The current code assumes that FILEID_KERNFS filehandles will never grow
in size. This is not a safe assumption and userland shouldn't be trying
to guess the size of the filehandle it'll get.
We have a macro for that: MAX_HANDLE_SZ.
The payload of a file_handle structure is not 64bit aligned. So far used
_alignas_() to align it to 64bit as a whole, which by accident has the
side-effect that the payload ends up being aligned to 64bit too, but
this is ugly, because it's really just an accident...
Let's do this properly, and just use proper unaligned 64bit reads to
access the field, and do not assume aligning the structure as a whole
also aligns the payload part of it.
Follow-up for: fd51a7d8b5
On 32bit the union won't be aligned automatically, needs to be enforced:
Assertion '((uintptr_t) _p) % alignof(uint64_t) == 0' failed at src/basic/pidfd-util.c:251, function pidfd_get_inode_id_impl(). Aborting.
Follow-up for 9c039ef5ff
I'd like to introduce a libsystemd helper for acquiring pidfd
inode id, which however means the fd passed to pidfd_check_pidfs()
can no longer be trusted. Let's add back the logic of allocating
a genuine pidfd allocated internally, which was remove in
5dc9d5b4ea.
Now that the necessary functions from log.h have been moved to macro.h,
we can stop including log.h in macro.h. This requires modifying source
files all over the tree to include log.h instead.
Daan De Meyer
Yu Watanabe
Jeff Layton
Lennart Poettering
Luca Boccassi
Mike Yuan
Daan De Meyer
Jan Vaclav