Add mikecat's argp test

set iomb to forbid i/o instructions from user space
add to test that they indeed trap in user space
thanks to pablogventura@gmail.com and nwolovick@gmail.com

Remove trailing white space with:
for f in *.{h,c}; do sed -i .sed 's/[[:blank:]]*$//' $f; done
(Thanks to Nicolás Wolovick)

i think this is a working concurrent logging scheme

every iput() and namei() must be inside a transaction

Fix compile error on newer gcc's

inaccessible page under the user stack page, to help exec deal w/ too-large args

fix usertests to correctly test what happens when you call
exec() with arguments that don't fit on a single page.

enterpgdir -> entrypgdir

make dirlookup and dirlink more similar

avoid deadlock by calling begin_trans() before locking any inodes

log write() data
usertest for big write()s
push begin_trans/commit_trans down into syscalls

Speedup sbrk tst a bit (forking 100Mbyte processes is slow)

Adjust sbrk test for large user address spaces
All tests pass

xv6: formatting, cleanup, rev5 (take 2)

make new code like old code

Variable declarations at top of function,
separate from initialization.

Use == 0 instead of ! for checking pointers.

Consistent spacing around {, *, casts.

Declare 0-p

make new code like old code

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.

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copyout() copies data to a va in a pagetable, for exec() &c
usertest that passes too many arguments, break exec

map kernel instructions r/o

my comment is wrong, exec handles BSS fine

Remove the stack guard page. Processes are now contiguous from 0 to proc->sz, which means our syscall argument validation is correct. Add a pointer validation test and remove the stack test, which

Remove the stack guard page. Processes are now contiguous from 0 to proc->sz, which means our syscall argument validation is correct. Add a pointer validation test and remove the stack test, which tested for the guard page.

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Space police

Cleanup if allocuvm fails to alloc. Add a test.

uptime() sys call for benchmarking
increase PHYSTOP

allow sbrk(-x) to de-allocate user memory

fix corner cases in exec of ELF
put an invalid page below the stack
have fork() handle invalid pages