We make assumptions about the comm name we set via PR_SET_NAME: that it
would reflect the process name, but that's only the case for the main
thread. Moreover, we cache the mmap() region without locking.
Let's hence be safe rather than sorry and support all this only in the
main thread.
It's a relatively small wrapper around safe_fork() now, hence let's move
it over, and make its signature even more alike. Also, set a different
process name for the polkit and askpw agents.
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.
Ultimately, O_CLOEXEC should be off in fd 0, 1, 2, but when we open
/dev/null here it's unlikely to be < 0, and after dupping the fd to 0,
1, 2 we turn off O_CLOEXEC explicitly anyway.
Unless we know that what we are about to open will return 0, 1 or 2 we
should always set O_CLOEXEC in order to be safe to other threads forking
of subprocesses at the wrong moment.
Just a minor tweak, making sure we execute as much as we can of the
funciton, but return the first error instead of the last we encounter.
This is usuelly how we do things when we have functions that continue on
the first error, so let's do it like that here too.
Let's fork off sync() ina process instead of a thread, as a safety
measure. This is beneficial to ensure that the original process can exit
without having to wait for the sync() to finish (note that the kernel
will delay process termination until all threads finished their
syscalls). In case of hanging NFS this increases the chance that PID 1
can safely transition to the "systemd-shutdown" process as the sync() is
initiated early on but definitely not waited for.
systemd creates several device nodes in /run/systemd/inaccessible/.
This makes CGroup's settings related to IO can take device node
files in the directory.
If multiple RestrictAddressFamilies= settings, some of them are
whitelist and the others are blacklist, are sent to bus, then parsing
result was corrupted.
This fixes the parse logic, now it is the same as one used in
load-fragment.c
If multiple SystemCallFilter= settings, some of them are whitelist
and the others are blacklist, are sent to bus, then the parse
result was corrupted.
This fixes the parse logic, now it is the same as one used in
load-fragment.c
Also remove the warning:
./src/shared/seccomp-util.c:1414:2: warning: #warning "Consider adding the right mmap() syscall definitions here!" [-Wcpp]
#warning "Consider adding the right mmap() syscall definitions here!"
Init rule variable iif oif and to, from
While foreign rules are added the network part is not attached.
attach manager to rules and use it in routing_policy_rule_free.
In general we'd leak anything that was allocated in the first parsing of
netdev, e.g. netdev name, host name, etc. Use normal netdev_unref to make sure
everything is freed.
--- command ---
/home/zbyszek/src/systemd/build2/test-network
--- stderr ---
/etc/systemd/network/wg0.netdev:3: Failed to parse netdev kind, ignoring: wireguard
/etc/systemd/network/wg0.netdev:5: Unknown section 'WireGuard'. Ignoring.
/etc/systemd/network/wg0.netdev:9: Unknown section 'WireGuardPeer'. Ignoring.
NetDev has no Kind configured in /etc/systemd/network/wg0.netdev. Ignoring
/etc/systemd/network/br0.network:13: Unknown lvalue 'NetDev' in section 'Network'
br0: netdev ready
=================================================================
==11666==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 4 byte(s) in 1 object(s) allocated from:
#0 0x7f3a314cf238 in __interceptor_strdup (/lib64/libasan.so.4+0x77238)
#1 0x7f3a30e71ad1 in free_and_strdup ../src/basic/string-util.c:870
#2 0x7f3a30d34fba in config_parse_ifname ../src/shared/conf-parser.c:981
#3 0x7f3a30d2f5b0 in next_assignment ../src/shared/conf-parser.c:155
#4 0x7f3a30d30303 in parse_line ../src/shared/conf-parser.c:273
#5 0x7f3a30d30dee in config_parse ../src/shared/conf-parser.c:390
#6 0x7f3a30d310a5 in config_parse_many_files ../src/shared/conf-parser.c:428
#7 0x7f3a30d3181c in config_parse_many ../src/shared/conf-parser.c:487
#8 0x55b4200f9b00 in netdev_load_one ../src/network/netdev/netdev.c:634
#9 0x55b4200fb562 in netdev_load ../src/network/netdev/netdev.c:778
#10 0x55b4200c607a in manager_load_config ../src/network/networkd-manager.c:1299
#11 0x55b4200818e0 in test_load_config ../src/network/test-network.c:128
#12 0x55b42008343b in main ../src/network/test-network.c:254
#13 0x7f3a305f8889 in __libc_start_main (/lib64/libc.so.6+0x20889)
SUMMARY: AddressSanitizer: 4 byte(s) leaked in 1 allocation(s).
-------
Quoting Lennart Poettering in
https://github.com/systemd/systemd/pull/6464#issuecomment-319029293:
> If the kernel allows us to query that data we should also be Ok with passing
> it on to our own caller, regardless if selinux is technically on or off...
The advantage is that this allows gcc to be smarter and reduce linkage:
(before)$ ldd build/libnss_systemd.so.2
linux-vdso.so.1 (0x00007ffeb46ff000)
librt.so.1 => /lib64/librt.so.1 (0x00007f2f60da6000)
libcap.so.2 => /lib64/libcap.so.2 (0x00007f2f60ba1000)
libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f2f60978000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f2f60759000)
libc.so.6 => /lib64/libc.so.6 (0x00007f2f60374000)
/lib64/ld-linux-x86-64.so.2 (0x00007f2f61294000)
libpcre2-8.so.0 => /lib64/libpcre2-8.so.0 (0x00007f2f600f0000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f2f5feec000)
(after )$ ldd build/libnss_systemd.so.2
linux-vdso.so.1 (0x00007ffe5f543000)
librt.so.1 => /lib64/librt.so.1 (0x00007f427dcaa000)
libcap.so.2 => /lib64/libcap.so.2 (0x00007f427daa5000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f427d886000)
libc.so.6 => /lib64/libc.so.6 (0x00007f427d4a1000)
/lib64/ld-linux-x86-64.so.2 (0x00007f427e196000)
Note that this only works in conjuction with the previous commit: either
of the two commits alone does not have the desired effect on linkage.
Replaces #6464.
