Consider the situation where two shared libraries libA and libB, both
depending (as in having a NEEDED dtag) on libC. libA is first
dlopen()-ed, which produces libC to be mapped and linked. When libB is
dlopen()-ed the DynamicLinker would re-map and re-link libC though,
causing any previous references to its old location to be invalid. And
if libA's PLT has been patched to point to libC's symbols, then any
further invocations to libA will cause the code to jump to a virtual
address that isn't mapped anymore, therefore causing a crash. This
situation was reported in #10014, although the setup was more convolved
in the ticket.
This commit fixes the issue by distinguishing between a main program
loading being performed by Loader.so, and a dlopen() call. The main
difference between these two cases is that in the former the
s_globals_objects maps is always empty, while in the latter it might
already contain dependencies for the library being dlopen()-ed. Hence,
when collecting dependencies to map and link, dlopen() should skip those
that are present in the global map to avoid the issue described above.
With this patch the original issue seen in #10014 is gone, with all
python3 modules (so far) loading correctly.
A unit test reproducing a simplified issue is also included in this
commit. The unit test includes the building of two dynamic libraries A
and B with both depending on libline.so (and B also depending on A); the
test then dlopen()s libA, invokes one its function, then does the same
with libB.
Generate a sorted, compressed series of ranges in a match table for
character classes, and use a binary search to find the matches.
This is about a 3-4x speedup for character class match performance. :^)
The callback should be called as soon as the connection is established,
and if we actually set the callback when it already is, we expect it to
be called immediately.
See #10042 for details. In short: qemu doesn't seem to implement that
feature, therefore the test correctly fails. However, that does not help
us, so we skip that test.
This makes it so we don't need to specify the full path to all the
helper scripts we include() from different places in the codebase and
feels a lot cleaner.
DisjointChunks<T> provides a nice interface over multiple sequential
Vector<T>'s, allowing the user to iterate over/index into/slice from
said buffers as if they were a single contiguous buffer.
To work with views on such objects, DisjointSpans<T> is provided, which
has the same behaviour but does not own the underlying objects.
This removes the awkward String::replace API which was the only String
API which mutated the String and replaces it with a new immutable
version that returns a new String with the replacements applied. This
also fixes a couple of UAFs that were caused by the use of this API.
As an optimization an equivalent StringView::replace API was also added
to remove an unnecessary String allocations in the format of:
`String { view }.replace(...);`
Command used:
grep -Pirn '(out|warn)ln\((?!["\)]|format,|stderr,|stdout,|output, ")' \
AK Kernel/ Tests/ Userland/
(Plus some manual reviewing.)
Let's pick ArgsParser as an example:
outln(file, m_general_help);
This will fail at runtime if the general help happens to contain braces.
Even if this transformation turns out to be unnecessary in a place or
two, this way the code is "more obviously" correct.
Commit 890c647e0f fixed an off-by-one bug, so the mapping of the page
at the very end of the user address space now works correctly.
This change adjusts the test so cover the corner cases the original
version was designed too.validate.
