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.
This makes things a bit easier to read I think, and also makes sure we
always use the _unlikely_ wrapper around it, which so far we used
sometimes and other times we didn't. Let's clean that up.
Let's replace usage of fputc_unlocked() and friends by __fsetlocking(f,
FSETLOCKING_BYCALLER). This turns off locking for the entire FILE*,
instead of doing individual per-call decision whether to use normal
calls or _unlocked() calls.
This has various benefits:
1. It's easier to read and easier not to forget
2. It's more comprehensive, as fprintf() and friends are covered too
(as these functions have no _unlocked() counterpart)
3. Philosophically, it's a bit more correct, because it's more a
property of the file handle really whether we ever pass it on to another
thread, not of the operations we then apply to it.
This patch reworks all pieces of codes that so far used fxyz_unlocked()
calls to use __fsetlocking() instead. It also reworks all places that
use open_memstream(), i.e. use stdio FILE* for string manipulations.
Note that this in some way a revert of 4b61c87511.
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)
The "nobody" user might possibly be seen by the journal or coredumping
code if unmapped userns-using processes are somehow visible to them.
Let's make sure we don't do the ACL magic for this user either, since
this is a special system user that might be backed by different real
users in different contexts.
This adds uid_is_system() and gid_is_system(), similar in style to
uid_is_dynamic(). That a helper like this is useful is illustrated by
the fact that test-condition.c didn't get the check right so far, which
this patch fixes.
So far I avoided adding license headers to meson files, but they are pretty
big and important and should carry license headers like everything else.
I added my own copyright, even though other people modified those files too.
But this is mostly symbolic, so I hope that's OK.
The advantage is that is the name is mispellt, cpp will warn us.
$ git grep -Ee "conf.set\('(HAVE|ENABLE)_" -l|xargs sed -r -i "s/conf.set\('(HAVE|ENABLE)_/conf.set10('\1_/"
$ git grep -Ee '#ifn?def (HAVE|ENABLE)' -l|xargs sed -r -i 's/#ifdef (HAVE|ENABLE)/#if \1/; s/#ifndef (HAVE|ENABLE)/#if ! \1/;'
$ git grep -Ee 'if.*defined\(HAVE' -l|xargs sed -i -r 's/defined\((HAVE_[A-Z0-9_]*)\)/\1/g'
$ git grep -Ee 'if.*defined\(ENABLE' -l|xargs sed -i -r 's/defined\((ENABLE_[A-Z0-9_]*)\)/\1/g'
+ manual changes to meson.build
squash! build-sys: use #if Y instead of #ifdef Y everywhere
v2:
- fix incorrect setting of HAVE_LIBIDN2
This adds IOVEC_INIT() and IOVEC_MAKE() for initializing iovec structures
from a pointer and a size. On top of these IOVEC_INIT_STRING() and
IOVEC_MAKE_STRING() are added which take a string and automatically
determine the size of the string using strlen().
This patch removes the old IOVEC_SET_STRING() macro, given that
IOVEC_MAKE_STRING() is now useful for similar purposes. Note that the
old IOVEC_SET_STRING() invocations were two characters shorter than the
new ones using IOVEC_MAKE_STRING(), but I think the new syntax is more
readable and more generic as it simply resolves to a C99 literal
structure initialization. Moreover, we can use very similar syntax now
for initializing strings and pointer+size iovec entries. We canalso use
the new macros to initialize function parameters on-the-fly or array
definitions. And given that we shouldn't have so many ways to do the
same stuff, let's just settle on the new macros.
(This also converts some code to use _cleanup_ where dynamically
allocated strings were using IOVEC_SET_STRING() before, to modernize
things a bit)
As a follow-up for db3f45e2d2 let's do the
same for all other cases where we create a FILE* with local scope and
know that no other threads hence can have access to it.
For most cases this shouldn't change much really, but this should speed
dbus introspection and calender time formatting up a bit.
Using conf.set() with a boolean argument does the right thing:
either #ifdef or #undef. This means that conf.set can be used unconditionally.
Previously I used '1' as the placeholder value, and that needs to be changed to
'true' for consistency (under meson 1 cannot be used in boolean context). All
checks need to be adjusted.
