Andreas Kling
2d045d2a64
Implement COW pages! :^)
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sys$fork() now clones all writable regions with per-page COW bits.
The pages are then mapped read-only and we handle a PF by COWing the pages.
This is quite delightful. Obviously there's lots of work to do still,
and it needs better data structures, but the general concept works.
2018-11-05 13:48:07 +01:00
Andreas Kling
72cdc62155
Replace zones with individually tracked physical pages.
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It's just a simple struct { ref_count, paddr }.
This will allow me to implement lazy zeroing and COW pages.
2018-11-05 10:23:00 +01:00
Andreas Kling
422b5403e5
Merge ExecSpace into ELFLoader.
2018-11-04 13:52:53 +01:00
Andreas Kling
da13c9a264
Map pages in read-only ELF sections as non-writable.
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This is so cool! :^) Now you'll crash if you try to write into your
.text or .rodata segments.
2018-11-03 11:36:45 +01:00
Andreas Kling
aa6d06b47e
Use ELF program headers to load executables smarter.
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This turned out way better than the old code. ELF loading is now quite
straightforward, and we don't need the weird concept of subregions anymore.
Next step is to respect the is_writable flag.
2018-11-03 11:29:30 +01:00
Andreas Kling
dd060d0fa8
Share code between spawn() and exec() implementations.
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Okay, now there's only one ELF loading client in the process launch code.
2018-11-03 10:55:02 +01:00
Andreas Kling
c5eec9cbfc
Factor out the "non-syscall" parts of sys$execve() into exec().
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..to prepare for sharing code with createUserProcess().
2018-11-03 10:20:23 +01:00
Andreas Kling
20fb1fc377
Fix some bugs in execve() and make sh use it for process launching.
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Interrupting children of sh now always works with ^C :^)
2018-11-03 02:08:06 +01:00
Andreas Kling
202bdb553c
Implemented sys$execve().
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It's really crufty, but it basically works!
2018-11-03 01:51:42 +01:00
Andreas Kling
8accc92c3c
Implement fork()!
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This is quite cool! The syscall entry point plumbs the register dump
down to sys$fork(), which uses it to set up the child process's TSS
in order to resume execution right after the int 0x80 fork() call. :^)
This works pretty well, although there is some problem with the kernel
alias mappings used to clone the parent process's regions. If I disable
the MM::release_page_directory() code, there's no problem. Probably there's
a premature freeing of a physical page somehow.
2018-11-02 20:41:58 +01:00
Andreas Kling
10b666f69a
Basic ^C interrupt implementation.
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For testing, I made cat put itself into a new process group.
This should eventually be done by sh between fork() and exec().
2018-11-02 14:06:48 +01:00
Andreas Kling
621217ffeb
Add tcsetpgrp()+tcgetpgrp().
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One more step on the path to being able to ^C a runaway process. :^)
2018-11-02 13:14:25 +01:00
Andreas Kling
d8f0dd6f3b
Start working on sessions and process groups.
2018-11-02 12:56:51 +01:00
Andreas Kling
90ddbca127
Free physical pages allocated for a process's page directory on exit.
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Also use a ProcessPagingScope instead of region aliasing to implement
create-process ELF loading.
2018-11-01 23:08:10 +01:00
Andreas Kling
c70afd045e
Use a freelist for GDT entries.
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Tweak the kmalloc space layout a bit. Get the spawn stress test up
and running again.
2018-11-01 16:23:12 +01:00
Andreas Kling
3a901ae36d
Way tighter locking in process creation.
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We no longer disable interrupts around the whole affair.
Since MM manages per-process data structures, this works quite smoothly now.
Only procfs had to be tweaked with an InterruptDisabler.
2018-11-01 14:41:49 +01:00
Andreas Kling
52607aa086
Allow processes to go into a BeingInspected state (used by procfs.)
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This ensures that the process won't get scheduled, and so inspecting
it is safe and easy without blocking interrupts.
2018-11-01 14:21:02 +01:00
Andreas Kling
fd03776443
Add a /proc/PID/fds text files that lists all the fds open in a process.
2018-11-01 14:00:28 +01:00
Andreas Kling
065f0aee35
Preallocate the maximum number of FileHandle pointers (fds) in every process.
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This could even use a more specific data structure since it doesn't need the
grow/shrink capabilities of a vector.
2018-11-01 13:39:28 +01:00
Andreas Kling
fce81d376c
Move Region and Subregion out of Process and make them free classes.
2018-11-01 13:21:02 +01:00
Andreas Kling
3e532ac7b6
Process now maps regions immediately when they are allocated.
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This avoids having to do a separate MM.mapRegionsForTask() pass.
Also, more Task => Process renaming that I apparently hadn't saved yet.
2018-11-01 13:15:46 +01:00
Andreas Kling
4e60551aec
Rename Task to Process.
2018-11-01 13:10:12 +01:00
