This large commit address several issues
- removed 386 directory: Jehanne is 64bit only
- simplified kernel options management
- rewritten boot process
- ported memory related stuff from 9front's 9/pc64
- removed devacpi
- removed old code
- deep refactor of awake syscall
- removed MCACHE support for mount
- fix libc's setjmp/longjmp
This commit introduce a special rendezvous point at (void*)~0 that
cannot be reached by any process, since it's not added to the
rendezvous group.
This turns the rendezvous syscall to a cheap way to block until
either a note or a wakeup from awake(2) occurs.
This new feature is used in libc's sleep: the test qa/kern/fork_chain
has shown that using a stack address as rendezvous point is not safe enougth
for sleep, since two different process forked from the same function can
call sleep with the same base pointer. This lead the wakeup variable in
jehanne_sleep to have the same address on both process.
TODO add a test that show this behaviour in the old code.
This way sleep() knows that it should not interrupt the process
to serve awake().
Also rename Proc.insyscall to Proc.inkernel since that's the meaning
of the flag, which is only read to serve awake()'s mechanics and
to accounttime(). Indeed faultAmd64 was setting insyscall to 1.
The "write on closed pipe" note should be posted only
if the write occurred on a closed pipe.
Before this fix, on any interrupt caused the note to be sent,
despite the pipe being open and fully working.
Awake can now interrupt several blocking syscalls (even
during note handling).
Among others, it can interrupt await, pread and pwrite.
It cannot interrupt several others for different reasons:
- awake cannot be interrupted by awake;
- syscalls like remove and create can be used for kernel comunication
and it would be hard to know if the effect occurred in the
receiving fs if they were interrupted;
- other syscalls do not need awake since they just provide access
to kernel infos (eg seek or fd2path)
NOTE: awakes registered before a note cannot occur during the note
handling and will be deferred till the next call to noted.
With this commit all functions declared in libc.h have been renamed
with the "jehanne_" prefix. This is done for several reason:
- it removes conflicts during symbol resolution when linking
standard C libraries like newlib or musl
- it allows programs depending on a standard C library to directly
link to a library depending on our non standard libc (eg libsec).
To ease transiction two files are provided:
- sys/include/lib9.h that can be included instead of <libc.h> to use
the old names (via a simple set of macros)
- sys/src/lib/c/lib9.c that can be compiled with a program where the
macro provided by lib9.h are too dumb (see for example rc or grep).
In the kernel port/lib.h has been modified accordingly and some of
the functions it directly provides has been renamed too (eg malloc
in qmalloc.c and print in devcons.c).
CID 155471 (#1 of 1): Buffer not null terminated (BUFFER_SIZE_WARNING)67.
buffer_size_warning: Calling strncpy with a maximum size argument of 256 bytes on destination array envcopy of size 256 bytes might leave the destination string unterminated.
OREAD and OWRITE are used as array indexes assuming that OREAD was zero
and OWRITE was one. Thus each related allocation reserved just 2 slot and
even Ep struct in usb.h reserved just 2 int for toggles.
Since OREAD is now 1 and OWRITE is 2 we have to allocate/reserve 3 slot
as long as we use them as array indexes (which we could change in the future).
Unfortunately this means we waste the index zero in those arrays that will
always be unused. This also means that, to loop in such arrays we must begin
with OREAD as index zero is always empty.
PRO-MEMORIA: if/when we introduce the walk() syscall, OSTAT might turn useless.
In that case we might remove it and thus consider to move back OREAD/OWRITE
to 0/1 respectively (which might or might not be a good idea, to be analyzed).
