Commit graph

1763 commits

Author SHA1 Message Date
Andreas Kling
ef32c71683 Kernel: Have modules export their name in a "module_name" string
This will show up in /proc/modules, and is also the name you can pass
to the module_unload() syscall for unloading the module.
2019-11-29 21:31:17 +01:00
Andreas Kling
3ad0e6e198 Kernel: Show module memory size in /proc/modules
Note that this only shows the size of the loaded module sections,
and does not include any memory allocated *by* the module.
2019-11-29 21:18:37 +01:00
Andreas Kling
e56daf547c Kernel: Disallow syscalls from writeable memory
Processes will now crash with SIGSEGV if they attempt making a syscall
from PROT_WRITE memory.

This neat idea comes from OpenBSD. :^)
2019-11-29 16:30:05 +01:00
Andreas Kling
f75a6b9daa Kernel: Demangle kernel C++ symbols correctly again
I broke this while implementing module linking. Also move the actual
demangling work to AK, in AK::demangle(const char*)
2019-11-29 14:59:15 +01:00
Andreas Kling
4ef6be8212 Kernel: Allow modules to link against anything in kernel.map :^)
We now use the symbols from kernel.map to link modules as they are
loaded into the kernel. This is pretty fricken cool!
2019-11-28 21:30:20 +01:00
Andreas Kling
1f67894bdd Kernel: Add /proc/modules to enumerate the currently loaded modules 2019-11-28 21:12:02 +01:00
Andreas Kling
a43b115a6c Kernel: Implement basic module unloading :^)
Kernel modules can now be unloaded via a syscall. They get a chance to
run some code of course. Before deallocating them, we call their
"module_fini" symbol.
2019-11-28 21:07:22 +01:00
Andreas Kling
6b150c794a Kernel: Implement very simple kernel module loading
It's now possible to load a .o file into the kernel via a syscall.
The kernel will perform all the necessary ELF relocations, and then
call the "module_init" symbol in the loaded module.
2019-11-28 20:59:11 +01:00
Andreas Kling
75ed262fe5 Kernel+ifconfig: Add an MTU value to NetworkAdapter
This defaults to 1500 for all adapters, but LoopbackAdapter increases
it to 65536 on construction.

If an IPv4 packet is larger than the MTU, we'll need to break it into
smaller fragments before transmitting it. This part is a FIXME. :^)
2019-11-28 14:14:26 +01:00
Andreas Kling
23a2e84873 Kernel: listen() should fail with EINVAL for already-connected sockets
This according to POSIX.
2019-11-27 16:01:22 +01:00
Andreas Kling
66a9c233be Kernel: Remove Process::state(), everyone should use Thread::state() 2019-11-27 15:31:50 +01:00
Andreas Kling
bd86ebbcc0 Kernel: Remove outdated FIXME about EINTR in select()
This is actually already implemented. :^)
2019-11-27 15:31:23 +01:00
Andreas Kling
0adbacf59e Kernel: Demangle userspace ELF symbols in backtraces
Turns out we can use abi::__cxa_demangle() for this, and all we need to
provide is sprintf(), realloc() and free(), so this patch exposes them.

We now have fully demangled C++ backtraces :^)
2019-11-27 14:06:24 +01:00
Andreas Kling
2d1bcce34a Kernel: Fix triple-fault when clicking on SystemServer in SystemMonitor
The fault was happening when retrieving a current backtrace for the
SystemServer process.

To generate a backtrace, we go into the paging scope of the process,
meaning we temporarily switch to using its page directory as our own.

Because kernel VM is allocated on demand, it's possible for a process's
mappings above the 3GB mark to be out-of-date. Normally this just gets
fixed up transparently by the page fault handler (which simply copies
the PDE from the canonical MM.kernel_page_directory() into the current
process.)

However, if the current kernel *stack* is in a piece of memory that
the backtraced process lacks up-to-date PDE's for, we still get a page
fault, but are unable to handle it, since the CPU wants to push to the
stack as part of calling the page fault handler. So we're screwed and
it's a triple-fault.

Fix this by always updating the kernel VM mappings before switching
into a paging scope. In practical terms, this is a 1KB memcpy() that
happens when generating a backtrace, or doing exec().
2019-11-27 12:40:42 +01:00
Andreas Kling
5b8cf2ee23 Kernel: Make syscall counters and page fault counters per-thread
Now that we show individual threads in SystemMonitor and "top",
it's also very nice to have individual counters for the threads. :^)
2019-11-26 21:37:38 +01:00
Andreas Kling
712ae73581 Kernel: Expose per-thread information in /proc/all
Previously it was not possible to see what each thread in a process was
up to, or how much CPU it was consuming. This patch fixes that.

SystemMonitor and "top" now show threads instead of just processes.
"ps" is gonna need some more fixing, but it at least builds for now.

