Commit graph

368 commits

Author SHA1 Message Date
Ben Gras
456359aa72 retire 64-bit conversion functions
Change-Id: Ib6b81403f877c363a286c654e0524fa1cb781b80
2013-06-24 16:50:57 +02:00
Ben Gras
8f2749cca8 vfs: patch for unpause()/revive() race condition
. unpause() and revive() can race - revive() can run during
	  a device i/o unblock, causing two sendnb()s to occur, and the
	  2nd one to fail
	. this can easily happen when a process is blocking on tty and
	  is then killed by a signal - tty cancels the i/o and then
	  kills the process by a signal

Change-Id: Ia319acaedfa336b78c030a2c4af7246959bdcf87
2013-06-14 23:58:43 +02:00
Ben Gras
9e43052b21 inline sendnb should not call send vector
. also vfs has to reply to a vm call - so use asynsend for that

Change-Id: I30ac1e591191dea5c99e25b03151a4415d1151b0
2013-06-12 07:04:53 +00:00
Ben Gras
9178749e13 libc syslog, syslogd, logger, uds fixes
changes necessary for libc syslog() using a unix domain socket.

	. libc syslog: don't use send() connect() for unix
	  datagram sockets, minix wants write() and ioctl()
	. syslogd: listen on _PATH_LOG unix domain socket
	. logger: warnings fixes
	. pfs: make uds dgram socket type nonblocking so
	  syslog() doesn't block
	. vfs: add sanity check for empty fd in unpause()

Change-Id: Ied136c6fe0cc288f5a53478f1eebccc1ab1f39fb
2013-06-12 07:04:52 +00:00
Ben Gras
f369157d95 pfs, vfs: increase various limits
. pipes in pfs
	. vnodes in vfs
	. thread stack sizes in vfs

Change-Id: Ib27dedd42f57a90821a5b950cd7ea25cb2b42f3f
2013-05-31 15:42:00 +00:00
Ben Gras
33a7ac7557 vfs: mmap support
. libc: add vfs_mmap, a way for vfs to initiate mmap()s.
	  This is a good special case to have as vfs is a slightly
	  different client from regular user processes. It doesn't do it
	  for itself, and has the dev & inode info already so the callback
	  to VFS for the lookup isn't necessary. So it has different info
	  to have to give to VM.
	. libc: also add minix_mmap64() that accepts a 64-bit offset, even
	  though our off_t is still 32 bit now.
	. On exec() time, try to mmap() in the executable if available.
	  (It is not yet available in this commit.)
	. To support mmap(), add do_vm_call that allows VM to lookup
	  (to ino+dev), do i/o from and close FD's on behalf of other
	  processes.

Change-Id: I831551e45a6781c74313c450eb9c967a68505932
2013-05-31 15:42:00 +00:00
Ben Gras
2d2a1a077d panic: declare as printf-style-checked
. and related fixes

Change-Id: I5131ac57dc53d8aec8d421a34c5ceea383404d7a
2013-05-31 13:35:25 +00:00
Ben Gras
5507a12d7c vfs: who_p fix
Change-Id: I0e04b6460907f5e67f6c90b2038d296d66b9a414
2013-05-31 09:28:38 +00:00
Ben Gras
4ebb889e7a libsys: panic hook feature
. vfs: use it to dump threads stacks

Change-Id: I7ae3521fc153a407505f11049629e6d4142cf7c7
2013-05-07 17:18:40 +00:00
Ben Gras
44f34e53d5 VFS: Implement REQ_BPEEK.
This commit introduces a new request type called REQ_BPEEK. It
requests minor device blocks from the FS.  Analogously to REQ_PEEK,
it requests the filesystem to get the requested blocks into its
cache, without actually copying the result anywhere.

Change-Id: If1d06645b0e17553a64b3167091e9d12efeb3d6f
2013-04-24 10:18:16 +00:00
Ben Gras
0cfff08e56 libexec: mmap support, prealloc variants
In libexec, split the memory allocation method into cleared and
non-cleared. Cleared gives zeroed memory, non-cleared gives 'junk'
memory (that will be overwritten anyway, and so needn't be cleared)
that is faster to get.

Also introduce the 'memmap' method that can be used, if available,
to map code and data from executables into a process using the
third-party mmap() mode.

