- Introduce lock classes and lock objects. Each lock class specifies a
name and set of flags (or properties) shared by all locks of a given
type. Currently there are three lock classes: spin mutexes, sleep
mutexes, and sx locks. A lock object specifies properties of an
additional lock along with a lock name and all of the extra stuff needed
to make witness work with a given lock. This abstract lock stuff is
defined in sys/lock.h. The lockmgr constants, types, and prototypes have
been moved to sys/lockmgr.h. For temporary backwards compatability,
sys/lock.h includes sys/lockmgr.h.
- Replace proc->p_spinlocks with a per-CPU list, PCPU(spinlocks), of spin
locks held. By making this per-cpu, we do not have to jump through
magic hoops to deal with sched_lock changing ownership during context
switches.
- Replace proc->p_heldmtx, formerly a list of held sleep mutexes, with
proc->p_sleeplocks, which is a list of held sleep locks including sleep
mutexes and sx locks.
- Add helper macros for logging lock events via the KTR_LOCK KTR logging
level so that the log messages are consistent.
- Add some new flags that can be passed to mtx_init():
- MTX_NOWITNESS - specifies that this lock should be ignored by witness.
This is used for the mutex that blocks a sx lock for example.
- MTX_QUIET - this is not new, but you can pass this to mtx_init() now
and no events will be logged for this lock, so that one doesn't have
to change all the individual mtx_lock/unlock() operations.
- All lock objects maintain an initialized flag. Use this flag to export
a mtx_initialized() macro that can be safely called from drivers. Also,
we on longer walk the all_mtx list if MUTEX_DEBUG is defined as witness
performs the corresponding checks using the initialized flag.
- The lock order reversal messages have been improved to output slightly
more accurate file and line numbers.
We really want to be able to say "auto NWAY", "limited NWAY", and
"no NWAY". Unfortunately, this does not appear to be possible with
the current mediaopt structure.
and change the u_int mtx_saveintr member of struct mtx to a critical_t
mtx_savecrit.
- On the alpha we no longer need a custom _get_spin_lock() macro to avoid
an extra PAL call, so remove it.
- Partially fix using mutexes with WITNESS in modules. Change all the
_mtx_{un,}lock_{spin,}_flags() macros to accept explicit file and line
parameters and rename them to use a prefix of two underscores. Inside
of kern_mutex.c, generate wrapper functions for
_mtx_{un,}lock_{spin,}_flags() (only using a prefix of one underscore)
that are called from modules. The macros mtx_{un,}lock_{spin,}_flags()
are mapped to the __mtx_* macros inside of the kernel to inline the
usual case of mutex operations and map to the internal _mtx_* functions
in the module case so that modules will use WITNESS and KTR logging if
the kernel is compiled with support for it.
sections.
- Add implementations of the critical_enter() and critical_exit() functions
and remove restore_intr() and save_intr().
- Remove the somewhat bogus disable_intr() and enable_intr() functions on
the alpha as the alpha actually uses a priority level and not simple bit
flag on the CPU.
- Switch to using critical_enter/exit instead of save/disable/restore_intr.
- Disable interrupts in Debugger().
This second change wasn't really supposed to go in, but since it's in
there and is useful so that one doesn't get spammed with clock interrupts
while in ddb, I'll leave it in unless people want it reverted.
- If there is no gdb device, just return without trying to return any
value since gdb_handle_exception() returns void.
- When calling prom_halt(), pass in a value telling it to actually halt
and not to randomly choose whether or not to halt or reboot depending on
whatever value happened to be in a0 when the call was made.
an AST results in a signal being delivered, we'll need to do a full register
restore so as to properly setup the signal handler. This is somewhat of
a pessimization, because ast() will be called twice in this case.
This fixes several problems that have been reported where signal intensive
userland apps (most notably dump) have been SEGV'ing for no fault of their
own.
Thanks to Peter Jeremy <peter.jeremy@alcatel.com.au> for presenting the
AST scenario which led to me fiinally figuring this out.
Reviewed by: jhb
fseeko(file_size, SEEK_SET) -> fseek(0L, SEEK_END)
1) File may grows between operations, so fseeko to file_size may miss
2) 0L, SEEK_END is the same code using in tail in all other places
method anymore since the code inside the RPC library has changed too much.
Now that the clnt_dg module has the necessary code internally, we can yank
out the local method code and turn on the ASYNC hack with clnt_control().
This will make the -m flag work again.
to make asynchronous RPCs. This is needed to help fix ypbind, which can no
longer override the clnt_dg_call() method (formerly the clntudp_call()
method) due to all the internal descriptor locking code in TI-RPC. Turning
on this flag allows us to send an RPC request, then return immediately,
and handle a reply later, rather than being forced to do the request
and reply in a single function call.
Also fix a byte ordering bug: when clnt_dg_call() increments the XID
prior to transmitting a request, it uses the raw value, which is wrong.
The XID is stored in network byte order, i.e. big-endian. The CLSET_XID
and CLGET_XID commands in clnt_dg_control() use ntohl()/htonl() to get
the byte ordering right, but because clnt_dg_call() does not do this,
using CLSET_XID/CLGET_XID doesn't actually work, unless you're on a
big endian host, which we aren't (yet). Fix clnt_dg_call() to byte swap
properly when doing the increment.
process we're looking for. (I don't think this can currently
happen, but it depends how the function is called).
PR: 25932
Submitted by: David Xu <davidx@viasoft.com.cn>
The PAM_FAIL_CHECK and PAM_END macros in su.c came from the util-linux
package's PAM patches to the BSD login.c
Submitted by: "David J. MacKenzie" <djm@web.us.uu.net>
If one is trying to dump or repair an ill system, give the user a fighting
chance. Refusing to operate w/o a very non-critical file (feature) is
just plain stupid.
