Multiple sessions doing CREATE INDEX CONCURRENTLY simultaneously are
supposed to be able to work in parallel, as evidenced by fixes in commit
c3d09b3bd23f specifically to support this case. In reality, one of the
sessions would be aborted by a misterious "deadlock detected" error.
Jeff Janes diagnosed that this is because of leftover snapshots used for
system catalog scans -- this was broken by 8aa3e47510b9 keeping track of
(registering) the catalog snapshot. To fix the deadlocks, it's enough
to de-register that snapshot prior to waiting.
Backpatch to 9.4, which introduced MVCC catalog scans.
Include an isolationtester spec that 8 out of 10 times reproduces the
deadlock with the unpatched code for me (Álvaro).
Author: Jeff Janes
Diagnosed-by: Jeff Janes
Reported-by: Jeremy Finzel
Discussion: https://postgr.es/m/CAMa1XUhHjCv8Qkx0WOr1Mpm_R4qxN26EibwCrj0Oor2YBUFUTg%40mail.gmail.com
Since 9.4, we've allowed the syntax "select union select" and variants
of that. However, the planner wasn't expecting a no-column set operation
and ended up treating the set operation as if it were UNION ALL.
Pre-v10, there seem to be some executor issues that would need to be
fixed to support such cases, and it doesn't really seem worth expending
much effort on. Just disallow it, instead.
Per report from Victor Yegorov.
Discussion: https://postgr.es/m/CAGnEbojGJrRSOgJwNGM7JSJZpVAf8xXcVPbVrGdhbVEHZ-BUMw@mail.gmail.com
The previous commit has shown that the sanity checks around freezing
aren't strong enough. Strengthening them seems especially important
because the existance of the bug has caused corruption that we don't
want to make even worse during future vacuum cycles.
The errors are emitted with ereport rather than elog, despite being
"should never happen" messages, so a proper error code is emitted. To
avoid superflous translations, mark messages as internal.
Author: Andres Freund and Alvaro Herrera
Reviewed-By: Alvaro Herrera, Michael Paquier
Discussion: https://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
Backpatch: 9.3-
Previously it was possible that a tuple was not pruned during vacuum,
even though its update xmax (i.e. the updating xid in a multixact with
both key share lockers and an updater) was below the cutoff horizon.
As the freezing code assumed, rightly so, that that's not supposed to
happen, xmax would be preserved (as a member of a new multixact or
xmax directly). That causes two problems: For one the tuple is below
the xmin horizon, which can cause problems if the clog is truncated or
once there's an xid wraparound. The bigger problem is that that will
break HOT chains, which in turn can lead two to breakages: First,
failing index lookups, which in turn can e.g lead to constraints being
violated. Second, future hot prunes / vacuums can end up making
invisible tuples visible again. There's other harmful scenarios.
Fix the problem by recognizing that tuples can be DEAD instead of
RECENTLY_DEAD, even if the multixactid has alive members, if the
update_xid is below the xmin horizon. That's safe because newer
versions of the tuple will contain the locking xids.
A followup commit will harden the code somewhat against future similar
bugs and already corrupted data.
Author: Andres Freund, with changes by Alvaro Herrera
Reported-By: Daniel Wood
Analyzed-By: Andres Freund, Alvaro Herrera, Robert Haas, Peter
Geoghegan, Daniel Wood, Yi Wen Wong, Michael Paquier
Reviewed-By: Alvaro Herrera, Robert Haas, Michael Paquier
Discussion:
https://postgr.es/m/E5711E62-8FDF-4DCA-A888-C200BF6B5742@amazon.comhttps://postgr.es/m/20171102112019.33wb7g5wp4zpjelu@alap3.anarazel.de
Backpatch: 9.3-
The logical slots have a fast code path for sending data so as not to
impose too high a per message overhead. The fast path skips checks for
interrupts and timeouts. However, the existing coding failed to consider
the fact that a transaction with a large number of changes may take a
very long time to be processed and sent to the client. This causes the
walsender to ignore interrupts for potentially a long time and more
importantly it will result in the walsender being killed due to
timeout at the end of such a transaction.
This commit changes the fast path to also check for interrupts and only
allows calling the fast path when the last keepalive check happened less
than half the walsender timeout ago. Otherwise the slower code path will
be taken.
