Commit Graph

21 Commits

Author SHA1 Message Date
Mateusz Guzik
f6f6d24062 Implement lockless resource limits.
Use the same scheme implemented to manage credentials.

Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.

Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
2015-06-10 10:48:12 +00:00
Mateusz Guzik
4ea6a9a28f Generalised support for copy-on-write structures shared by threads.
Thread credentials are maintained as follows: each thread has a pointer to
creds and a reference on them. The pointer is compared with proc's creds on
userspace<->kernel boundary and updated if needed.

This patch introduces a counter which can be compared instead, so that more
structures can use this scheme without adding more comparisons on the boundary.
2015-06-10 10:43:59 +00:00
Mateusz Guzik
cdcf242896 Fix up module unload for syscall_module_handler consumers.
After r273707 it was registering syscalls as static.

This fixes hwpmc module unload.

Reported by: markj
2014-11-01 22:36:40 +00:00
Mateusz Guzik
e015b1ab0a Avoid dynamic syscall overhead for statically compiled modules.
The kernel tracks syscall users so that modules can safely unregister them.

But if the module is not unloadable or was compiled into the kernel, there is
no need to do this.

Achieve this by adding SY_THR_STATIC_KLD macro which expands to SY_THR_STATIC
during kernel build and 0 otherwise.

Reviewed by:	kib (previous version)
MFC after:	2 weeks
2014-10-26 19:42:44 +00:00
Xin LI
5e5fd037d6 Call chainevh callback when we are invoked with neither MOD_LOAD nor
MOD_UNLOAD.  This makes it possible to add custom hooks for other module
events.

Return EOPNOTSUPP when there is no callback available.

Pointed out by:	jhb
Reviewed by:	jhb
MFC after:	1 month
2010-10-21 20:31:50 +00:00
Xin LI
00e3c12e03 In syscall_module_handler(): all switch branches return, remove
unreached code as pointed out in a Chinese forum [1].

[1] http://www.freebsdchina.org/forum/viewtopic.php?t=50619

Pointed out by:		btw616 <btw s qq com>
MFC after:		1 month
2010-10-21 08:57:25 +00:00
Konstantin Belousov
153ac44cf6 Count number of threads that enter and leave dynamically registered
syscalls. On the dynamic syscall deregistration, wait until all
threads leave the syscall code. This somewhat increases the safety
of the loadable modules unloading.

Reviewed by:	jhb
Tested by:	pho
MFC after:	1 month
2010-06-28 18:06:46 +00:00
Konstantin Belousov
0687ba3e90 Introduce SYSCALL_INIT_HELPER and SYSCALL32_INIT_HELPER macros and
neccessary support functions to allow registering dynamically loaded
syscalls from the MOD_LOAD handlers. Helpers handle registration
failures semi-automatically.

Reviewed by:	jhb
MFC after:	2 weeks
2010-03-19 10:56:30 +00:00
John Baldwin
da672ec2ca Various style fixes. 7 space indent is just odd. 2008-09-18 20:10:11 +00:00
John Baldwin
03e161fdb1 Make system call modules a bit more robust:
- If we fail to register the system call during MOD_LOAD, then note that
  so that we don't try to deregister it or invoke the chained event handler
  during the subsequent MOD_UNLOAD event.  Doing the deregister when the
  register failed could result in trashing system call entries.
- Add a SI_SUB_SYSCALLS just before starting up init and use that to
  register syscall modules instead of SI_SUB_DRIVERS.  Registering system
  calls as late as possible increases the chances that any other module
  event handlers or SYSINITs in a module are executed to initialize the
  data in a kld before a syscall dependent on that data is able to be
  invoked.

MFC after:	3 days
2006-08-01 16:32:20 +00:00
Poul-Henning Kamp
3e019deaed Do a pass over all modules in the kernel and make them return EOPNOTSUPP
for unknown events.

A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
2004-07-15 08:26:07 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Andrew R. Reiter
9b3851e9e3 - Lock down the ``module'' structure by adding an SX lock that is used by
all the global bits of ``module'' data.  This commit adds a few generic
  macros, MOD_SLOCK, MOD_XLOCK, etc., that are meant to be used as ways
  of accessing the SX lock.  It is also the first step in helping to lock
  down the kernel linker and module systems.

Reviewed by: jhb, jake, smp@
2002-03-18 07:45:30 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
Alfred Perlstein
78525ce318 sysvipc loadable.
new syscall entry lkmressys - "reserved loadable syscall"

Make syscall_register allow overwriting of such entries (lkmressys).
2000-12-01 08:57:47 +00:00
Peter Wemm
d1f088dab5 Trim unused options (or #ifdef for undoc options).
Submitted by:	phk
1999-10-11 15:19:12 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Doug Rabson
c049aba8c3 Call the chained module handler before unregistering the syscall so that
errors can be detected.

Submitted by: "A.Yu.Isupov" <isupov@moonhe.jinr.ru>
PR:	      kern/12239
1999-06-27 09:38:44 +00:00
Peter Wemm
46db48360d Move lkmnosys() from kern_lkm.c to here. 1999-01-17 18:58:04 +00:00
Doug Rabson
a35261ef91 Implement a mechanism for a module to report a small amount of module
specific data back to the user via kldstat(2).  Use that mechanism in
the syscall handler to report the syscall number used.
1999-01-09 14:59:50 +00:00
Doug Rabson
4c3df79450 Implement support for adding syscalls in KLD modules.
Submitted by: Assar Westerlund <assar@sics.se>
1999-01-09 14:15:41 +00:00