The indentation for emacs'es meson-mode is added .dir-locals.
All files are reindented automatically, using the lasest meson-mode from git.
Indentation should now be fairly consistent.
Tests can be run with 'ninja-build test' or using 'mesontest'.
'-Dtests=unsafe' can be used to include the "unsafe" tests in the
test suite, same as with autotools.
v2:
- use more conf.get guards are optional components
- declare deps on generated headers for test-{af,arphrd,cap}-list
v3:
- define environment for tests
Most test don't need this, but to be consistent with autotools-based build, and
to avoid questions which tests need it and which don't, set the same environment
for all tests.
v4:
- rework test generation
Use a list of lists to define each test. This way we can reduce the
boilerplate somewhat, although the test listings are still pretty verbose. We
can also move the definitions of the tests to the subdirs. Unfortunately some
subdirs are included earlier than some of the libraries that test binaries
are linked to. So just dump all definitions of all tests that cannot be
defined earlier into src/test. The `executable` definitions are still at the
top level, so the binaries are compiled into the build root.
v5:
- tag test-dnssec-complex as manual
v6:
- fix HAVE_LIBZ typo
- add missing libgobject/libgio defs
- mark test-qcow2 as manual
It's crucial that we can build systemd using VS2010!
... er, wait, no, that's not the official reason. We need to shed old systems
by requring python 3! Oh, no, it's something else. Maybe we need to throw out
345 years of knowlege accumulated in autotools? Whatever, this new thing is
cool and shiny, let's use it.
This is not complete, I'm throwing it out here for your amusement and critique.
- rules for sd-boot are missing. Those might be quite complicated.
- rules for tests are missing too. Those are probably quite simple and
repetitive, but there's lots of them.
- it's likely that I didn't get all the conditions right, I only tested "full"
compilation where most deps are provided and nothing is disabled.
- busname.target and all .busname units are skipped on purpose.
Otherwise, installation into $DESTDIR has the same list of files and the
autoconf install, except for .la files.
It'd be great if people had a careful look at all the library linking options.
I added stuff until things compiled, and in the end there's much less linking
then in the old system. But it seems that there's still a lot of unnecessary
deps.
meson has a `shared_module` statement, which sounds like something appropriate
for our nss and pam modules. Unfortunately, I couldn't get it to work. For the
nss modules, we need an .so version of '2', but `shared_module` disallows the
version argument. For the pam module, it also didn't work, I forgot the reason.
The handling of .m4 and .in and .m4.in files is rather awkward. It's likely
that this could be simplified. If make support is ever dropped, I think it'd
make sense to switch to a different templating system so that two different
languages and not required, which would make everything simpler yet.
v2:
- use get_pkgconfig_variable
- use sh not bash
- use add_project_arguments
v3:
- drop required:true and fix progs/prog typo
v4:
- use find_library('bz2')
- add TTY_GID definition
- define __SANE_USERSPACE_TYPES__
- use join_paths(prefix, ...) is used on all paths to make them all absolute
v5:
- replace all declare_dependency's with []
- add more conf.get guards around optional components
v6:
- drop -pipe, -Wall which are the default in meson
- use compiler.has_function() and compiler.has_header_symbol instead of the
hand-rolled checks.
- fix duplication in 'liblibsystemd' library name
- use the right .sym file for pam_systemd
- rename 'compiler' to 'cc': shorter, and more idiomatic.
v7:
- use ENABLE_ENVIRONMENT_D not HAVE_ENVIRONMENT_D
- rename prefix to prefixdir, rootprefix to rootprefixdir
("prefix" is too common of a name and too easy to overwrite by mistake)
- wrap more stuff with conf.get('ENABLE...') == 1
- use rootprefix=='/' and rootbindir as install_dir, to fix paths under
split-usr==true.
v8:
- use .split() also for src/coredump. Now everything is consistent ;)
- add rootlibdir option and use it on the libraries that require it
v9:
- indentation
v10:
- fix check for qrencode and libaudit
v11:
- unify handling of executable paths, provide options for all progs
This makes the meson build behave slightly differently than the
autoconf-based one, because we always first try to find the executable in the
filesystem, and fall back to the default. I think different handling of
loadkeys, setfont, and telinit was just a historical accident.
