On musl, O_ACCMODE is defined as (03|O_SEARCH), unlike glibc which
defines it as (O_RDONLY|O_WRONLY|O_RDWR). Additionally, O_SEARCH is
simply defined as O_PATH.
This causes problems for systemd on musl, as it changes the
behaviour of open_mkdir_at_full() to return -EINVAL if O_PATH is
included in flags due to the fact that O_ACCMODE includes O_SEARCH
(i.e. O_PATH). Consequently, this makes the test-fs-util test fail.
Upstream musl seems content with this behaviour and doesn't seem
interested in matching glibc's behaviour due to that defining it this
way allows for O_SEARCH to match POSIX better by allowing it to open
directories where read permission is missing. Apparently musl does some
emulation in other places to make this work more consistently as well.
Initially I took the approach of working around this by redefining
O_SEARCH as O_RDONLY if O_SEARCH == O_PATH. This fixes the test and is
the approach taken by both XZ[1] and Gzip[2][3], but was not taken as
redefining system headers potentially could be problematic.
Instead, introduce O_ACCMODE_STRICT which just is a copy of glibc's
O_ACCMODE and use it everywhere. This way we don't have to deal with
unusual definitions of O_ACCMODE from C standard libraries other than
glibc.
[1]: https://git.tukaani.org/?p=xz.git;a=blob;f=src/xz/file_io.c;h=8c83269b13fa31284f7ea5f3627a1dfbce7d6e14;hb=HEAD#l72
[2]: https://git.savannah.gnu.org/cgit/gnulib.git/tree/lib/fcntl.in.h
(lines 380 and 396, commit d7f551b30f3f2a0fa57c1b10c12f4eea41a9b89e)
[3]: https://lists.gnu.org/archive/html/bug-gzip/2025-01/msg00000.html
getxattr_at_malloc() calls getxattr_pinned_internal() with size 0 to get
the size of the xattr, and then asserts because n > 0
```
Assertion '(size_t) n <= size' failed at src/basic/xattr-util.c:107, function getxattr_pinned_internal().
```
Follow-up for b8df25dcfe
Follow-up for b58c240312
We need to be extremely careful with using the path associated with fd,
since it contains the resolved path if a symlink was opened. In particular,
it's really not desirable to return the resolved executable path in
pin_callout_binary(), which would end up as argv[0] in udev_event_spawn(),
potentially changing the behavior of spawned process.
If we cannot find the callout we need in the build dir let's look for it
in $PATH as last resort.
This makes invoke_callout_binary() usable for all binaries we install
into $PATH (as opposed to /usr/lib/systemd), but has no effect
on callout binaries specified with full path.
This is useful, since we soon want to invoke journalctl as a callout.
Follow-up for ed024abac6
and 9fbe26cfa8
Also, let's not get too tangled up in the style of defining variables
in between. The functions are short enough, and vars involved are still
effectively at the beginning... Put differently, the separation from
'int r' is too deliberate and brings no actual value in my eyes.
If we have multiple trusted fs (i.e. luks or dm-verity) we generate via
repart at boot, we must make sure they cannot be "misappropriated", i.e.
used for a different mount they were intended for.
Hence, let's introduce "mount constraint" data (encoded in xattrs on the
root inode of the fs) that tells us where a file system has to be
mounted, and what the gpt partition metadata has to be for the fs to be
valid.
Inspired by this thread:
https://lists.freedesktop.org/archives/systemd-devel/2025-March/051244.html
- SO_PEERGROUPS is since kernel v4.13
(28b5ba2aa0f55d80adb2624564ed2b170c19519e),
- SO_BINDTOIFINDEX is since kernel v5.1
(f5dd3d0c9638a9d9a02b5964c4ad636f06cf7e2c).
Let's turn on validatefs automatically for all auto-discovered
partitions.
Let's add an x-systemd.validatefs option to optionally turn this on for
fstab listed file systems.
strv_skip was written to carefully return the original array, but this turns
out to be an unnecessary complication. After the previous patch, no caller
cares about the distinction between NULL and { NULL }, but various callers need
to wrap the process the returned value with strv_isempty(), sometimes more than
once. Let's always return NULL for an empty result to allow callers to be
simplified.
Yu Watanabe
Stefan Hansson
Luca Boccassi
Busayo Dada
Michal Sekletar
Daan De Meyer
Mike Yuan
Lennart Poettering
Zbigniew Jędrzejewski-Szmek