Backpatched to 9.4
Petr Jelinek, reviewed by Kyotaro HORIGUCHI, Yura Sokolov, Craig
Ringer and Robert Haas.
Discussion: https://postgr.es/m/e082a56a-fd95-a250-3bae-0fff93832510@2ndquadrant.com
I noticed that _SPI_execute_plan initially sets spierrcontext.arg = NULL,
and only fills it in some time later. If an error were to happen in
between, _SPI_error_callback would try to dereference the null pointer.
This is unlikely --- there's not much between those points except
push-snapshot calls --- but it's clearly not impossible. Tweak the
callback to do nothing if the pointer isn't set yet.
It's been like this for awhile, so back-patch to all supported branches.
Notably, this permits linking to the 32-bit Perl binaries advertised on
perl.org, namely Strawberry Perl and ActivePerl. This has a side effect
of permitting linking to binaries built with obsolete MSVC versions.
By default, MSVC 2012 and later require a "safe exception handler table"
in each binary. MinGW-built, 32-bit DLLs lack the relevant exception
handler metadata, so linking to them failed with error LNK2026. Restore
the semantics of MSVC 2010, which omits the table from a given binary if
some linker input lacks metadata. This has no effect on 64-bit builds
or on MSVC 2010 and earlier. Back-patch to 9.3 (all supported
versions).
Reported by Victor Wagner.
Discussion: https://postgr.es/m/20160326154321.7754ab8f@wagner.wagner.home
Commits 5a5c2feca3fd858e70ea348822595547e6fa6c15 and
b5178c5d08ca59e30f9d9428fa6fdb2741794e65 introduced support for modern
MSVC-built, 32-bit Perl, but they broke use of MinGW-built, 32-bit Perl
distributions like Strawberry Perl and modern ActivePerl. Perl has no
robust means to report whether it expects a -D_USE_32BIT_TIME_T ABI, so
test this. Back-patch to 9.3 (all supported versions).
The chief alternative was a heuristic of adding -D_USE_32BIT_TIME_T when
$Config{gccversion} is nonempty. That banks on every gcc-built Perl
using the same ABI. gcc could change its default ABI the way MSVC once
did, and one could build Perl with gcc and the non-default ABI.
The GNU make build system could benefit from a similar test, without
which it does not support MSVC-built Perl. For now, just add a comment.
Most users taking the special step of building Perl with MSVC probably
build PostgreSQL with MSVC.
Discussion: https://postgr.es/m/20171130041441.GA3161526@rfd.leadboat.com
When a worker is flagged as BGW_NEVER_RESTART and we fail to start it,
or if it is not marked BGW_NEVER_RESTART but is terminated before
startup succeeds, what BgwHandleStatus should be reported? The
previous code really hadn't considered this possibility (as indicated
by the comments which ignore it completely) and would typically return
BGWH_NOT_YET_STARTED, but that's not a good answer, because then
there's no way for code using GetBackgroundWorkerPid() to tell the
difference between a worker that has not started but will start
later and a worker that has not started and will never be started.
So, when this case happens, return BGWH_STOPPED instead. Update the
comments to reflect this.
The preceding fix by itself is insufficient to fix the problem,
because the old code also didn't send a notification to the process
identified in bgw_notify_pid when startup failed. That might've
been technically correct under the theory that the status of the
worker was BGWH_NOT_YET_STARTED, because the status would indeed not
change when the worker failed to start, but now that we're more
usefully reporting BGWH_STOPPED, a notification is needed.
Without these fixes, code which starts background workers and then
uses the recommended APIs to wait for those background workers to
start would hang indefinitely if the postmaster failed to fork a
worker.
Amit Kapila and Robert Haas
Discussion: http://postgr.es/m/CAA4eK1KDfKkvrjxsKJi3WPyceVi3dH1VCkbTJji2fuwKuB=3uw@mail.gmail.com
This patch fixes a couple of low-probability bugs that could lead to
reporting an irrelevant errno value (and hence possibly a wrong SQLSTATE)
concerning directory-open or file-open failures. It also fixes places
where we took shortcuts in reporting such errors, either by using elog
instead of ereport or by using ereport but forgetting to specify an
errcode. And it eliminates a lot of just plain redundant error-handling
code.
