if we hold a spin mutex, since we can trivially get into deadlocks if we
start switching out of processes that hold spinlocks. Checking to see if
interrupts were disabled was a sort of cheap way of doing this since most
of the time interrupts were only disabled when holding a spin lock. At
least on the i386. To fix this properly, use a per-process counter
p_spinlocks that counts the number of spin locks currently held, and
instead of checking to see if interrupts are disabled in the witness code,
check to see if we hold any spin locks. Since child processes always
start up with the sched lock magically held in fork_exit(), we initialize
p_spinlocks to 1 for child processes. Note that proc0 doesn't go through
fork_exit(), so it starts with no spin locks held.
Consulting from: cp
- Kthread functions return an error status, they don't set errno to an
error status.
- Remove the BUGS section as all the bugs listed have been fixed now.
This is needed even with `-o space' as the kernel decides to be "helpful"
and not really do space optimization. Looking at src/sys/ufs/ffs/ffs_alloc.c
we see why: if (fs->fs_minfree <= 5 ||
fs->fs_cstotal.cs_nffree >
(off_t)fs->fs_dsize * fs->fs_minfree / (2 * 100))
break;
log(LOG_NOTICE, "%s: optimization changed from SPACE to TIME\n"
I have picked `1' vs. `0' just incase some code somewhere has the assumption
the %free can never be `0'.
Helped with understanding why -m 1 made a different: imp
into an interruptable sleep and we increment a sleep count, we make sure
that we are the thread that will decrement the count when we wakeup.
Otherwise, what happens is that if we get interrupted (signal) and we
have to wake up, but before we get our mutex, some thread that wants
to wake us up detects that the count is non-zero and so enters wakeup_one(),
but there's nothing on the sleep queue and so we don't get woken up. The
thread will still decrement the sleep count, which is bad because we will
also decrement it again later (as we got interrupted) and are already off
the sleep queue.
an IP header with ip_len in network byte order. For certain
values of ip_len, this could cause icmp_error() to write
beyond the end of an mbuf, causing mbuf free-list corruption.
This problem was observed during generation of ICMP redirects.
We now make quite sure that the copy of the IP header kept
for icmp_error() is stored in a non-shared mbuf header so
that it will not be modified by ip_output().
Also:
- Calculate the correct number of bytes that need to be
retained for icmp_error(), instead of assuming that 64
is enough (it's not).
- In icmp_error(), use m_copydata instead of bcopy() to
copy from the supplied mbuf chain, in case the first 8
bytes of IP payload are not stored directly after the IP
header.
- Sanity-check ip_len in icmp_error(), and panic if it is
less than sizeof(struct ip). Incoming packets with bad
ip_len values are discarded in ip_input(), so this should
only be triggered by bugs in the code, not by bad packets.
This patch results from code and suggestions from Ruslan, Bosko,
Jonathan Lemon and Matt Dillon, with important testing by Mike
Tancsa, who could reproduce this problem at will.
Reported by: Mike Tancsa <mike@sentex.net>
Reviewed by: ru, bmilekic, jlemon, dillon
Since the compiler lays out the stuct so that pointers are naturally
(8-byte) aligned aligned, adding the int ki_layout didn't change the size of
the stuct; it just converted the alignment padding to a usable struct
field.
Reviewed by: David Cross <dec@freebsd.org>, jkh <jkh@freebsd.org>
Approved by: jkh <jkh@freebsd.org>
Obtained from: Ian Dowse <iedowse@maths.tcd.ie>, David Cross <dec@freebsd.org>
We have been running this patch on a production NIS server for 2.5 weeks now.
Normally we would have ypserv die at least once a week, and often many times
a day.
This patch treats and error from select as zeroing out the FD_SET to indicate
that no fds are ready for reading. This is safe because the rpc code
always re-inits the FDSET before calling select.
and also obey most of the rules of english in their construction.
Add a help screen for the security menu which gives the user a rough idea
just what the various security profiles do.
more robust. They would correctly return ENOMEM for the first time when
the buffer was exhausted, but subsequent calls in this case could cause
writes ouside of the buffer bounds.
Approved by: rwatson
list was cleared.
Rules with null suffixes would not be rebuilt when the suffixes were
added again.
Adding null suffix rules would fail when a rule for the same source was
declared before the suffix list was cleared.
PR: 23328, 24102
Reviewed by: will
Approved by: rwatson
in vr_init(). The VIA Rhine chip happens to be able to automatically
read its station address from the EEPROM automatically when reset,
so you don't need to program the filter if you want to keep using the
factory default address, but if you want to change it with "ifconfig vr0
ether xx:xx:xx:xx:xx:xx" then we need to manually set it in the init
routine.
sys/contrib/dev/acpica/Subsystem/Hardware/Attic/hwxface.c to the proper
location after AcpiEnterSleepState().
- Wait for the WAK_STS bit
- Evaluate the _WAK method and check result code
structure rather than assuming that the device vnode would reside
in the FFS filesystem (which is obviously a broken assumption with
the device filesystem).
in the hopes that they will actually *read* the comment above
it and *follow* the instructions so as to cause all the rest
of us less a lot less grief.
