Commit Graph

241 Commits

Author SHA1 Message Date
alc
6aaed2f8ea Giant is no longer required by vm_waitproc() and vmspace_exitfree().
Eliminate it acquisition and release around vm_waitproc() in kern_wait().
2004-07-30 20:31:02 +00:00
alc
8a38bc6b2c - Use atomic ops for updating the vmspace's refcnt and exitingcnt.
- Push down Giant into shmexit().  (Giant is acquired only if the vmspace
   contains shm segments.)
 - Eliminate the acquisition of Giant from proc_rwmem().
 - Reduce the scope of Giant in exit1(), uncovering the destruction of the
   address space.
2004-07-27 03:53:41 +00:00
julian
a488bebcd2 When calling scheduler entrypoints for creating new threads and processes,
specify "us" as the thread not the process/ksegrp/kse.
You can always find the others from the thread but the converse is not true.
Theorotically this would lead to runtime being allocated to the wrong
entity in some cases though it is not clear how often this actually happenned.
(would only affect threaded processes and would probably be pretty benign,
but it WAS a bug..)

Reviewed by: peter
2004-07-18 23:36:13 +00:00
davidxu
1920ad199e Add code to support debugging threaded process.
1. Add tm_lwpid into kse_thr_mailbox to indicate which kernel
   thread current user thread is running on. Add tm_dflags into
   kse_thr_mailbox, the flags is written by debugger, it tells
   UTS and kernel what should be done when the process is being
   debugged, current, there two flags TMDF_SSTEP and TMDF_DONOTRUNUSER.

   TMDF_SSTEP is used to tell kernel to turn on single stepping,
   or turn off if it is not set.

   TMDF_DONOTRUNUSER is used to tell kernel to schedule upcall
   whenever possible, to UTS, it means do not run the user thread
   until debugger clears it, this behaviour is necessary because
   gdb wants to resume only one thread when the thread's pc is
   at a breakpoint, and thread needs to go forward, in order to
   avoid other threads sneak pass the breakpoints, it needs to remove
   breakpoint, only wants one thread to go. Also, add km_lwp to
   kse_mailbox, the lwp id is copied to kse_thr_mailbox at context
   switch time when process is not being debugged, so when process
   is attached, debugger can map kernel thread to user thread.

2. Add p_xthread to proc strcuture and td_xsig to thread structure.
   p_xthread is used by a thread when it wants to report event
   to debugger, every thread can set the pointer, especially, when
   it is used in ptracestop, it is the last thread reporting event
   will win the race. Every thread has a td_xsig to exchange signal
   with debugger, thread uses TDF_XSIG flag to indicate it is reporting
   signal to debugger, if the flag is not cleared, thread will keep
   retrying until it is cleared by debugger, p_xthread may be
   used by debugger to indicate CURRENT thread. The p_xstat is still
   in proc structure to keep wait() to work, in future, we may
   just use td_xsig.

3. Add TDF_DBSUSPEND flag, the flag is used by debugger to suspend
   a thread. When process stops, debugger can set the flag for
   thread, thread will check the flag in thread_suspend_check,
   enters a loop, unless it is cleared by debugger, process is
   detached or process is existing. The flag is also checked in
   ptracestop, so debugger can temporarily suspend a thread even
   if the thread wants to exchange signal.

4. Current, in ptrace, we always resume all threads, but if a thread
   has already a TDF_DBSUSPEND flag set by debugger, it won't run.

Encouraged by: marcel, julian, deischen
2004-07-13 07:20:10 +00:00
alc
ea94acfaa6 Push down the acquisition and release of the page queues lock into
pmap_remove_pages().  (The implementation of pmap_remove_pages() is
optional.  If pmap_remove_pages() is unimplemented, the acquisition and
release of the page queues lock is unnecessary.)

Remove spl calls from the alpha, arm, and ia64 pmap_remove_pages().
2004-07-13 02:49:22 +00:00
marcel
57e7de678f Implement the PT_LWPINFO request. This request can be used by the
tracing process to obtain information about the LWP that caused the
traced process to stop. Debuggers can use this information to select
the thread currently running on the LWP as the current thread.

The request has been made compatible with NetBSD for as much as
possible. This implementation differs from NetBSD in the following
ways:
1.  The data argument is allowed to be smaller than the size of the
    ptrace_lwpinfo structure known to the kernel, but not 0. This
    is opposite to what NetBSD allows. The reason for this is that
    we can extend the structure without affecting older binaries.
2.  On NetBSD the tracing process is to set the pl_lwpid field to
    the Id of the LWP it wants information of. We don't do that.
    Our ptrace interface allows passing the LWP Id instead of the
    PID. The tracing process is to set the PID to the LWP Id it
    wants information of.
3.  When the PID is actually the PID of the tracing process, this
    request returns the information about the LWP that caused the
    process to stop. This was the whole purpose of the request in
    the first place.

