Now that the necessary functions from log.h have been moved to macro.h,
we can stop including log.h in macro.h. This requires modifying source
files all over the tree to include log.h instead.
Let's return the size in a return parameter instead of the return value.
And if NULL is specified this tells us the caller doesn't care about the
size and expects a NUL terminated string. In that case look for an
embedded NUL byte, and refuse in that case.
This should lock things down a bit, as we'll systematically refuse
embedded NUL strings now when we expect strings.
Given we have the generic interface, let's hook it up everywhere.
This doesnt bother with the Reload() call usually, since that's more
involved, but hooks up the other relevant functions where applicable.
Let's drop support systems lacking memfds, i.e. pre kernel 3.17 systems.
This allows us to drastically simplify the "data fd" concept, so far
that we can remove it entirely.
This replaces acquire_data_fd() with a specialized call to
memfd_new_and_seal(), not that memfds can be the only implementation of
the concept.
The values that were previously hardcoded in sd-varlink.c are now defined
in new varlink_set_info_systemd() and that function is called everywhere
where we create a server.
This will allow units (scopes/slices/services) to override the default
systemd-oomd setting DefaultMemoryPressureDurationSec=.
The semantics of ManagedOOMMemoryPressureDurationSec= are:
- If >= 1 second, overrides DefaultMemoryPressureDurationSec= from oomd.conf
- If is empty, uses DefaultMemoryPressureDurationSec= from oomd.conf
- Ignored if ManagedOOMMemoryPressure= is not "kill"
- Disallowed if < 1 second
Note the corresponding dbus property is DefaultMemoryPressureDurationUSec
which is in microseconds. This is consistent with other time-based
dbus properties.
Parsing DefaultMemoryPressureDurationSec= is currently split between
conf parser, main() and manager_start() methods. This commit centralizes
parsing and bounds checking logic within a single custom conf parser
function.
This tries to get rid of most manual sigprocmask() changes, in favour
of:
1. The SD_EVENT_SIGNAL_PROCMASK flag to sd_event_add_signal()
2. The sd_event_set_signal_exit() call for handling SIGTERM/SIGINT
3. Move masking of SIGWINCH into ptyfwd, out of nspawn/vmspawn/run
And while we are at it get rid of a bunch of event source fields whose
lifetime is bound to the sd_event object they belong to anyway, and make
use of the "floating" event source feature of sd-event instead.
It's time. sd-json was already done earlier in this cycle, let's now
make sd-varlink public too.
This is mostly just a search/replace job of epical proportions.
I left some functions internal (mostly IDL handling), and I turned some
static inline calls into regular calls.
This is preparation for making our Varlink API a public API. Since our
Varlink API is built on top of our JSON API we need to make that public
first (it's a nice API, but JSON APIs there are already enough, this is
purely about the Varlink angle).
I made most of the json.h APIs public, and just placed them in
sd-json.h. Sometimes I wasn't so sure however, since the underlying data
structures would have to be made public too. If in doubt I didn#t risk
it, and moved the relevant API to src/libsystemd/sd-json/json-util.h
instead (without any sd_* symbol prefixes).
This is mostly a giant search/replace patch.
This means the main config file is loaded also from /run and /usr.
We should load the main config file from all the places where we load drop-ins.
I realize I had a giant blind spot: I always assumed that we load config files
from /etc, /run, /usr/local/lib, /usr/lib. But it turns out that we only used
those paths for drop-ins. For the main config file, we only looked in /etc. The
docs actually partially described this behaviour, i.e. most SYNOPSIS sections
and some parts of the text, but not others.
This is strange, because 6495361c7d was completely
bogus with the behaviour before this patch. We had a huge discussion before it
was merged, and clearly nobody noticed this. Similarly, in the previous version
of the current pull request, we had a long discussion about the appropriate
order of directories, and apparently nobody noticed that there was no order,
because only looked in one directory. So the blind spot seems to have been
shared.
Also, systemd-analyze cat-config behaved incorrectly, i.e. its behaviour matches
the new behaviour.
Possibly, in the future it'll make it easier to add support for --root.
This essentially reverts 5656cdfeea. I find it
much easier to understand what is going on when the
path-relative-to-the-search-path is passed in full, instead of being constructed
from two parts, with one of the parts being implicit in some places.
Also, we call 'systemd-analyze cat-config <path>' with <path> with the same
meaning, so this makes the internal and external APIs more consistent.
The `.mem_total` variable has `uint64_t` type, therefore, when multiplying the number
`20971512` by the number `1024` with the suffix `U`, we will not get the expected result of
`21,474,828,288`, since the number `20971512` without an explicit type indication has
`uint32_t` type.
First, multiplication will occur in accordance with the `uint32_t` type; this operation will
cause a **type overflow**, and only then will this result be assigned to a `uint64_t` type
variable.
It's worth adding the `UL` suffix to the number `20971512` to avoid **overflow**.
Found by Linux Verification Center (portal.linuxtesting.ru) with SVACE.
Author A. Slepykh.
Let's be friendly in what we accept: whenever we define a JSON
structure, let's also allow decimal strings where we want an integer.