In service of all this, export fd.c's formerly-static function
ReadDirExtended, so that external callers can make use of the coding
pattern
dir = AllocateDir(path);
while ((de = ReadDirExtended(dir, path, LOG)) != NULL)
if they'd like to treat directory-open failures as mere LOG conditions
rather than errors. Also fix FreeDir to be a no-op if we reach it
with dir == NULL, as such a coding pattern would cause.
Then, remove code at many call sites that was throwing an error or log
message for AllocateDir failure, as ReadDir or ReadDirExtended can handle
that job just fine. Aside from being a net code savings, this gets rid of
a lot of not-quite-up-to-snuff reports, as mentioned above. (In some
places these changes result in replacing a custom error message such as
"could not open tablespace directory" with more generic wording "could not
open directory", but it was agreed that the custom wording buys little as
long as we report the directory name.) In some other call sites where we
can't just remove code, change the error reports to be fully
project-style-compliant.
Also reorder code in restoreTwoPhaseData that was acquiring a lock
between AllocateDir and ReadDir; in the unlikely but surely not
impossible case that LWLockAcquire changes errno, AllocateDir failures
would be misreported. There is no great value in opening the directory
before acquiring TwoPhaseStateLock, so just do it in the other order.
Also fix CheckXLogRemoved to guarantee that it preserves errno,
as quite a number of call sites are implicitly assuming. (Again,
it's unlikely but I think not impossible that errno could change
during a SpinLockAcquire. If so, this function was broken for its
own purposes as well as breaking callers.)
And change a few places that were using not-per-project-style messages,
such as "could not read directory" when "could not open directory" is
more correct.
Back-patch the exporting of ReadDirExtended, in case we have occasion
to back-patch some fix that makes use of it; it's not needed right now
but surely making it global is pretty harmless. Also back-patch the
restoreTwoPhaseData and CheckXLogRemoved fixes. The rest of this is
essentially cosmetic and need not get back-patched.
Michael Paquier, with a bit of additional work by me
Discussion: https://postgr.es/m/CAB7nPqRpOCxjiirHmebEFhXVTK7V5Jvw4bz82p7Oimtsm3TyZA@mail.gmail.com
Invoking the Makefile without an explicit target was building every
possible target instead of just the "all" target. Back-patch to 9.3
(all supported versions).
The various has_*_privilege() functions all support an optional
WITH GRANT OPTION added to the supported privilege types to test
whether the privilege is held with grant option. That is, all except
has_sequence_privilege() variations. Fix that.
Back-patch to all supported branches.
Discussion: https://postgr.es/m/005147f6-8280-42e9-5a03-dd2c1e4397ef@joeconway.com
Traditionally IANA has distributed their timezone data in pure source
form, replete with extensive historical comments. As of release 2017c,
they've added a compact single-file format that omits comments and
abbreviates command keywords. This form is way shorter than the pure
source, even before considering its allegedly better compressibility.
Hence, let's distribute the data in that form rather than pure source.
I'm pushing this now, rather than at the next timezone database update,
so that it's easy to confirm that this data file produces compiled zic
output that's identical to what we were getting before.
Discussion: https://postgr.es/m/1915.1511210334@sss.pgh.pa.us
hstoreUniquePairs() often called memcpy with equal source and destination
pointers. Although this is almost surely harmless in practice, it's
undefined according to the letter of the C standard. Some versions of
valgrind will complain about it, and some versions of libc as well
(cf. commit ad520ec4a). Tweak the code to avoid doing that.
Noted by Tomas Vondra. Back-patch to all supported versions because
of the hazard of libc assertions.
Discussion: https://postgr.es/m/bf84d940-90d4-de91-19dd-612e011007f4@fuzzy.cz
When nodeValuesscan.c was written, it was impossible to have a SubPlan in
VALUES --- any sub-SELECT there would have to be uncorrelated and thereby
would produce an InitPlan instead. We therefore took a shortcut in the
logic that throws away a ValuesScan's per-row expression evaluation data
structures. This was broken by the introduction of LATERAL however; a
sub-SELECT containing a lateral reference produces a correlated SubPlan.
