When systemd-firstboot (or any other unit which uses the tty) is started,
systemd will reset the terminal. If systemd-vconsole-setup happens to be
running at that time, it'll error out when it tries to use the vconsole fd and
gets an EIO from ioctl.
e019ea738d was the first fix. It added an
implicit ordering between units using the tty and systemd-vconsole-setup.
(The commit title is wrong. The approach was generalized, but the commit title
wasn't updated.)
Then cea32691c3 was added to restart
systemd-vconsole-setup.service from systemd-firstboot.service. This was OK,
with the ordering in place, systemd-vconsole-setup.service would wait until
systemd-firstboot.service exited. But this wasn't enough, because we want the
key mappings to be loaded immediately after systemd-firstboot writes the
config. 8eb668b9ab implemented that, but actually
reintroduced the original issue. I had to drop the ordering between the two
units because otherwise we'd deadlock, waiting from firstboot for
vconsole-setup which wouldn't start while firstboot was running.
Restarting vconsole-setup.service from systemd-firstboot.service works just
fine, but when vconsole-setup.service is started earlier, it may be interrupted
by systemd-firstboot.service.
To resolve the issue, let's take a lock around the tty device. The reset is
performed after fork, so the (short) delay should not matter too much.
In xopenat_lock() the assert on <path> is dropped so that we can call
xopenat(fd, NULL) to get a copy of the original fd.
Fixes#26908.
We recently codified in the coding style that for openat() style APIs,
an empty path can be passed both as the empty string and as NULL, so
let's make sure we follow that style in xopenat().
The comment makes a reference to the function fchmod_path() but this
function does not exist in the source tree.
However, the function fchmod_opath() exists; it was introduced by the
commit 4dfaa528d4.
As the comment tells, the function futimens_opath() introduced by the
commit f25bff5eaf is similar to the
function fchmod_opath(); therefore, it should reference it.
This fixes the typo in the comment by referencing the proper function
fchmod_opath().
Let's port one more over.
Note that this changes behaviour of file_in_same_dir() in some regards.
Specifically, a trailing slash of the input path will be treated
differently: previously we'd operate below that dir then, instead of the
parent. I think that makes little sense however, and I think the code
using this function doesn't expect that either.
Moroever, addresses some corner cases if the path is specified as "/" or
".", i.e. where e cannot extract a parent. These will now be treated as
error, which I think is much cleaner.
-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
The compiler should recognize that these are constant expressions, but
let's better make this explicit, so that the linker can safely share the
initializations all over the place.
The three functions for reading cwd, exe and root symlinks of processes
already share a common core: get_process_link_contents(). Let's refactor
that a bit, and move formatting of the /proc/self/ path into this helper
function instead of doing that in the caller, thus sharing more code.
While we are at it, make the return parameters optional, in case the
information if the links are readable is interesting, but the contents
is not. (This also means safe_getcwd() and readlinkat_malloc() are
updated to make the return parameter optional, as these are called by
the relevant three functions)
Same idea as 03677889f0.
No functional change intended. The type of the iterator is generally changed to
be 'const char*' instead of 'char*'. Despite the type commonly used, modifying
the string was not allowed.
I adjusted the naming of some short variables for clarity and reduced the scope
of some variable declarations in code that was being touched anyway.
This is a wrapper around openat(). It works mostly the same, except for
one thing: it race-freely reports whether we just created the indicated
file in case O_CREAT is passed without O_EXCL.
The variable is not useful outside of the loop (it'll always be null
after the loop is finished), so we can declare it inline in the loop.
This saves one variable declaration and reduces the chances that somebody
tries to use the variable outside of the loop.
For consistency, 'de' is used everywhere for the var name.
Let's define two helpers strdupa_safe() + strndupa_safe() which do the
same as their non-safe counterparts, except that they abort if called
with allocations larger than ALLOCA_MAX.
This should ensure that all our alloca() based allocations are subject
to this limit.
afaics glibc offers three alloca() based APIs: alloca() itself,
strndupa() + strdupa(). With this we have now replacements for all of
them, that take the limit into account.
These functions are used pretty much independently of locale, i.e. the
only info relevant is whether th locale is UTF-8 or not. Hence let's
give this its own pair of .c/.h files.
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
Gaël PORTAY
Lennart Poettering
Antonio Alvarez Feijoo
Yu Watanabe
Luca Boccassi