</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>systemd.break=</varname></term>
+ <term><varname>rd.systemd.break=</varname></term>
+ <listitem>
+ <para>Parameters understood by
+ <citerefentry><refentrytitle>systemd-debug-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ to pause the boot process at a certain point and spawn a debug shell.</para>
+
+ <xi:include href="version-info.xml" xpointer="v258"/>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><varname>systemd.run=</varname></term>
<term><varname>systemd.run_success_action=</varname></term>
<xi:include href="version-info.xml" xpointer="v215"/></listitem>
</varlistentry>
+
+ <varlistentry>
+ <term><varname>systemd.break=</varname></term>
+ <term><varname>rd.systemd.break=</varname></term>
+
+ <listitem><para>Takes one of <option>pre-udev</option>, <option>pre-basic</option>,
+ <option>pre-mount</option>, or <option>pre-switch-root</option> (the default for the
+ <literal>rd.</literal> option). It also accepts multiple values separated by comma
+ (<literal>,</literal>). These options allow to pause the boot process at a certain point and spawn a
+ debug shell. After exiting this shell, the system will resume booting. The option prefixed with
+ <literal>rd.</literal> is honored only in the initrd, while the one without prefix is only honored in
+ the main system.</para>
+
+ <table>
+ <title>Available breakpoints</title>
+
+ <tgroup cols='4'>
+ <colspec colname='breakpoint' />
+ <colspec colname='description' />
+ <colspec colname='initrd' />
+ <colspec colname='main' />
+ <thead>
+ <row>
+ <entry>Breakpoints</entry>
+ <entry>Description</entry>
+ <entry>Can be used in the initrd</entry>
+ <entry>Can be used in the main system</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry><option>pre-udev</option></entry>
+ <entry>Before starting to process kernel uevents, i.e., before <filename>systemd-udevd.service</filename> starts.</entry>
+ <entry>✓</entry>
+ <entry>✓</entry>
+ </row>
+ <row>
+ <entry><option>pre-basic</option></entry>
+ <entry>Before leaving early boot and regular services start, i.e., before <filename>basic.target</filename> is reached.</entry>
+ <entry>✓</entry>
+ <entry>✓</entry>
+ </row>
+ <row>
+ <entry><option>pre-mount</option></entry>
+ <entry>Before the root filesystem is mounted, i.e., before <filename>sysroot.mount</filename> starts.</entry>
+ <entry>✓</entry>
+ <entry>✗</entry>
+ </row>
+ <row>
+ <entry><option>pre-switch-root</option></entry>
+ <entry>Before switching from the initrd to the real root.</entry>
+ <entry>✓</entry>
+ <entry>✗</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <xi:include href="version-info.xml" xpointer="v258"/></listitem>
+ </varlistentry>
</variablelist>
</refsect1>
<member><citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>systemd.system-credentials</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
+ <member><citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
</simplelist></para>
</refsect1>
#include <unistd.h>
#include "alloc-util.h"
+#include "bitfield.h"
#include "creds-util.h"
#include "dropin.h"
#include "errno-util.h"
+#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "generator.h"
static bool arg_debug_shell = false;
static char *arg_debug_tty = NULL;
static char *arg_default_debug_tty = NULL;
+static uint32_t arg_breakpoints = 0;
STATIC_DESTRUCTOR_REGISTER(arg_default_unit, freep);
STATIC_DESTRUCTOR_REGISTER(arg_mask, strv_freep);
STATIC_DESTRUCTOR_REGISTER(arg_debug_tty, freep);
STATIC_DESTRUCTOR_REGISTER(arg_default_debug_tty, freep);
+typedef enum BreakpointType {
+ BREAKPOINT_PRE_UDEV,
+ BREAKPOINT_PRE_BASIC,
+ BREAKPOINT_PRE_SYSROOT_MOUNT,
+ BREAKPOINT_PRE_SWITCH_ROOT,
+ _BREAKPOINT_TYPE_MAX,
+ _BREAKPOINT_TYPE_INVALID = -EINVAL,
+} BreakpointType;
+
+typedef enum BreakpointValidity {
+ BREAKPOINT_DEFAULT = 1 << 0,
+ BREAKPOINT_IN_INITRD = 1 << 1,
+ BREAKPOINT_ON_HOST = 1 << 2,
+} BreakpointValidity;
+
+typedef struct BreakpointInfo {
+ BreakpointType type;
+ const char *name;
+ const char *unit;
+ BreakpointValidity validity;
+} BreakpointInfo;
+
+static const struct BreakpointInfo breakpoint_info_table[_BREAKPOINT_TYPE_MAX] = {
