Commit graph

24 commits

Author SHA1 Message Date
Ben Gras
2bfeeed885 drop segment from safecopy invocations
. all invocations were S or D, so can safely be dropped
	  to prepare for the segmentless world
	. still assign D to the SCP_SEG field in the message
	  to make previous kernels usable
2012-06-16 16:22:51 +00:00
Thomas Veerman
ca7a466f48 TTY: don't allow multiple readers on tty minor
TTY has no way of keeping track of multiple readers for a tty minor
device. Instead, it stores a read request for the last reader only.
Consequently, the first ("overwritten") reader gets stuck on a read
request that's never going to be finished. Also, the overwriting
causes a grant mismatch in VFS when TTY returns a reply for the
second reader.

This patch is a work around for the actual problem (i.e., keeping track
of multiple readers). It checks whether there is a read operation in
progress and returns an error if it is --preventing that reader from
getting overwritten and stuck. It fixes a bug triggered by executing
'top | more' and pressing the space bar for a while (easily reproducable
in a VM, not on hardware).
2012-04-13 13:22:13 +00:00
Ben Gras
7336a67dfe retire PUBLIC, PRIVATE and FORWARD 2012-03-25 21:58:14 +02:00
Ben Gras
6a73e85ad1 retire _PROTOTYPE
. only good for obsolete K&R support
	. also remove a stray ansi.h and the proto cmd
2012-03-25 16:17:10 +02:00
David van Moolenbroek
b4d909d415 Split block/character protocols and libdriver
This patch separates the character and block driver communication
protocols. The old character protocol remains the same, but a new
block protocol is introduced. The libdriver library is replaced by
two new libraries: libchardriver and libblockdriver. Their exposed
API, and drivers that use them, have been updated accordingly.
Together, libbdev and libblockdriver now completely abstract away
the message format used by the block protocol. As the memory driver
is both a character and a block device driver, it now implements its
own message loop.

The most important semantic change made to the block protocol is that
it is no longer possible to return both partial results and an error
for a single transfer. This simplifies the interaction between the
caller and the driver, as the I/O vector no longer needs to be copied
back. Also, drivers are now no longer supposed to decide based on the
layout of the I/O vector when a transfer should be cut short. Put
simply, transfers are now supposed to either succeed completely, or
result in an error.

After this patch, the state of the various pieces is as follows:
- block protocol: stable
- libbdev API: stable for synchronous communication
- libblockdriver API: needs slight revision (the drvlib/partition API
  in particular; the threading API will also change shortly)
- character protocol: needs cleanup
- libchardriver API: needs cleanup accordingly
- driver restarts: largely unsupported until endpoint changes are
  reintroduced

As a side effect, this patch eliminates several bugs, hacks, and gcc
-Wall and -W warnings all over the place. It probably introduces a
few new ones, too.

Update warning: this patch changes the protocol between MFS and disk
drivers, so in order to use old/new images, the MFS from the ramdisk
must be used to mount all file systems.
2011-11-23 14:06:37 +01:00
David van Moolenbroek
c51cd5fe91 Server/driver protocols: no longer allow third-party copies.
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed
to know which actual process to copy data from/to, as that process may
not always be the caller. Now that we have full safecopy support, these
fields have become useless for that purpose: the owner of the grant is
*always* the caller. Allowing the caller to supply another endpoint is
in fact dangerous, because the callee may then end up using a grant
from a third party. One could call this a variant of the confused
deputy problem.

From now on, safecopy calls should always use the caller's endpoint as
grant owner. This fully obsoletes the DL_ENDPT field in the
inet/ethernet protocol. IO_ENDPT has other uses besides identifying the
grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only
because that is a more fitting name (it should never be used for I/O
after all), but also in order to intentionally break any old system
source code outside the base system. If this patch breaks your code,
fixing it is fairly simple:

- DL_ENDPT should be replaced with m_source;
- IO_ENDPT should be replaced with m_source when used for safecopies;
- IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g.
  when setting REP_ENDPT, matching requests in CANCEL calls, getting
  DEV_SELECT flags, and retrieving of the real user process's endpoint
  in DEV_OPEN.

The changes in this patch are binary backward compatible.
2011-04-11 17:35:05 +00:00
David van Moolenbroek
f56c4001d5 TTY/LOG driver cleanup:
- remove non-safecopy support from TTY
- make TTY warning-free with gcc -Wall
- remove obsolete diagnostics support
2011-03-25 10:43:24 +00:00
Erik van der Kouwe
7de730afe4 Add scancode reading capability to TTY 2010-04-15 06:55:42 +00:00
Arun Thomas
436d6012a3 Convert drivers/ and servers/ over to bsdmake
-Move libdriver to lib/
-Install all boot image services on filesystem to aid restartability
2010-03-22 21:25:22 +00:00
Kees van Reeuwijk
c6eb51d66a Rewrite some functions to ANSI style. 2010-01-27 10:19:13 +00:00
Ben Gras
4cd6875d05 don't flush output for SIGWINCH. found by Joren l'Ami. 2009-04-06 09:39:42 +00:00
Ben Gras
c078ec0331 Basic VM and other minor improvements.
Not complete, probably not fully debugged or optimized.
2008-11-19 12:26:10 +00:00
Ben Gras
8ea438ae93 Retired DEV_{READ,WRITE,GATHER,SCATTER,IOCTL} (safe versions *_S are to
be used and drivers should never receieve these 'unsafe' variants
any more).
2007-02-07 16:22:19 +00:00
Ben Gras
1c8b206a5d . Safe I/O, ioctl() and DIAGNOSTICS variants conversion - safe copies,
include grant id in DEV_REVIVE messages.
. Removal of TTY_FLAGS field (and so O_NONBLOCK support).
. Fixed CANCEL behaviour and return code on blocking I/O,
  previously handled by O_NONBLOCK
. Totally removed REVIVE replies, previously still possible on
  blocking ioctls (REVIVE directly called) and ptys (missing TTY_REVIVE
  check), removes deadlock bug with FS
. Removed obsolete *COMPAT options and associated code
2006-06-20 09:02:54 +00:00
Ben Gras
f877da3aec endpoint migration for drivers.
mostly renaming message field names to the new names.

tty stored process numbers in chars in tty and pty structs - now ints.
2006-03-03 10:21:45 +00:00
Ben Gras
e3709af1b8 Andy's code fixes 2005-09-11 17:09:11 +00:00
Ben Gras
e2e90b1fdc Remove double-blank lines (Al) 2005-08-22 15:17:42 +00:00
Ben Gras
0e3bef8597 pty select() support 2005-08-05 13:50:58 +00:00
Philip Homburg
537d7ddcdf Replace REVIVE with notify. 2005-08-01 14:40:21 +00:00
Ben Gras
471e0448c3 Changed timer library function args.
Added select() support for tty fd's (not ptys yet).
2005-06-17 13:37:41 +00:00
Ben Gras
b480fa7c18 removed dead code bits 2005-05-13 11:45:12 +00:00
Ben Gras
fad180960f added code to un-register tty's interrupt at exit time; fixed compiler
warnings
2005-05-12 16:03:43 +00:00
Ben Gras
96e9faf535 userlandified and enabled PTY's 2005-05-09 14:35:26 +00:00
Ben Gras
9865aeaa79 Initial revision 2005-04-21 14:53:53 +00:00