myproc() points to a different thread.
myproc();
sched();
myproc(); // this proc maybe different than the one before sched
Thus, in a function that operates on one thread better to retrieve the
current process once at the start of the function.
Allocate proper kernel page table immediately in main using boot allocator
Remove pginit
Simplify address space layout a tiny bit
More to come (e.g., superpages to simplify static table)
Variable declarations at top of function,
separate from initialization.
Use == 0 instead of ! for checking pointers.
Consistent spacing around {, *, casts.
Declare 0-parameter functions as (void) not ().
Integer valued functions return -1 on failure, 0 on success.
Do not commit to new memory image until
nothing can go wrong, avoiding bad2 case.
Be sure to allocate enough stack space for argv.
Load executable before initializing stack, to
keep ELF loops together.
Make argv loop clearer.
Various changes made while offline.
+ bwrite sector argument is redundant; use b->sector.
+ reformatting of files for nicer PDF page breaks
+ distinguish between locked, unlocked inodes in type signatures
+ change FD_FILE to FD_INODE
+ move userinit (nee proc0init) to proc.c
+ move ROOTDEV to param.h
+ always parenthesize sizeof argument
- Got rid of dummy proc[0]. Now proc[0] is init.
- Added initcode.S to exec /init, so that /init is
just a regular binary.
- Moved exec out of sysfile to exec.c
- Moved code dealing with fs guts (like struct inode)
from sysfile.c to fs.c. Code dealing with system call
arguments stays in sysfile.c
- Refactored directory routines in fs.c; should be simpler.
- Changed iget to return *unlocked* inode structure.
This solves the lookup-then-use race in namei
without introducing deadlocks.
It also enabled getting rid of the dummy proc[0].
