brenext(), when parsing a '*' quantifier, forgot to return any "value"
for the token; per the equivalent case in next(), it should return
value 1 to indicate that greedy rather than non-greedy behavior is
wanted. The result is that the compiled regexp could behave like 'x*?'
rather than the intended 'x*', if we were unlucky enough to have
a zero in v->nextvalue at this point. That seems to happen with some
reliability if we have '.*' at the beginning of a BRE-mode regexp,
although that depends on the initial contents of a stack-allocated
struct, so it's not guaranteed to fail.
Found by Alexander Lakhin using valgrind testing. This bug seems
to be aboriginal in Spencer's code, so back-patch all the way.
Discussion: https://postgr.es/m/16814-6c5e3edd2bdf0d50@postgresql.org
We found last February that the error-case tests added by commit
008cf0409 failed on OpenBSD, because that platform doesn't really
check locale names. At the time it seemed that that was only an issue
for LC_CTYPE, but testing on a more recent version of OpenBSD shows
that it's now equally lax about LC_COLLATE.
Rather than dropping the LC_COLLATE test too, put back LC_CTYPE
(reverting c4b0edb07), and adjust these tests to accept the different
error message that we get if setlocale() doesn't reject a bogus locale
name. The point of these tests is not really what the backend does
with the locale name, but to show that createdb quotes funny locale
names safely; so we're not losing test reliability this way.
Back-patch as appropriate.
Discussion: https://postgr.es/m/231373.1610058324@sss.pgh.pa.us
On reflection, the order of operations in PostgresMain() is wrong.
These timeouts ought to be shut down before, not after, we do the
post-command-read CHECK_FOR_INTERRUPTS, to guarantee that any
timeout error will be detected there rather than at some ill-defined
later point (possibly after having wasted a lot of work).
This is really an error in the original idle_in_transaction_timeout
patch, so back-patch to 9.6 where that was introduced.
The documentation of pg_rewind mentioned the use of restore_command and
primary_conninfo as options available at startup to fetch missing WAL
segments that could be used to find the point of divergence for the
rewind. This is confusing because when finding the point of divergence
the target cluster is offline, so this option is not available.
Issue introduced by 878bd9a, so backpatch down to 9.6. The
documentation of 13 and HEAD was already right as this sentence has been
changed by a7e8ece when introducing -c/--restore-target-wal.
Reported-by: Amine Tengilimoglu
Discussion: https://postgr.es/m/CADTdw-w_0MP=iQrfizeU4QU5fcZb+w8P_oPeLL+WznWf0kbn3w@mail.gmail.com
Backpatch-through: 9.6
The deadlocks that the recovery conflict on lock is involved in can
happen between hot-standby backends and the startup process.
If a backend takes an access exclusive lock on the table and which
finally triggers the deadlock, that deadlock can be detected
as expected. On the other hand, previously, if the startup process
took an access exclusive lock and which finally triggered the deadlock,
that deadlock could not be detected and could remain even after
deadlock_timeout passed. This is a bug.
The cause of this bug was that the code for handling the recovery
conflict on lock didn't take care of deadlock case at all. It assumed
that deadlocks involving the startup process and backends were able
to be detected by the deadlock detector invoked within backends.
But this assumption was incorrect. The startup process also should
have invoked the deadlock detector if necessary.
To fix this bug, this commit makes the startup process invoke
the deadlock detector if deadlock_timeout is reached while handling
the recovery conflict on lock. Specifically, in that case, the startup
process requests all the backends holding the conflicting locks to
check themselves for deadlocks.
Back-patch to v9.6. v9.5 has also this bug, but per discussion we decided
not to back-patch the fix to v9.5. Because v9.5 doesn't have some
infrastructure codes (e.g., 37c54863cf) that this bug fix patch depends on.
We can apply those codes for the back-patch, but since the next minor
version release is the final one for v9.5, it's risky to do that. If we
unexpectedly introduce new bug to v9.5 by the back-patch, there is no
chance to fix that. We determined that the back-patch to v9.5 would give
more risk than gain.
Author: Fujii Masao
Reviewed-by: Bertrand Drouvot, Masahiko Sawada, Kyotaro Horiguchi
Discussion: https://postgr.es/m/4041d6b6-cf24-a120-36fa-1294220f8243@oss.nttdata.com
In power_var_int(), the computation of the number of significant
digits to use in the computation used log(Abs(exp)), which isn't safe
because Abs(exp) returns INT_MIN when exp is INT_MIN. Use fabs()
instead of Abs(), so that the exponent is cast to a double before the
absolute value is taken.
Back-patch to 9.6, where this was introduced (by 7d9a4737c2).