+ { BREAKPOINT_PRE_UDEV, "pre-udev", "breakpoint-pre-udev.service", BREAKPOINT_IN_INITRD | BREAKPOINT_ON_HOST },
+ { BREAKPOINT_PRE_BASIC, "pre-basic", "breakpoint-pre-basic.service", BREAKPOINT_IN_INITRD | BREAKPOINT_ON_HOST },
+ { BREAKPOINT_PRE_SYSROOT_MOUNT, "pre-mount", "breakpoint-pre-mount.service", BREAKPOINT_IN_INITRD },
+ { BREAKPOINT_PRE_SWITCH_ROOT, "pre-switch-root", "breakpoint-pre-switch-root.service", BREAKPOINT_IN_INITRD | BREAKPOINT_DEFAULT },
+};
+
+static BreakpointType parse_breakpoint_from_string_one(const char *s) {
+ assert(s);
+
+ FOREACH_ARRAY(i, breakpoint_info_table, ELEMENTSOF(breakpoint_info_table))
+ if (streq(i->name, s))
+ return i->type;
+
+ return _BREAKPOINT_TYPE_INVALID;
+}
+
+static int parse_breakpoint_from_string(const char *s, uint32_t *ret_breakpoints) {
+ uint32_t breakpoints = 0;
+ int r;
+
+ assert(ret_breakpoints);
+
+ /* Empty value? set default breakpoint */
+ if (isempty(s)) {
+ if (in_initrd()) {
+ FOREACH_ARRAY(i, breakpoint_info_table, ELEMENTSOF(breakpoint_info_table))
+ if (i->validity & BREAKPOINT_DEFAULT) {
+ breakpoints |= 1 << i->type;
+ break;
+ }
+ } else
+ log_warning("No default breakpoint defined on the host, ignoring breakpoint request from kernel command line.");
+ } else
+ for (;;) {
+ _cleanup_free_ char *t = NULL;
+ BreakpointType tt;
+
+ r = extract_first_word(&s, &t, ",", EXTRACT_DONT_COALESCE_SEPARATORS);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ tt = parse_breakpoint_from_string_one(t);
+ if (tt < 0) {
+ log_warning("Invalid breakpoint value '%s', ignoring.", t);
+ continue;
+ }
+
+ if (in_initrd() && !FLAGS_SET(breakpoint_info_table[tt].validity, BREAKPOINT_IN_INITRD))
+ log_warning("Breakpoint '%s' not valid in the initrd, ignoring.", t);
+ else if (!in_initrd() && !FLAGS_SET(breakpoint_info_table[tt].validity, BREAKPOINT_ON_HOST))
+ log_warning("Breakpoint '%s' not valid on the host, ignoring.", t);
+ else
+ breakpoints |= 1 << tt;
+ }
+
+ *ret_breakpoints = breakpoints;
+
+ return 0;
+}
+
static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
int r;
return free_and_strdup_warn(&arg_default_unit, value);
+ } else if (streq(key, "systemd.break")) {
+ uint32_t breakpoints = 0;
+
+ r = parse_breakpoint_from_string(value, &breakpoints);
+ if (r < 0)
+ return log_warning_errno(r, "Failed to parse breakpoint value '%s': %m", value);
+
+ arg_breakpoints |= breakpoints;
+
} else if (!value) {
const char *target;
RET_GATHER(r, install_debug_shell_dropin());
}
+ BIT_FOREACH(i, arg_breakpoints)
+ if (strv_extend(&arg_wants, breakpoint_info_table[i].unit) < 0)
+ return log_oom();
+
if (get_credentials_dir(&credentials_dir) >= 0)
RET_GATHER(r, process_unit_credentials(credentials_dir));
link_endswith "$OUT_DIR/early/default.target.wants/debug-shell.service" /lib/systemd/system/debug-shell.service
grep -F "/dev/tty666" "$OUT_DIR/early/debug-shell.service.d/50-tty.conf"
+# systemd.break (default)
+: "debug-shell: regular + systemd.break"
+CMDLINE="$CMDLINE systemd.break"
+SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-udev.service"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-mount.service"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-switch-root.service"
+
+# systemd.break=pre-switch-root
+: "debug-shell: regular + systemd.break=pre-switch-root"
+CMDLINE="$CMDLINE systemd.break=pre-switch-root"
+SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-udev.service"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-mount.service"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-switch-root.service"
+
+# systemd.break=pre-mount
+: "debug-shell: regular + systemd.break=pre-mount"
+CMDLINE="$CMDLINE systemd.break=pre-mount"
+SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-udev.service"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-mount.service"
+test ! -h "$OUT_DIR/early/default.target.wants/breakpoint-pre-switch-root.service"
+
+# systemd.break=pre-basic
+: "debug-shell: regular + systemd.break=pre-basic"
+CMDLINE="$CMDLINE systemd.break=pre-basic"
+SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/default.target.wants/breakpoint-pre-basic.service" /lib/systemd/system/breakpoint-pre-basic.service
+
+# systemd.break=pre-udev
+: "debug-shell: regular + systemd.break=pre-udev"
+CMDLINE="$CMDLINE systemd.break=pre-udev"
+SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/default.target.wants/breakpoint-pre-udev.service" /lib/systemd/system/breakpoint-pre-udev.service
+
+# systemd.break=pre-udev,pre-basic,pre-mount,pre-switch-root
+: "debug-shell: regular + systemd.break=pre-udev,pre-basic,pre-mount,pre-switch-root"
+rm -f "$OUT_DIR/early/default.target.wants/breakpoint-pre-udev.service"
+rm -f "$OUT_DIR/early/default.target.wants/breakpoint-pre-basic.service"
+CMDLINE="$CMDLINE systemd.break=pre-udev,pre-basic,pre-mount,pre-switch-root"
+SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/default.target.wants/breakpoint-pre-udev.service" /lib/systemd/system/breakpoint-pre-udev.service
+link_endswith "$OUT_DIR/early/default.target.wants/breakpoint-pre-basic.service" /lib/systemd/system/breakpoint-pre-basic.service
+
# Now override the default target via systemd.unit=
: "debug-shell: regular + systemd.unit="
CMDLINE="$CMDLINE systemd.unit=my-fancy.target"
SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
link_endswith "$OUT_DIR/early/initrd.target.wants/debug-shell.service" /lib/systemd/system/debug-shell.service
+# rd.systemd.break (default)
+: "debug-shell: initrd + rd.systemd.break"
+CMDLINE="$CMDLINE rd.systemd.break"
+SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-switch-root.service" /lib/systemd/system/breakpoint-pre-switch-root.service
+
+# rd.systemd.break=pre-udev
+: "debug-shell: initrd + rd.systemd.break=pre-udev"
+CMDLINE="$CMDLINE rd.systemd.break=pre-udev"
+SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-udev.service" /lib/systemd/system/breakpoint-pre-udev.service
+
+# rd.systemd.break=pre-basic
+: "debug-shell: initrd + rd.systemd.break=pre-basic"
+CMDLINE="$CMDLINE rd.systemd.break=pre-basic"
+SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-basic.service" /lib/systemd/system/breakpoint-pre-basic.service
+
+# rd.systemd.break=pre-mount
+: "debug-shell: initrd + rd.systemd.break=pre-mount"
+CMDLINE="$CMDLINE rd.systemd.break=pre-mount"
+SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-mount.service" /lib/systemd/system/breakpoint-pre-mount.service
+
+# rd.systemd.break=pre-switch-root
+: "debug-shell: initrd + rd.systemd.break=pre-switch-root"
+rm -f "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-switch-root.service"
+CMDLINE="$CMDLINE rd.systemd.break=pre-switch-root"
+SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-switch-root.service" /lib/systemd/system/breakpoint-pre-switch-root.service
+
+# rd.systemd.break=pre-udev,pre-basic,pre-mount,pre-switch-root
+: "debug-shell: initrd + rd.systemd.break=pre-udev,pre-mount,pre-switch-root"
+rm -f "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-udev.service"
+rm -f "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-basic.service"
+rm -f "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-mount.service"
+rm -f "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-switch-root.service"
+CMDLINE="$CMDLINE rd.systemd.break=pre-udev,pre-basic,pre-mount,pre-switch-root"
+SYSTEMD_IN_INITRD=1 SYSTEMD_PROC_CMDLINE="$CMDLINE" run_and_list "$GENERATOR_BIN" "$OUT_DIR"
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-udev.service" /lib/systemd/system/breakpoint-pre-udev.service
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-basic.service" /lib/systemd/system/breakpoint-pre-basic.service
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-mount.service" /lib/systemd/system/breakpoint-pre-mount.service
+link_endswith "$OUT_DIR/early/initrd.target.wants/breakpoint-pre-switch-root.service" /lib/systemd/system/breakpoint-pre-switch-root.service
+
# Override the default target
: "debug-shell: initrd + rd.systemd.unit"
CMDLINE="$CMDLINE rd.systemd.unit=my-fancy-initrd.target"
--- /dev/null
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# This file is part of systemd.
+#
+# systemd 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.
