Fixup for d2ebd50d7f
and 6920049fad:
- add a comment that the last arg must be NULL and adjust the assert.
- move initialization around so that fields are declared,
initialized, and consumed in the same order.
- move declaration of pos adjacent do declaration of command_line.
This makes it easy to see that it was not initialized correctly.
- initialize buffers before writing the pointer into the args array.
This makes no difference for the compiler, but it just feels "wrong"
to do it in opposite order.
Because pos was off, we would ignore args after the timeout, and also
overwrite the buffer if enough args were used.
I think this is case shows clearly that declaring all variables at the
top of the function, with some initialized and other not, is very
error-prone. The compiler has no issue with declaring variables whereever,
and we should take advantage of this to make it keep declaration,
initialization, and use close. (Within reason of course.)
This is a little helper I used when preparing the tests for auxv
parsing. Just looking at hexdump output is pretty hard. We could
enhance it to display some specific data types better.
Chasing symlinks is a core function that's used in a lot of places
so it deservers a less verbose names so let's rename it to chase()
and chaseat().
We also slightly change the pattern used for the chaseat() helpers
so we get chase_and_openat() and similar.
This is a combination of fdopen() and fd_reopen(). i.e. it first reopens
the fd, and then converts that into a FILE*.
We do this at various places already manually. let's move this into a
helper call of its own.
The test files are /proc//auxv files copies from various architecutres
signified by the file name suffix.
Those tests are fairly simple, but when we run them on n architectures, we do
~n² cross-arch tests.
No functional change. (We already checked for ELFCLASS32 or ELFCLASS64 before,
so even though there's a new check for other architectures, the only caller
only passes ELFCLASS32 or ELFCLASS64.)
On top of taking a directory file descriptor, we use xopenat() so
that the function can also be used to work on existing file
descriptors to image files including all the logic to use O_DIRECT
and fallback to O_RDONLY if needed.
btrfs_get_block_device_fd() returns -ENOTTY if fstatfs().f_type !=
BTRFS_SUPER_MAGIC
btrfs_get_block_device_fd() is run by verify_fsroot_dir() by
verify_xbootldr() by find_xbootldr_and_warn() if
statx($presumed-XBOOTLDR).stx_dev_major == 0 ("maybe a btrfs device")
Every bootctl verb_install() runs find_xbootldr_and_warn(), by default
with /boot
If your /boot .stx_dev_major=0 but /not/ btrfs, bootctl install/update
quietly exits 1 with no note so as to what exactly failed (debug also
empty, and the strace isn't exactly clear since no syscall actually
failed)
This is the case on ZFS and the Debian filesystem layout: /boot/efi is
the ESP, and everything else under / is ZFS:
$ sudo env SYSTEMD_LOG_LEVEL=debug bootctl update
Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy
Found container virtualization none.
File system "/boot" is not a FAT EFI System Partition (ESP) file system.
Using EFI System Partition at /boot/efi.
Checking whether /boot/efi/EFI/systemd/ contains any files…
$ echo $?
1
and funnier still:
$ sudo bootctl update --graceful
$ echo $?
1
Which is great, and also breaks postinst, which runs precisely the
latter, with no feedback at all
By checking for -ENOTTY we accept that the path being investigated
"is not it" if it's on ZFS (and any other filesystem that returns
.stx_dev_major == 0 but isn't btrfs)