Change-Id: I26694fd3c21deb8b97e01ed675dfc14719b0672b
2013-04-24 10:18:16 +00:00
Xiaoguang Sun
20e6c9329f Change function prototype to use endpoint_t instead of int 2013-04-23 17:15:15 +02:00
Ben Gras
072d916c1c vfs: fix null deref, pfs: add fchmod()
. vfs read_only() assumes vnode->v_vmnt is non-NULL, but it can
	  be NULL sometimes
	. e.g. fchmod() on UDS triggered NULL deref; add a check and
	  add REQ_CHMOD to pfs so unix domain sockets can be fchmod()ded
	. add to test56

Change-Id: I83c840f101b647516897cc99fcf472116d762012
2013-04-19 17:06:56 +02:00
Ben Gras
cef94e096e vfs: make m_out non-global
m_out is shared between threads as the reply message, and it can happen
results get overwritten by another thread before the reply is sent. This
change

	. makes m_out local to the message handling function,
	  declared on the stack of the caller
	. forces callers of reply() to give it a message, or
	  declare the reply message has no significant fields except
	  for the return code by calling replycode()

Change-Id: Id06300083a63c72c00f34f86a5c7d96e4bbdf9f6
2013-04-12 23:40:38 +00:00
Antoine Leca
9131e98a7d utimens(2) system call
Variant of utime(2) with struct timespec (with ns precision)
instead of time_t values; also allows for tv_nsec members
the values UTIME_NOW (force update to current time) or
UTIME_OMIT (allow to set either atim or mtim independently.)

Provides a superset of utimes(2), futimes(2), lutimes(2),
and futimens(2).
Provides the same subset of utimensat(2) as does NetBSD 6.
Also import utimens() and lutimeNS() from NetBSD-current.
2013-04-12 18:55:39 +00:00
Antoine Leca
4069cef7f9 Subsecond timestamps support for FS
Expand REQ_UTIME to include tv_nsec members
(as in struct timespec) in addition to tv_sec==time_t

Designed with help from David van Moolenbroek
2013-04-12 11:11:59 +02:00
Thomas Cort
516fec97d9 libc: add clock_settime() system call.
This also adds the sys_settime() kernel call which allows for the adjusting
of the clock named realtime in the kernel. The existing sys_stime()
function is still needed for a separate job (setting the boottime). The
boottime is set in the readclock driver. The sys_settime() interface is
meant to be flexible and will support both clock_settime() and adjtime()
when adjtime() is implemented later.

settimeofday() was adjusted to use the clock_settime() interface.

One side note discovered during testing: uptime(1) (part of the last(1)),
uses wtmp to determine boottime (not Minix's times(2)). This leads `uptime`
to report odd results when you set the time to a time prior to boottime.
This isn't a new bug introduced by my changes. It's been there for a while.
2013-04-04 15:04:54 +02:00
Thomas Cort
e67fc5771d libc: add clock_getres()/clock_gettime() system calls.
In order to make it more clear that ticks should be used for timers
and realtime should be used for timestamps / displaying the date/time,
getuptime() was renamed to getticks() and getuptime2() was renamed to
getuptime().

Servers, drivers, libraries, tests, etc that use getuptime()/getuptime2()
have been updated. In instances where a realtime was calculated, the
calculation was changed to use realtime.

System calls clock_getres() and clock_gettime() were added to PM/libc.
2013-04-04 15:04:53 +02:00
Thomas Veerman
6ee180f5f7 VFS: wikify README
Change-Id: I746f7c8ddabd1e047b8d536df14586c5b1594d55
2013-03-21 15:20:34 +00:00
Ben Gras
4f9139778d vfs: coredump fix: write zeroes for missing memory 2013-03-20 20:05:31 +00:00
Thomas Veerman
76ddef10da UDS: terminate canonical path string
When you provided a string with junk after the terminating nul to a
UNIX domain socket and used bind(2), the canonical path function would
not properly terminate the new string. This caused VFS to return
ENAMETOOLONG on an otherwise valid path name.

Test case is added to test56.

Change-Id: I883b6be23d9e4ea13c3cee28cbb3726343df037f
2013-03-08 15:42:32 +00:00
Ben Gras
a9f55a2e46 VFS, FSes: add REQ_PEEK request type
REQ_PEEK behaves just like REQ_READ except that it does not copy
data anywhere, just obtains the blocks from the FS into the cache.

To be used by the future mmap implementation.

Change-Id: I1b56de304f0a7152b69a72c8962d04258adb44f9
2013-03-07 10:57:38 +00:00
Lionel Sambuc
8f3fbf7cc1 Cleanup: Remove minix.bootprog.mk
The build system distinction between "bootprog" and "service" is
meaningless as boot programs are standard services.

As minix.service.mk simply imports minix.bootprog.mk, reduce confusion
by removing minix.bootprog.mk and placing the rules in minix.service.mk.

Change-Id: I4056b1e574bed59a8c890239b41b1a7c7cad63e8
2013-03-06 11:56:56 +01:00
Thomas Veerman
49ad4e8888 Spring cleanup
Remove old versions of system calls and system calls that don't have
a libc api interface anymore (dup, dup2, creat).

