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grub2/SOURCES/0278-Reimplement-boot_count...

197 lines
5.6 KiB

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 4 Oct 2018 14:22:09 -0400
Subject: [PATCH] Reimplement boot_counter
This adds "increment" and "decrement" commands, and uses them to maintain our
variables in 01_fallback_counter. It also simplifies the counter logic, so
that there are no nested tests that conflict with each other.
Apparently, this *really* wasn't tested well enough.
Resolves: rhbz#1614637
Signed-off-by: Peter Jones <pjones@redhat.com>
[lorbus: add comments and revert logic changes in 01_fallback_counting]
Signed-off-by: Christian Glombek <lorbus@fedoraproject.org>
---
Makefile.util.def | 6 +++
grub-core/Makefile.core.def | 5 ++
grub-core/commands/increment.c | 105 ++++++++++++++++++++++++++++++++++++
util/grub.d/01_fallback_counting.in | 22 ++++++++
4 files changed, 138 insertions(+)
create mode 100644 grub-core/commands/increment.c
create mode 100644 util/grub.d/01_fallback_counting.in
diff --git a/Makefile.util.def b/Makefile.util.def
index 08cc98ddb..eca3dfa75 100644
--- a/Makefile.util.def
+++ b/Makefile.util.def
@@ -448,6 +448,12 @@ script = {
installdir = grubconf;
};
+script = {
+ name = '01_fallback_counting';
+ common = util/grub.d/01_fallback_counting.in;
+ installdir = grubconf;
+};
+
script = {
name = '01_menu_auto_hide';
common = util/grub.d/01_menu_auto_hide.in;
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 6864e780f..c8a50b4fc 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -362,6 +362,11 @@ kernel = {
extra_dist = kern/mips/cache_flush.S;
};
+module = {
+ name = increment;
+ common = commands/increment.c;
+};
+
program = {
name = grub-emu;
mansection = 1;
diff --git a/grub-core/commands/increment.c b/grub-core/commands/increment.c
new file mode 100644
index 000000000..79cf13765
--- /dev/null
+++ b/grub-core/commands/increment.c
@@ -0,0 +1,105 @@
+/* increment.c - Commands to increment and decrement variables. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2006,2007,2008 Free Software Foundation, Inc.
+ *
+ * GRUB 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/dl.h>
+#include <grub/term.h>
+#include <grub/time.h>
+#include <grub/types.h>
+#include <grub/misc.h>
+#include <grub/extcmd.h>
+#include <grub/i18n.h>
+#include <grub/env.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+typedef enum {
+ INCREMENT,
+ DECREMENT,
+} operation;
+
+static grub_err_t
+incr_decr(operation op, int argc, char **args)
+{
+ const char *old;
+ char *new;
+ long value;
+
+ if (argc < 1)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, N_ ("no variable specified"));
+ if (argc > 1)
+ return grub_error (GRUB_ERR_BAD_ARGUMENT, N_ ("too many arguments"));
+
+ old = grub_env_get (*args);
+ if (!old)
+ return grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("No such variable \"%s\""),
+ *args);
+
+ value = grub_strtol (old, NULL, 0);
+ if (grub_errno != GRUB_ERR_NONE)
+ return grub_errno;
+
+ switch (op)
+ {
+ case INCREMENT:
+ value += 1;
+ break;
+ case DECREMENT:
+ value -= 1;
+ break;
+ }
+
+ new = grub_xasprintf ("%ld", value);
+ if (!new)
+ return grub_errno;
+
+ grub_env_set (*args, new);
+ grub_free (new);
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_cmd_incr(struct grub_command *cmd UNUSED,
+ int argc, char **args)
+{
+ return incr_decr(INCREMENT, argc, args);
+}
+
+static grub_err_t
+grub_cmd_decr(struct grub_command *cmd UNUSED,
+ int argc, char **args)
+{
+ return incr_decr(DECREMENT, argc, args);
+}
+
+static grub_command_t cmd_incr, cmd_decr;
+
+GRUB_MOD_INIT(increment)
+{
+ cmd_incr = grub_register_command ("increment", grub_cmd_incr, N_("VARIABLE"),
+ N_("increment VARIABLE"));
+ cmd_decr = grub_register_command ("decrement", grub_cmd_decr, N_("VARIABLE"),
+ N_("decrement VARIABLE"));
+}
+
+GRUB_MOD_FINI(increment)
+{
+ grub_unregister_command (cmd_incr);
+ grub_unregister_command (cmd_decr);
+}
diff --git a/util/grub.d/01_fallback_counting.in b/util/grub.d/01_fallback_counting.in
new file mode 100644
index 000000000..be0e770ea
--- /dev/null
+++ b/util/grub.d/01_fallback_counting.in
@@ -0,0 +1,22 @@
+#! /bin/sh -e
+
+# Boot Counting
+# The boot_counter env var can be used to count down boot attempts after an
+# OSTree upgrade and choose the rollback deployment when 0 is reached. Both
+# boot_counter and boot_success need to be (re-)set from userspace.
+cat << EOF
+insmod increment
+# Check if boot_counter exists and boot_success=0 to activate this behaviour.
+if [ -n "\${boot_counter}" -a "\${boot_success}" = "0" ]; then
+ # if countdown has ended, choose to boot rollback deployment (default=1 on
+ # OSTree-based systems)
+ if [ "\${boot_counter}" = "0" -o "\${boot_counter}" = "-1" ]; then
+ set default=1
+ set boot_counter=-1
+ # otherwise decrement boot_counter
+ else
+ decrement boot_counter
+ fi
+ save_env boot_counter
+fi
+EOF