In addition to checking in $PATH, also check /usr/sbin/, /sbin for programs.
In Fedora $PATH includes /usr/sbin, (and /sbin is is a symlink to /usr/sbin),
but in Debian, those directories are not included in the path.
C.f. https://github.com/mesonbuild/meson/issues/1576.
- call all the options 'xxx-path' for clarity.
- sort man/rules/meson.build properly so it's stable
This was exposed by the previous commit. This could be potentially
unpleasant, but we are saved by the fact that this code path was only
taken for journald crashes, where we control COMM and know that it doesn't
contain any special characters. Use log_dispatch which does not do any
format processing to push the message out.
I think it would be a good idea to move such fixed, picked values out of
the main sources into the head of a file, to make sure they are
ultimately tunables.
We check these a number of times, hence let's unify these checks here.
This also allows us to make the PID 1 check more elaborate as we can
check both the PID and the cgroup. Checking the PID has the benefit that
we'll also cover cases where PID 1 might still be in the root cgroup, and
the cgroup check has the benefit that we also cover crashes in forked
off crasher processes (the way we actually do it in systemd)
Given that this is a field primarily processed by computers, and not so
much by humans, assign "1" instead of "yes". Also, use parse_boolean()
as we usually do for parsing it again.
This makes things more alike udev options (as one example), such as
SYSTEMD_READY where we also spit out "1" and "0", and parse with
parse_boolean().
[guest@fedora ~]$ coredumpctl
No coredumps found.
[guest@fedora ~]$ ./coredumpctl
Hint: You are currently not seeing messages from other users and the system.
Users in groups 'adm', 'systemd-journal', 'wheel' can see all messages.
Pass -q to turn off this notice.
No coredumps found.
Fixes#1733.
We would only log a terse message when pid1 or systemd-journald crashed.
It seems better to reuse the normal code paths as much as possible,
with the following differences:
- if pid1 crashes, we cannot launch the helper, so we don't analyze the
coredump, just write it to file directly from the helper invoked by the
kernel;
- if journald crashes, we can produce the backtrace, but we don't log full
structured messages.
With comparison to previous code, advantages are:
- we go through most of the steps, so for example vacuuming is performed,
- we gather and log more data. In particular for journald and pid1 crashes we
generate a backtrace, and for pid1 crashes we record the metadata (fdinfo,
maps, etc.),
- coredumpctl shows pid1 crashes.
A disavantage (inefficiency) is that we gather metadata for journald crashes
which is then ignored because _TRANSPORT=kernel does not support structued
messages.
Messages for the systemd-journald "crash" have _TRANSPORT=kernel, and
_TRANSPORT=journal for the pid1 "crash".
Feb 26 16:27:55 systemd[1]: systemd-journald.service: Main process exited, code=dumped, status=11/SEGV
Feb 26 16:27:55 systemd[1]: systemd-journald.service: Unit entered failed state.
Feb 26 16:37:54 systemd-coredump[18801]: Process 18729 (systemd-journal) of user 0 dumped core.
Feb 26 16:37:54 systemd-coredump[18801]: Coredump diverted to /var/lib/systemd/coredump/core.systemd-journal.0.36c14bf3c6ce4c38914f441038990979.18729.1488145074000000.lz4
Feb 26 16:37:54 systemd-coredump[18801]: Stack trace of thread 18729:
Feb 26 16:37:54 systemd-coredump[18801]: #0 0x00007f46d6a06b8d fsync (libpthread.so.0)
Feb 26 16:37:54 systemd-coredump[18801]: #1 0x00007f46d71bfc47 journal_file_set_online (libsystemd-shared-233.so)
Feb 26 16:37:54 systemd-coredump[18801]: #2 0x00007f46d71c1c31 journal_file_append_object (libsystemd-shared-233.so)
Feb 26 16:37:54 systemd-coredump[18801]: #3 0x00007f46d71c3405 journal_file_append_data (libsystemd-shared-233.so)
Feb 26 16:37:54 systemd-coredump[18801]: #4 0x00007f46d71c4b7c journal_file_append_entry (libsystemd-shared-233.so)
Feb 26 16:37:54 systemd-coredump[18801]: #5 0x00005577688cf056 write_to_journal (systemd-journald)
Feb 26 16:37:54 systemd-coredump[18801]: #6 0x00005577688d2e98 dispatch_message_real (systemd-journald)
Feb 26 16:37:54 kernel: systemd-coredum: 9 output lines suppressed due to ratelimiting
Feb 26 16:37:54 systemd-journald[18810]: Journal started
Feb 26 16:50:59 systemd-coredump[19229]: Due to PID 1 having crashed coredump collection will now be turned off.
