We now support these mount flags:
* MS_NODEV: disallow opening any devices from this file system
* MS_NOEXEC: disallow executing any executables from this file system
* MS_NOSUID: ignore set-user-id bits on executables from this file system
The fourth flag, MS_BIND, is defined, but currently ignored.
O_EXEC is mentioned by POSIX, so let's have it. Currently, it is only used
inside the kernel to ensure the process has the right permissions when opening
an executable.
At the moment, the actual flags are ignored, but we correctly propagate them all
the way from the original mount() syscall to each custody that resides on the
mounted FS.
No need to pass around RefPtr<>s and NonnullRefPtr<>s and no need to
heap-allocate them.
Also remove VFS::mount(NonnullRefPtr<FS>&&, StringView path) - it has been
unused for a long time.
We're gonna need to handle overflow better than this, but at least this
way we can see the top of the menu, even if we can't scroll down to see
the rest of it.
For #1043.
This is probably not the final design we'll want for this, but for now
let's run the HTTP client code as a separate user to reduce exposure
for the standard "anon" user account.
Note that "protocol" is also added to the "lookup" group, in order to
allow ProtocolServer to contact LookupServer for DNS requests.
Other implementations of pthread_setname_np() do not take the name
length as an argument.
For pthread_getname_np(), other implementations take the buffer size
as a size_t.
This patch brings us in line with other implementations.
While I was updating syscalls to stop passing null-terminated strings,
I added some helpful struct types:
- StringArgument { const char*; size_t; }
- ImmutableBuffer<Data, Size> { const Data*; Size; }
- MutableBuffer<Data, Size> { Data*; Size; }
The Process class has some convenience functions for validating and
optionally extracting the contents from these structs:
- get_syscall_path_argument(StringArgument)
- validate_and_copy_string_from_user(StringArgument)
- validate(ImmutableBuffer)
- validate(MutableBuffer)
There's still so much code around this and I'm wondering if we should
generate most of it instead. Possible nice little project.
In order to preserve the absolute path of the process root, we save the
custody used by chroot() before stripping it to become the new "/".
There's probably a better way to do this.
The chroot() syscall now allows the superuser to isolate a process into
a specific subtree of the filesystem. This is not strictly permanent,
as it is also possible for a superuser to break *out* of a chroot, but
it is a useful mechanism for isolating unprivileged processes.
The VFS now uses the current process's root_directory() as the root for
path resolution purposes. The root directory is stored as an uncached
Custody in the Process object.
Note that I'm developing some helper types in the Syscall namespace as
I go here. Once I settle on some nice types, I will convert all the
other syscalls to use them as well.
The join_thread() syscall is not supposed to be interruptible by
signals, but it was. And since the process death mechanism piggybacked
on signal interrupts, it was possible to interrupt a pthread_join() by
killing the process that was doing it, leading to confusing due to some
assumptions being made by Thread::finalize() for threads that have a
pending joiner.
This patch fixes the issue by making "interrupted by death" a distinct
block result separate from "interrupted by signal". Then we handle that
state in join_thread() and tidy things up so that thread finalization
doesn't get confused by the pending joiner being gone.
Test: Tests/Kernel/null-deref-crash-during-pthread_join.cpp
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 :^)
