The patch below (hopefully) improves some signaling problems
found by Nathan.
It also contains some cleanup of the sa_upcall_userret() function
removing any sleep calls using PCATCH.
Unblocked threads now only use an upcall stack after they
acquire the virtual CPU.
This prevents unblocked threads from stealing all available
upcall stacks.
Tested by Nick Hudson.
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.
Bump the kernel rev up to 1.6V
be returning because the code path that calls is will very likely call
setrunnable() again on the returned thread, leading to a panic because
the thread returned is already at LSRUN. This fixes a problem where netbsd
would panic when using gdb (5.3) on a process with multiple lwp's like this:
% gdb program
(gdb) run
^C
(gdb) quit
sa_switch() invocations while exiting. Test P_SA instead of L_SA, out
of paranoia. Avoids a possible remrunqueue panic reported by Havard
Eidnes.
Release the kernel lock before calling the userret function to exit in
sigexit(). Problem noted by Paul Kranenburg.
timeout
the semantics of 'timeout' parameter differ to POSIX for the syscall
(not const, may be modified by kernel if interrupted from the wait) -
libc will provide appropriate wrapper
since sigwaitinfo(2) will be implemented as wrapper around sigtimedwait()
too, remove it's reserved slot and move sigqueue slot 'up', freeing
slot #246
* Change the semantics of proc_unstop() slightly, so that it is
responsible for making all stopped LWPs runnable, instead of
all-but-one. Return value is a LWP that can be interrupted if doing
so is necessary to take a signal. Adjust callers of proc_stop() to
the new, simpler semantics.
* When a non-continue signal is delivered to a stopped process and
there is a LWP sleeping interruptably, call setrunnable() (by way
of the 'out:' target in psignal1) instead of calling unsleep() so
that it becomes LSSTOP in issignal() and continuable by
proc_unstop(). Addresses PR kern/19990 by Martin Husemann, with
suggestions from enami tsugutomo.
kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals
kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)
based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe
This is done by adding an extra argument to mi_switch() and
cpu_switch() which specifies the new process. If NULL is passed,
then the new function chooseproc() is invoked to wait for a new
process to appear on the run queue.
Also provides an opportunity for optimisations if "switching to self".
Also added are C versions of the setrunqueue() and remrunqueue()
low-level primitives if __HAVE_MD_RUNQUEUE is not defined by MD code.
All these changes are contingent upon the __HAVE_CHOOSEPROC flag being
defined by MD code to indicate that cpu_switch() supports the changes.
* struct sigacts gets a new sigact_sigdesc structure, which has the
sigaction and the trampoline/version. Version 0 means "legacy kernel
provided trampoline". Other versions are coordinated with machine-
dependent code in libc.
* sigaction1() grows two more arguments -- the trampoline pointer and
the trampoline version.
* A new __sigaction_sigtramp() system call is provided to register a
trampoline along with a signal handler.
* The handler is no longer passed to sensig() functions. Instead,
sendsig() looks up the handler by peeking in the sigacts for the
process getting the signal (since it has to look in there for the
trampoline anyway).
* Native sendsig() functions now select the appropriate trampoline and
its arguments based on the trampoline version in the sigacts.
Changes to libc to use the new facility will be checked in later. Kernel
version not bumped; we will ride the 1.6C bump made recently.
deal with shortages of the VM maps where the backing pages are mapped
(usually kmem_map). Try to deal with this:
* Group all information about the backend allocator for a pool in a
separate structure. The pool references this structure, rather than
the individual fields.
* Change the pool_init() API accordingly, and adjust all callers.
* Link all pools using the same backend allocator on a list.
* The backend allocator is responsible for waiting for physical memory
to become available, but will still fail if it cannot callocate KVA
space for the pages. If this happens, carefully drain all pools using
the same backend allocator, so that some KVA space can be freed.
* Change pool_reclaim() to indicate if it actually succeeded in freeing
some pages, and use that information to make draining easier and more
efficient.
* Get rid of PR_URGENT. There was only one use of it, and it could be
dealt with by the caller.
From art@openbsd.org.
ltsleep() is calling CURSIG() which can call issignal() and issignal()
could not deal with being called from a locked context. This happens
when a process receives SIGTTIN, and issignal() calls psignal() to
post SIGCHLD to the parent.
XXX: It is really messy to have issignal() handle the job control
functionality and the whole signal interlocking protocol needs to
be re-designed. For now this fix (provided by enami) does the trick.
I've been running with this fix for weeks, and atatat has stress-tested
the kernel running ~30 make kernels...
wrap this all up in a CHECKSIGS() macro. Also, in psignal1(),
signotify() SRUN and SIDL processes if __HAVE_AST_PERPROC is defined.
Per discussion w/ mycroft.
only signal handler array sharable between threads
move other random signal stuff from struct proc to struct sigctx
This addresses kern/10981 by Matthew Orgass.
in the non-MULTIPROCESSOR case (LOCKDEBUG requires it). Scheduler
lock is held upon entry to mi_switch() and cpu_switch(), and
cpu_switch() releases the lock before returning.
