--introspect-cli follows the same deferred pattern as --help: parse_argv()
only records the action, and it is executed in the same place where
ACTION_HELP and ACTION_VERSION are handled.
The help is looked up by explicit name: in the multicall configuration
the systemd and systemd-executor commands share one binary, so the
"first COMMAND" default would depend on link order.
The "This program takes no positional arguments." line is dropped from
the help output — the default "[OPTION…]" synopsis already says so.
(And also, this is not quite true. It does take positional args when
called as init.)
It'd be nice if we could not repeat the information about the option
list a second time. But I don't see a nice way to do this, since
(by design) with the macro approach, the macros must be intertwined
with the parse_argv() code. But that code in turn refers to a bunch
of variables, so lifting out the function is not immediately possible.
So I think it's best to keep the existing approach where we provide
a list of options, without additional context, and skip them using
a custom routine.
Latest glibc uses _Generic to have strstr() and other functions return
const char* or char* based on whether the input is a const char* or a
char*. This causes build failures as we previously always expected a char*.
Let's fix the compilation failures and add our own macros similar to glibc's
to have string functions that return a mutable or const pointer depending on
the input.
Kernel API file systems typically use either "raw" or "seq_file" to
implement their various interface files. The former are really simple
(to point I'd call them broken), in that they have no understanding of
file offsets, and return their contents again and again on every read(),
and thus EOF is indicated by a short read, not by a zero read. The
latter otoh works like a typical file: you read until you get a
zero-sized read back.
We have read_virtual_file() to read the "raw" files, and can use regular
read_full_file() to read the "seq_file" ones.
Apparently all files in the top-level /proc/ directory use 'seq_file'.
but we accidentally used read_virtual_file() for them. Fix that.
Also clarify in a comment what the rules are.
Fixes: #36131
This has been depracted since v254 (2023). Let's kill it for
good now, it has been long enough with 2y. Noone has shown up who wants
to keep it. And given it doesn't work in SB world anyway, and is not
measured is quite problematic security wise.
If getopt_long() is called for a list of arguments and it is freed, then
calling getopt_long() for another list will trigger use-after-free.
The function proc_cmdline_filter_pid1_args() may be called before or during
parsing program arguments (typically named as parse_argv()), hence we cannot
use getopt_long() in proc_cmdline_filter_pid1_args().
Fixes#28366.
The kernel command line may contain newlines which kernel happily
accepts, but we'd ignore everything past the first newline. Let's fix
that by replacing read_one_line_file() with read_full_file().
When we are running in a container, we parse the command line of PID1 in
proc_cmdline_parse() or friends. Previously, first we merge the command
line nulstr as a single string, and then split by using
extract_first_word(). That's not only redundant, but also unsafe when
the command line argument contain a space.
This drops the redundant steps, hence we can safely parse arguments with
space.
I changed imports of util.h to initrd-util.h, or added an import of
initrd-util.h, to keep compilation working. It turns out that many files didn't
import util.h directly.
When viewing the patch, don't be confused by git rename detection logic:
a new .c file is added and two functions moved into it.
So far when parsing /proc/cmdline we'd consider backslashes as
mechanisms for escaping whitepace or quotes. This changes things so that
they are retained as they are instead. The kernel itself doesn't allow such
escaping, and hence we shouldn't do so either (see lib/cmdline.c in the
kernel sources; it does support "" quotes btw).
This fix is useful to allow specifying backslash escapes in the "root="
cmdline option to be passed through to systemd-fstab-generator. Example:
root=/dev/disk/by-partlabel/Root\x20Partition
Previously we'd eat up the "\" so that we'd then look for a device
/dev/disk/by-partlabel/Rootx20Partition which never shows up.
The original logic was logging an "ignored" debug message, but it was still
going ahead and calling proc_cmdline_parse_given() on the NULL line. Fix that
to skip that explicitly when the EFI variable wasn't really read.