When the traced process has exited, this request will return the
LWP Id 0, indicating that the process state is not the result of
an event specific to a LWP.
2004-07-12 05:07:50 +00:00
bde
747f331358 (1) Removed the bogus condition "p->p_pid != 1" on calling sched_exit()
from exit1().  sched_exit() must be called unconditionally from exit1().
    It was called almost unconditionally because the only exits on system
    shutdown if at all.

(2) Removed the comment that presumed to know what sched_exit() does.
    sched_exit() does different things for the ULE case.  The call became
    essential when it started doing load average stuff, but its caller
    should not know that.

(3) Didn't fix bugs caused by bitrot in the condition.  The condition was
    last correct in rev.1.208 when it was in wait1().  There p was spelled
    curthread->td_proc and was for the waiting parent; now p is for the
    exiting child.  The condition was to avoid lowering init's priority.
    It should be in sched_exit() itself.  Lowering of priorities is broken
    in other ways in at least the 4BSD scheduler, and doing it for init
    causes less noticeable problems than doing it for for shells.

Noticed by:	julian (1)
2004-06-21 14:49:50 +00:00
bde
b65b61b58a Update p_runtime on exit. This fixes calcru() on zombies, and prepares
for not calling calcru() on exit.  calcru() on a zombie can happen if
ttyinfo() (^T) picks one.

PR:		52490
2004-06-21 14:03:38 +00:00
davidxu
d11f8ce42b Add comment to reflect that we should retry after thread singling failed. 2004-06-18 11:13:49 +00:00
davidxu
70a732669b Remove a bogus panic. It is possible more than one threads will
be suspended in thread_suspend_check, after they are resumed, all
threads will call thread_single, but only one can be success,
others should retry and will exit in thread_suspend_check.
2004-06-18 06:21:09 +00:00
tjr
58dbd6e669 Remove remnants of PGINPROF. 2004-06-08 10:37:30 +00:00
tjr
80d36400ed Move TDF_SA from td_flags to td_pflags (and rename it accordingly)
so that it is no longer necessary to hold sched_lock while
manipulating it.

Reviewed by:	davidxu
2004-06-02 07:52:36 +00:00
tmm
7b769ce88f Retire cpu_sched_exit(); it is not used any more. 2004-05-26 12:09:39 +00:00
davidxu
e7578c3795 Clear KSE thread flags after KSE thread mode is ended. The side effect
of not clearing the flags for execv() syscall will result that a new
program runs in KSE thread mode without enabling it.

Submitted by: tjr
Modified by: davidxu
2004-05-21 14:50:23 +00:00
julian
790c941069 Remove misplaced duplicate comment and slightly reformat the
version that was in the right place.
2004-05-09 22:29:14 +00:00
imp
74cf37bd00 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-05 21:03:37 +00:00
green
aae79f39c1 Add the missing Giant when doing anything with VFS -- in this case,
releasing the ktrace vnode.
2004-03-18 18:15:58 +00:00
jhb
275240297d - Replace wait1() with a kern_wait() function that accepts the pid,
options, status pointer and rusage pointer as arguments.  It is up to
  the caller to copyout the status and rusage to userland if needed.  This
  lets us axe the 'compat' argument and hide all that functionality in
  owait(), by the way.  This also cleans up some locking in kern_wait()
  since it no longer has to drop locks around copyout() since all the
  copyout()'s are deferred.
- Convert owait(), wait4(), and the various ABI compat wait() syscalls to
  use kern_wait() rather than wait1() or wait4().  This removes a bit
  more stackgap usage.

Tested on:	i386
Compiled on:	i386, alpha, amd64
2004-03-17 20:00:00 +00:00
peter
bd5efd4600 Make the process_exit eventhandler run without Giant. Add Giant hooks
in the two consumers that need it.. processes using AIO and netncp.
Update docs.  Say that process_exec is called with Giant, but not to
depend on it.  All our consumers can handle it without Giant.
2004-03-14 02:06:28 +00:00
peter
1cb95fd2b7 Push Giant down a little further:
- no longer serialize on Giant for thread_single*() and family in fork,
  exit and exec
- thread_wait() is mpsafe, assert no Giant
- reduce scope of Giant in exit to not cover thread_wait and just do
  vm_waitproc().
- assert that thread_single() family are not called with Giant
- remove the DROP/PICKUP_GIANT macros from thread_single() family
- assert that thread_suspend_check() s not called with Giant
- remove manual drop_giant hack in thread_suspend_check since we know it
  isn't held.
- remove the DROP/PICKUP_GIANT macros from thread_suspend_check() family
- mark kse_create() mpsafe
2004-03-13 22:31:39 +00:00
jhb
4e1bd1e348 - Push down Giant in exit() and wait().
- Push Giant down a bit in coredump() and call coredump() with the proc
  lock already held rather than unlocking it only to turn around and
  relock it.

