Commit graph

1265 commits

Author SHA1 Message Date
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
Lionel Sambuc
e4fa9802cb ARM: Enable caches
First round, some more optimizations are possible and should be
activated.

Change-Id: I3b7dee7c82fbffd823a08bec1c5d5ebcf769f92f
2013-02-18 09:08:26 +01:00
Lionel Sambuc
c3ae1bdfcd Switch to disable bin. exp. wait time in RS 2013-02-16 19:35:19 +01:00
Kees Jongenburger
f240e1eaf5 vm:Display boot process name upon failure to load or execute.
Change-Id: I80fdaca09ae255622083b16dee72715f009dc0ee
2013-02-16 11:20:45 +01:00
Ben Gras
3bc6d7df06 impove memory accounting
. the total amount of memory in the system didn't include the memory
	  used by the boot-time modules and some dynamic allocation by the
	  kernel at boot time (to map in VM). especially apparent on our
	  ARM board with 'only' 512MB of memory and a huge ramdisk.
	. also: *add* the VM loaded module to the freelist after it has
	  been allocated for & mapped in instead of cutting it *out* of the
	  freelist! so we get a few more MB free..

Change-Id: If37ac32b21c9d38610830e21421264da4f20bc4f
2013-02-11 19:31:57 +01:00
Ben Gras
d1df256de9 VM: slight pagedir mapping generalization
. allow any number of pde's used for pagedir mapping
	. allows >1024 NR_PROCS on x86, >64 on ARM
	. allows NR_PROCS to be the same in both cases
	. also cleanup: allocating spare PDE's is not necessary
	  throw that function out

Change-Id: Ibb8f8cf6e7db6a4d6384b6911d1a3f3f5e5d8256
2013-02-10 21:50:34 +01:00
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
Ben Gras
b7ea9f3fd1 vm: fix sanity checks on arm
The 'polarity' of the RW bit is inversed on ARM, causing one
of the sanity check compensations to fail. ARM now runs basic
stuff with sanity checks passing.

Change-Id: Iee28ab63e430e759f204eeb204b24c301d5ea3c9
2013-02-01 16:45:56 +00:00
Ben Gras
08cb986d3f vm: fix kernel-requested mappings for arm
. make vm tell kernel virtual locations of mappings
	. makes _minix_kerninfo feature work
	. fix for mappings being larger than what 1 pde can address
	  (e.g. devices memory requested on arm)
	. still requires a special case for devices memory for the
	  kernel, which has to switch to virtual addressing

Change-Id: I2e94090aa432346fa4da0edeba72f0b7406c2ad7
2013-01-29 17:57:04 +00:00
Thomas Veerman
06e2adbeaa VFS: fix select again
Change-Id: Ia5e26cdbfe38e3fb293dd57269a76b15c1fe236b
2013-01-25 17:42:36 +00:00
Thomas Veerman
b3250450fe VM: ARM needs more spare pages 2013-01-25 17:07:02 +00:00
Thomas Veerman
dad3b4e8c8 ARM: Provide linker script for VM 2013-01-25 17:07:01 +00:00
Thomas Veerman
0968a93748 PFS: verify nrbytes 2013-01-25 17:03:06 +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
b1c4ba4ab6 ARM updates
Due to the ABI we are using we have to use the earm architecture
moniker for the build system to behave correctly. This involves
then some headers to move around.

There is also a few related Makefile updates as well as minor
source code corrections.
2013-01-17 10:03:58 +01:00
Lionel Sambuc
0ac803292e Fix warnings trivial warnings.
Fix warnings about:
 . Unused variables
 . format mismatch in printf/scanf format string and arguments
 . Missing parenthesis around assignment as truth values
 . Clang warnings anout unknown GCC pragma
2013-01-14 11:44:31 +01:00
Lionel Sambuc
22e69f558e Cleaning usage of MAJOR/MINOR
Change-Id: I4d7718c51967930375a5f0657b61f869745cf644
2013-01-14 11:36:26 +01:00
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
Ben Gras
ecf9b40841 vm: fix region reporting bug
. logic was backwards, causing no reporting ever
	. this broke coredumps ('Warning: Program has too many regions')
2013-01-09 19:50:52 +00:00
Ben Gras
b258ab0e66 vm: restore stacktrace on SIGSEGV 2013-01-08 15:47:37 +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
Kees Jongenburger
fce5ff6513 vm: Fix sparepage resource leak.
Fix a sparepage resource leak by preventing to call
vm_getsparepage twice.