VFS still contains support for old system call numbers for the new stat
system calls (i.e., 65, 66, 67) to keep supporting old binaries built for
MINIX 3.2.1 (prior to the release).

Change-Id: I721779b58a50c7eeae20669de24658d55d69b25b
2013-03-06 09:56:08 +00:00
Thomas Veerman
473547c777 VFS: implement pipe2
Change-Id: Iedc8042dd73a903456b25ba665d12577f5589ca2
2013-02-28 10:08:53 +00:00
Thomas Veerman
fa78dc389f socket: implement SOCK_CLOEXEC and SOCK_NONBLOCK
Change-Id: I3fa36fa999c82a192d402cb4d913bd397e106e53
2013-02-28 10:08:53 +00:00
Thomas Veerman
fd610ba1b0 VFS: add ability to open files O_CLOEXEC
.adjust libc to make use of it (undo __minix diff)

Change-Id: I90a1aa219fcd1b12b6bc60e72176f326eac8184a
2013-02-28 10:08:53 +00:00
Lionel Sambuc
f640210005 Removing obsolete _NBSD_LIBC define
Change-Id: Ia6ce84ccdf36cf6f64540b990baaa7d85c53533d
2013-02-26 09:44:24 +00:00
Lionel Sambuc
8e4736f2df Removing obsolete _MINIX define
Change-Id: Id33ac7e973d1c0e249b690fe44a597474fac6076
2013-02-26 09:44:20 +00:00
Thomas Veerman
2b90964e33 VFS: don't garbage collect if file is already closed 2013-02-21 10:29:08 +00:00
Thomas Veerman
cfcce207c1 VFS: prevent unmapping drivers that don't support reopening
libchardriver does not support DEV_REOPEN and will return ERESTART
when you do try it. This made VFS unhappy and concluded erroneously
that the driver was EDEADEPT.
2013-02-21 10:29:08 +00:00
Ben Gras
298b41b523 libexec: detect short files
if an exec() fails partway through reading in the sections, the target
process is already gone and a defunct process remains. sanity checking
the binary beforehand helps that.

test10 mutilates binaries and exec()s them on purpose; making an exec()
fail cleanly in such cases seems like acceptable behaviour.

fixes test10 on ARM.

Change-Id: I1ed9bb200ce469d4d349073cadccad5503b2fcb0
2013-02-04 12:04:35 +01:00
Thomas Veerman
06e2adbeaa VFS: fix select again
Change-Id: Ia5e26cdbfe38e3fb293dd57269a76b15c1fe236b
2013-01-25 17:42:36 +00:00
Thomas Veerman
b180f32ab3 VFS/PFS: remove remnants of file position in pipes 2013-01-23 11:14:34 +00:00
Thomas Veerman
306f3ccd6f VFS: fix select bug on pipes 2013-01-23 11:14:34 +00:00
Lionel Sambuc
f14fb60209 Libraries updates and cleanup
* Updating common/lib
 * Updating lib/csu
 * Updating lib/libc
 * Updating libexec/ld.elf_so
 * Corrected test on __minix in featuretest to actually follow the
   meaning of the comment.
 * Cleaned up _REENTRANT-related defintions.
 * Disabled -D_REENTRANT for libfetch
 * Removing some unneeded __NBSD_LIBC defines and tests

Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
2013-01-14 11:36:26 +01:00
Thomas Veerman
bdfef53dbf VFS: initialize variables 2013-01-11 12:46:44 +00:00
Thomas Veerman
aa521228a5 VFS: Coverity appeasements 2013-01-11 09:42:01 +00:00
Thomas Veerman
ea8ff9284a Add stack trace dumps for VFS over serial 2013-01-11 09:18:36 +00:00
Thomas Veerman
625f4ae4a3 VFS: add documentation about internal working 2013-01-11 09:18:36 +00:00
Thomas Veerman
23c5f56e32 VFS: change locking to ease concurrent FSes
This patch uses stricter locking for REQ_LINK, REQ_MKDIR, REQ_MKNOD,
REQ_RENAME, REQ_RMDIR, REQ_SLINK and REQ_UNLINK. For all requests, VFS
locks the directory in which we add or remove an inode with VNODE_WRITE.
I.e., the operations have exclusive access to that directory.

Furthermore, REQ_CHOWN, REQ_CHMOD, and REQ_FTRUNC now lock the vmnt
VMNT_READ; VMNT_WRITE was unnecessary.
2013-01-11 09:18:35 +00:00
Thomas Veerman
3de8d1cf6e VFS/PFS: remove notion of position in pipes
Because pipes have no file position. VFS maintained (file) offsets into a
buffer internal to PFS and stored them in vnodes for simplicity, mixing
the responsibilities of filp and vnode objects.