Requested by:	peter
2004-03-05 22:39:53 +00:00
jhb
d76d631711 Drop sched_lock around the wakeup of the parent process after setting
the process state to zombie when a process exits to avoid a lock order
reversal with the sleepqueue locks.  This appears to be the only place
that we call wakeup() with sched_lock held.
2004-02-27 18:39:09 +00:00
truckman
05861c09f2 A Linux thread created using clone() should not send SIGCHLD to its
parent if no signal is specified in the clone() flags argument.

PR:		42457
MFC after:	2 weeks
2004-02-19 06:43:48 +00:00
truckman
da322e8d35 When reparenting a process to init, make sure that p_sigparent is
set to SIGCHLD.  This avoids the creation of orphaned Linux-threaded
zombies that init is unable to reap.  This can occur when the parent
process sets its SIGCHLD to SIG_IGN.  Fix a similar situation in the
PT_DETACH code.

Tested by:	"Steven Hartland" <killing AT multiplay.co.uk>
2004-02-11 22:06:02 +00:00
jhb
279b2b8278 Locking for the per-process resource limits structure.
- struct plimit includes a mutex to protect a reference count.  The plimit
  structure is treated similarly to struct ucred in that is is always copy
  on write, so having a reference to a structure is sufficient to read from
  it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
  limits from a process to keep the limit structure from changing out from
  under you while reading from it.
- Various global limits that are ints are not protected by a lock since
  int writes are atomic on all the archs we support and thus a lock
  wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
  behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
  either an rlimit, or the current or max individual limit of the specified
  resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
  other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
  (it didn't used the stackgap when it should have) but uses lim_rlimit()
  and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
  but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits.  It
  also no longer uses the stackgap for accessing sysctl's for the
  ibcs2_sysconf() syscall but uses kernel_sysctl() instead.  As a result,
  ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.

Submitted by:	mtm (mostly, I only did a few cleanups and catchups)
Tested on:	i386
Compiled on:	alpha, amd64
2004-02-04 21:52:57 +00:00
rwatson
9929c2e385 Reduce gratuitous includes: don't include jail.h if it's not needed.
Presumably, at some point, you had to include jail.h if you included
proc.h, but that is no longer required.

Result of:	self injury involving adding something to struct prison
2004-01-21 17:10:47 +00:00
cognet
690de3f7ac Better fix than my previous commit:
in exit1(), make sure the p_klist is empty after sending NOTE_EXIT.
The process won't report fork() or execve() and won't be able to handle
NOTE_SIGNAL knotes anyway.
This fixes some race conditions with do_tdsignal() calling knote() while
the process is exiting.

Reported by:	Stefan Farfeleder <stefan@fafoe.narf.at>
MFC after:	1 week
2003-11-14 18:49:01 +00:00
davidxu
abb4420bbe Rename P_THREADED to P_SA. P_SA means a process is using scheduler
activations.
2003-06-15 00:31:24 +00:00
obrien
3b8fff9e4c Use __FBSDID(). 2003-06-11 00:56:59 +00:00
jhb
dc1245470e Wait for the real interval timer callout handler to finish executing if it
is currently executing when we try to remove it in exit1().  Without this,
it was possible for the callout to bogusly rearm itself and eventually
refire after the process had been free'd resulting in a panic.

PR:		kern/51964
Reported by:	Jilles Tjoelker <jilles@stack.nl>
Reviewed by:	tegge, bde
2003-06-09 21:46:22 +00:00
jhb
89a4eb17de - Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
  M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
  sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
  that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
  and thread_stopped() are now MP safe.

