In case no real/physical IEEE 802 address is available, both the expired
"draft-leach-uuids-guids-01" (section "4. Node IDs when no IEEE 802
network card is available") and RFC 2518 (section "6.4.1 Node Field
Generation Without the IEEE 802 Address") recommend (quoted from RFC
2518):
"The ideal solution is to obtain a 47 bit cryptographic quality random
number, and use it as the low 47 bits of the node ID, with the _most_
significant bit of the first octet of the node ID set to 1. This bit
is the unicast/multicast bit, which will never be set in IEEE 802
addresses obtained from network cards; hence, there can never be a
conflict between UUIDs generated by machines with and without network
cards."
Unfortunately, this incorrectly explains how to implement this and
the FreeBSD UUID generator code inherited this generation bug from
the broken reference code in the standards draft. They should instead
specify the "_least_ significant bit of the first octet of the node ID"
as the multicast bit in a memory and hexadecimal string representation
of a 48-bit IEEE 802 MAC address.
This standards bug arised from a false interpretation, as the multicast
bit is actually the _most_ significant bit in IEEE 802.3 (Ethernet)
_transmission order_ of an IEEE 802 MAC address. The standards authors
forgot that the bitwise order of an _octet_ from a MAC address _memory_
and hexadecimal string representation is still always from left (MSB,
bit 7) to right (LSB, bit 0).
Fortunately, this UUID generation bug could have occurred on systems
without any Ethernet NICs only.
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
in OpenBSD by Niels Provos. The patch introduces a bitmap of allocated
file descriptors which is used to locate available descriptors when a new
one is needed. It also moves the task of growing the file descriptor table
out of fdalloc(), reducing complexity in both fdalloc() and do_dup().
Debts of gratitude are owed to tjr@ (who provided the original patch on
which this work is based), grog@ (for the gdb(4) man page) and rwatson@
(for assistance with pxeboot(8)).
ithread_remove_handler() may fail to remove the interrupt handler if
it decides to let the ithread do the removal. The problem is that during
boot "cold" is set, which causes msleep() to return immediately. This
will cause ithread_remove_handler() to fail to wait for the ithread
to do the removal from the handler TAILQ before freeing the handler
back to the heap. Bad things will happen when some other user of the
TAILQ, such as ithread_add_handler() or the actual ithread attempts to use
the freed handler. Fix the problem by forcing ithread_remove_handler()
to do the actual removal itself if the "cold" flag is set.
Reviewed by: jhb
a maximum dump size of 0, return a size-related error, rather
than returning success. Otherwise, waitpid() will incorrectly
return a status indicating that a core dump was created. Note
that the specific error doesn't actually matter, since it's lost.
MFC after: 2 weeks
PR: 60367
Submitted by: Valentin Nechayev <netch@netch.kiev.ua>
avoid relying on the minimum memory allocation size to avoid problems.
The check is somewhat redundant because the consumers of the returned
structure will check that sa_len is a protocol-specific larger size.
Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: nectar
MFC after: 30 days
setting the new process' p_pgrp again before inserting it in the p_pglist.
Without it we can get the new process to be inserted in a different p_pglist
than the one p2->p_pgrp points to, and this is not something we want to happen.
This is not a fix, merely a bandaid, but it will work until someone finds a
better way to do it.
Discussed with: jhb (a long time ago)
in slightly less usual states:
If the thread is on a run queue, display "running" if the thread is
actually running, otherwise, "runnable".
If the thread is sleeping, and it's on a sleep queue, display the
name of the queue, otherwise "unknown" -- previously, in this situation
we would display "iowait".
If the thread is waiting on a lock, display *lockname.
If the thread is suspended, display "suspended" -- previously, in
this situation we would display "iowait".
If the thread is waiting for an interrupt, display "intrwait" --
previously, in this situation we would display "iowait".
If the thread is in a state not handled by the above, display
"unknown" -- previously, we would print "iowait".
Among other things, this avoids displaying "iowait" when the foreground
process turns out to be suspended waiting for a debugger to properly
attach.
holding the mutex. Because the sigacts pointer can't change while
the process is "live" (proc locking (x)), we know our pointer is still
valid.
In communication with: truckman
Reviewed by: jhb
on a non-recursive mutex will fail but will not trigger any assertions.
- Add an assertion to mtx_lock() that one never recurses on a non-recursive
mutex. This is mostly useful for the non-WITNESS case.
Requested by: deischen, julian, others (1)
Add empty line before first code line in functions with no local
variables.
Properly terminate comment sentences.
Indent lines which are longer that 80 characters.
Move v_addpollinfo closer to the rest of poll-related functions.
Move DEBUG_VFS_LOCKS ifdefed block to the end of file.
Obtained from: bde (partly)
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.
Reviewed by: deischen, dfr
o promote several m_tag_* routines to inline
o add an m_tag_setup inline to set the fixed fields in a packet tag
o add an m_tag_free method pointer to each mtag to support, for example,
allocating tags from zones
o have m_tag_find check if the tag list is not empty before calling
m_tag_locate to search
Reviewed by: brooks, silence from others
with one of std{in,out,err} open. This helps with the file descriptor
leaks reported on -current. This should probably be merged into 5.2.
Reviewed by: ru
Tested by: Bjoern A. Zeeb <bzeeb-lists@lists.zabbadoz.net>
function back to near the beginning of the file. Rev.1.194 moved it into
the middle of auxiliary functions following kern_execve(). Moved the
__mac_execve() syscall function up together with execve(). It was new in
rev1.1.196 and perfectly misplaced after execve().
sched_cpu() locks an sx lock (allproc_lock) which can sleep if it fails to
acquire the lock, it is not safe to execute this in a callout handler from
softclock().