Fixes #66.
2019-11-26 21:37:30 +01:00
Andreas Kling
86a9a52355 Kernel: Process::for_each_thread() should show the main thread of PID 0 2019-11-26 21:25:11 +01:00
Sergey Bugaev
8aef0a0755 Kernel: Handle fstat() on sockets 2019-11-26 19:58:25 +01:00
Andreas Kling
67d2875d60 Build: Bump the default disk image size from 500MB to 600MB
This gives us a little more leeway for installing ports, etc.
2019-11-26 12:54:33 +01:00
Hüseyin ASLITÜRK
794ca16cca Kernel: Implement the setkeymap() syscall. 2019-11-25 11:53:02 +01:00
Andreas Kling
f2d1e591b6 Demos: Remove "RetroFetch"
We should just get good enough to run "neofetch" or something like that
instead of having this half-baked thing.
2019-11-25 00:07:00 +01:00
Andreas Kling
3dc87be891 Kernel: Mark mmap()-created regions with a special bit
Then only allow regions with that bit to be manipulated via munmap()
and mprotect(). This prevents messing with non-mmap()ed regions in
a process's address space (stacks, shared buffers, ...)
2019-11-24 12:26:21 +01:00
Andreas Kling
fd4349a9f2 ProtocolServer+LibProtocol: Introduce a server for handling downloads
This patch adds ProtocolServer, a server that handles network requests
on behalf of its clients. The first protocol implemented is HTTP.

The idea here is to use a plug-in architecture where any number of
protocols can be added and implemented without having to mess around
with each client program that wants to use the protocol.

A simple client API is provided through LibProtocol::Client. :^)
2019-11-23 21:50:32 +01:00
Andreas Kling
61f611bf3c IPv4: Protect the list of unacked TCP packets with a lock
Otherwise things get racy and crashy.
2019-11-23 21:44:47 +01:00
Andreas Kling
5d8324f133 Applications: Remove unused/unfinished "Downloader" program 2019-11-23 19:26:57 +01:00
Andreas Kling
9a157b5e81 Revert "Kernel: Move Kernel mapping to 0xc0000000"
This reverts commit bd33c66273.

This broke the network card drivers, since they depended on kmalloc
addresses being identity-mapped.
2019-11-23 17:27:09 +01:00
Jesse Buhagiar
bd33c66273 Kernel: Move Kernel mapping to 0xc0000000
The kernel is now no longer identity mapped to the bottom 8MiB of
memory, and is now mapped at the higher address of `0xc0000000`.

The lower ~1MiB of memory (from GRUB's mmap), however is still
identity mapped to provide an easy way for the kernel to get
physical pages for things such as DMA etc. These could later be
mapped to the higher address too, as I'm not too sure how to
go about doing this elegantly without a lot of address subtractions.
2019-11-22 16:23:23 +01:00
Drew Stratford
ee0eed26f4 Ext2FileSystem: set_metadata_dirty(true) during write_directory().
This adds a call to set_metadata_dirty(true) to
Ext2FS::write_directory(). This fixes a bug wherein InodeWatchers
weren't alerted on directory updates.
2019-11-21 13:04:38 +01:00
Andreas Kling
554f28901b Kernel: Build with -fno-asynchronous-unwind-tables
We'll never use exceptions in the kernel, so there's no need for unwind
tables and we can save ourselves some space.
2019-11-21 12:47:49 +01:00
Sergey Bugaev
16b9b3f228 Kernel: Don't interrupt short writes
Remove explicit checking for pending signals from writing code paths,
since this is handled automatically when blocking, and should not
happen if the write() call is "short", i.e. doesn't block. All the
other syscalls already work like this.

Fixes https://github.com/SerenityOS/serenity/issues/797
2019-11-19 14:07:24 +01:00
Andreas Kling
0e9e70ca4f IPv4: Disconnected non-blocking sockets were not signalling EOF
After a socket has disconnected, we shouldn't return -EAGAIN. Instead
we should allow userspace to read/recvfrom the socket until its packet
queue has been exhausted.

At that point, we now return 0, signalling EOF.

It might be even better to start returning -ENOTCONN after signalling
EOF once. I'm not sure how that should work, needs looking into.
2019-11-18 17:37:54 +01:00
Andreas Kling
b0f38c1733 Build: Oops, typo in the path to LibHTML code generators in makeall.sh
This worked locally because I already had the built generators lying
around, but failed for other people who hadn't built them yet. Oops!
2019-11-18 16:45:14 +01:00
Andreas Kling
da23864c8d LibHTML: Let's just build host-side tools in makeall.sh instead
Instead of trying to build the host-side code generator helpers right
before we need them in the LibHTML build process, just build them ahead
of time in makeall.sh, like we already do for {IPC,Form}Compiler.
2019-11-18 16:30:18 +01:00
Andreas Kling
c23addd1fb Kernel: When userspaces calls a removed syscall, fail with ENOSYS
This is a bit gentler than jumping to 0x0, which always crashes the
whole process. Also log a debug message about what happened, and let
the user know that it's probably time to rebuild the program.
2019-11-18 12:35:14 +01:00
Andrew Kaster
618aebdd8a Kernel+LibPthread: pthread_create handles pthread_attr_t
Add an initial implementation of pthread attributes for:
  * detach state (joinable, detached)
  * schedule params (just priority)
  * guard page size (as skeleton) (requires kernel support maybe?)
  * stack size and user-provided stack location (4 or 8 MB only, must be aligned)

Add some tests too, to the thread test program.