Reviewed by:	arch@
Approved by:	re (rwatson)
2003-05-13 20:36:02 +00:00
jhb
9e17fca425 Initialize and destroy the struct proc mutex in the proc zone's init and
fini routines instead of in fork() and wait().  This has the nice side
benefit that the proc lock of any process on the allproc list is always
valid and sched_lock doesn't have to be used to test against PRS_NEW
anymore.
2003-05-01 21:16:38 +00:00
jhb
a0bf3a3e6f - Protect p_numthreads with the sched_lock.
- Protect p_singlethread with both the sched_lock and the proc lock.
- Protect p_suspcount with the proc lock.
2003-04-23 18:46:51 +00:00
davidxu
d5ff3e991d Fix lock order reversal problem. 2003-04-21 14:42:04 +00:00
jhb
b09e86b501 Adjust a few comments. 2003-04-17 22:22:47 +00:00
jeff
a033a84006 - Adjust sched hooks for fork and exec to take processes as arguments instead
of ksegs since they primarily operation on processes.
 - KSEs take ticks so pass the kse through sched_clock().
 - Add a sched_class() routine that adjusts a ksegrp pri class.
 - Define a sched_fork_{kse,thread,ksegrp} and sched_exit_{kse,thread,ksegrp}
   that will be used to tell the scheduler about new instances of these
   structures within the same process.  These will be used by THR and KSE.
 - Change sched_4bsd to reflect this API update.
2003-04-11 03:39:07 +00:00
jeff
1b4d7b91ce - Borrow the KSE single threading code for exec and exit. We use the check
if (p->p_numthreads > 1) and not a flag because action is only necessary
   if there are other threads.  The rest of the system has no need to
   identify thr threaded processes.
 - In kern_thread.c use thr_exit1() instead of thread_exit() if P_THREADED
   is not set.
2003-04-01 01:26:20 +00:00
jeff
46e6ba39f1 - Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with
a follow on commit to kern_sig.c
 - signotify() now operates on a thread since unmasked pending signals are
   stored in the thread.
 - PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.
2003-03-31 22:49:17 +00:00
jhb
98a481610a Replace the at_fork, at_exec, and at_exit functions with the slightly more
flexible process_fork, process_exec, and process_exit eventhandlers.  This
reduces code duplication and also means that I don't have to go duplicate
the eventhandler locking three more times for each of at_fork, at_exec, and
at_exit.

Reviewed by:	phk, jake, almost complete silence on arch@
2003-03-24 21:15:35 +00:00
des
d0bee7242c Unregisterize, ansify. 2003-03-19 00:49:40 +00:00
des
e97206db4c Whitespace cleanup. 2003-03-19 00:33:38 +00:00
jhb
f02ef38080 - Cache a reference to the credential of the thread that starts a ktrace in
struct proc as p_tracecred alongside the current cache of the vnode in
  p_tracep.  This credential is then used for all later ktrace operations on
  this file rather than using the credential of the current thread at the
  time of each ktrace event.
- Now that we have multiple ktrace-related items in struct proc that are
  pointers, rename p_tracep to p_tracevp to make it less ambiguous.

Requested by:	rwatson (1)
2003-03-13 18:24:22 +00:00
tjr
2230824221 Tidy up previous change: move comment about obtaining an exclusive
reference where it belongs, and remove a blank line to make it more
obvious what the comment applies to.
2003-03-13 00:57:47 +00:00
tjr
59d5730195 In wait1(), remove the zombie process from zombproc before removing
it from its pgrp to avoid leaving zombies around with p_pgrp == NULL.
This bug was apparent as a NULL-dereference in the pid selection code
in fork1().
2003-03-12 11:10:04 +00:00
davidxu
bb4f70ad77 Fix threaded process job control bug. SMP tested.
Reviewed by: julian
2003-03-11 00:07:53 +00:00
julian
3fc9836d46 Change the process flags P_KSES to be P_THREADED.
This is just a cosmetic change but I've been meaning to do it for about a year.
2003-02-27 02:05:19 +00:00
imp
cf874b345d Back out M_* changes, per decision of the TRB.
Approved by: trb
2003-02-19 05:47:46 +00:00
tjr
6ebeaa8ec8 Use the proc lock to protect p_realtimer instead of Giant, and obtain
sched_lock around accesses to p_stats->p_timer[] to avoid a potential
race with hardclock. getitimer(), setitimer() and the realitexpire()
callout are now Giant-free.
2003-02-17 10:03:02 +00:00
jeff
590a39e29b - Split the struct kse into struct upcall and struct kse. struct kse will
soon be visible only to schedulers.  This greatly simplifies much the
   KSE code.

Submitted by:	davidxu
2003-02-17 05:14:26 +00:00
alfred
d9a7e5d627 Fix LOR with PROC/filedesc. Introduce fdesc_mtx that will be used as a
barrier between free'ing filedesc structures.  Basically if you want to
access another process's filedesc, you want to hold this mutex over the
entire operation.
2003-02-15 05:52:56 +00:00