Unfortunately, pkill doesn't distinguish between kernel and user space
processes, so we need to make sure we don't accidentally kill kernel
threads.
Normally, a kernel thread ignores all signals, but there are a few that
do. A quick grep on the kernel source tree (as of kernel 4.6.0) shows
the following source files which use allow_signal():
drivers/isdn/mISDN/l1oip_core.c
drivers/md/md.c
drivers/misc/mic/cosm/cosm_scif_server.c
drivers/misc/mic/cosm_client/cosm_scif_client.c
drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
drivers/staging/rtl8188eu/core/rtw_cmd.c
drivers/staging/rtl8712/rtl8712_cmd.c
drivers/target/iscsi/iscsi_target.c
drivers/target/iscsi/iscsi_target_login.c
drivers/target/iscsi/iscsi_target_nego.c
drivers/usb/atm/usbatm.c
drivers/usb/gadget/function/f_mass_storage.c
fs/jffs2/background.c
fs/lockd/clntlock.c
fs/lockd/svc.c
fs/nfs/nfs4state.c
fs/nfsd/nfssvc.c
While not all of these are necessarily kthreads and some functionality
may still be unimpeded, it's still quite harmful and can cause
unexpected side-effects, especially because some of these kthreads are
storage-related (which we obviously don't want to kill during bootup).
During discussion at #15226, @dezgeg suggested the following
implementation:
for pid in $(pgrep -v -f '@'); do
if [ "$(cat /proc/$pid/cmdline)" != "" ]; then
kill -9 "$pid"
fi
done
This has a few downsides:
* User space processes which use an empty string in their command line
won't be killed.
* It results in errors during bootup because some shell-related
processes are already terminated (maybe it's pgrep itself, haven't
checked).
* The @ is searched within the full command line, not just at the
beginning of the string. Of course, we already had this until now, so
it's not a problem of his implementation.
I posted an alternative implementation which doesn't suffer from the
first point, but even that one wasn't sufficient:
for pid in $(pgrep -v -f '^@'); do
readlink "/proc/$pid/exe" &> /dev/null || continue
echo "$pid"
done | xargs kill -9
This one spawns a subshell, which would be included in the processes to
kill and actually kills itself during the process.
So what we have now is even checking whether the shell process itself is
in the list to kill and avoids killing it just to be sure.
Also, we don't spawn a subshell anymore and use /proc/$pid/exe to
distinguish between user space and kernel processes like in the comments
of the following StackOverflow answer:
http://stackoverflow.com/a/12231039
We don't need to take care of terminating processes, because what we
actually want IS to terminate the processes.
The only point where this (and any previous) approach falls short if we
have processes that act like fork bombs, because they might spawn
additional processes between the pgrep and the killing. We can only
address this with process/control groups and this still won't save us
because the root user can escape from that as well.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Fixes: #15226
A user noticed the example for `hosts`, took the `mode` permissions literally, and ended up with surprising behavior on their system. Updating the documentation to not reference a real config file which might have real permissions requirements.
Continuation of 79c3c16dcbb3b45c0f108550cb89ccd4fc855e3b. Systemd 229
sets the default RLIMIT_CORE to infinity, causing systems to be
littered with core dumps when systemd.coredump.enable is disabled.
This restores the 15.09 soft limit of 0 and hard limit of infinity.
This reverts commit 45c218f893.
Busybox's modprobe causes numerous "Unknown symbol" errors in the
kernel log, even though the modules do appear to load correctly.
Systemd 229 sets kernel.core_pattern to "|/bin/false" by default,
unless systemd-coredump is enabled. Revert back to the default of
writing "core" in the current directory.
Also add required systemd services for starting/stopping mdmon.
Closes#13447.
abbradar: fixed `mdadmShutdown` service name according to de facto conventions.
Since we don't restart sysinit.service in switch-to-configuration, this
additionally overrides systemd-binfmt.service to depend on
proc-sys-fs-binfmt_misc.automount, which is normally provided by
sysinit.service.
- Enforce that an option declaration has a "defaultText" if and only if the
type of the option derives from "package", "packageSet" or "nixpkgsConfig"
and if a "default" attribute is defined.
- Enforce that the value of the "example" attribute is wrapped with "literalExample"
if the type of the option derives from "package", "packageSet" or "nixpkgsConfig".
- Warn if a "defaultText" is defined in an option declaration if the type of
the option does not derive from "package", "packageSet" or "nixpkgsConfig".
- Warn if no "type" is defined in an option declaration.
This reverts commit b861bf8ddf, because according to @mdorman [1] this
change rendered his NixOS systems unbootable, and we probably don't want that.
[1] b861bf8ddf (commitcomment-16058598)
Allow usage of list of strings instead of a comma-separated string
for filesystem options. Deprecate the comma-separated string style
with a warning message; convert this to a hard error after 16.09.