Also, LibC: Move pthread declarations to sys/types.h, where they belong.
2019-11-18 09:04:32 +01:00
Andreas Kling
3da6d89d1f Kernel+LibC: Remove the isatty() syscall
This can be implemented entirely in userspace by calling tcgetattr().
To avoid screwing up the syscall indexes, this patch also adds a
mechanism for removing a syscall without shifting the index of other
syscalls.

Note that ports will still have to be rebuilt after this change,
as their LibC code will try to make the isatty() syscall on startup.
2019-11-17 20:03:42 +01:00
Andreas Kling
3093b019d0 Kernel: Let's have sys$uname() report "i686" instead of "i386"
We wouldn't be able to run on an 80386 without considerable changes,
so let's be honest here and call it i686.
2019-11-17 19:39:12 +01:00
Andreas Kling
8ccbd7002b Ext2FS: Rename allocate_inode() => find_a_free_inode()
Since this function doesn't actually mark the inode as allocated,
let's tone down the name a little bit.
2019-11-17 19:19:02 +01:00
Andreas Kling
a712d4ac0c Ext2FS: Writing to a slow symlink should not treat it like a fast one
We would misinterpret short writes to the first 60 bytes of a slow
symlink as writes to a fast symlink.
2019-11-17 19:19:00 +01:00
Andreas Kling
5d08665d9a Ext2FS: Remove unnecessary extra cache lookup in get_inode() 2019-11-17 19:11:19 +01:00
Andreas Kling
ba997c0a72 Ext2FS: Add some FIXME's while browsing this code 2019-11-17 18:59:14 +01:00
Andreas Kling
b2df670cf5 Kernel: Just hang if VFS::mount_root() fails 2019-11-17 18:58:25 +01:00
Andreas Kling
e34ed04d1e Kernel+LibPthread+LibC: Create secondary thread stacks in userspace
Have pthread_create() allocate a stack and passing it to the kernel
instead of this work happening in the kernel. The more of this we can
do in userspace, the better.

This patch also unexposes the raw create_thread() and exit_thread()
syscalls since they are now only used by LibPthread anyway.
2019-11-17 17:29:20 +01:00
Andreas Kling
02f89dc419 Kernel+SystemMonitor: Show VM region "shared" and "stack" bits in UI
Expose these two region bits through /proc/PID/vm and show them in the
SystemMonitor process memory map view.
2019-11-17 12:15:46 +01:00
Andreas Kling
794758df3a Kernel: Implement some basic stack pointer validation
VM regions can now be marked as stack regions, which is then validated
on syscall, and on page fault.

If a thread is caught with its stack pointer pointing into anything
that's *not* a Region with its stack bit set, we'll crash the whole
process with SIGSTKFLT.

Userspace must now allocate custom stacks by using mmap() with the new
MAP_STACK flag. This mechanism was first introduced in OpenBSD, and now
we have it too, yay! :^)
2019-11-17 12:15:43 +01:00
Andreas Kling
8d4d63d9b6 Ext2FS: Minor cleanup, remove an unused function 2019-11-16 17:29:09 +01:00
Andreas Kling
73d6a69b3f Kernel: Release the big process lock while yielding in sys$yield()
Otherwise, a thread calling sched_yield() will prevent other threads
in that process from entering the kernel.
2019-11-16 12:18:59 +01:00
Andreas Kling
7ef9c703d2 Kernel: Unbreak SlabAllocator after startup-time constructors
Now that the kernel supports startup-time constructors, we were first
doing slab_alloc_init(), and then the constructors ran later on,
zeroing out the freelist pointers.

This meant that all slab allocators thought they were completelty
exhausted and forwarded all requests to kmalloc() instead.
2019-11-15 12:48:39 +01:00
Andreas Kling
cb5021419e Kernel: Move Thread::m_joinee_exit_value into the JoinBlocker
There's no need for this to be a permanent Thread member. Just use a
reference in the JoinBlocker instead.
2019-11-14 21:04:34 +01:00
Andreas Kling
69efa3f630 Kernel+LibPthread: Implement pthread_join()
It's now possible to block until another thread in the same process has
exited. We can also retrieve its exit value, which is whatever value it
passed to pthread_exit(). :^)
2019-11-14 20:58:23 +01:00