With this patch PFS ignores the position field in REQ_READ and REQ_WRITE
requests making VFS' job a lot simpler.
2013-01-11 09:18:35 +00:00
Thomas Veerman
7c8b3ddfed VFS: fix locking bugs
.sync and fsync used unnecessarily restrictive locking type
.fsync violated locking order by obtaining a vmnt lock after a filp lock
.fsync contained a TOCTOU bug
.new_node violated locking rules (didn't upgrade lock upon file creation)
.do_pipe used unnecessarily restrictive locking type
.always lock pipes exclusively; even a read operation might require to do
 a write on a vnode object (update pipe size)
.when opening a file with O_TRUNC, upgrade vnode lock when truncating
.utime used unnecessarily restrictive locking type
.path parsing:
  .always acquire VMNT_WRITE or VMNT_EXCL on vmnt and downgrade to
   VMNT_READ if that was what was actually requested. This prevents the
   following deadlock scenario:
   thread A:
     lock_vmnt(vmp, TLL_READSER);
     lock_vnode(vp, TLL_READSER);
     upgrade_vmnt_lock(vmp, TLL_WRITE);

   thread B:
     lock_vmnt(vmp, TLL_READ);
     lock_vnode(vp, TLL_READSER);

   thread A will be stuck in upgrade_vmnt_lock and thread B is stuck in
   lock_vnode. This happens when, for example, thread A tries create a
   new node (open.c:new_node) and thread B tries to do eat_path to
   change dir (stadir.c:do_chdir). When the path is being resolved, a
   vnode is always locked with VNODE_OPCL (TLL_READSER) and then
   downgraded to VNODE_READ if read-only is actually requested. Thread
   A locks the vmnt with VMNT_WRITE (TLL_READSER) which still allows
   VMNT_READ locks. Thread B can't acquire a lock on the vnode because
   thread A has it; Thread A can't upgrade its vmnt lock to VMNT_WRITE
   (TLL_WRITE) because thread B has a VMNT_READ lock on it.

   By serializing vmnt locks during path parsing, thread B can only
   acquire a lock on vmp when thread A has completely finished its
   operation.
2013-01-11 09:18:35 +00:00
Kees Jongenburger
c0c581a635 vfs:fix for variable 'rfp' set but not used.
mount.c: In function 'mount_pfs':
mount.c:395:17: error: variable 'rfp' set but not used [-Werror=unused-but-set-variable]

Change-Id: I2f22590ab4e3a4a1678e9096626ebca53d2660e6
2013-01-07 09:12:27 +01:00
Ben Gras
8aeac26999 vfs: fix clobbering fd_nr
dumpcore: fd_nr can be in use as blocking fd but will then be clobbered
by common_open, causing disaster for exiting unpause().
2012-12-11 12:00:57 +01:00
David van Moolenbroek
766047123a VFS: fix off-by-one in get_name() 2012-11-30 12:24:47 +00:00
Thomas Veerman
179261a9b6 mtab: support moving mount points
Also fix canonical_path function; it fails to parse some paths
2012-11-29 10:50:51 +00:00
Thomas Veerman
d9f4f71916 Implement dynamic mtab support
With this patch /etc/mtab becomes obsolete.
2012-11-26 15:20:18 +00:00
Thomas Veerman
de83b2a9d9 VFS: change 'last_dir' to match locking assumption
new_node makes the assumption that when it does last_dir on a path, a
successive advance would not yield a lock on a vmnt, because last_dir
already locked the vmnt. This is true except when last_dir resolves
to a directory on the parent vmnt of the file that was the result of
advance. For example,
 # cd /
 # echo foo > home
where home is on a different (sub) partition than / is (default
install). last_dir would resolve to / and advance would resolve to
/home.

With this change, last_dir resolves to the root node on the /home
partition, making the assumption valid again.
2012-11-26 15:20:18 +00:00
David van Moolenbroek
7dd286e6b8 VFS: do not save device node for new regular files
The VFS/FS protocol does not require the file server to supply a
special device node number in response to a REQ_CREATE request, as
this call creates only regular files. Therefore, VFS should not
erroneously save this piece of information from the REQ_CREATE reply
either.
2012-11-15 14:29:59 +00:00
Thomas Veerman
14e470be81 VFS: fix TOCTOU bug in sync 2012-11-14 13:24:53 +00:00
Thomas Veerman
ed23a7a7d2 VFS: fix reboot panic with mounted FUSE FS
Upon reboot VFS semi-exits all processes and unmounts the file system.
However, upon unmount, exiting FUSE file systems might need service from
the file system (due to libc). As the FUSE process is halfway the exit
procedure, it doesn't have a valid root directory and working directory.
Trying to do system calls then triggers a sanity check in VFS.

