variable appears to be "
-			"a symlink. In order to avoid sandbox violations (see bug "
-			"#378403), you must adjust PORTAGE_TMPDIR instead of using "
-			"the symlink located at '%s'. A suitable PORTAGE_TMPDIR "
-			"setting would be '%s'.") % \
-			(os.path.join(tmpdir, "portage"), checkdir)
-			lines = []
-			lines.append("")
-			lines.append("")
-			lines.extend(wrap(msg, 72))
-			lines.append("")
-			for line in lines:
-				if line:
-					line = "!!! %s" % (line,)
-				writemsg("%s\n" % (line,), noiselevel=-1)
-			return 1
-	else:
-		checkdir = tmpdir
+	checkdir = first_existing(os.path.join(settings["PORTAGE_TMPDIR"], "portage"))
 
 	if not os.access(checkdir, os.W_OK):
 		writemsg(_("%s is not writable.\n"