15.09 was just released, so this provides a deprecation period during
the 16.03 release.
closes#10518
Signed-off-by: Robin Gloster <mail@glob.in>
It's not entirely clear why this happens, but sometimes /proc/1/exe
returns a bogus value, like
/ar3a3j6b9livhy5fcfv69izslhgk4gcz-systemd-217/lib/systemd/systemd. In
any case, we can just conservatively assume that we need to restart
systemd when this happens.
Fixes#10261.
Fixes references coming from the mdadm udev rules.
This addresses #12722 (mdadm udev rules have references to /usr/bin) but
still won't fix the warning, though (if we want to fix the warnings, we
will have to patch the udev rules generater in services/hardware/udev).
For common mdraid functionality, this shouldn't fix anything, because
the wrong references seem to only apply to containers, see these
(wrapped) lines from ${mdadm}/lib/udev/rules.d/63-md-raid-arrays.rules:
# Tell systemd to run mdmon for our container, if we need it.
ENV{MD_LEVEL}=="raid[1-9]*",
ENV{MD_CONTAINER}=="?*",
PROGRAM="/usr/bin/readlink $env{MD_CONTAINER}",
ENV{MD_MON_THIS}="%c"
ENV{MD_MON_THIS}=="?*",
PROGRAM="/usr/bin/basename $env{MD_MON_THIS}",
ENV{SYSTEMD_WANTS}+="mdmon@%c.service"
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Partially reverts commit 901163c0c7.
This has broken remote SSH into initrd because ${cfg.shell} is not
expanded. Also, nsswitch is useless without libnss_files.so which
are installed by initrd-ssh.
- add missing types in module definitions
- add missing 'defaultText' in module definitions
- wrap example with 'literalExample' where necessary in module definitions
Setting nixosVersion to something custom is useful for meaningful GRUB
menus and /nix/store paths, but actuallly changing it rebulids the
whole system path (because of `nixos-version` script and manual
pages). Also, changing it is not a particularly good idea because you
can then be differentitated from other NixOS users by a lot of
programs that read /etc/os-release.
This patch introduces an alternative option that does all you want
from nixosVersion, but rebuilds only the very top system level and
/etc while using your label in the names of system /nix/store paths,
GRUB and other boot loaders' menus, getty greetings and so on.
This hopefully fixes intermittent initrd failures where udevd cannot
create a Unix domain socket:
machine# running udev...
machine# error getting socket: Address family not supported by protocol
machine# error initializing udev control socket
machine# error getting socket: Address family not supported by protocol
The "unix" kernel module is supposed to be loaded automatically, and
clearly that works most of the time, but maybe there is a race
somewhere. In any case, no sane person would run a kernel without Unix
domain sockets, so we may as well make it builtin.
http://hydra.nixos.org/build/30001448
This hopefully fixes intermittent test failures like
http://hydra.nixos.org/build/29962437
router# [ 240.128835] INFO: task mke2fs:99 blocked for more than 120 seconds.
router# [ 240.130135] Not tainted 3.18.25 #1-NixOS
router# [ 240.131110] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
assuming that these are caused by high load on the host.
... because we make it built-in by default.
I can't imagine anyone who wanted to purge this module from his/her system,
so let's keep it simple, at least for now.
Previously this barfed with:
updating GRUB 2 menu...
fileparse(): need a valid pathname at /nix/store/zldbbngl0f8g5iv4rslygxwp0dbg1624-install-grub.pl line 391.
warning: error(s) occured while switching to the new configuration
The most complex problems were from dealing with switches reverted in
the meantime (gcc5, gmp6, ncurses6).
It's likely that darwin is (still) broken nontrivially.
Clearly it would be the best if we'd directly generate mount units
instead of converting /etc/fstab. But in order to do that we need to
test it throughly so this approach is for the next stable release.
This fix however is intended for inclusion into release-14.12 and
release-15.09.
Using a simple regular expression unfortunately isn't sufficient for
proper mount unit name quoting/escaping and there is a utility in
systemd called systemd-escape which does nothing less than that.
Of course, using an external program to escape the unit name is way more
expensive and causes us to fork for each mount point.
But given that we already do quite a lot of forks just for unit starting
and stopping, I think it doesn't matter that much. Well, except if you
have a whole bunch of mount points.
However, if the latter is the case and you have thousands of mount
points, you probably have stumbled over this already if your mount point
contains a dash.
As for my motivation to fix this: I've stumbled on this while trying to
fix the "none" backend test for NixOps (see NixOS/nixops#350), where the
target machines use /nix/.ro-store and /nix/.rw-store as mount points.
The implementation we had so far did improperly escape it so those mount
points got the following unit files:
* nix-.ro-store.mount
* nix-.rw-store.mount
The correct names for these units are however:
* nix-.ro\x2dstore.mount
* nix-.rw\x2dstore.mount
So using systemd-escape now properly generates these names.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
mmc_block and sdhci_acpi are both necessary for a Bay Trail Chromebook with an
internal eMMC drive. The sdhci_acpi module is detectable but I can not figure
out a way to check whether the mmc_block module is needed by just looking at
/sys/