Largely from Bill Sommerfeld, with some minor bug fixes and
machine-dependent code hacking from me.
- Change ktrace interface to pass in the current process, rather than
p->p_tracep, since the various ktr* function need curproc anyway.
- Add curproc as a parameter to mi_switch() since all callers had it
handy anyway.
- Add a second proc argument for inferior() since callers all had
curproc handy.
Also, miscellaneous cleanups in ktrace:
- ktrace now always uses file-based, rather than vnode-based I/O
(simplifies, increases type safety); eliminate KTRFLAG_FD & KTRFAC_FD.
Do non-blocking I/O, and yield a finite number of times when receiving
EWOULDBLOCK before giving up.
- move code duplicated between sys_fktrace and sys_ktrace into ktrace_common.
- simplify interface to ktrwrite()
which indicates that the process is actually running on a
processor. Test against SONPROC as appropriate rather than
combinations of SRUN and curproc. Update all context switch code
to properly set SONPROC when the process becomes the current
process on the CPU.
cause a core to drop, and whether the core dropped, or, if it did
not, why not (i.e. error number). Logs process ID, name, signal that
hit it, and whether the core dump was successful.
logging only happens if kern_logsigexit is non-zero, and it can be
changed by the new sysctl(3) value KERN_LOGSIGEXIT. The name of this
sysctl and its function are taken from FreeBSD, at the suggestion
of Greg Woods in PR 6224. Default behavior is zero for a normal
kernel, and one for a kernel compiled with DIAGNOSTIC.
core filename format, which allow to change the name of the core dump,
and to relocate it in a directory. Credits to Bill Sommerfeld for giving me
the idea :)
The default core filename format can be changed by options DEFCORENAME and/or
kern.defcorename
Create a new sysctl tree, proc, which holds per-process values (for now
the corename format, and resources limits). Process is designed by its pid
at the second level name. These values are inherited on fork, and the corename
fomat is reset to defcorename on suid/sgid exec.
Create a p_sugid() function, to take appropriate actions on suid/sgid
exec (for now set the P_SUGID flag and reset the per-proc corename).
Adjust dosetrlimit() to allow changing limits of one proc by another, with
credential controls.
calls to reflect this. Also, block statclock rather than softclock during
in the proclist locking functions, to address a problem reported on
current-users by Sean Doran.
write lock when doing PID allocation, and during the process exit path.
Use a read lock every where else, including within schedcpu() (interrupt
context). Note that holding the write lock implies blocking schedcpu()
from running (blocks softclock).
PID allocation is now MP-safe.
Note this actually fixes a bug on single processor systems that was probably
extremely difficult to tickle; it was possible that schedcpu() would run
off a bad pointer if the right clock interrupt happened to come in the
middle of a LIST_INSERT_HEAD() or LIST_REMOVE() to/from allproc.
and PID allocation MP-safe. A new process state is added: SDEAD. This
state indicates that a process is dead, but not yet a zombie (has not
yet been processed by the process reaper).
SDEAD processes exist on both the zombproc list (via p_list) and deadproc
(via p_hash; the proc has been removed from the pidhash earlier in the exit
path). When the reaper deals with a process, it changes the state to
SZOMB, so that wait4 can process it.
Add a P_ZOMBIE() macro, which treats a proc in SZOMB or SDEAD as a zombie,
and update various parts of the kernel to reflect the new state.
* Increase the size of sigset_t to accomodate 128 signals -- adding new
versions of sys_setprocmask(), sys_sigaction(), sys_sigpending() and
sys_sigsuspend() to handle the changed arguments.
* Abstract the guts of sys_sigaltstack(), sys_setprocmask(), sys_sigaction(),
sys_sigpending() and sys_sigsuspend() into separate functions, and call them
from all the emulations rather than hard-coding everything. (Avoids uses
the stackgap crap for these system calls.)
* Add a new flag (p_checksig) to indicate that a process may have signals
pending and userret() needs to do the full (slow) check.
* Eliminate SAS_ALTSTACK; it's exactly the inverse of SS_DISABLE.
* Correct emulation bugs with restoring SS_ONSTACK.
* Make the signal mask in the sigcontext always use the emulated mask format.
* Store signals internally in sigaction structures, rather than maintaining a
bunch of little sigsets for each SA_* bit.
* Keep track of where we put the signal trampoline, rather than figuring it out
in *_sendsig().
* Issue a warning when a non-emulated sigaction bit is observed.
* Add missing emulated signals, and a native SIGPWR (currently not used).
* Implement the `not reset when caught' semantics for relevant signals.
Note: Only code touched by the i386 port has been modified. Other ports and
emulations need to be updated.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the rest of the MI portion changes.
this will be KNF'd shortly. :-)
not used by anything, for now), and implement MNT_NOCOREDUMP by checking
whether or not MNT_NOCOREDUMP is set on the file system where the dump
would land (i.e. the file system of the process's current working
directory), and disallowing the core dump if it's set.
kleink