+
+[Unit]
+Description=Breakpoint Before Basic System
+Documentation=man:systemd-debug-generator(8)
+DefaultDependencies=no
+Conflicts=shutdown.target emergency.target
+After=sysinit.target sockets.target paths.target slices.target tmp.mount systemd-vconsole-setup.service
+Before=basic.target
+
+[Service]
+Environment=SHELL_PROMPT_PREFIX="pre-basic "
+Type=oneshot
+ExecStartPre=-plymouth --wait quit
+# Execute shell with "-" prefix to not consider the unit failed if it exits with
+# a non-zero value
+ExecStart=-{{SUSHELL}}
+StandardInput=tty-force
+StandardOutput=inherit
+StandardError=inherit
+KillMode=process
+IgnoreSIGPIPE=no
+# bash ignores SIGTERM
+KillSignal=SIGHUP
+
+# Unset locale for the console getty since the console has problems
+# displaying some internationalized messages.
+UnsetEnvironment=LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION
--- /dev/null
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# This file is part of systemd.
+#
+# systemd 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.
+
+[Unit]
+Description=Breakpoint Before Mounting the Root Filesystem on /sysroot
+Documentation=man:systemd-debug-generator(8)
+AssertPathExists=/etc/initrd-release
+DefaultDependencies=no
+Conflicts=shutdown.target emergency.target
+After=basic.target systemd-vconsole-setup.service
+Before=initrd-root-fs.target sysroot.mount systemd-fsck-root.service
+
+[Service]
+Environment=SHELL_PROMPT_PREFIX="pre-mount "
+Type=oneshot
+ExecStartPre=-plymouth --wait quit
+# Execute shell with "-" prefix to not consider the unit failed if it exits with
+# a non-zero value
+ExecStart=-{{SUSHELL}}
+StandardInput=tty-force
+StandardOutput=inherit
+StandardError=inherit
+KillMode=process
+IgnoreSIGPIPE=no
+# bash ignores SIGTERM
+KillSignal=SIGHUP
+
+# Unset locale for the console getty since the console has problems
+# displaying some internationalized messages.
+UnsetEnvironment=LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION
--- /dev/null
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# This file is part of systemd.
+#
+# systemd 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.
+
+[Unit]
+Description=Breakpoint Before Switching Root
+Documentation=man:systemd-debug-generator(8)
+AssertPathExists=/etc/initrd-release
+DefaultDependencies=no
+Conflicts=shutdown.target emergency.target
+Wants=remote-fs.target
+After=initrd.target initrd-parse-etc.service sysroot.mount remote-fs.target systemd-vconsole-setup.service
+Before=initrd-cleanup.service
+
+[Service]
+Environment=SHELL_PROMPT_PREFIX="pre-switch-root "
+Type=oneshot
+ExecStartPre=-plymouth --wait quit
+# Execute shell with "-" prefix to not consider the unit failed if it exits with
+# a non-zero value
+ExecStart=-{{SUSHELL}}
+StandardInput=tty-force
+StandardOutput=inherit
+StandardError=inherit
+KillMode=process
+IgnoreSIGPIPE=no
+# bash ignores SIGTERM
+KillSignal=SIGHUP
+
+# Unset locale for the console getty since the console has problems
+# displaying some internationalized messages.
+UnsetEnvironment=LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION
--- /dev/null
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# This file is part of systemd.
+#
+# systemd 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.
+
+[Unit]
+Description=Breakpoint Before Starting to Process Kernel uevents
+Documentation=man:systemd-debug-generator(8)
+DefaultDependencies=no
+Conflicts=shutdown.target emergency.target
+Wants=systemd-journald.socket
+After=systemd-journald.socket systemd-vconsole-setup.service
+Before=systemd-udevd.service systemd-udev-trigger.service
+
+[Service]
+Environment=SHELL_PROMPT_PREFIX="pre-udev "
+Type=oneshot
+ExecStartPre=-plymouth --wait quit
+# Execute shell with "-" prefix to not consider the unit failed if it exits with
+# a non-zero value
+ExecStart=-{{SUSHELL}}
+StandardInput=tty-force
+StandardOutput=inherit
+StandardError=inherit
+KillMode=process
+IgnoreSIGPIPE=no
+# bash ignores SIGTERM
+KillSignal=SIGHUP
+
+# Unset locale for the console getty since the console has problems
+# displaying some internationalized messages.
+UnsetEnvironment=LANG LANGUAGE LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION
{ 'file' : 'blockdev@.target' },
{ 'file' : 'bluetooth.target' },
{ 'file' : 'boot-complete.target' },
+ { 'file' : 'breakpoint-pre-basic.service.in' },
+ { 'file' : 'breakpoint-pre-mount.service.in' },
+ { 'file' : 'breakpoint-pre-switch-root.service.in' },
+ { 'file' : 'breakpoint-pre-udev.service.in' },
{ 'file' : 'capsule@.service.in' },
{ 'file' : 'capsule.slice' },
{ 'file' : 'console-getty.service.in' },