This new view, backed by a GColumnsView, joins the existing table and icon
views :^) Even though it displays a file tree, its data is provided by the very
same GFileSystemModel that the other two views use.
This commit also includes my attempt at making an icon for the new mode.
This is a shiny new widget that can display a tree using Miller columns ^:)
In many cases, the columns view can be used as an alternative to tree view,
but it has its own set of limitations:
* It can only display one model column (so it cannot replace a table)
* It takes up a lot of horizontal space, so it's only suitable if the item text
is fairly short
* It can only display one subtree at a time
But as long as a usecase doesn't suffer from these limitations, a columns view
can be *much* more intuitive than a tree view.
We used to have two different models for displaying file system contents:
the FileManager-grade table-like directory model, which exposed rich data
(such as file icons with integrated image previews) about contents of a
single directory, and the tree-like GFileSystemModel, which only exposed
a tree of file names with very basic info about them.
This commit unifies the two. The new GFileSystemModel can be used both as a
tree-like and as a table-like model, or in fact in both ways simultaneously.
It exposes rich data about a file system subtree rooted at the given root.
The users of the two previous models are all ported to use this new model.
As Sergey pointed out, it's silly to have proper entries for . and ..
in TmpFS when we can just synthesize them on the fly.
Note that we have to tolerate removal of . and .. via remove_child()
to keep VFS::rmdir() happy.
The userspace execve() wrapper now measures all the strings and puts
them in a neat and tidy structure on the stack.
This way we know exactly how much to copy in the kernel, and we don't
have to use the SMAP-violating validate_read_str(). :^)
When loading a new executable, we now map the ELF image in kernel-only
memory and parse it there. Then we use copy_to_user() when initializing
writable regions with data from the executable.
Note that the exec() syscall still disables SMAP protection and will
require additional work. This patch only affects kernel-originated
process spawns.
LookupServer now runs as lookup:lookup, allowing connections from other
members of the "lookup" group.
This is enforced through file system permissions by having the service
socket (/tmp/portal/lookup) be mode 0660.
Now the LookupServer program can't overwrite other people's files if it
starts misbehaving. That's pretty cool :^)
This fixes a null RefPtr deref (which asserts) in the scheduler if a
file descriptor being select()'ed is closed by a second thread while
blocked in select().
Test: Kernel/null-deref-close-during-select.cpp
Since ELFDynamicObject needs the actual virtual address of the .dynamic
section in the loaded image, and not the file offset like we assumed
before, due to MAP_PRIVATE secretly giving us a MAP_SHARED, we can
remove all of the Dynamic* code from ELFImage.
ELFDynamicLoader only needs ELFImage to get the Program headers at this
point. More consolidation opportunities seem likely in the future.
We need to workaround the fact that MAP_PRIVATE when passed a file
descriptor doesn't work the way we expect. We can't change the
permissions on our mmap to PROT_WRITE if the original executable doesn't
have PROT_WRITE.
Because of this, we need to construct our ELFDynamicObject using the
actual virtual address of the .dynamic section, instead of using the
offset into the ELFImage that was actually getting modified by accident
...somehow. Not clear what was going on.
Make mmap return -ENOTSUP in this case to make sure users don't get
confused and think they're using a private mapping when it's actually
shared. It's currenlty not possible to open a file and mmap it
MAP_PRIVATE, and change the perms of the private mapping to ones that
don't match the permissions of the underlying file.
We were not recomputing the internal dimensions after a font changed,
which caused things to look very off.
It's still not perfect as we're always using the same (small) font for
bold text, which obviously sticks out like a sore pinky when the rest
of the terminal text is large.
