If kmalloc backtraces are enabled during backtracing, things don't go
super well when the backtrace code calls kmalloc()..
With this fixed, it's basically possible to get all kmalloc backtraces
on the debugger by running (as root):
sysctl kmalloc_stacks=1
This adds a bounds check to the loop that writes to the buffer
'recognized_symbols'. This prevents buffer overflows in the
case when a programs backtrace is particularly large.
Fixes#371.
After reading a bunch of POSIX specs, I've learned that a file descriptor
is the number that refers to a file description, not the description itself.
So this patch renames FileDescriptor to FileDescription, and Process now has
FileDescription* file_description(int fd).
The current working directory is now stored as a custody. Likewise for a
process executable file. This unbreaks /proc/PID/fd which has not been
working since we made the filesystem bigger.
This still needs a bunch of work, for instance when renaming or removing
a file somewhere, we have to update the relevant custody links.
This is in preparation for eventually using it in userspace.
LinearAddress.h has not been moved for the time being (as it seems to be
only used by a very small part of the code).
Stash away the ELFLoader used to load an executable in Process so we can use
it for symbolicating userspace addresses later on. This will make debugging
userspace programs a lot nicer. :^)
The scheduler now operates on threads, rather than on processes.
Each process has a main thread, and can have any number of additional
threads. The process exits when the main thread exits.
This patch doesn't actually spawn any additional threads, it merely
does all the plumbing needed to make it possible. :^)
Also use a simple array of { dword, const char* } for the KSyms and put the
whole shebang in kmalloc_eternal() memory. This was a fugly source of
kmalloc perma-frag.