Feb 26 16:51:00 systemd[1]: Caught <SEGV>, dumped core as pid 19228.
Feb 26 16:51:00 systemd[1]: Freezing execution.
Feb 26 16:51:00 systemd-coredump[19229]: Process 19228 (systemd) of user 0 dumped core.
Stack trace of thread 19228:
#0 0x00007fab82075c47 kill (libc.so.6)
#1 0x000055fdf7c38b6b crash (systemd)
#2 0x00007fab824175c0 __restore_rt (libpthread.so.0)
#3 0x00007fab82148573 epoll_wait (libc.so.6)
#4 0x00007fab8366f84a sd_event_wait (libsystemd-shared-233.so)
#5 0x00007fab836701de sd_event_run (libsystemd-shared-233.so)
#6 0x000055fdf7c4a380 manager_loop (systemd)
#7 0x000055fdf7c402c2 main (systemd)
#8 0x00007fab82060401 __libc_start_main (libc.so.6)
#9 0x000055fdf7c3818a _start (systemd)
Poor machine ;)
Unit systemd-coredump@1-3854-0.service is failed/failed, not counting it.
TIME PID UID GID SIG COREFILE EXE
Fri 2017-02-24 11:11:00 EST 10002 1000 1000 6 none /home/zbyszek/src/systemd-work/.libs/lt-Sat 2017-02-25 00:49:32 EST 26921 0 0 11 error /usr/libexec/fprintd
Sat 2017-02-25 11:56:30 EST 30703 1000 1000 - - /usr/bin/python3.5
Sat 2017-02-25 13:16:54 EST 3275 1000 1000 11 present /usr/bin/bash
Sat 2017-02-25 17:25:40 EST 4049 1000 1000 11 truncated /usr/bin/bash
For info and gdb output, the filename is marked in red and "(truncated)" is
appended. (Red is necessary because the annotation is hard to see when running
under a pager.)
Fixed#3883.
A few times I have seen the hint unexpectedly. Add this so debug info
so it's easier to see what's happening.
...
Unit systemd-coredump@0-3119-0.service is failed/failed, not counting it.
Unit systemd-coredump@1-3854-0.service is activating/start-pre, counting it.
...
-- Notice: 1 systemd-coredump@.service unit is running, output may be incomplete.
We logged about this, but did not attach information directly to the log
entry. It *would* be nice to log the full untruncated size, but afaict, to do
this, we would have to read the full data from the kernel. Doing this just to
log that information seems a bit excessive, in particular when the limit could
be set quite low. So for now let's just add a boolean field.
Most of the fields in the context array come from the kernel (passed
through argv), but two are special: comm and exe. We allocate them
ourselves. We forgot to initialize context[CONTEXT_COMM] with the value
we allocated (introduced in 9aa8202314).
To simplify things, just set context[CONTEXT_COMM] and context[CONTEXT_EXE],
and free those two fields at the end.
Fixes#5442.
Implement --since/--until (-S/-U) in the same fashion as journalctl.
This lets the user filter the results a bit so it would be easier to
find relevant info in case there were many core dumps.
Our coredump handler operates on a "context" supplied by the kernel via
the core_pattern arguments. When we pass off a coredump for processing
to coredumpd we pass along enough information for this context to be
reconstructed. This information is passed in the usual journal fields,
and that means we extended the 1s granularity timestamp to 1µs
granularity by appending 6 zeroes. We need to chop them off again when
reconstructing the original kernel context.