This fix first exits normal processes which should then allow for
unmounting FUSE file systems. Then VFS exits all processes including
File Servers and unmounts the rest of the file system.
2012-11-14 13:18:16 +00:00
Thomas Veerman
badec36b33 VFS: fix deadlock when out of worker threads
There is a deadlock vulnerability when there are no worker threads
available and all of them blocked on a worker thread that's waiting for a
reply from a driver or a reply from an FS that needs to make a back call. In
these cases the deadlock resolver thread should kick in, but didn't in all
cases. Moreover, POSIX calls from File Servers weren't handled properly
anymore, which also could lead to deadlocks.
2012-11-14 13:12:37 +00:00
Arne Welzel
e35c4f78d2 VFS: fix check_bsf() locking
The check_bsf() macro uses assert(mutex_trylock(&bsf_lock)) and
assumes bsf_lock is locked afterwards. This breaks when compiling
with NOASSERTS="yes". Also: macro to function transition.
2012-09-28 14:57:34 +02:00
Arne Welzel
7e1074732b VFS: resolve unused parameter if NOASSERTS="yes"
If VFS is compiled with NOASSERTS="yes", ctty_opcl() does not
use the op parameter. Change to "non-assert()" sanity check.
2012-09-28 14:57:32 +02:00
Ben Gras
60014efb3e vfs: pm_dumpcore: always clean up process
. whenever this function is called, pm will expect
	  the process to be cleaned up
	. so don't abort the process entirely on error
	. fixes a later 'forking on top of in-use child' vfs panic
2012-09-19 17:13:17 +02:00
Thomas Veerman
c087a60ed2 VFS: fix GCC compilation error 2012-09-17 15:29:38 +00:00
Thomas Veerman
3881e732a9 VFS: panic when unmount_all fails 2012-09-17 11:01:46 +00:00
Thomas Veerman
992799b91f VFS: make all IPC asynchronous
By decoupling synchronous drivers from VFS, we are a big step closer to
supporting driver crashes under all circumstances. That is, VFS can't
become stuck on IPC with a synchronous driver (e.g., INET) and can
recover from crashing block drivers during open/close/ioctl or during
communication with an FS.

In order to maintain serialized communication with a synchronous driver,
the communication is wrapped by a mutex on a per driver basis (not major
numbers as there can be multiple majors with identical endpoints). Majors
that share a driver endpoint point to a single mutex object.

In order to support crashes from block drivers, the file reopen tactic
had to be changed; first reopen files associated with the crashed
driver, then send the new driver endpoint to FSes. This solves a
deadlock between the FS and the block driver;
  - VFS would send REQ_NEW_DRIVER to an FS, but he FS only receives it
    after retrying the current request to the newly started driver.
  - The block driver would refuse the retried request until all files
    had been reopened.
  - VFS would reopen files only after getting a reply from the initial
    REQ_NEW_DRIVER.

When a character special driver crashes, all associated files have to
be marked invalid and closed (or reopened if flagged as such). However,
they can only be closed if a thread holds exclusive access to it. To
obtain exclusive access, the worker thread (which handles the new driver
endpoint event from DS) schedules a new job to garbage collect invalid
files. This way, we can signal the worker thread that was talking to the
crashed driver and will release exclusive access to a file associated
with the crashed driver and prevent the garbage collecting worker thread
from dead locking on that file.

Also, when a character special driver crashes, RS will unmap the driver
and remap it upon restart. During unmapping, associated files are marked
invalid instead of waiting for an endpoint up event from DS, as that
event might come later than new read/write/select requests and thus
cause confusion in the freshly started driver.

When locking a filp, the usage counters are no longer checked. The usage
counter can legally go down to zero during filp invalidation while there
are locks pending.

DS events are handled by a separate worker thread instead of the main
thread as reopening files could lead to another crash and a stuck thread.
An additional worker thread is then necessary to unlock it.

