9 Commits

Author SHA1 Message Date
David van Moolenbroek
89a4204b83 VFS: split block, character device handling
All functions prefixed with bdev_ are moved into bdev.c, and those
prefixed with cdev_ are now in cdev.c.  The code in both files are
converted to KNF.  The little (IOCTL-related) code left in device.c
is also cleaned up but should probably be moved into other existing
source files.  This is left to a future patch.  In general, VFS is
long overdue for a source code rebalancing, and the patch here is
only a step in the right direction.

Change-Id: I2fb25734b5778b44f2ff6d2ce331a8e2146e20b0
2016-08-05 11:16:30 +00:00
David van Moolenbroek
232819dd49 VFS: store process suspension state as union
Previously, VFS would use various subsets of a number of fproc
structure fields to store state when the process is blocked
(suspended) for various reasons.  As a result, there was a fair
amount of abuse of fields, hidden state, and confusion as to
which fields were used with which suspension states.

Instead, the suspension state is now split into per-state
structures, which are then stored in a union.  Each of the union's
structures should be accessed only right before, during, and right
after the fp_blocked_on field is set to the corresponding blocking
type.  As a result, it is now very clear which fields are in use
at which times, and we even save a bit of memory as a side effect.

Change-Id: I5c24e353b6cb0c32eb41c70f89c5cfb23f6c93df
2016-08-05 11:15:15 +00:00
David van Moolenbroek
4b12166f26 VFS: workaround to allow TIOCSCTTY on PTYs
Fix /dev/tty-related issues in tmux(1) by hardcoding the PTY major
in VFS in addition to the TTY major.  Even though this is exactly
what we did NOT want to have to do, the actual fix for this issue
is going to take a little longer.

Change-Id: I24c75eaf688b9ebd28e931f2e445b8442cfdac78
2015-09-01 11:42:03 +00:00
David van Moolenbroek
29e004d23b VFS: make message pointer management more robust
The previous approach of storing pointers to messages structures for
thread-blocking sendrec operations relied on several assumptions,
which if violated could lead to odd cases of memory corruption.
With this patch, VFS resets pointers right after use, avoiding that
any dangling pointers are accidentally dereferenced later.  This
approach was already used in some cases, but not all of them.

Change-Id: I752d994ea847b46228bd2ccf4e537deceb78fbaf
2015-08-31 12:58:39 +00:00
David van Moolenbroek
bd851af48f VFS: merge scratchpad into fproc
There is no reason to keep these tightly coupled data structures
separate.  Moreover, there is no reason to have a union of file
descriptor and file pointer, since the second can be derived from
the first.  The result are somewhat cleaner VFS internals.

Change-Id: I854da7d8291177878eecfc3077ef0a9e0cc82aaa
2015-08-13 13:45:02 +00:00
David van Moolenbroek
e296281ce2 VFS: do not make cloned devices setuid/setgid
Change-Id: Ifd97444dd54334ccbc8780df9473450998ab7489
2014-09-29 16:16:27 +00:00
David van Moolenbroek
d3434cb55b VFS: convert EINTR to EAGAIN for nonblocking I/O
The conversion was never properly implemented for asynchronous
character drivers, and got lost during the removal of the
synchronous character protocol.

Change-Id: Ib858806859aa7a52d6b391d4c6c521a2be361fdd
2014-08-31 17:29:47 +00:00
David van Moolenbroek
27d0ecdb62 VFS: unbreak select on /dev/tty
The remapping from /dev/tty to the real controlling terminal in the
device code was confusing the select code.  The latter is now aware
of this case and should handle it properly, at the cost of one extra
field in the filp structure.

There is a nasty, hopefully sufficiently rare case of /dev/tty being
kept open while controlling terminals are changing, that we are still
not handling.  Doing so would require more than just a few changes,
but the code should at least detect and cleanly fail on this case.

Test77 now has a basic test set for selecting on /dev/tty.

Change-Id: Iaedea449cdb728d0e66a9de8faacdfd9638dfe92
2014-08-28 16:30:48 +00:00
Lionel Sambuc
433d6423c3 New sources layout
Change-Id: Ic716f336b7071063997cf5b4dae6d50e0b4631e9
2014-07-31 16:00:30 +02:00