Change-Id: I06557d47b90a7cca74e0a86921c2579f9618685d
2013-01-07 09:12:09 +01:00
Ben Gras
29edcad310 vm: replace phys avl by array
. make vm be able to use malloc() by overriding brk()
   and minix_mmap() functions
 . phys regions can then be malloc()ed and free()d instead
   of being in an avl tree, which is slightly faster
 . 'offset' field in phys_region can go too (offset is implied
   by position in array) but leads to bigger code changes
2012-12-26 16:14:41 +00:00
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
Lionel Sambuc
456a46e6bf Removing useless minix/types.h header
Change-Id: If5f922279b87f075f301b64c7786caa18b434c2a
2012-12-07 13:58:06 +01:00
David van Moolenbroek
3027cf8694 RS: do not zero process name for boot processes
This bug was preventing services with IPC restrictions from being
started before the boot processes are edited from /etc/rc.
2012-12-06 13:24:30 +00:00
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
Ben Gras
bcbee7d9e1 RS: fix for fix 2012-11-22 16:25:07 +01:00
Erik van der Kouwe
57c748b968 Remove ability to pass commands to bootloader 2012-11-22 19:16:17 +01:00
Erik van der Kouwe
22fa466268 Restore poweroff to some of it's former glory (on QEMU, at least) 2012-11-21 20:28:37 +01:00
Ben Gras
a89ec8bc3b can't get_block(NO_DEV) any more
. 'anonymous' cache blocks (retrieved with NO_DEV as dev
	  parameter) were used to implement read()s from holes in
	  inodes that should return zeroes
	. this is an awkward special case in the cache code though
	  and there's a more direct way to implement the same functionality:
	  instead of copying from a new, anonymous, zero block, to
	  the user target buffer, simply sys_safememset the user target
	  buffer directly. as this was the only use of this feature,
	  this is all that's needed to simplify the cache code a little.
2012-11-16 16:37:44 +01:00
Ben Gras
2d43bf5807 RS: invoke a shell explicitly for scripts
. don't rely on the scripts to be executable
	  (and they aren't any more)
2012-11-16 16:34:14 +01:00
Ben Gras
d27f8afc45 iso9660fs: initialize buffer cache 2012-11-16 11:09:03 +00:00
Tomas Hruby
dedb53fb10 ipc.h - IPC defined as functions again
- CHOOSETRAP define makes impossible to use some common words
  like send, receive and notify in any other context, for
  instance as members or structures

- any reasonable compiler inlines the static inline functions so
  no extra function call overhead is introduced by this change

- this gets us back to the situation before the SYSCALL/SYSENTER
  change. It is not perfect, but it used to work and still does.
2012-11-15 16:51:59 +01:00
Lionel Sambuc
9152e1c5a7 Upgrading build system to new NetBSD revision
The tested targets are the followgin ones:
 * tools
 * distribution
 * sets
 * release

The remaining NetBSD targets have not been disabled nor tested
*at all*. Try them at your own risk, they may reboot the earth.

For all compliant Makefiles, objects and generated files are put in
MAKEOBJDIR, which means you can now keep objects between two branch
switching. Same for DESTDIR, please refer to build.sh options.

Regarding new or modifications of Makefiles a few things:
 * Read share/mk/bsd.README
 * If you add a subdirectory, add a Makefile in it, and have it called
   by the parent through the SUBDIR variable.
 * Do not add arbitrary inclusion which crosses to another branch of
   the hierarchy; If you can't do without it, put a comment on why.
   If possible, do not use inclusion at all.
 * Use as much as possible the infrastructure, it is here to make
   life easier, do not fight it.

