Commit Graph

341 Commits

Author SHA1 Message Date
c8a92af4d2 Whoops! bugfix 2022-10-14 18:21:09 +02:00
1c3377fc98 Prepare for cloning address spaces, not there yet 2022-10-14 18:17:57 +02:00
e43777bd31 Apparently, it just works now. 2022-10-14 18:00:33 +02:00
97a8a4a4a2 Solve rebase 2022-10-14 17:39:24 +02:00
81f56083c5 Almost there! 2022-10-14 17:38:29 +02:00
cdb73836b0 Some more multiple address space stuff
This page-faults. This is because the memory where the ELF should be is all zeroes, which the CPU tries to interpret.
2022-10-14 17:37:51 +02:00
bb7887a29d Add basic address space infrastructure 2022-10-14 17:34:29 +02:00
177282d79c Use the more appropriate size_t 2022-10-14 17:33:06 +02:00
5abd8814e3 Kernel: Continue moving utilities to a separate subdirectory 2022-10-14 17:33:06 +02:00
e21b608af4 Utilities: Start moving utilities into specific headers in a utils/ subdirectory 2022-10-14 17:31:47 +02:00
9b3c7816a3 Scheduler: pop the interrupt state when returning early from load_user_task() 2022-10-14 16:54:52 +02:00
26211bd49f It (almost) works now
The only thing doing weird stuff is exec(), so that's commented out and throws ENOSYS right now.

But we have two user tasks running in parallel, isolated from each other!
2022-10-14 16:46:00 +02:00
0c7c249935 exec is still doing some weird stuff, totally corrupting the page tables 2022-10-13 22:20:24 +02:00
5d41b4b113 Almost there...
exec() is not working yet. But the rest are!!
2022-10-13 22:13:04 +02:00
24272c57ef Almost there! 2022-10-13 21:55:51 +02:00
83982a24e2 add a comment 2022-10-13 21:21:02 +02:00
ee712432bd Some more multiple address space stuff
This page-faults. This is because the memory where the ELF should be is all zeroes, which the CPU tries to interpret.
2022-10-13 21:14:39 +02:00
229b06c63b Add basic address space infrastructure 2022-10-13 19:19:51 +02:00
522aa2f812 mmap, munmap: Add more checks 2022-10-13 18:50:12 +02:00
83e6b8cd21 VMM: Fix naming convention 2022-10-13 18:42:53 +02:00
57482e4e93 VMM: Make it even nicer 2022-10-13 18:15:52 +02:00
b360307f41 VMM: Make it so much gooder
There are still some fixes to be made, but I think this is already way cleaner than before.
2022-10-13 17:58:13 +02:00
9f2c9fb190 Kernel: Make Utilities be inline 2022-10-13 17:17:28 +02:00
b0e1b8a2b2 Missed some empty lines 2022-10-12 20:51:24 +02:00
2dd3a23092 Kernel: remove warnings when a standard IO syscall returns an error
That will probably happen a lot. We want userspace to tell us IF THE ERROR IS RELEVANT.
So, these unnecessary warnings are just noise.
Userspace may also use these functions to check for file descriptors.
For example, libc does this at program initialization, it checks whether fd 0 and 1 exist (by calling lseek() and seeing if it fails with errno=EBADF).
2022-10-12 20:50:21 +02:00
52944ba5d8 Kernel/VMM: Add support for larger pages to getFlags() 2022-10-12 20:05:27 +02:00
69a9f7f06a Kernel: Move VMM from a class to a namespace
Also, rename the ugly Paging::VirtualMemoryManager name to just 'VMM'. Which is now used instead of kernelVMM.
2022-10-12 20:02:25 +02:00
5f8376409d Kernel, libc: Implement EFAULT 2022-10-12 19:25:35 +02:00
e37ff67da2 Make exec return an error if the loaded executable would use more memory than is currently available 2022-10-12 19:22:08 +02:00
9cddf9485d ELFLoader: Make check_elf_image return how much memory the executable will use on success 2022-10-12 19:20:14 +02:00
4091799701 Kernel, libc: Add ENOEXEC (Exec format error) 2022-10-12 19:15:44 +02:00
8a7ddfca80 exec: Use check_elf_image()
This allows exec to recover if an error should occur when loading the executable.

Thus, the calling process will be notified instead of killed.
2022-10-12 18:43:48 +02:00
1a54342454 Sanity check 2022-10-12 18:38:18 +02:00
d4c4c0177d compilation fix :) 2022-10-12 18:37:32 +02:00
3ac9fed23a ELFLoader: Add check_elf_image() and check_elf_image_from_filesystem()
These two functions validate an image, without actually loading it. Very useful for exec!
2022-10-12 18:37:00 +02:00
261fc73146 ELFLoader: Read the ELF file header by header using the VFS
Instead of just allocating one big redundant blob of memory and reading into it, then having to free it...
2022-10-12 18:23:52 +02:00
e9df5fd663 exec: Copy pathname into kernel memory, since the user memory where it resides is going to be freed 2022-10-12 18:04:20 +02:00
bcbf43e55c Kernel/std: Add strdup() 2022-10-12 18:03:54 +02:00
531afc3d6f libc: Add support for the new exec() system call
execv() is a temporary wrapper that ignores the second parameter, while execve() and execvp() still error out.
2022-10-12 17:45:58 +02:00
f8b3567042 Kernel: Add an exec() syscall
Very bare-bones for now. Doesn't support arguments or environment (we don't have that stuff right now), and the executable is not a valid ELF, it terminates the task.

