Commit Graph

392 Commits

Author SHA1 Message Date
755242719c VMM: Add a few memsets
This seems to fix exec() making weird page tables!!
2022-10-19 07:56:08 +02:00
671f2a2de3 Kernel, libc: Implement waitpid()
FIXME: exec() is now doing weird page table stuff. But at least it works, no panics :)
2022-10-18 21:30:52 +02:00
bb00e3c112 Kernel: Guard against recursive panics
Previously, when we panicked (page-fault for example) while dumping a kernel panic, it would just loop over and over again.

Now, we check if we were already in a panic, and limit the dump:
- No stack trace.
- Only a few registers.
- Only serial (since we can page fault while writing to the framebuffer)

This should make recursive panics much more difficult to achieve.
If we page-fault while writing to console, we don't even see a panic (not even in serial) and eventually triple-fault.
So this patch is actually more user-friendly.
2022-10-18 21:08:21 +02:00
59506b8852 Kernel: Show current_task's name in the log 2022-10-18 18:41:17 +02:00
52d391507d Kernel: Rename the getpid() syscall to getprocid()
Now, we have one single system call to fetch all sorts of identifiers:
PID, PPID, UID, GID; EUID, EGID, and more...
2022-10-18 17:36:17 +02:00
a9d3bdba6f Kernel: Keep track of a task's PPID 2022-10-18 17:18:37 +02:00
bdf1bb15a1 StackTracer: only show kernel addresses for now, until there are more checks 2022-10-18 17:14:09 +02:00
48d68a3e31 Kernel: Switch back to kernel address space on kernel panic 2022-10-18 17:13:43 +02:00
92d8c9d4d5 Next version! 2022-10-17 21:28:35 +02:00
4f41b9ed37 Scheduler: Implement a find_by_pid function 2022-10-17 20:40:38 +02:00
8b17065718 Kernel, libc: Rename gettid() to getpid() and move it to unistd.h 2022-10-17 20:08:44 +02:00
87ef210759 Kernel, libc: Remove spawn()
Now, fork() and exec() are both implemented. More POSIX-y, thus spawn can be removed.
2022-10-17 19:55:01 +02:00
a2c05de604 mmap(), mprotect(), munmap(): Check more stuff 2022-10-17 19:32:24 +02:00
593daba651 Kernel: Remove unused headers in main.cpp 2022-10-17 19:23:53 +02:00
ea8a42b8c0 Kernel: Add a name field to the Task structure 2022-10-17 19:12:47 +02:00
34fc6996b0 UserHeap: allocate needed memory in request_virtual_pages 2022-10-17 18:52:11 +02:00
92634048fc UserHeap: some nice improvements 2022-10-17 18:49:19 +02:00
64f5078494 Kernel, libc: Implement fork()
This time for real.

Also, add a new per-user-task virtual address allocator (UserHeap), so that mmap'ed pages are in user range and can be copied.
2022-10-17 18:43:35 +02:00
966fdc76d7 Move userspace task to userspace memory 2022-10-17 17:30:05 +02:00
b334e1cd50 VMM: check if the entry is already present 2022-10-17 17:26:16 +02:00
682be58d97 AddressSpace: copy instead of linking 2022-10-17 17:24:33 +02:00
250db2c90f Scheduler: add an append_task() function 2022-10-17 17:14:22 +02:00
c2fa4f380d Kernel: Use the new Task member functions 2022-10-17 17:07:25 +02:00
ce10fb5743 fcntl(F_DUPFD): Allocate any file descriptor greater than or equal to arg 2022-10-17 17:01:22 +02:00
891651f2d6 Task: Move functions operating on Task to member functions
Also, add an alloc_fd_greater_than_or_equal() function, for use in fcntl(F_DUPFD)
2022-10-17 17:00:07 +02:00
e34045a78c Kernel: on stack smashing detection, do not trigger a normal panic
That triggers stack traces, which we do not want in a stack smash fail situation
2022-10-16 19:04:24 +02:00
9b39d618de Kernel, libc: Implement spawn()
This function is a Luna alternative to fork() and exec().

Why? Simply because I can't figure out for the life of me how to implement a working fork().

So meanwhile, we have spawn() as a replacement. exec() still exists, though.
2022-10-16 18:48:35 +02:00
a1146a5ce2 Panic: show panic message on screen 2022-10-16 18:23:33 +02:00
d2e2883a79 Kernel: Make mkdir() accessible to userspace 2022-10-16 17:22:12 +02:00
18fbccafb7 VFS: add an exists() function 2022-10-16 16:58:18 +02:00
d62eb6c791 Tests: Add test framework 2022-10-16 15:31:58 +02:00
f8154ce230 Kernel: Implement mkdir() from a single path
This is done using dirname() and basename() :)
2022-10-16 14:45:25 +02:00
8c0a57f0c2 Kernel: Copy strrchr, dirname and basename over from libc 2022-10-16 14:36:25 +02:00
1624f0360d exec: More logging 2022-10-15 17:47:57 +02:00
68403dc029 Kernel: Make AddressSpaces reference-counted 2022-10-15 17:40:33 +02:00
eca7227fda StackTracer: Stop when instruction is at nullptr 2022-10-15 17:31:57 +02:00
aca1367158 Kernel: Switch to strlcpy() as well
Surprisingly, most uses of strncpy() are in places where strncpy() is actually a better choice.
For example, copying to a fixed-length char array in a structure.
2022-10-15 17:30:34 +02:00
4bad782aad Kernel: Increment the maximum number of file descriptors a task can have
Doesn't use up more space in the Task structure, and now we are above the Minimum Acceptable Value as defined by POSIX (20), I think.
2022-10-15 14:20:29 +02:00
62a2bcf2ff Kernel: Add a clock() system call 2022-10-15 13:17:26 +02:00
3a9dddaa57 Kernel, libc: Remove the rand() system call
That's why we now have a VFS and a /dev pseudo-filesystem. To provide that kind of things.

Remember, everything is a file!!

The new way to ask the kernel for random numbers is to read from /dev/random.
2022-10-15 13:04:48 +02:00
613f8170b6 Kernel, libc: Implement mprotect() and use proper PROT_* values 2022-10-15 12:57:14 +02:00
62d631f1b4 Kernel: Rename assert.h to kassert.h so IDEs pickup the kernel header instead of the userspace one 2022-10-15 12:56:48 +02:00
1e86acd4c0 libc: Implement fcntl(F_DUPFD) and dup() 2022-10-15 11:16:34 +02:00
36bb1cab5c FileDescriptor: add operator=() so that the fcntl(F_DUPFD syscall compiles :) 2022-10-15 11:16:18 +02:00
5c61252061 Kernel: Add a new fcntl() system call 2022-10-15 10:56:06 +02:00
3eb1bff2e9 Task: add an alloc_fd() function 2022-10-15 10:45:12 +02:00
91d76a2ee4 Devices: Add a new RandomDevice :)
This new device uses the seeded Mersenne PRNG we use in the kernel.
This device is not meant for regular userspace use, but more for userspace to seed their own PRNGs from.

If the DeviceFS is mounted at /dev, this device can be found at /dev/random.
2022-10-14 20:14:49 +02:00
faaf930a14 Moon 0.12-dev 2022-10-14 19:55:29 +02:00
97461c7c1f Prepare for moon 0.11 2022-10-14 19:49:52 +02:00
e0aa552fae Kernel: Add a move() function
The standard C++ move() function.
2022-10-14 19:04:56 +02:00
f82fbbe60c Make address spaces not cloned by default 2022-10-14 18:23:04 +02:00
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