Sets and package are now used to track files.
We have one set called "minix", composed of one package called "minix-sys"
2012-11-15 16:07:29 +01:00
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
Ben Gras
6cf98dbe00 vm: reduce noise in merged pagetable.c 2012-11-09 19:00:46 +01:00
Ben Gras
3771a0833d vm: merge i386 and arm pagetable code 2012-11-09 18:46:03 +01:00
Ben Gras
b1da7fafd0 vm: fix a null dereference on out-of-memory
. also make other out-of-memory conditions less fatal
	. add a test case for a user program using all the memory
	  it can
	. remove some diagnostic prints for situations that are normal
	  when running out of memory so running the test isn't noisy
2012-11-09 18:36:51 +01:00
David van Moolenbroek
ff84d11216 PM: do not panic if sys_sigsend returns ENOMEM 2012-11-09 16:11:02 +00:00
Ben Gras
196021cd82 drop safemap code 2012-10-30 13:55:42 +01:00
Ben Gras
aefc6db005 vm: fix potential null deref 2012-10-24 19:47:47 +02:00
Ben Gras
bd3cde4571 Move primary cache code to libminixfs.
Add primary cache management feature to libminixfs as mfs and ext2
currently do separately, remove cache code from mfs and ext2, and make
them use the libminixfs interface. This makes all fields of the buf
struct private to libminixfs and FS clients aren't supposed to access
them at all. Only the opaque 'void *data' field (the FS block contents,
used to be called bp) is to be accessed by the FS client.

The main purpose is to implement the interface to the 2ndary vm cache
just once, get rid of some code duplication, and add a little
abstraction to reduce the code inertia of the whole caching business.

Some minor sanity checking and prohibition done by mfs in this code
as removed from the generic primary cache code as a result:
        - checking all inodes are not in use when allocating/resizing
          the cache
        - checking readonly filesystems aren't written to
        - checking the superblock isn't written to on mounted filesystems

The minixfslib code relies on fs_blockstats() in the client filesystem to
return some FS usage information.
2012-10-23 19:48:38 +02:00
David van Moolenbroek
46fca87456 VM: munmap fix 2012-10-13 19:08:28 +02:00
Ben Gras
d343041caa VM: make mapping types explicit
Introduce explicit abstractions for different mapping types,
handling the instantiation, forking, pagefaults and freeing of
anonymous memory, direct physical mappings, shared memory and
physically contiguous anonymous memory as separate types, making
region.c more generic.

Also some other genericification like merging the 3 munmap cases
into one.

COW and SMAP safemap code is still implicit in region.c.
2012-10-12 14:52:01 +02:00
Ben Gras
fd4ddef49a VM: munmap used by VM for itself is no longer used 2012-10-12 14:51:35 +02:00
Arun Thomas
471a03a362 ARM support for kernel and vm 2012-10-07 21:38:03 -04:00
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
2cdbb3041d procfs: make ipc vectors available 2012-09-26 17:14:14 +02:00
Ben Gras
2d72cbec41 SYSENTER/SYSCALL support
. add cpufeature detection of both
	. use it for both ipc and kernelcall traps, using a register
	  for call number
	. SYSENTER/SYSCALL does not save any context, therefore userland
	  has to save it
	. to accomodate multiple kernel entry/exit types, the entry
	  type is recorded in the process struct. hitherto all types
	  were interrupt (soft int, exception, hard int); now SYSENTER/SYSCALL
	  is new, with the difference that context is not fully restored
	  from proc struct when running the process again. this can't be
	  done as some information is missing.
	. complication: cases in which the kernel has to fully change
	  process context (i.e. sigreturn). in that case the exit type
	  is changed from SYSENTER/SYSEXIT to soft-int (i.e. iret) and
	  context is fully restored from the proc struct. this does mean
	  the PC and SP must change, as the sysenter/sysexit userland code
	  will otherwise try to restore its own context. this is true in the
	  sigreturn case.
	. override all usage by setting libc_ipc=1
2012-09-24 15:53:43 +02:00
Ben Gras
8a3b6ca3bb remove unused <tools.h> 2012-09-20 12:24:22 +02:00
Ben Gras
b16aacc7f3 vm: fix failed alloc condition 2012-09-19 22:24:56 +02:00
Ben Gras
bc4c07f4f1 coverity appeasement - redundant check 2012-09-19 17:19:57 +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
Ben Gras
25817b0854 vm: change NO_MEM to a more impossible value
fixes an assert() firing when starting X. thanks to the report by pikpik.

	. NO_MEM was 0, which is actually an existing piece
	  of physical memory. it can't be allocated because it's reserved
	  for bios data (by the kernel), but it can be mapped in (e.g.
	  by X), causing sanity check disaster.
	. NONCONTIGUOUS is also obsolete as all allocations are single-page
	  now, i.e. NONCONTIGUOUS is really the default and only mode.
2012-09-19 15:31:36 +02:00
Ben Gras
fe6e291f59 vm, kernel, top: report memory usage of vm, kernel 2012-09-18 23:43:52 +02:00
Ben Gras
aa82e375c6 VM: remove dead code 2012-09-18 18:40:57 +02:00
Ben Gras
d526f1a0db some coverity fixes. 2012-09-18 15:11:51 +02:00
Ben Gras
ddf1981004 VM: restore >4k secondary cache functionality
. by storing length in the yielded blocks node again
2012-09-18 13:17:52 +02:00
Ben Gras
ed1af3c86c VM: full munmap
complete munmap implementation; single-page references made
a general munmap() implementation possible to write cleanly.

