Due to "historical reasons" both gcc and clang treat *all* trailing
arrays members as flexible arrays, this has an evil side effect
of inhibiting bounds checks on such members as __builtin_object_size
cannot say for sure that:
struct {
...
type foo[3];
}
has a trailing foo member of fixed size rather than unspecified.
Ideally we should use -fstrict-flex-arrays as is, but we have to
tolerate kernel uapi headers that use [0] and third party libraries
written in c89 that may use [1] like curl.
in_initrd() was really doing two things: checking if we're in the initrd, and
also verifying that the initrd is set up correctly. But this second check is
complicated, in particular it would return false for overlayfs, even with an
upper tmpfs layer. It also doesn't support the use case of having an initial
initrd with tmpfs, and then transitioning into an intermediate initrd that is
e.g. a DDI, i.e. a filesystem possibly with verity arranged as a disk image.
We don't need to check if we're in initrd in every program. Instead, concerns
are separated:
- in_initrd() just does a simple check for /etc/initrd-release.
- When doing cleanup, pid1 checks if it's on a tmpfs before starting to wipe
the old root. The only case where we want to remove the old root is when
we're on a plain tempory filesystem. With an overlay, we'd be creating
whiteout files, which is not very useful. (*)
This should resolve https://bugzilla.redhat.com/show_bug.cgi?id=2137631
which is caused by systemd refusing to treat the system as an initrd because
overlayfs is used.
(*) I think the idea of keeping the initrd fs around for shutdown is outdated.
We should just have a completely separate exitrd that is unpacked when we want
to shut down. This way, we don't waste memory at runtime, and we also don't
transition to a potentially older version of systemd. But we don't have support
for this yet.
This replaces 0fef5b0f0b.
Follow-up to c47511da7e.
```
archlinux_systemd_ci: In file included from ../build/src/dissect/dissect.c:15:
archlinux_systemd_ci: ../build/src/basic/build.h:4:10: fatal error: version.h: No such file or directory
archlinux_systemd_ci: 4 | #include "version.h"
archlinux_systemd_ci: | ^~~~~~~~~~~
archlinux_systemd_ci: compilation terminated.
```
```
archlinux_systemd_ci: In file included from ../build/src/journal/cat.c:13:
archlinux_systemd_ci: ../build/src/basic/build.h:4:10: fatal error: 'version.h' file not found
archlinux_systemd_ci: #include "version.h"
archlinux_systemd_ci: ^~~~~~~~~~~
archlinux_systemd_ci: 1 error generated.
```
```
archlinux_systemd_ci: In file included from ../build/src/sysext/sysext.c:10:
archlinux_systemd_ci: ../build/src/basic/build.h:4:10: fatal error: version.h: No such file or directory
archlinux_systemd_ci: 4 | #include "version.h"
archlinux_systemd_ci: | ^~~~~~~~~~~
archlinux_systemd_ci: compilation terminated.
archlinux_systemd_ci: FAILED: systemd-inhibit.p/src_login_inhibit.c.o
```
```
archlinux_systemd_ci: In file included from ../build/src/login/inhibit.c:12:
archlinux_systemd_ci: ../build/src/basic/build.h:4:10: fatal error: version.h: No such file or directory
archlinux_systemd_ci: 4 | #include "version.h"
archlinux_systemd_ci: | ^~~~~~~~~~~
archlinux_systemd_ci: compilation terminated.
```
...
So far recurse_dir() will call the callback whenever we enter a
directory, and then pass the struct dirent for that directory, and an fd
for the directory the dirent is part of (i.e. the parent of the
directory we call things for). For the top-level dir the function is
invoked for we will not call the callback however, because we have no
dirent for that, and not fd for the directory the top-level dir is part
of. Let's add a flag to call it anyway, and in that case pass a NULL
dirent and -1 as directory fd.
This is useful when we want to treat the top-level dir the same as any
dir further down.
This is done opt-in since the callback must be ablet to handle a NULL
dirent and a -1 directory fd.
We are not interested in the struct dirent data, hence there's no point
in passing RECURSE_DIR_ENSURE_TYPE. Let's drop it, and thus avoid some
extrac work on file systems where readdir() does not report .d_type.
Also drop RECURSE_DIR_SAME_MOUNT, because DDIs after all may contain
multiple partitions, and we mount them all together. The --list command
really should report the full set of files in an image.
In tests it's useful to be able to delete temporary directories
via a file descriptor to them, so let's add rm_rf_physical_and_close()
which gets the file descriptor path via /proc and tries to remove it
that way.
The logic of running_in_chroot() has been the same since the introduction of
this function in b4f10a5e89: if /proc is not
mounted, the function returns -ENOENT and all callers treat this as false. But
that might be the most common case of chrooted calls, esp. in all the naïve
chroots that were done with the chroot binary without additional setup.
(In particular rpm executes all scriptlets in a chroot without bothering to set
up /proc or /sys, and we have codepaths in sysusers and tmpfiles to support
running in such an environment.)
This change effectively shortcircuits various calls to udevadm, downgrades
logging in tmpfiles, and disables all verbs marked with VERB_ONLINE_ONLY in
systemctl. detect-virt -r is also affected:
$ sudo chroot /var/lib/machines/rawhide
before> systemd-detect-virt -r && echo OK
Failed to check for chroot() environment: No such file or directory
after> systemd-detect-virt -r && echo OK
OK
Back in e2857b3d87 I added this function
as static inline in order to avoid linking libmount into libshared.
Nevertheless, a dependency on libmount was added to libbasic in
9e7f941acb, and later moved to libshared
in 77c772f227. So the shenanigan with an
inline function is not useful, let's make it a normal function.
This reverts commit 1f22621ba3.
As described in the reverted commit, we don't want to get rid of the check
completely. But the check requires opting-in by setting SYSTEMD_IN_INITRD=lenient,
which is cumbersome and doesn't seem to actually happen.
https://bugzilla.redhat.com/show_bug.cgi?id=2137631 is caused by systemd refusing
to treat the system as an initrd because overlayfs is used. Let's revert this
approach and do something that doesn't require opt-in instead.
I don't think it makes sense to keep support for "SYSTEMD_IN_INITRD=lenient" or
"SYSTEMD_IN_INITRD=auto". To get "auto" behaviour, just unset the option. And
"lenient" will be reimplemented as a better check. Thus the changes to the
option interface are completely reverted.
This helps in avoiding compiling errors on musl. Definition of
IFF_LOOPBACK is the reason for including linux/if_arp.h, this however
could be obtained from net/if.h glibc header equally and makes it
portable as well.
The name "def.h" originates from before the rule of "no needless abbreviations"
was established. Let's rename the file to clarify that it contains a collection
of various semi-related constants.
