Before reserving address space in SYS_EXEC verify that ELF address
space is actually loadable. For example when trying to execute the
kernel binary in userspace, binarys address space would overlap with
current kernel address space. Now kernel won't crash anymore and
will just send SIGKILL to the process calling exec*().
SATA drives can now be used with banan-os. This allows much faster
disk access (writing 10 MiB from 30s to 1.5s). This can definitely
be optimized but the main slow down is probably the whole disk
structure in the os.
AHCI drive is now the default when running qemu.
I allocated 1 bitmap page per 8 data pages. Bitmap page can actually
store 8*PAGE_SIZE data pages.
Also properly set last bits in bitmap. I did not care about endianness
but now we set the bits on unsigned long longs instead of bytes.
This is kinda weird behaviour, but it ensures the user cannot
create e.g. CharacterDevice with mode having IFLNK.
The Inode overrider is the only one setting the mode.
RamInode is now a general RamInode with no data. RamFileInode is now
a inode for regular files. This is much cleaner and more intuitive
since there is no reason for most non-regular inodes to hold data
Vector.
Every inode holds a weak pointer to shared file data. This contains
physical addresses of pages for inode file data. Physical addresses
are allocated and read on demand.
When last shared mapping is unmapped. The inodes shared data is freed
and written to the inode.
MemoryBackedRegion now inherits from this and is used for private
anonymous mappigs. This will make shared mappings and file backed
mappings much easier to implement.
All executable files are now read from disk and paged on demand.
This was a big rewrite of the old ELF library but in the end
everything seems much cleaner, since all the old functionality was
not actually needed for execution.
I have to do some measurements, but I feel like memory usage dropped
quite a bit after this change.
Userspace programs can call tty_ctrl() to disable/enable tty from
handling input and displaying output.
This API is probably going to change in the future to ioctl calls
but I'm not sure how ioctl is used and what functionality should it
have. I decided to create whole new function and syscall for now.
Next I will expose framebuffer in /dev/fb0 and then I can start work
on graphical environment! :D
We now validate pointers passed by the user, to forbid arbitary
memory read/write. Now the user is only allowed to pass in pointers
in their own mapped memory space (or null).
Bananymous
Bananymous