Timers (such as nd6_timer) typically free/destroy some data in callout
(softint). If we apply psz/psref for such data, we cannot do free/destroy
process in there because synchronization of psz/psref cannot be used in
softint. So run timer callbacks in workqueue works (normal LWP context).
Doing workqueue_enqueue a work twice (i.e., call workqueue_enqueue before
a previous task is scheduled) isn't allowed. For nd6_timer and
rt_timer_timer, this doesn't happen because callout_reset is called only
from workqueue's work. OTOH, ip{,6}flow_slowtimo's callout can be called
before its work starts and completes because the callout is periodically
called regardless of completion of the work. To avoid such a situation,
add a flag for each protocol; the flag is set true when a work is
enqueued and set false after the work finished. workqueue_enqueue is
called only if the flag is false.
Proposed on tech-net and tech-kern.
Reverting the whole change set just messes up many files uselessly
because changes to them (except for if.h) are proper.
- Remove ifa_pslist_entry that breaks kvm(3) users (e.g., netstat -ia)
- Change IFADDR_{READER,WRITER}_* macros to use old IFADDR_* (or just NOP)
for now
Fix PR kern/51325
Kick out the list of async-signal-safe functions (it is now in
sigaction(2)) because this is not a programmer-facing document.
XXX: if anyone knows definitively whether SIGEMT is actually used by
XXX: anything, please update the weasel words I put in.
slots, which become accessible upon kernel entry (syscall, cpu switch,
or whatever). Put the NOX bit in the user recursive slot, so the whole
tree does not appear as executable in kernel mode.
This is already what is done in the kernel pmap.
up the module segments into one big RWX chunk. Split this chunk into two
different text and data+bss+rodata chunks. The latter is made non-
executable. This also provides some kind of ASLR, since the chunks are
not necessarily contiguous.
the NOX bit. With the top level recursive slot, however, several levels
are recursively omitted, which implies that each entry that is not the
child of NOX-ed parents actually appears somewhere in the virtual space
as executable via this slot, even if it is followed by an underlying
entry that has the NOX bit.
This recursive slot is only used to edit the page tree itself. Make it
non-executable.