The cleanest fix for this would be to give up the optimization of
discarding the expression eval state. But that still seems pretty
unappetizing for long VALUES lists. It seems to work to just prevent
the subexpressions from hooking into the ValuesScan node's subPlan
list, so let's do that and see how well it works. (If this breaks,
due to additional connections between the subexpressions and the outer
query structures, we might consider compromises like throwing away data
only for VALUES rows not containing SubPlans.)
Per bug #14924 from Christian Duta. Back-patch to 9.3 where LATERAL
was introduced.
Discussion: https://postgr.es/m/20171124120836.1463.5310@wrigleys.postgresql.org
This is necessary for ActivePerl 5.18 onwards and for Strawberry Perl.
It is not sufficient for 32-bit builds with newer Visual Studio; these
fail with error LINK2026. Back-patch to 9.3 (all supported versions).
Reported by Victor Wagner.
Discussion: https://postgr.es/m/20160326154321.7754ab8f@wagner.wagner.home
Previously, any attempt to request a 3.x protocol version other than
3.0 would lead to a hard connection failure, which made the minor
protocol version really no different from the major protocol version
and precluded gentle protocol version breaks. Instead, when the
client requests a 3.x protocol version where x is greater than 0, send
the new NegotiateProtocolVersion message to convey that we support
only 3.0. This makes it possible to introduce new minor protocol
versions without requiring a connection retry when the server is
older.
In addition, if the startup packet includes name/value pairs where
the name starts with "_pq_.", assume that those are protocol options,
not GUCs. Include those we don't support (i.e. all of them, at
present) in the NegotiateProtocolVersion message so that the client
knows they were not understood. This makes it possible for the
client to request previously-unsupported features without bumping
the protocol version at all; the client can tell from the server's
response whether the option was understood.
It will take some time before servers that support these new
facilities become common in the wild; to speed things up and make
things easier for a future 3.1 protocol version, back-patch to all
supported releases.
Robert Haas and Badrul Chowdhury
Discussion: http://postgr.es/m/BN6PR21MB0772FFA0CBD298B76017744CD1730@BN6PR21MB0772.namprd21.prod.outlook.com
Discussion: http://postgr.es/m/30788.1498672033@sss.pgh.pa.us
The scripts in contrib/start-scripts/osx don't work at all on macOS
10.10 (Yosemite) or later, because they depend on SystemStarter which
Apple deprecated long ago and removed in 10.10. Add a new subdirectory
contrib/start-scripts/macos with scripts that use the newer launchd
infrastructure.
Since this problem is independent of which Postgres version you're using,
back-patch to all supported branches.
Discussion: https://postgr.es/m/31338.1510763554@sss.pgh.pa.us
Apart from calling write_stderr() on failure, the handler depends on no
PostgreSQL facilities. We have experienced crashes before reaching the
former call site. Given such an early crash, this change cannot hurt
and may produce a helpful dump. Absent an early crash, this change has
no effect. Back-patch to 9.3 (all supported versions).
Takayuki Tsunakawa
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F80CD13@G01JPEXMBYT05
PostgreSQL running as a Windows service crashed upon calling
write_stderr() before MemoryContextInit(). This fix completes work
started in 5735efee15540765315aa8c1a230575e756037f7. Messages this
early contain only ASCII bytes; if we removed the CurrentMemoryContext
requirement, the ensuing conversions would have no effect. Back-patch
to 9.3 (all supported versions).
Takayuki Tsunakawa, reviewed by Michael Paquier.
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F80CC73@G01JPEXMBYT05
This suite had been a proper superset of the regular ecpg test suite,
but the three newest tests didn't reach it. To make this less likely to
recur, delete the extra schedule file and pass the TCP-specific test on
the command line. Back-patch to 9.3 (all supported versions).
Since commit 868898739a8da9ab74c105b8349b7b5c711f265a, it has assumed
"localhost" resolves to both ::1 and 127.0.0.1. We gain nothing from
that assumption, and it does not hold in a default installation of Red
Hat Enterprise Linux 5. Back-patch to 9.3 (all supported versions).
The test runs only as part of "checktcp". This is a back-patch to 9.5
and 9.4 of part of commit 868898739a8da9ab74c105b8349b7b5c711f265a.
Oversight in commit 61bee9f756ce875f3b678099a6bb9654bd2fa21a.
