Update advisory format and introduce some automation

Simplify the advisory format by dropping the -Backport tags and instead
stick to using just the -Commit tags.  To identify backports, put a
substring of git-describe into the release version in the brackets next
to the commit ref.  This way, it not only identifies that the fix (or
regression) is on the release/2.YY/master branch, it also disambiguates
regressions/fixes in the branch from those in the tarball.

Add a README to make it easier for consumers to understand the format.
Additionally, the Release wiki needs to be updated to inform the release
manager to:

1. Generate a NEWS snipped from the advisories directory

AND

2. on release/2.YY/master, replace the advisories directory with a text
   file pointing to the advisories directory in master so that we don't
   have to update multiple locations.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Andreas K. Hüttel <dilfridge@gentoo.org>

scripts/process-advisories.sh

@@ -0,0 +1,85 @@
+#!/bin/bash -e
+# Copyright The GNU Toolchain Authors.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <https://www.gnu.org/licenses/>.
+
+if ! [ -d advisories ]; then
+  echo "error: Run me from the toplevel directory of the glibc repository."
+  exit 1
+fi
+
+command=$1
+
+usage () {
+    cat >&2 <<EOF
+usage: $0 {update|news}
+EOF
+    exit 1
+}
+
+command="$1"
+
+case "$command" in
+    update|news)
+    ;;
+    *)
+        usage
+        ;;
+esac
+
+get_rel() {
+  rel=$(git describe $1 | sed 's/glibc-\([^g]\+\)-g.*/\1/')
+  # If the latest tag for the commit is the development tag, then increment
+  # the release version.
+  if echo $rel | grep -q "\.9000"; then
+    rel=$(echo $rel | sed 's/2\.\([0-9]\+\)\.9000.*/\1/')
+    rel="2.$((rel+1))"
+  fi
+  echo $rel
+}
+
+advisories_update() {
+  advisory=$1
+
+  if [ -z $1 ]; then
+    echo "Usage: $0 update GLIBC-SA-YYYY-NNNN"
+    exit 1
+  fi
+
+  advisory_file=advisories/$advisory
+
+  grep --color=none Commit $advisory_file | awk '{printf "%s %s\n", $1, $2}' |
+    while read t r; do
+      rel=$(get_rel $r)
+      echo "*** Updating: $t $r ($rel)"
+      sed -i "s/^$t $r.*/$t $r ($rel)/" $advisory_file
+    done
+}
+
+advisories_news() {
+  rel=$(get_rel "HEAD")
+  for f in $(grep -l "^Fix-Commit: .* ($rel)$" advisories/*); do
+    echo -e "  $(basename $f):"
+    cve_id=$(sed -n 's/CVE-Id: \(.*\)/\1/p' $f)
+    echo "$(head -1 $f) ($cve_id)" | fold -w 68 -s |
+      while read line; do
+	echo "    $line"
+      done
+    echo
+  done
+}
+
+advisories_$command $2