Finally, with everything asynchronous a race condition in do_select
surfaced. A select entry was only marked in use after succesfully sending
initial select requests to drivers and having to wait. When multiple
select() calls were handled there was opportunity that these entries
were overwritten. This had as effect that some select results were
ignored (and select() remained blocking instead if returning) or do_select
tried to access filps that were not present (because thrown away by
secondary select()). This bug manifested itself with sendrecs, but was
very hard to reproduce. However, it became awfully easy to trigger with
asynsends only.
2012-09-17 11:01:45 +00:00
Ben Gras
e4ac80eb60 various warning/errorwarning fixes for gcc47
. warnings (sometimes promoted to errors) in servers/ and kernel/
 . -Os for ext2 boot module to make it small enough
2012-08-27 16:19:18 +02:00
Ben Gras
31d8526346 libexec: add load_offset feature, used for ld.so
. ld.so is linked at 0 but it can relocate itself; we
	  wish to load ld.so higher though to trap NULL dereferences.
	  if we know we have to execute ld.so, vfs tells libexec to put it
	  higher.
2012-08-12 23:22:54 +02:00
Thomas Veerman
66dbf73049 VFS: fix locking bug in clone_opcl
When VFS runs out of vnodes after closing a vnode in opcl, common_open
will try to unlock a vnode through unlock_filp that has already been
unlocked in clone_opcl. By first obtaining and locking a new vnode this
situation is prevented; if there are no free vnodes, common_open will
unlock a still locked vnode.
2012-07-30 10:01:16 +00:00
Thomas Veerman
f6b0d662b5 VFS: check path components for NAME_MAX length 2012-07-30 09:44:58 +00:00
David van Moolenbroek
0b4c154160 VFS: call req_inhibread again 2012-07-19 14:36:51 +00:00
David van Moolenbroek
e0742978f1 VFS: do not resolve symlinks in rename(2) 2012-07-18 14:59:45 +00:00
Thomas Veerman
0d3ccd8908 VFS: fix coverity defects 2012-07-17 10:29:22 +00:00
Thomas Veerman
fd60f03129 VFS: remove support for sync FS communication 2012-07-17 10:12:53 +00:00
Thomas Veerman
06f49fe167 VFS: prevent buffer overflow
If an FS returns faulty struct dirent data, VFS could overflow
a buffer that holds this data.
2012-07-17 08:49:41 +00:00
Ben Gras
cbcdb838f1 various coverity-inspired fixes
. some strncpy/strcpy to strlcpy conversions
	. new <minix/param.h> to avoid including other minix headers
	  that have colliding definitions with library and commands code,
	  causing parse warnings
	. removed some dead code / assignments
2012-07-16 14:00:56 +02:00
Thomas Veerman
77dbd766c1 VFS: Use safe string copy functions 2012-07-16 10:57:43 +00:00
Ben Gras
50e2064049 No more intel/minix segments.
This commit removes all traces of Minix segments (the text/data/stack
memory map abstraction in the kernel) and significance of Intel segments
(hardware segments like CS, DS that add offsets to all addressing before
page table translation). This ultimately simplifies the memory layout
and addressing and makes the same layout possible on non-Intel
architectures.

There are only two types of addresses in the world now: virtual
and physical; even the kernel and processes have the same virtual
address space. Kernel and user processes can be distinguished at a
glance as processes won't use 0xF0000000 and above.

No static pre-allocated memory sizes exist any more.

Changes to booting:
        . The pre_init.c leaves the kernel and modules exactly as
          they were left by the bootloader in physical memory
        . The kernel starts running using physical addressing,
          loaded at a fixed location given in its linker script by the
          bootloader.  All code and data in this phase are linked to
          this fixed low location.
        . It makes a bootstrap pagetable to map itself to a
          fixed high location (also in linker script) and jumps to
          the high address. All code and data then use this high addressing.
        . All code/data symbols linked at the low addresses is prefixed by
          an objcopy step with __k_unpaged_*, so that that code cannot
          reference highly-linked symbols (which aren't valid yet) or vice
          versa (symbols that aren't valid any more).
        . The two addressing modes are separated in the linker script by
          collecting the unpaged_*.o objects and linking them with low
          addresses, and linking the rest high. Some objects are linked
          twice, once low and once high.
        . The bootstrap phase passes a lot of information (e.g. free memory
          list, physical location of the modules, etc.) using the kinfo
          struct.
        . After this bootstrap the low-linked part is freed.
        . The kernel maps in VM into the bootstrap page table so that VM can
          begin executing. Its first job is to make page tables for all other
          boot processes. So VM runs before RS, and RS gets a fully dynamic,
          VM-managed address space. VM gets its privilege info from RS as usual
          but that happens after RS starts running.
        . Both the kernel loading VM and VM organizing boot processes happen
	  using the libexec logic. This removes the last reason for VM to
	  still know much about exec() and vm/exec.c is gone.

Further Implementation:
        . All segments are based at 0 and have a 4 GB limit.
        . The kernel is mapped in at the top of the virtual address
          space so as not to constrain the user processes.
        . Processes do not use segments from the LDT at all; there are
          no segments in the LDT any more, so no LLDT is needed.
        . The Minix segments T/D/S are gone and so none of the
          user-space or in-kernel copy functions use them. The copy
          functions use a process endpoint of NONE to realize it's
          a physical address, virtual otherwise.
        . The umap call only makes sense to translate a virtual address
          to a physical address now.
        . Segments-related calls like newmap and alloc_segments are gone.
        . All segments-related translation in VM is gone (vir2map etc).
        . Initialization in VM is simpler as no moving around is necessary.
        . VM and all other boot processes can be linked wherever they wish
          and will be mapped in at the right location by the kernel and VM
          respectively.