When a value contained an XML declaration naming some other encoding,
this function interpreted UTF8 bytes as the named encoding, yielding
mojibake. xml_parse() already has similar logic. This would be
necessary but not sufficient for non-UTF8 databases, so preserve
behavior there until the xpath facility can support such databases
comprehensively. Back-patch to 9.3 (all supported versions).
Pavel Stehule and Noah Misch
Discussion: https://postgr.es/m/CAFj8pRC-dM=tT=QkGi+Achkm+gwPmjyOayGuUfXVumCxkDgYWg@mail.gmail.com
An LDAP URL without a host name such as "ldap://" or without a base DN
such as "ldap://localhost" would cause a crash when reading pg_hba.conf.
If no binddn is configured, an error message might end up trying to print a
null pointer, which could crash on some platforms.
Author: Thomas Munro <thomas.munro@enterprisedb.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
Upon further review, our Bonjour code doesn't actually work with the
Avahi not-too-compatible compatibility library. While you can get it
to work on non-macOS platforms if you link to Apple's own mDNSResponder
code, there don't seem to be many people who care about that. Leaving in
the AC_SEARCH_LIBS call seems more likely to encourage people to build
broken configurations than to do anything very useful.
Hence, remove the AC_SEARCH_LIBS call and put in a warning comment instead.
Discussion: https://postgr.es/m/2D8331C5-D64F-44C1-8717-63EDC6EAF7EB@brightforge.com
On macOS the relevant functions require no special library, but elsewhere
we need to pull in libdns_sd.
Back-patch to supported branches. No docs change since the docs do not
suggest that this is a Mac-only feature.
Luke Lonergan
Discussion: https://postgr.es/m/2D8331C5-D64F-44C1-8717-63EDC6EAF7EB@brightforge.com
The point of having separate ResourceOwnerEnlargeFoo and
ResourceOwnerRememberFoo functions is so that resource allocation
can happen in between. Doing it in some other order is just wrong.
OpenTemporaryFile() did open(), enlarge, remember, which would leak the
open file if the enlarge step ran out of memory. Because fd.c has its own
layer of resource-remembering, the consequences look like they'd be limited
to an intratransaction FD leak, but it's still not good.
IncrBufferRefCount() did enlarge, remember, incr-refcount, which would blow
up if the incr-refcount step ever failed. It was safe enough when written,
but since the introduction of PrivateRefCountHash, I think the assumption
that no error could happen there is pretty shaky.
The odds of real problems from either bug are probably small, but still,
back-patch to supported branches.
Thomas Munro and Tom Lane, per a comment from Andres Freund
isdigit(), isspace(), etc are likely to give surprising results if passed a
signed char. We should always cast the argument to unsigned char to avoid
that. Error in commit 63d6b97fd, found by buildfarm member gaur.
Back-patch to 9.3, like that commit.
json{b}_populate_recordset() used the tuple descriptor created from the
query-level AS clause without worrying about whether it matched the actual
input record type. If it didn't, that would usually result in a crash,
though disclosure of server memory contents seems possible as well, for a
skilled attacker capable of issuing crafted SQL commands. Instead, use
the query-supplied descriptor only when there is no input tuple to look at,
and otherwise get a tuple descriptor based on the input tuple's own type
marking. The core code will detect any type mismatch in the latter case.
Michael Paquier and Tom Lane, per a report from David Rowley.
Back-patch to 9.3 where this functionality was introduced.
Security: CVE-2017-15098
By default, $PGUSER has permission to unlink $PGLOG. If $PGUSER
replaces $PGLOG with a symbolic link, the server will corrupt the
link-targeted file by appending log messages. Since these scripts open
$PGLOG as root, the attack works regardless of target file ownership.
"make install" does not install these scripts anywhere. Users having
manually installed them in the past should repeat that process to
acquire this fix. Most script users have $PGLOG writable to root only,
located in $PGDATA. Just before updating one of these scripts, such
users should rename $PGLOG to $PGLOG.old. The script will then recreate
$PGLOG with proper ownership.
Reviewed by Peter Eisentraut. Reported by Antoine Scemama.
Security: CVE-2017-12172
In the v10 branch, also back-patch the effects of 1ff01b390 and c29c57890
on these files, to reduce future maintenance issues. (I'd do it further
back, except that the 9.X branches differ anyway due to xlog-to-wal
link tag renaming.)
