The variable is always initialized, but the compiler might not notice
that. With gcc-9.2.1-1.fc31:
$ CFLAGS='-Werror=maybe-uninitialized -Og' meson build
$ ninja -C build
[...]
../src/basic/tmpfile-util.c: In function ‘mkostemp_safe’:
../src/basic/tmpfile-util.c:76:12: error: ‘fd’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
76 | if (fd < 0)
| ^
On my machine stat returns size 22, but only 20 bytes are read:
openat(AT_FDCWD, "/sys/firmware/efi/efivars/LoaderTimeInitUSec-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f", O_RDONLY|O_NOCTTY|O_CLOEXEC) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=22, ...}) = 0
read(3, "\6\0\0\0", 4) = 4
read(3, "7\0001\0001\0003\0005\0002\0007\0\0\0", 18) = 16
Failed to read LoaderTimeInitUSec: Input/output error
Let's just accept that the kernel is returning inconsistent results.
It seems to happen two only two variables on my machine:
/sys/firmware/efi/efivars/LoaderTimeInitUSec-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f
/sys/firmware/efi/efivars/LoaderTimeMenuUSec-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f
so it might be related to the way we write them.
Let's improve memory allocation for call such as strv_extend() that just
one item to an strv: these are often called in a loop, where they used
to be very ineffecient, since we'd allocate byte-exact space. With this
change let's improve on that, by allocating exponentially by rounding up
to the next exponent of 2. This way we get GREEDY_REALLOC()-like
behaviour without passing around state.
In fact this should be good enough so that we could replace existing
loops around GREEDY_REALLOC() for strv build-up with plain strv_extend()
and get similar behaviour.
This adds a new safe_fork() flag. If set the child process' fd 1 becomes
fd 2 of the caller. This is useful for invoking tools (such as various
mkfs/fsck implementations) that output status messages to stdout, but
which we invoke and don't want to pollute stdout with their output.
This is not a new system call at all (since kernel 2.2), however it's
not exposed in glibc (a wrapper is exposed however in sigqueue(), but it
substantially simplifies the system call). Since we want a nice fallback
for sending signals on non-pidfd systems for pidfd_send_signal() let's
wrap rt_sigqueueinfo() since it takes the same siginfo_t parameter.
Reloading the SELinux label cache here enables a light-wight follow-up of a SELinux policy change, e.g. adding a label for a RuntimeDirectory.
Closes: #13363
usually we want to create new files with mode 0666 (modulated by the
umask). Sometimes we want more restrictive access though, let's add an
explicit flag support for that.
(Note that we don't bother with arbitrary access modes to keep things
simple: just "open as umask permits" and "private to me", nothing else)
This adds xfopenat() which is to fopen() what xopendirat() is to
opendir(), i.e. the "at" counterpart to fopen().
(Similar to the xopendir() case, we prefix this with "x", in case libc
gains this natively eventually.)
This makes the code do what the documentation says. The code had no inkling
about initrd.target, so I think this change is fairly risky. As a fallback,
default.target will be loaded, so initramfses which relied on current behaviour
will still work, as along as they don't have a different initrd.target.
In an initramfs created with recent dracut:
$ ls -l usr/lib/systemd/system/{default.target,initrd.target}
lrwxrwxrwx. usr/lib/systemd/system/default.target -> initrd.target
-rw-r--r--. usr/lib/systemd/system/initrd.target
So at least for dracut, there should be no difference.
Also avoid a pointless allocation.
Lennart Poettering
Yu Watanabe
Anita Zhang
Thomas Haller
Zbigniew Jędrzejewski-Szmek
Mike Gilbert
Christian Göttsche
Kevin Kuehler