This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
This renames wait_for_terminate_and_warn() to
wait_for_terminate_and_check(), and adds a flags parameter, that
controls how much to log: there's one flag that means we log about
abnormal stuff, and another one that controls whether we log about
non-zero exit codes. Finally, there's a shortcut flag value for logging
in both cases, as that's what we usually use.
All callers are accordingly updated. At three occasions duplicate logging
is removed, i.e. where the old function was called but logged in the
caller, too.
This adds a new safe_fork() wrapper around fork() and makes use of it
everywhere. The new wrapper does a couple of things we previously did
manually and separately in a safer, more correct and automatic way:
1. Optionally resets signal handlers/mask in the child
2. Sets a name on all processes we fork off right after forking off (and
the patch assigns useful names for all processes we fork off now,
following a systematic naming scheme: always enclosed in () – in order
to indicate that these are not proper, exec()ed processes, but only
forked off children, and if the process is long-running with only our
own code, without execve()'ing something else, it gets am "sd-" prefix.)
3. Optionally closes all file descriptors in the child
4. Optionally sets a PR_SET_DEATHSIG to SIGTERM in the child, in a safe
way so that the parent dying before this happens being handled
safely.
5. Optionally reopens the logs
6. Optionally connects stdin/stdout/stderr to /dev/null
7. Debug logs about the forked off processes.
Our CODING_STYLE suggests not comparing with NULL, but relying on C's
downgrade-to-bool feature for that. Fix up some code to match these
guidelines. (This is not comprehensive, the coccinelle output for this
is unfortunately kinda borked)
When vconsole-setup is called without arguments, search for a usable
console instead of using /dev/tty0.
/dev/tty0 — pointing to the current active console — it not necessarily
usable and in such case vconsole-setup would exit with failure. In particular
when systemd-vconsole-setup.service was restarted from within an X
session, it always failed.
If the function searching for a usable source terminal fails, the first
encountered error is returned to the caller.
Closes#5367.
Additional changes:
- true/false functions with 'is_ prefix are renamed to functions with
'verify_vc_' prefix and return 0 on success and negative error on
failure
- O_NOCTTY flag is used when opening terminals
On a machine without a VGA console, /dev/tty{0,1,…} exist, so
systemd-vconsole-setup is started, but all setfont operations fail.
setfont has a bunch of return codes for different failure modes. It uses
EX_OSERR when the communication with the kernel using ioctls fails. This isn't
too specific, but at least it's only used this general class of errors. Let's
swallow the error in this case to avoid systemd-vconsole-setup.service failing
on cloud vms.
On a machine from https://bugzilla.redhat.com/show_bug.cgi?id=1272686#c4:
$ build/systemd-vconsole-setup
setfont: putfont: 512,8x16: failed: -1
putfont: PIO_FONT: Invalid argument
/usr/bin/setfont failed with error code 71.
Setting fonts failed with a "system error", ignoring.
$ SYSTEMD_LOG_LEVEL=debug build/systemd-vconsole-setup
Found container virtualization none.
Sysfs UTF-8 flag enabled
UTF-8 kbdmode enabled on /dev/tty0
Executing "/usr/bin/setfont -C /dev/tty0 eurlatgr"...
setfont: putfont: 512,8x16: failed: -1
putfont: PIO_FONT: Invalid argument
/usr/bin/setfont failed with error code 71.
Executing "/usr/bin/loadkeys -q -C /dev/tty0 -u us"...
/usr/bin/loadkeys succeeded.
Setting fonts failed with a "system error", ignoring.
$ lspci | grep -i vga
$ ls /dev/tty?
/dev/tty0 /dev/tty2 /dev/tty4 /dev/tty6 /dev/tty8
/dev/tty1 /dev/tty3 /dev/tty5 /dev/tty7 /dev/tty9
If we have a better test for /dev/tty? being connected to something that has a
font, we could avoid running setfont at all… ATM, I'm not aware of a simple
test like that.
This makes it quite a bit easier to see what failed.
strv_join is called inline in log_debug so that it is under the conditional
that kills the whole thing if debugging is disabled.
is_allocated() and is_allocated_byfd():
Checks if the console is allocated by its index (first function) or
its open descriptor (second function).
is_settable():
Checks if the console is in xlate or unicode mode, so we can adjust
is safely without interfering with X.
Add toggle_utf8() and toggle_utf8_sysfs() and use them in place of old
enable/disable functions. toggle_utf8() also adds iutf8 setting and is
set up to be called per-console (in subsequent patches).
Note, that old disable_utf8() didn't bother checking if it was ok
to change the kbdmode.
GIO_SCRNMAP / GIO_UNISCRNMAP are related to what setfont does with -m
option - namely setting intermediate map from 8bit values into unicode
values. This map is global, so single setfont invocation sets it for
all applicable consoles.
Furthermore calling GIO_SCRNMAP before GIO_UNISCRNMAP causes issues as
the former corrupts values > 255 (UNI alone would be sufficient).
The bug can be easily tested with the following conf:
KEYMAP=pl
FONT=LatArCyrHeb-16
FONT_MAP=8859-2
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
Introduce a proper enum, and don't pass around string ids anymore. This
simplifies things quite a bit, and makes virtualization detection more
similar to architecture detection.
The latest consolidation cleanup of write_string_file() revealed some users
of that helper which should have used write_string_file_no_create() in the
past but didn't. Basically, all existing users that write to files in /sys
and /proc should not expect to write to a file which is not yet existant.
Merge write_string_file(), write_string_file_no_create() and
write_string_file_atomic() into write_string_file() and provide a flags mask
that allows combinations of atomic writing, newline appending and automatic
file creation. Change all users accordingly.
Also, when the child is potentially long-running make sure to set a
death signal.
Also, ignore the result of the reset operations explicitly by casting
them to (void).
This undoes part of 8931278c8a.
We really should stick to kernel-style "int" return values from
functions, and not covnert success into boolean returns.
If we don't check the error of the child process, systemd-vconsole-setup
would exit with 0 even if it could not really setup the console.
For a simple test, move loadkeys elsewhere and execute
systemd-vconsole-setup:
[root@localhost ~]# strace -f -e execve /usr/lib/systemd/systemd-vconsole-setup
execve("/usr/lib/systemd/systemd-vconsole-setup", ["/usr/lib/systemd/systemd-vconsol"...], [/* 15 vars */]) = 0
Process 171 attached
[pid 171] execve("/usr/bin/loadkeys", ["/usr/bin/loadkeys", "-q", "-C", "/dev/tty0", "br-abnt2"], [/* 15 vars */]) = -1 ENOENT (No such file or directory)
[pid 171] +++ exited with 1 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=171, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
+++ exited with 0 +++
Note that loadkeys returned 1 while systemd-vconsole-setup return 0.
Since the font and keyboard setup are already serialized, refactor the
code a little bit so the functions do the wait by themselves. One change
in behavior in this patch is that we don't return early, but we do try
to setup the keyboard even if the font load failed.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
loop_write() didn't follow the usual systemd rules and returned status
partially in errno and required extensive checks from callers. Some of
the callers dealt with this properly, but many did not, treating
partial writes as successful. Simplify things by conforming to usual rules.
If the format string contains %m, clearly errno must have a meaningful
value, so we might as well use log_*_errno to have ERRNO= logged.
Using:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/'
Plus some whitespace, linewrap, and indent adjustments.
As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
Lennart Poettering