Let's make sure btrfs_subvol_make() can operate on O_PATH fds, just like
mkdirat().
Fixes a bunch of tmpfiles errors at boot if we try to create btrfs
subvols, introduced by e54c79ccc2
Fixes: e54c79ccc2
Currently, we mount via file descriptors using /proc/self/fd. This
works, but it means that in /proc/mounts and various other files,
the source of the mount will be listed as /proc/self/fd/xxx. For other
software that parses these files, /proc/self/fd/xxx doesn't mean anything,
or worse, it means the completely wrong thing, as it will refer to one of
their own file descriptors instead.
Let's improve the situation by using /proc/pid/fd instead. This allows
processes parsing /proc/mounts to do the right thing more often than not.
One scenario where even this doesn't work if when containers are involved,
as with the pid namespace unshared, even /proc/pid/fd will mean the wrong
thing, but it's no worse than /proc/self/fd which will always means the wrong
thing.
This also doesn't work if we mount via file descriptor and then exit, as the pid will
be gone, but it does work as long as the process that did the mount is alive, which
makes it useful for systemd-dissect --with for example if the program we run in the
image wants to parse /proc/mounts.
This is supposed to be a help for compilers to apply optimizations on
functions where they can't determine whether they are const/pure on
their own. For static, local functions the compiler can do this on its
own easily however, hence the decoration with pure/const is just noise.
Let's drop it, and let the compiler to its thing better.
(Use it for exported functions, since compilers can't 'reach-over' into
other modules to determine if they are pure, except if LTO is used)
Add function to create openssl pkey from ECC curve and point, and function to
get curve id and x/y point from existing ECC pkey. Also add function to create
new ECC key for specified curve.
Also add DEFINE_TRIVIAL_CLEANUP_FUNC_FULL_MACRO() to handle case when func() is
a macro, not a function symbol; specifically in this case it is used for
OPENSSL_free() which is a macro.
Fixes
| ../git/src/basic/user-util.c:708:30: error: use of undeclared identifier 'LOCK_EX'; did you mean 'LOCK_BSD'?
| 708 | r = unposix_lock(fd, LOCK_EX);
| | ^~~~~~~
| | LOCK_BSD
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Private mappings are required when F_SEAL_WRITE is set on a memfd,
because otherwise you could end up with writable mappings through
mprotect() and other calls. This is a limitation of the kernel
implementation, and might be lifted by future extensions.
Regardless, the current code tests for the full `is_sealed()` before
using MAP_PRIVATE. This might end up using MAP_SHARED for write-sealed
memfds, which will be refused by the kernel.
Fix this and make memfd_map() check for exactly `F_SEAL_WRITE`.
Rather than always setting all seals, make `memfd_set_seals()` employ
the original set of seals, that is: SEAL+GROW+SHRINK+WRITE
Historically, the memfd code was used with the out-of-tree memfd
patches, which merely supported a single seal ("SEALED", which
effectively was GROW+SHRINK+WRITE). When the code was adapted to the
upstream memfd seals, it was extended to the full seal set. With more
and more seals being added upstream, this because more problematic. In
particular, it is unclear what the function really is meant to achieve.
Instead of just adding all seals, the function is returned to its
original purpose: seal the memfd so futher modifications to its content
are prevented.
With `F_SEAL_SEAL` a memfd can disable further sealing operations,
effectively sealing the set of seals. Testing for it ensures that no
further seals can be added, it never prevents seals from being dropped,
since seals cannot be dropped, ever.
Now testing for `F_SEAL_SEAL` makes sense if you want to ensure that
some seals are *not* set. That is, you either test for the entire set of
seals to match a local set, or you verify that a specific seal is not
set. Neither is what we are doing, so it feels wrong requiring it to be
set.
By dropping the requirement for `F_SEAL_SEAL`, the same FD can be shared
with other entities while retaining the ability to further restrict the
set of seals later on (e.g., being able to mark a region as executable
later on, and then adding `F_SEAL_EXEC`).
In chaseat() we call dir_fd_is_root() several places, and the final
result depends on it. If the root path specified to `chase()` is not
normalized but points to "/", e.g. "/../", assertions in `chaseat()` or
`chase()` may be triggered.
Previously, in path_is_root_at(), if statx() does not provide mount ID,
path_get_mnt_id_at() was called, but it also calls statx(). Let's avoid
the second trial.
Lennart Poettering
Daan De Meyer
Yu Watanabe
Sam James
Mike Yuan
Luca Boccassi
Xiaotian Wu
Dan Streetman
OMOJOLA JOSHUA
Khem Raj
David Rheinsberg