threads consuming the result of pfind() will not need to check for a NULL
credential pointer or other signs of an incompletely created process.
However, this also means that pfind() cannot be used to test for the
existence or find such a process. Annotate pfind() to indicate that this
is the case. A review of curent consumers seems to indicate that this is
not a problem for any of them. This closes a number of race conditions
that could result in NULL pointer dereferences and related failure modes.
Other related races continue to exist, especially during iteration of the
allproc list without due caution.
Discussed with: tjr, green
have already done this, so I have styled the patch on their work:
1) introduce a ip_newid() static inline function that checks
the sysctl and then decides if it should return a sequential
or random IP ID.
2) named the sysctl net.inet.ip.random_id
3) IPv6 flow IDs and fragment IDs are now always random.
Flow IDs and frag IDs are significantly less common in the
IPv6 world (ie. rarely generated per-packet), so there should
be smaller performance concerns.
The sysctl defaults to 0 (sequential IP IDs).
Reviewed by: andre, silby, mlaier, ume
Based on: NetBSD
MFC after: 2 months
Only the actual loopback address should be declared passive, other
addresses are very likely to be desirable to announce.
Check for IFF_LOOPBACK instead of IFF_PASSIVE to determine if we have
an unknown interface type.
simple errx() function.
Improve behavior when bzlib/zlib are missing by detecting and
issuing an error message on attempts to read gzip/bzip2 compressed
archives.
connect to, re-check that the local UNIX domain socket hasn't been
closed while we slept, and if so, return EINVAL. This affects the
system running both with and without Giant over the network stack,
and recent ULE changes appear to cause it to trigger more
frequently than previously under load. While here, improve catching
of possibly closed UNIX domain sockets in one or two additional
circumstances. I have a much larger set of related changes in
Perforce, but they require more testing before they can be merged.
One debugging printf is left in place to indicate when such a race
takes place: this is typically triggered by a buggy application
that simultaenously connect()'s and close()'s a UNIX domain socket
file descriptor. I'll remove this at some point in the future, but
am interested in seeing how frequently this is reported. In the
case of Martin's reported problem, it appears to be a result of a
non-thread safe syslog() implementation in the C library, which
does not synchronize access to its logging file descriptor.
Reported by: mbr
the interface as IFF_NEEDSGIANT so if_start is run holding Giant.
Note: mutexes are initialized in the softc for this driver, but the
locking appears inadequate to allow Giant-free operation.
the interface as IFF_NEEDSGIANT so if_start is run holding Giant.
Note: this driver does declare and occasionally reference mutexes,
but I believe not nearly enough to provide safety.
now include the contents if any SSDT table as well. This makes use
of the property that one can concatenate the body of SSDT tables to
the DSDT, updating the DSDT header (length and checksum) and end up
with a larger and valid DSDT table. Hence, this also works with -f.
Reviewed by: njl@
