The rule is that you don't get to call scheduler-related functions (e.g.
wakeup()) above the clock interrupt. Going to statclock unnecessarily
hoses e.g. serial interrupts on the SPARC.
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.
processes.
- Create a new data structure, the proclist_desc, which contains a
pointer to a proclist, and eventually, a pointer to the lock for that
proclist. Declare a static array of proclist_descs, proclists[],
consisting of allproc, deadproc, and zombproc.
(thus causing s_leader to become NULL) by storing the session ID separately
in the session structure. Export the session ID to userspace in the
eproc structure.
Submitted by Tom Proett <proett@nas.nasa.gov>.
thorpej