But it's a start!
2022-10-12 17:42:01 +02:00
25a460e3c6 Scheduler: clear user tasks' registers 2022-10-12 17:12:06 +02:00
136c0b3ae9 Scheduler: add a reset_task function
This can be used later to implement execve()
2022-10-12 17:08:45 +02:00
4e3ef9593d Scheduler: Move ELF image freeing to ELFLoader 2022-10-12 17:08:17 +02:00
a6f0a7056f Scheduler: Set the user_task field in a Task at creation time
We were previously looking at its segment registers to see if they were user-like, but this method is bad.
What is the task was executing a system call?

So now, we store that value at creation time.
2022-10-12 17:07:39 +02:00
edda41a7bb libc: Implement fseek(), ftell() and rewind()
All three use the new syscall seek() (with its lseek() wrapper in unistd.h)!!
2022-10-12 15:56:03 +02:00
854f585e1a Kernel: Add a seek() system call
Now, time for libc support!!
2022-10-12 15:28:52 +02:00
97b7572933 VFS: Implement a new type of Node, VFS_DEVICE
This is used to differentiate normal files from devices.
2022-10-12 15:22:34 +02:00
0f5910add7 Kernel/Utilities: Add new round_{up,down}_to_nearest_page functions 2022-10-12 14:51:04 +02:00
baa71b09cc Kernel: Build with -fstack-protector-strong instead of -fstack-protector-all
We lose a LITTLE bit of security, while allowing the compiler to optimize MUCH more.

Very simple functions, like most functions in misc/utils.cpp, were being made very big when some of them can just be "jmp thingy" or "and rax, something" and waste much less space.

This change makes more sense, I think.
2022-10-12 14:50:31 +02:00
4768d5fc12 ELFLoader: Consider the offset when calculating how many pages to map
If a section needs to be mapped at 0x50f50 and its size is 0x200, then that address space exceeds one page.
But since 0x200 is less than one page, we only map one page.

If we count the offset, 0xf50 + 0x200 need two pages. So we can map the right amount of memory.
2022-10-12 14:40:06 +02:00
bbd9f1d187 VMM: Add FIXME 2022-10-12 14:35:34 +02:00
15f340dbbe VMM: Do not map recursively 2022-10-12 14:34:12 +02:00
28469497e9 Change build system to accept arbitrary CFLAGS during the build process
For the kernel, at least.
2022-10-12 14:31:41 +02:00
d3cb642e5f Scheduler: add FIXME 2022-10-12 14:30:57 +02:00
0ee9bd7290 Scheduler: free a task's ELF image.
Now that we have support for larger pages, this works!!
2022-10-12 14:30:46 +02:00
eaea4603c6 MemoryManager: Fix logging when built with debug logging
That is to say, -DMM_DEBUG
2022-10-12 14:29:30 +02:00
4021cb3ac0 KernelHeap: do not crash the entire system
Previously, calling free_virtual_page(s) would cause an assertion fail if the address was not in the kernel heap range.
Now, we just return.
2022-10-12 14:28:48 +02:00
ad9c7af0bf VMM: add FIXME 2022-10-12 14:27:47 +02:00
950f4ef608 VMM: Add support for larger pages
getPhysical() now stops at a larger page, unmap() can unmap a larger page, but map() just transforms it into a normal page.
getFlags() larger pages support is still pending.

