Commit graph

1284 commits

Author SHA1 Message Date
Robert Morris c4f6a241cd avoid a double-lock of initproc->lock if child of init is reparenting 2019-07-07 07:03:28 -04:00
Robert Morris 7114bf43ed Merge branch 'riscv-proc' of g.csail.mit.edu:xv6-dev into riscv-proc 2019-07-07 06:39:58 -04:00
Robert Morris 62313be582 another fork test 2019-07-07 06:39:31 -04:00
Frans Kaashoek dabbc348bc Maybe fix two races identified by rtm (thx!):
- during exit(), hold p's parent lock and p's lock across all changes
to p and its parent (e.g., reparenting and wakeup1).  the lock
ordering between concurrent exits of children, parent, and great
parent might work out because processes form a tree.

- in wakeup1() test and set p->state atomically by asking caller to
have p locked.

a correctness proof would be desirable.
2019-07-06 16:38:41 -04:00
Robert Morris 75b0c6fc91 back-port fork/exit/exit tests to xv6-riscv 2019-07-05 12:33:26 -04:00
Robert Morris be88befed7 two exit/exit tests 2019-07-05 11:44:51 -04:00
Frans Kaashoek fab5e7c1de Make size in stat.h be a uint64
Supporting print long using %l (a bit of cheat)
Modify ls to print size using %l
We should probably update size in inode too.
2019-07-04 08:57:23 -04:00
Frans Kaashoek 6bfb078b14 x 2019-07-04 08:54:16 -04:00
Frans Kaashoek 47e69250d0 Simplify wakeup1 2019-07-03 15:38:30 -04:00
Frans Kaashoek cee830af24 Apply some corresponding bug fixes from wq branch here 2019-07-03 15:18:55 -04:00
Frans Kaashoek ccf299850b Remove some debugging code 2019-07-02 20:52:30 -04:00
Frans Kaashoek 26f306113a Fix a lost wakeup bug: the disk driver's wakeup() can run after the
reading process acquired p->lock and released virtio lock in sleep(),
but before the process had set p->status to SLEEPING, because the
wakeup tested p->status without holding p's lock.  Thus, wakeup can
complete without seeing any process SLEEPING and then p sets p->status
to SLEEPING.

Fix some other issues:

- Don't initialize proc lock in allocproc(), because freeproc() sets
np->state = UNUSED and allocproc() can choose np and calls initlock()
on the process's lock, releasing np's lock accidentally.  Move
initializing proc's lock to init.

- Protect nextpid using ptable.lock (and move into its own function)

Some clean up:
- Don't acquire p->lock when it p is used in a private way (e.g., exit()/grow()).
- Move find_runnable() back into scheduler().
2019-07-02 19:29:14 -04:00
Frans Kaashoek 1e4d7065d6 Merge branch 'riscv' into riscv-proc 2019-07-02 14:19:31 -04:00
Frans Kaashoek 84c759fc02 x 2019-07-02 14:09:38 -04:00
Frans Kaashoek 37ac6f8f4f Don't start processes at the end of the proc table 2019-07-02 13:55:52 -04:00
Frans Kaashoek da51735980 Avoid two cores selecting the same process to run 2019-07-02 13:40:33 -04:00
Robert Morris f59c1bf1d8 try to continue from walk() failing to allocate a page-table page 2019-07-02 11:45:06 -04:00
Robert Morris b27f275014 avoid allocproc() returning a struct proc with non-zero p->sz 2019-07-02 11:17:50 -04:00
Robert Morris 1540c8b15a COW tests 2019-07-02 11:04:35 -04:00
Frans Kaashoek 67702cf706 Checkpoint switching to per-process locks, in attempt clarify xv6's
locking plan, which is a difficult to understand because ptable lock
protects many invariants.  This implementation has a bug: once in a
while xv6 unlocks a proc lock that is locked by another core.
2019-07-02 09:14:47 -04:00
Robert Morris 40f1041a0a don't enable interrupts until done with sstatus, scause, &c 2019-07-02 05:20:11 -04:00
Robert Morris 535ac52efa oops, don't hold mycpu() result across intr_off() 2019-07-01 17:54:41 -04:00
Robert Morris abfe9999f4 have fork() fail, not panic, if not enough phys mem 2019-07-01 17:46:06 -04:00
Robert Morris 18e76a6c47 sbrk() returns a pointer, so it should be 64 bits 2019-07-01 17:01:50 -04:00
Robert Morris 9b99f00743 oops, don't hold mycpu() result across intr_off() 2019-07-01 14:15:18 -04:00
Robert Morris 0498bfd159 timer interrupt in the kernel -> yield 2019-07-01 13:46:11 -04:00
Frans Kaashoek c34bd3d167 Checkpoint some progress compiling xv6.pdf 2019-07-01 13:02:24 -04:00
Frans Kaashoek 2c0338fe42 x 2019-07-01 08:28:14 -04:00
Frans Kaashoek af6c35e14b Introduce alloc3_desc and UsedArea to make code easier to read 2019-07-01 08:20:35 -04:00
Robert Morris a8305b7318 FD_DEVICE 2019-06-13 10:29:27 -04:00
Robert Morris 46744c4a13 for spinlocks, use gcc intrinsics, but say what they compile to 2019-06-13 10:00:50 -04:00
Robert Morris ca39672a30 clean up virtio code 2019-06-13 09:40:17 -04:00
Robert Morris 4adf016925 eliminate ramdisk 2019-06-13 06:57:38 -04:00
Robert Morris de9d72c908 virtio disk driver 2019-06-13 06:49:02 -04:00
Robert Morris 5753553213 separate source into kernel/ user/ mkfs/ 2019-06-11 09:57:14 -04:00
Robert Morris 91ba81110a gdb backtraces: -ggdb, -fno-omit-frame-pointer, BSIZE=1024 2019-06-06 13:54:03 -04:00
Robert Morris 8607051b5f fix a create()/unlink() deadlock 2019-06-06 10:38:11 -04:00
Robert Morris 31ef85f552 add plic.c 2019-06-06 05:19:59 -04:00
Robert Morris b05bcce939 add kernelvec 2019-06-06 05:19:35 -04:00
Robert Morris dff7ab3f8f make -O work with asm volatile(...) 2019-06-05 15:05:56 -04:00
Robert Morris 5684556c19 clean up -Wall 2019-06-05 14:31:13 -04:00
Robert Morris 5eb1cb4972 push_off() and pop_off() in myproc() 2019-06-05 14:14:57 -04:00
Robert Morris 3113643768 spinlocks using gcc intrinsics
push_off() / pop_off()
set up per-hart plic stuff so all harts get device interrupts
2019-06-05 14:05:46 -04:00
Robert Morris f1a727b971 start at support for multiple CPUs 2019-06-05 11:42:03 -04:00
Robert Morris ec3d3a1fce yield if timer interrupt
all user tests passed
2019-06-04 14:25:48 -04:00
Robert Morris a82772594e timer interrupts -> supervisor software interrupt 2019-06-04 14:20:37 -04:00
Robert Morris cff3ce6e04 more sbrk fixes 2019-06-04 11:31:50 -04:00
Robert Morris 0e131b2263 fix a problem with end. make uartputc() wait until h/w is ready. 2019-06-04 10:43:45 -04:00
Robert Morris b78894f34e check that arguments aren't more than a page in exec() 2019-06-04 06:51:01 -04:00
Robert Morris 0f684b9150 fix exec argc 2019-06-04 06:45:09 -04:00