And do not use it in the IMPORT{cmdline} udev code. Wherever we expose
direct interfaces to check the kernel cmdline, let's not consult our
systemd-specific EFI variable, but strictly use the actual kernel
variable, because that's what we claim we do. i.e. it's fine to use the
EFI variable for our own settings, but for the generic APIs to the
kernel cmdline we should not use it.
Specifically, this applies to IMPORT{cmdline} and
ConditionKernelCommandLine=. In the latter case we weren#t checking the
EFI variable anyway, hence let's do the same for the udev case, too.
Fixes: #15739
In SecureBoot mode this is probably not what you want. As your cmdline
is cryptographically signed like when using Type #2 EFI Unified Kernel
Images (https://systemd.io/BOOT_LOADER_SPECIFICATION/) The user's
intention is then that the cmdline should not be modified. You want to
make sure that the system starts up as exactly specified in the signed
artifact.
This makes the naming more consistent: we now have
bootctl systemd-efi-options,
$SYSTEMD_EFI_OPTIONS
and the SystemdOptions EFI variable.
(SystemdEFIOptions would be redundant, because it is only used in the context
of efivars, and users don't interact with that name directly.)
bootctl is adjusted to use 2sp indentation, similarly to systemctl and other
programs.
Remove the prefix with the old name from 'bootctl systemd-efi-options' output,
since it's redundant and we don't want the old name anyway.
In various circumstances, overriding the kernel commandline can be inconvenient.
People have different bootloaders, and e.g. the grub config can be pretty scary.
grubby helps, but it isn't always available.
This option adds an alternative mechanism that can quite convenient on EFI
systems. cmdline settings have higher priority, because they can be (usually)
changed on the bootloader prompt.
$SYSTEMD_EFI_OPTIONS can be used to override, same as $SYSTEMD_PROC_CMDLINE.
It if of course related to /proc/cmdline parsing, but is higher-level
functionality built on top of it. It should be in shared/ because it
is something to be used by pid1 and related utilities, not something for
level-level libraries.
Whenever I see EXTRACT_QUOTES, I'm always confused whether it means to
leave the quotes in or to take them out. Let's say "unquote", like we
say "cunescape".
The functions to retrieve and print process cmdlines were based on the
assumption that they contain printable ASCII, and everything else
should be filtered out. That assumption doesn't hold in today's world,
where people are free to use unicode everywhere.
This replaces the custom cmdline reading code with a more generic approach
using utf8_escape_non_printable_full().
For kernel threads, truncation is done on the parenthesized name, so we'll
get "[worker]", "[worker…]", …, "[w…]", "[…", "…" as we reduce the number of
available columns.
This implementation is most likely slower for very long cmdlines, but I don't
think this is very important. The common case is to have short commandlines,
and should print those properly. Absurdly long cmdlines are the exception,
which needs to be handled correctly and safely, but speed is not too important.
Fixes#12532.
v2:
- use size_t for the number of columns. This change propagates into various
other functions that call get_process_cmdline(), increasing the size of the
patch, but the changes are rather trivial.
This introduces a wrapper around extrac_first_word() called
proc_cmdline_extract_first(), which suppresses "rd." parameters
depending on the specified calls.
This allows us to share more code between proc_cmdline_parse_given() and
proc_cmdline_get_key(), and makes it easier to reuse this logic for
other purposes.
This was mostly prompted by seeing the expression "in_initrd() && flags
& PROC_CMDLINE_RD_STRICT", which uses & and && without any brackets.
Let's make that a bit more readable and hide all doubts about operator
precedence.
Our current set of flags allows an option to be either
use just in initrd or both in initrd and normal system.
This new flag is intended to be used in the case where
you want apply some settings just in initrd or just
in normal system.
Comes with tests.
Also add direct test for $SYSTEMD_PROC_CMDLINE.
In test-proc-cmdline, "true" was masquerading as PROC_CMDLINE_STRIP_RD_PREFIX,
fix that. Also, reorder functions to match call order.
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Daan De Meyer
Lennart Poettering
Integral
Zbigniew Jędrzejewski-Szmek
Mike Yuan
Frantisek Sumsal
Filipe Brandenburger
Arian van Putten
Lukas Nykryn