Other changes:
        . The multiboot code is less special: it does not use mb_print
          for its diagnostics any more but uses printf() as normal, saving
          the output into the diagnostics buffer, only printing to the
          screen using the direct print functions if a panic() occurs.
        . The multiboot code uses the flexible 'free memory map list'
          style to receive the list of free memory if available.
        . The kernel determines the memory layout of the processes to
          a degree: it tells VM where the kernel starts and ends and
          where the kernel wants the top of the process to be. VM then
          uses this entire range, i.e. the stack is right at the top,
          and mmap()ped bits of memory are placed below that downwards,
          and the break grows upwards.

Other Consequences:
        . Every process gets its own page table as address spaces
          can't be separated any more by segments.
        . As all segments are 0-based, there is no distinction between
          virtual and linear addresses, nor between userspace and
          kernel addresses.
        . Less work is done when context switching, leading to a net
          performance increase. (8% faster on my machine for 'make servers'.)
	. The layout and configuration of the GDT makes sysenter and syscall
	  possible.
2012-07-15 22:30:15 +02:00
Ben Gras
0fb2f83da9 drop from segments physcopy/vircopy invocations
. sys_vircopy always uses D for both src and dst
	. sys_physcopy uses PHYS_SEG if and only if corresponding
	  endpoint is NONE, so we can derive the mode (PHYS_SEG or D)
	  from the endpoint arg in the kernel, dropping the seg args
	. fields in msg still filled in for backwards compatability,
	  using same NONE-logic in the library
2012-06-18 12:28:40 +00:00
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
Ben Gras
85ff5a947e dumpcore: use ptrace function to trigger a coredump
. dumpcore currently relies on minix segments
	. also ptrace dumpcore fix
2012-06-15 12:13:50 +02:00
Ben Gras
769af57274 further libexec generalization
. new mode for sys_memset: include process so memset can be
	  done in physical or virtual address space.
	. add a mode to mmap() that lets a process allocate uninitialized
	  memory.
	. this allows an exec()er (RS, VFS, etc.) to request uninitialized
	  memory from VM and selectively clear the ranges that don't come
	  from a file, leaving no uninitialized memory left for the process
	  to see.
	. use callbacks for clearing the process, clearing memory in the
	  process, and copying into the process; so that the libexec code
	  can be used from rs, vfs, and in the future, kernel (to load vm)
	  and vm (to load boot-time processes)
2012-06-07 15:15:02 +02:00
Ben Gras
040362e379 exec() cleanup, generalization, improvement
. make exec() callers (i.e. vfs and rs) determine the
	  memory layout by explicitly reserving regions using
	  mmap() calls on behalf of the exec()ing process,
	  i.e. handling all of the exec logic, thereby eliminating
	  all special exec() knowledge from VM.
	. the new procedure is: clear the exec()ing process
	  first, then call third-party mmap()s to reserve memory, then
	  copy the executable file section contents in, all using callbacks
	  tailored to the caller's way of starting an executable
	. i.e. no more explicit EXEC_NEWMEM-style calls in PM or VM
	  as with rigid 2-section arguments
	. this naturally allows generalizing exec() by simply loading
	  all ELF sections
	. drop/merge of lots of duplicate exec() code into libexec
	. not copying the code sections to vfs and into the executable
	  again is a measurable performance improvement (about 3.3% faster
	  for 'make' in src/servers/)
2012-06-07 15:15:01 +02:00
Ben Gras
41b869d4d6 drop aout support
justification: soon we won't be able to execute sep I&D aouts at
all (because of the vanishing segments), which was the default mode
to generate them so most binaries will be sep I&D.

this makes the vfs/rs exec() unification work simpler.