At least now we don't page fault because we're trying to free a larger page.
2022-10-12 14:27:26 +02:00
525d567af6 VMM: When unmapping a page, invalidate the TLB for that page 2022-10-12 14:24:34 +02:00
c9ebe89899 Kernel/KernelHeap: Add MODULE #define 2022-10-12 14:04:41 +02:00
cf160d1260 Scheduler: Use misc/utils.h instead of doing everything manually.
That way the code is cleaner + we have one single point of failure.
2022-10-12 13:18:35 +02:00
66add380cf Kernel/Utilities: add a new get_top_of_stack convenience function 2022-10-12 13:17:58 +02:00
cf3f61e373 Kernel: More GDT refactoring 2022-10-12 13:12:46 +02:00
c1f9d3323f Kernel: Refactor TSS loading to make it cleaner >.< 2022-10-12 13:07:28 +02:00
97eacc027e Kernel: Use PAGE_SIZE in more places 2022-10-12 13:05:57 +02:00
f5deb1048a Kernel: Add functions to push and pop the interrupt state
This can be useful when you want to disable interrupts, but then only enable them back if they were previously enabled.
2022-10-12 12:58:56 +02:00
b3e16068ef Kernel: Add Utilities::get_rflags(), and thus Interrupts::are_enabled() 2022-10-12 12:56:55 +02:00
e90b90c556 Kernel, libc: Round up to nearest page-aligned size instead of down 2022-10-12 12:15:12 +02:00
1e16a78106 libc: Document functions in sys/mman.h 2022-10-12 12:06:45 +02:00
96b1d1c2f2 Devices: Tell a device which name you want it to be instantiated with
This allows us to create a device in any path, with any filename.
2022-10-12 10:54:46 +02:00
eb03ae91e0 Devices: Add a new Serial device
This device permits userspace to interface with the serial port.
2022-10-12 10:44:30 +02:00
eaf7a1620b Next version! 2022-10-11 21:42:23 +02:00
25ab31c7ce Remove unnecessary comments 2022-10-11 21:32:28 +02:00
d3ac590e24 Kernel: Remove the sys_getversion() syscall
User programs can now acquire this information by reading /dev/version.
2022-10-11 21:31:28 +02:00
112e375b5e Kernel: Add a FIXME 2022-10-11 21:21:27 +02:00
12cf37d0a7 Kernel/syscalls: Modify sys_write to accept a file descriptor and write to it
Previously, sys_write only wrote to the tty. Now, it uses the VFS interface, as it should.
2022-10-11 21:06:12 +02:00
e764647133 Devices: add a new ConsoleDevice
This new device is the userspace interface to the text console/tty.
2022-10-11 21:04:50 +02:00
b1fcfd0d74 VersionDevice: Ignore offset instead of erroring out + set flags to 0 2022-10-11 21:04:14 +02:00
e67ef7778c VFS: Support writing to files 2022-10-11 21:03:30 +02:00
0c451e504e Kernel: Mounting /dev MUST succeed 2022-10-11 19:53:55 +02:00
04da26bff5 kernel: add a few comments 2022-10-11 19:51:24 +02:00
0131193379 ELFLoader, Scheduler: Transition to use VFS
We should start to drop the old InitRD API, which only allows for files to be loaded from the initrd, and which forces pathnames to be relative (bin/init)
With VFS, we can load any kind of file from any kind of filesystem, and using paths that make sense (/bin/init)
2022-10-11 19:33:48 +02:00
86b50a6aa0 Remove random demos
Cool, but cumbersome in practice: have to continually restart until I get the demo I want.

So let's stick to init for now.
2022-10-11 19:25:19 +02:00
0a7d4a530d VFS, DeviceFS: Implement a device filesystem
For now, we just have a version device. (this will allow us to get rid of sys_getversion!!)
More should be implemented soon.
2022-10-11 19:21:16 +02:00
a198cf8d8d Add initrd_mkdir to registered directories in the initrd 2022-10-11 18:25:11 +02:00
4aa3da8c12 VFS: Add basic mount(), unmount() and mkdir() functions (not accessible to userspace yet) 2022-10-11 18:23:00 +02:00
1278cec065 VFS: Add a 'type' flag to Nodes, implement EISDIR 2022-10-11 17:48:11 +02:00
7a097f16ea apps: add a new example app which does all kinds of stdio misbehaving >.< 2022-10-11 17:31:06 +02:00
667d308fc3 kernel/main.cpp: remove obsolete reference to _userspace 2022-10-11 17:30:40 +02:00
6088031c49 stdio: log stuff more 2022-10-11 17:19:03 +02:00
81815a0bdd Refactor sys/stdio.cpp 2022-10-11 17:10:44 +02:00
2a755fcd93 sys_open(): actually return EMFILE if the process has used all of its file slots 2022-10-11 17:03:16 +02:00
1b84c443fe Merge branch VFS into main
Reviewed-on: #10
2022-10-10 18:25:43 +00:00
da2ede3450 Kernel, libc, userspace: Implement file descriptors
Kernel: Implement a descriptor struct which stores the opened node and read offset, and give each task 8 of those.
Implement three syscalls: sys_read, sys_open and sys_close (sys_write still writes to the console instead of using a fd, for now)
Implement three new errors: ENOENT, EBADF and EMFILE.

libc: Implement the new errors, and the new syscalls in syscall().
Also fix _RETURN_WITH_ERRNO() to set errno correctly, which was making strerror() return null, thus crashing perror().

userspace: make init demonstrate the new file API.
2022-10-10 20:21:39 +02:00
63b2de4e3c Basic FDs 2022-10-10 19:00:24 +02:00
da84f1713c InitRD: Use get_blocks_from_size() 2022-10-10 18:45:49 +02:00
bbe7c6e658 VFS: Implement resolve_path and form the initial ramdisk's VFS properly
Finally, resolve_path: a function which takes a path (/etc/fstab for example), and walks the VFS:
In this case, it would start with the root FS node, and ask it: "do you have a directory/file named etc?"
The node could say 'yes', 'no', or 'i'm not a directory, I'm a file' (should not be the case for the VFS root, but for the other ones it could be)
If it says yes, we continue and ask the child if it has a file named fstab. Etc...
2022-10-10 18:44:43 +02:00
2be70d0bc1 VFS: Use 64-bit numbers in read()
There is no need for any kind of 32-bit compatibility.
2022-10-09 21:30:38 +02:00
8158ddc94f VFS: be more verbose 2022-10-09 21:19:22 +02:00