	. memory: let the MIOCRAMSIZE ioctl set the imgrd device
	  size (but only to 0)
	. let the ramdisk command set sizes to 0
	. use this command to set /dev/imgrd to 0 after mounting /usr
	  in /etc/rc, so the boot time ramdisk is freed (about 4MB
	  currently)
2012-09-18 13:17:52 +02:00
Ben Gras
16c3870b2e VM: abstract datastructures a bit
. a little less duplication in region.c
2012-09-18 13:17:51 +02:00
Ben Gras
0d1f2e6be2 VM: simplify slab allocator
. only keep a list of non-empty, non-full pages with slab objects
	. simplifies alloc/free operations and reduces list management overhead
2012-09-18 13:17:50 +02:00
Ben Gras
19e6dad47b VM: only single page chunks
. only reference single pages in process data structures
   to simplify page faults, copy-on-write, etc.
 . this breaks the secondary cache for objects that are
   not one-page-sized; restored in a next commit
2012-09-18 13:17:49 +02:00
Ben Gras
6d7b770761 VM: static data structure for mem allocation
. allocate physical memory using a fixed, pre-allocated bitmap so there
   are no call cycles and it's avilable earlier
2012-09-18 13:17:48 +02:00
Ben Gras
2cb560297c VM: remove unused dma memory support functions from vm
. unused calls / data structures
2012-09-18 13:17:47 +02:00
Ben Gras
8821c73a9e VM: forget about 'holes'
. unused data structures and code
2012-09-18 13:17:46 +02:00
Ben Gras
6410f4b5db VM: some sanitycheck fixes
minor fixes to restore SANITYCHECKS
2012-09-18 13:17:45 +02:00
Thomas Veerman
c087a60ed2 VFS: fix GCC compilation error 2012-09-17 15:29:38 +00:00
Thomas Veerman
edefb7b35f PM: don't deliver signals to VM 2012-09-17 11:01:46 +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
Sébastien Boisvert
373cb6526c IPC server: do not loop to find syscall handler
Instead of using a loop to find a matching ipc (inter process
communication) system call type, the offset in the call table can be
simply calculated in constant time.

Also, when the interprocess communication server receives an ipc
system call from a process, ipc should tell VM to watch the process
only once. This patch fixes that also.

(Patch and commit message slightly edited by committer.)
2012-09-10 19:20:03 +02:00
Ben Gras
3c57102616 devman: initialize libvtreefs hooks
. uninitialized cleanup hook was causing devman crashes
	  on reboot, calling uninitialized cleanup hook whenever it
	  didn't happen to be 0
2012-08-31 19:12:49 +02:00
Ben Gras
053fa581b5 vm: remove stack handling for signals
. moved to the kernel as the handling was only
	  reading it; the kernel may as well write it too
2012-08-29 17:31:38 +02:00
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
Arun Thomas
7ca1ce7968 VM: Add PTF_READ page table flag 2012-08-17 00:17:52 +02:00
Arun Thomas
fc9b3f9bdd VM: allow for 16KB chunk alignment 2012-08-17 00:17:52 +02:00
Arun Thomas
c78b56a9e5 RS: Make PCI code optional 2012-08-17 00:17:51 +02:00
David van Moolenbroek
5456f2728e ext2: resolve Coverity warnings 2012-08-14 09:11:19 +00:00
Arun Thomas
697f0d097f Rename sys_vmctl_get_cr3_i386 2012-08-12 23:30:54 +02:00
Arun Thomas
263ec1e885 pm: update for ARM 2012-08-12 23:30:54 +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
David van Moolenbroek
be87fdda3d PM: resolve Coverity warnings 2012-08-09 00:16:35 +02:00
David van Moolenbroek
aa5531fc67 IS: resolve Coverity warnings 2012-08-09 00:16:35 +02:00
David van Moolenbroek
fd8c6c1d30 IPC: resolve Coverity warnings 2012-08-09 00:16:35 +02:00