Previously, chase_symlinks() always returned an absolute path, which
changed after 5bc244aaa9. This commit
fixes chase_symlinks() so it returns absolute paths all the time again.
This is useful when operating in the ESP, which is untrusted territory,
and where under no circumstances we should be tricked by symlinks into
doing anything we don't want to.
This should be enough to make us remember that constraint. A more heavy-weight
approach like renaming the option to CHASE_WARN_NSS_LOOKUP would be possible,
but it'd make the callers quite verbose and doesn't seem worth it.
There's little reason to require this, given that we can just say that
if a relative path is specified it is to be read relative to the root.
This fixes a bootctl bug introduced by
3730dc5d5b which didn't bother prefixing
paths as necessary.
We have free_and_replace() and friends, they are all named with lower
letters, even they are macros, not functions.
For consistency, let's rename CLOSE_AND_REPLACE() with lower letters.
This also mekes the macro used more places.
let's better be safe and use heap allocation for paths which might be
unbounded.
In particular as previously we copied the stack memory to heap anyway,
via a noop path_make_absolute_cwd() call.
Zbigniew Jędrzejewski-Szmek
Daan De Meyer
Lennart Poettering
Michal Sekletar
Yu Watanabe