need to reparent the process to initproc, so that child wouldn't
have its p_pptr pointer still pointing on the exited parent
pointed out by Dave Sainty in private mail (the patch in kern/14443
didn't have this bug)
reparented back to original parent before it's killed.
This makes the original parent aware that the child has exited if
the debugger failed to wait() on the debugged zombie before exiting.
Since we clear tracing flags before killing the child, the reparenting
logic in wait4() wouldn't be triggered, so it's necessary to do it here.
Problem reported and fix provided in kern/14443 by David Sainty.
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
counters. These counters do not exist on all CPUs, but where they
do exist, can be used for counting events such as dcache misses that
would otherwise be difficult or impossible to instrument by code
inspection or hardware simulation.
pmc(9) is meant to be a general interface. Initially, the Intel XScale
counters are the only ones supported.
gets reset properly when the old parent exits before the child. A flag
is set in old parent process when the child is reparented in ptrace(2).
If it's set when process is exiting, all running processes have their
'old parent process' pointer checked and reset if appropriate. Also
change to use 'struct proc *' pointer directly, rather than pid_t.
This fixes security/14444 by David Sainty.
Reviewed by Christos Zoulas.
space is already torn down in uvmspace_free() when the vmspace
refrence count reaches 0. Move the shmexit() call into uvmspace_free().
Note that there is a beneficial side-effect of deferring the unmap
to uvmspace_free() -- on systems where TLB invalidations are
particularly expensive, the unmapping of the address space won't
have to cause TLB invalidations; uvmspace_free() is going to be
run in a context other than the exiting process's, so the "pmap is
active" test will evaluate to FALSE in the pmap module.
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.
emulation-specific data
add process exit, exec and fork function hooks into struct emul:
* e_proc_fork() - called in fork1() after the new forked process is setup
* e_proc_exec() - called in sys_execve() after the executed process is setup
* e_proc_exit() - called in exit1() after all the other process cleanups are
done, right before machine-dependant switch to new context; also called
for "old" emulation from sys_execve() if emulation of executed program and
the original process is different
This was discussed on tech-kern.
<vm/pglist.h> -> <uvm/uvm_pglist.h>
<vm/vm_inherit.h> -> <uvm/uvm_inherit.h>
<vm/vm_kern.h> -> into <uvm/uvm_extern.h>
<vm/vm_object.h> -> nothing
<vm/vm_pager.h> -> into <uvm/uvm_pager.h>
also includes a bunch of <vm/vm_page.h> include removals (due to redudancy
with <vm/vm.h>), and a scattering of other similar headers.
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
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.
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.
body of reaper(), right before the call to uvm_exit(). cpu_wait() must
be done before uvm_exit() because the resources it frees might be located
in the PCB.
- When the exit signal is specified to be 0, don't just assume they
meant SIGCHLD. In the Linux world, this appears to mean "don't deliver
an exit signal at all".
- Simplify P_EXITSIG(); don't check against initproc here, just change
the exit signal to SIGCHLD if reparenting to initproc.
A very simple clone(2) test program now works, and the MpegTV package
starts, but doesn't run properly yet (I believe there is a separate
bug which keeps it from working properly).
parent, specified at fork time. Specify a new flag to wait4(2), WALTSIG,
to wait for processes which use an alternate exit signal.
This is required for clone(2).
- no longer conditionalized
- when traced, charge time to real parent, not debugger
- make it clear for future rototillers that p_estcpu should be moved
to the "copy" region of struct proc.
parents for children's p_estcpu. I think this problem has always been there.
It's particularly noticable with X because the server builds up non-trivial
CPU, and hence, non-trivial p_estcpu scheduler penalty. The repeatedly
forked children were always starting from scratch and receiving a scheduler
preference.
* 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.
