From 2cb7e0aaedad73b076ea18c6900b0e86c5760d79 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 15:00:47 +0200 Subject: Adding upstream version 247.3. Signed-off-by: Daniel Baumann --- src/systemctl/systemctl-switch-root.c | 77 +++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 src/systemctl/systemctl-switch-root.c (limited to 'src/systemctl/systemctl-switch-root.c') diff --git a/src/systemctl/systemctl-switch-root.c b/src/systemctl/systemctl-switch-root.c new file mode 100644 index 0000000..9ed40e6 --- /dev/null +++ b/src/systemctl/systemctl-switch-root.c @@ -0,0 +1,77 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "bus-error.h" +#include "bus-locator.h" +#include "parse-util.h" +#include "path-util.h" +#include "proc-cmdline.h" +#include "signal-util.h" +#include "stat-util.h" +#include "systemctl-switch-root.h" +#include "systemctl-util.h" +#include "systemctl.h" + +int switch_root(int argc, char *argv[], void *userdata) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + _cleanup_free_ char *cmdline_init = NULL; + const char *root, *init; + sd_bus *bus; + int r; + + if (arg_transport != BUS_TRANSPORT_LOCAL) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot switch root remotely."); + + if (argc < 2 || argc > 3) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Wrong number of arguments."); + + root = argv[1]; + + if (argc >= 3) + init = argv[2]; + else { + r = proc_cmdline_get_key("init", 0, &cmdline_init); + if (r < 0) + log_debug_errno(r, "Failed to parse /proc/cmdline: %m"); + + init = cmdline_init; + } + + init = empty_to_null(init); + if (init) { + const char *root_systemd_path = NULL, *root_init_path = NULL; + + root_systemd_path = prefix_roota(root, "/" SYSTEMD_BINARY_PATH); + root_init_path = prefix_roota(root, init); + + /* If the passed init is actually the same as the systemd binary, then let's suppress it. */ + if (files_same(root_init_path, root_systemd_path, 0) > 0) + init = NULL; + } + + /* Instruct PID1 to exclude us from its killing spree applied during the transition. Otherwise we + * would exit with a failure status even though the switch to the new root has succeed. */ + assert(saved_argv); + assert(saved_argv[0]); + saved_argv[0][0] = '@'; + + r = acquire_bus(BUS_MANAGER, &bus); + if (r < 0) + return r; + + /* If we are slow to exit after the root switch, the new systemd instance will send us a signal to + * terminate. Just ignore it and exit normally. This way the unit does not end up as failed. */ + r = ignore_signals(SIGTERM, -1); + if (r < 0) + log_warning_errno(r, "Failed to change disposition of SIGTERM to ignore: %m"); + + log_debug("Switching root - root: %s; init: %s", root, strna(init)); + + r = bus_call_method(bus, bus_systemd_mgr, "SwitchRoot", &error, NULL, "ss", root, init); + if (r < 0) { + (void) default_signals(SIGTERM, -1); + + return log_error_errno(r, "Failed to switch root: %s", bus_error_message(&error, r)); + } + + return 0; +} -- cgit v1.2.3