Fixes: #4779
(Note that we only do this for the journal metadata, not for the xattrs,
as the xattrs are only supposed to store the original 1:1 info we
acquired from the kernel.)
This adds a unified "copy_flags" parameter to all copy_xyz() function
calls, replacing the various boolean flags so far used. This should make
many invocations more readable as it is clear what behaviour is
precisely requested. This also prepares ground for adding support for
more modes later on.
$ ./coredumpctl --no-pager -1
TIME PID UID GID SIG COREFILE EXE
Sun 2016-11-06 10:10:51 EST 29514 1002 1002 - - /usr/bin/python3.5
$ ./coredumpctl info 29514
PID: 29514 (python3)
UID: 1002 (zbyszek)
GID: 1002 (zbyszek)
Reason: ZeroDivisionError
Timestamp: Sun 2016-11-06 10:10:51 EST (3h 22min ago)
Command Line: python3 systemd_coredump_exception_handler.py
Executable: /usr/bin/python3.5
Control Group: /user.slice/user-1002.slice/user@1002.service/gnome-terminal-server.service
Unit: user@1002.service
User Unit: gnome-terminal-server.service
Slice: user-1002.slice
Owner UID: 1002 (zbyszek)
Boot ID: 1531fd22ec84429e85ae888b12fadb91
Machine ID: 519a16632fbd4c71966ce9305b360c9c
Hostname: laptop
Storage: none
Message: Process 29514 (systemd_coredump_exception_handler.py) of user zbyszek failed with ZeroDivisionError: division by
Traceback (most recent call last):
File "systemd_coredump_exception_handler.py", line 134, in <module>
g()
File "systemd_coredump_exception_handler.py", line 133, in g
f()
File "systemd_coredump_exception_handler.py", line 131, in f
div0 = 1 / 0
ZeroDivisionError: division by zero
Local variables in innermost frame:
a=3
h=<function f at 0x7efdc14b6ea0>
Embedding sd_id128_t's in constant strings was rather cumbersome. We had
SD_ID128_CONST_STR which returned a const char[], but it had two problems:
- it wasn't possible to statically concatanate this array with a normal string
- gcc wasn't really able to optimize this, and generated code to perform the
"conversion" at runtime.
Because of this, even our own code in coredumpctl wasn't using
SD_ID128_CONST_STR.
Add a new macro to generate a constant string: SD_ID128_MAKE_STR.
It is not as elegant as SD_ID128_CONST_STR, because it requires a repetition
of the numbers, but in practice it is more convenient to use, and allows gcc
to generate smarter code:
$ size .libs/systemd{,-logind,-journald}{.old,}
text data bss dec hex filename
1265204 149564 4808 1419576 15a938 .libs/systemd.old
1260268 149564 4808 1414640 1595f0 .libs/systemd
246805 13852 209 260866 3fb02 .libs/systemd-logind.old
240973 13852 209 255034 3e43a .libs/systemd-logind
146839 4984 34 151857 25131 .libs/systemd-journald.old
146391 4984 34 151409 24f71 .libs/systemd-journald
It is also much easier to check if a certain binary uses a certain MESSAGE_ID:
$ strings .libs/systemd.old|grep MESSAGE_ID
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
MESSAGE_ID=%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x
$ strings .libs/systemd|grep MESSAGE_ID
MESSAGE_ID=c7a787079b354eaaa9e77b371893cd27
MESSAGE_ID=b07a249cd024414a82dd00cd181378ff
MESSAGE_ID=641257651c1b4ec9a8624d7a40a9e1e7
MESSAGE_ID=de5b426a63be47a7b6ac3eaac82e2f6f
MESSAGE_ID=d34d037fff1847e6ae669a370e694725
MESSAGE_ID=7d4958e842da4a758f6c1cdc7b36dcc5
MESSAGE_ID=1dee0369c7fc4736b7099b38ecb46ee7
MESSAGE_ID=39f53479d3a045ac8e11786248231fbf
MESSAGE_ID=be02cf6855d2428ba40df7e9d022f03d
MESSAGE_ID=7b05ebc668384222baa8881179cfda54
MESSAGE_ID=9d1aaa27d60140bd96365438aad20286