after unification, common I&D aout could be added back quite simply.
2012-06-07 12:43:16 +02:00
David van Moolenbroek
1817f7fc07 VFS: fix "process already free" panic on reboot
Reported by Claudiu Dan Gheorghe, debugged by Thomas and myself
2012-05-02 17:42:50 +02:00
Thomas Veerman
068d443d12 VFS: unlock vmnt when out of vnodes 2012-04-27 08:51:13 +00:00
Thomas Veerman
b6ff38065f VFS: release what can be released
Only attempt to release blocked processes that are blocked. There is
no use in trying to find more blocked processes than we know that are
blocked (on a pipe).
2012-04-27 08:51:02 +00:00
Thomas Veerman
7b81254069 VFS: simplify stat for pipes
According to POSIX the st_size field of struct stat is undefined for
fifos and anonymous pipes. Thus we can do anything we want. We save a
copy by not being accurate on pipe sizes.
2012-04-27 08:50:49 +00:00
Thomas Veerman
db8198d99d VFS: use S_IS* macros 2012-04-27 08:49:38 +00:00
Thomas Veerman
96bbc5da3e VFS: I_PIPE is redundant
Also, use S_IS* macros instead of manual comparison.
2012-04-27 08:49:38 +00:00
Ben Gras
755102d67f AT_SUN_EXECNAME support
. vfs: pass execname in aux vectors
	. ld.elf_so: use this to expand $ORIGIN
	. this requires the executable to reserve more
	  space at exec() calling time
2012-04-26 13:32:39 +02:00
David van Moolenbroek
26f817243b VFS: reimplement truncate mtime/ctime fix
POSIX mandates that a file's modification and change time be left
untouched upon truncate/ftruncate iff the file size does not change.
However, an open(O_TRUNC) call must always update the modification and
change time of the file, even if it was already zero-sized. VFS uses
the file systems' truncate call to implement O_TRUNC. This patch
replaces git-255ae85, which did not take into account the open case.
The size check is now moved into VFS, so that individual file systems
need not check for this case anymore.
2012-04-20 11:35:59 +02:00
Ben Gras
3945cfbfd3 block ioctls: pass request number 2012-04-18 11:01:15 +02:00
Ben Gras
53002f6f6c recognize and execute dynamically linked executables
. generalize libexec slightly to get some more necessary information
	  from ELF files, e.g. the interpreter
	. execute dynamically linked executables when exec()ed by VFS
	. switch to netbsd variant of elf32.h exclusively, solves some
	  conflicting headers
2012-04-16 00:41:42 +00:00
Thomas Veerman
26ec619a30 VFS: fix filp reuse race
Pipes consist of two filps (read filp and write filp) and a shared
vnode. When the writer leaves the filp reference count drops to
zero and subsequent find_filp()s should not find the filp when a
reader looks for it and the reader gets EOF. However, the pipe()
system call tries to find two filps, marks them in use, and only
after a successful node creation on PFS, overwrites the shared
vnode with the new vnode. Consequently, this leaves a small window
where a just closed 'pipe write filp' gets reused and marked as
present, before becoming the actual new 'pipe write filp' for a new
pipe. A reader for the old pipe will think a writer is present and
wait for that writer to write something or to leave; both actions
should revive the suspended reader. This will never happen and the
reader will be stuck forever.
2012-04-13 13:22:57 +00:00
Thomas Veerman
e292ba487e VFS: more three-level-lock sanity checking 2012-04-13 13:22:42 +00:00
Thomas Veerman
933120b0b1 VFS: add getting active threads control msg 2012-04-13 13:21:01 +00:00
Thomas Veerman
e1a73469c8 VFS: remove debug print 2012-04-13 13:20:28 +00:00
Thomas Veerman
c2bb739760 VFS: let know when skipping reply 2012-04-13 13:19:45 +00:00
Thomas Veerman
91a38b6d4e VFS: fix dead lock
When running out of worker threads to handle device replies a dead
lock resolver thread is used. However, it was only used for FS
endpoints; it is now used for "system processes" (drivers and FS
endpoints). Also, drivers were marked as system process when they
were not "forced" to map (i.e., mapping was done before endpoint was
alive).
2012-04-13 13:19:10 +00:00
Thomas Veerman
b956493367 VFS: fix new signed/unsigned comparisons 2012-04-13 13:00:11 +00:00
Thomas Veerman
defe329519 VFS: warnings are errors 2012-04-13 12:59:32 +00:00
Thomas Veerman
0d63d9e125 VFS: enable sending control messages 2012-04-13 12:54:55 +00:00
Thomas Veerman
f571466c56 VFS: find job only if request is an transaction 2012-04-13 12:52:52 +00:00
Thomas Veerman
8f55767619 VFS: make m_in job local
By making m_in job local (i.e., each job has its own copy of m_in instead
of refering to the global m_in) we don't have to store and restore m_in
on every thread yield. This reduces overhead. Moreover, remove the
assumption that m_in is preserved. Do_XXX functions have to copy the
system call parameters as soon as possible and only pass those copies to
other functions.

Furthermore, this patch cleans up some code and uses better types in a lot
of places.
2012-04-13 12:50:38 +00:00
Ben Gras
1e2b3f4326 vfs: more regions for coredumps 2012-04-12 14:29:59 +02:00
Ben Gras
204ae72525 retire _ANSI and <minix/ansi.h> 2012-03-25 21:58:27 +02:00