This patch purely replaces JSON_VARIANT_UNSIGNED by
_JSON_VARIANT_TYPE_INVALID in the various JsonDispatch[] tables, so that
we'll happily accept any type in json_dispatch(), so that
json_dispatch_uint64() and related tools can do their thing.
This does not switch over OCI (as a JSON structure not defined by us).
varlink_dispatch() is a simple wrapper around json_dispatch() that
returns clean, standards-compliant InvalidParameter error back to
clients, if the specified JSON cannot be parsed properly.
For this json_dispatch() is extended to return the offending field's
name. Because it already has quite a few parameters, I then renamed
json_dispatch() to json_dispatch_full() and made json_dispatch() a
wrapper around it that passes the new argument as NULL. While doing so I
figured we should also get rid of the bad= argument in the short
wrapper, since it's only used in the OCI code.
To simplify the OCI code this adds a second wrapper oci_dispatch()
around json_dispatch_full(), that fills in bad= the way we want.
Net result: instead of one json_dispatch() call there are now:
1. json_dispatch_full() for the fully feature mother of all dispathers.
2. json_dispatch() for the simpler version that you want to use most of
the time.
3. varlink_dispatch() that generates nice Varlink errors
4. oci_dispatch() that does the OCI specific error handling
And that's all there is.
This allows distros to install configuration file templates in /usr/lib/systemd
for example.
Currently we install "empty" config files in /etc/systemd/. They serve two
purposes:
- The file contains commented-out values that show the default settings.
- It is easier to edit the right file if it is already there, the user doesn't
have to type in the path correctly, and the basic file structure is already in
place so it's easier to edit.
Things that have happened since this approach was put in place:
- We started supporting drop-ins for config files, and drop-ins are the
recommended way to create local configuration overrides.
- We have systemd-analyze cat-config which takes care of iterating over
all possible locations (/etc, /run, /usr, /usr/local) and figuring out
the right file.
- Because of the first two points, systemd-analyze cat-config is much better,
because it takes care of finding all the drop-ins and figuring out the
precedence. Looking at files manually is still possible of course, but not
very convenient.
The disadvantages of the current approach with "empty" files in /etc:
- We clutter up /etc so it's harder to see what the local configuration actually is.
- If a user edits the file, package updates will not override the file (e.g.
systemd.rpm uses %config(noreplace). This means that the "documented defaults"
will become stale over time, if the user ever edits the main config file.
Thus, I think that it's reasonable to:
- Install the main config file to /usr/lib so that it serves as reference for
syntax and option names and default values and is properly updated on package
upgrades.
- Recommend to users to always use drop-ins for configuration and
systemd-analyze cat-config to view the documentation.
This setting makes this change opt-in.
Fixes#18420.
[zjs: add more text to the description]
systemd's own cgroup hierarchy is special to us, we use it to actually
manage processes. Because of that many calls tha apply to cgroups are
only ever called with the SYSTEMD_CGROUP_CONTROLLER as controller
argument. Let's hence remove the argument altogether.
This in particular touches the kill and xattr routines.
This changes no behaviour, we just drop an argument that is always set
to the same value anyway.
This is preparation to eventually getting rid of the cgroupvs1, because
on cgroupvs2 the cgroup paths do not change for different controllers,
there's only a single hierarchy there.
If there are no "ManagedOOMSwap" entries to monitor, then the event source
can be completely disabled. This scenario appears to be common and avoiding
the wake-ups can save idle energy consumption.
This was discovered while using Sysprof for various GNOME 45 performance
tuning. systemd-oomd goes from waking up a few times a second to no
wake-ups helping keep a laptop in deep(er) sleep.
Signed-off-by: Christian Hergert <chergert@redhat.com>
When closing the FILE handle attached to a memstream, it may attempt to
do a realloc() that may fail during OOM situations, in which case we are
left with the buffer pointer pointing to NULL and buffer size > 0. For
example:
```
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
void *realloc(void *ptr, size_t size) {
return NULL;
}
int main(int argc, char *argv[])
{
FILE *f;
char *buf;
size_t sz = 0;
f = open_memstream(&buf, &sz);
if (!f)
return -ENOMEM;
fputs("Hello", f);
fflush(f);
printf("buf: 0x%lx, sz: %lu, errno: %d\n",
(unsigned long) buf, sz, errno);
fclose(f);
printf("buf: 0x%lx, sz: %lu, errno: %d\n",
(unsigned long) buf, sz, errno);
return 0;
}
```
```
$ gcc -o main main.c
$ ./main
buf: 0x74d4a0, sz: 5, errno: 0
buf: 0x0, sz: 5, errno: 0
```
This might do unexpected things if the underlying code expects a valid
pointer to the memstream buffer after closing the handle.
Found by Nallocfuzz.
Daan De Meyer
Yu Watanabe
Mike Yuan
Lennart Poettering
Sea-Eun Lee
Zbigniew Jędrzejewski-Szmek
Ryan Wilson
aslepykh
Franck Bui
Christian Hergert
Frantisek Sumsal
David Tardon