Discussion: https://postgr.es/m/CAEZATCVd6pMkz=BrZEgBKyqqJrt2xghr=fNc8+Z=5xC6cgWrWA@mail.gmail.com
If the substring start index and length overflow when added together,
substring() misbehaved, either throwing a bogus "negative substring
length" error on a case that should succeed, or failing to complain that
a negative length is negative (and instead returning the whole string,
in most cases). Unsurprisingly, the text, bytea, and bit variants of
the function all had this issue. Rearrange the logic to ensure that
negative lengths are always rejected, and add an overflow check to
handle the other case.
Also install similar guards into detoast_attr_slice() (nee
heap_tuple_untoast_attr_slice()), since it's far from clear that
no other code paths leading to that function could pass it values
that would overflow.
Patch by myself and Pavel Stehule, per bug #16804 from Rafi Shamim.
Back-patch to v11. While these bugs are old, the common/int.h
infrastructure for overflow-detecting arithmetic didn't exist before
commit 4d6ad3125, and it doesn't seem like these misbehaviors are bad
enough to justify developing a standalone fix for the older branches.
Discussion: https://postgr.es/m/16804-f4eeeb6c11ba71d4@postgresql.org
The behavior of cross-type comparisons among date/time data types was
not really explained anywhere. You could probably infer it if you
recognized the applicability of comments elsewhere about datatype
conversions, but it seems worthy of explicit documentation.
Per bug #16797 from Dana Burd.
Discussion: https://postgr.es/m/16797-f264b0b980b53b8b@postgresql.org
90fbf7c has taken care of that for HEAD. This includes the portion of
the fixes that applies to the documentation, where needed depending on
the branch.
Author: Justin Pryzby
Discussion: https://postgr.es/m/20201227202604.GC26311@telsasoft.com
Backpatch-through: 9.5
There's a second call of get_eval_mcontext() that should also be
get_stmt_mcontext(). This is actually dead code, since no
interesting allocations happen before switching back to the
original context, but we should keep it in sync with the other
call to forestall possible future bugs.
Discussion: https://postgr.es/m/f075f7be-c654-9aa8-3ffc-e9214622f02a@enterprisedb.com
Commit a6b1f5365 intended to place the transient "target" list of
a CALL statement in the function's statement-lifespan context,
but I fat-fingered that and used get_eval_mcontext() instead of
get_stmt_mcontext(). The eval_mcontext belongs to the "simple
expression" infrastructure, which is destroyed at transaction end.
The net effect is that a CALL in a procedure to another procedure
that has OUT or INOUT parameters would fail if the called procedure
did a COMMIT.
Per report from Peter Eisentraut. Back-patch to v11, like the
prior patch.
Discussion: https://postgr.es/m/f075f7be-c654-9aa8-3ffc-e9214622f02a@enterprisedb.com
The code in charge of processing a single invalidation message has been
using since 568d413 the structure for relation mapping messages. This
had fortunately no consequence as both locate the database ID at the
same location, but it could become a problem in the future if this area
of the code changes.
Author: Konstantin Knizhnik
Discussion: https://postgr.es/m/8044c223-4d3a-2cdb-42bf-29940840ce94@postgrespro.ru
Backpatch-through: 9.5
In postgres_fdw, the cached connections to foreign servers will not be
closed until the local session exits if the user mappings or foreign servers
that those connections depend on are dropped. Those connections can be
leaked.
To fix that connection leak issue, after a change to a pg_foreign_server
or pg_user_mapping catalog entry, this commit makes postgres_fdw close
the connections depending on that entry immediately if current
transaction has not used those connections yet. Otherwise, mark those
connections as invalid and then close them at the end of current transaction,
since they cannot be closed in the midst of the transaction using them.
Closed connections will be remade at the next opportunity if necessary.
Back-patch to all supported branches.
Author: Bharath Rupireddy
Reviewed-by: Zhihong Yu, Zhijie Hou, Fujii Masao
Discussion: https://postgr.es/m/CALj2ACVNcGH_6qLY-4_tXz8JLvA+4yeBThRfxMz7Oxbk1aHcpQ@mail.gmail.com
This makes existing sessions reflect "ALTER ROLE ... [NO]INHERIT" as
quickly as they have been reflecting "GRANT role_name". Back-patch to
9.5 (all supported versions).
Reviewed by Nathan Bossart.
Discussion: https://postgr.es/m/20201221095028.GB3777719@rfd.leadboat.com
If a database shutdown (smart or fast) is commanded between the time
some process decides to request a new background worker and the time
that the postmaster can launch that worker, then nothing happens
because the postmaster won't launch any bgworkers once it's exited
PM_RUN state. This is fine ... unless the requesting process is
waiting for that worker to finish (or even for it to start); in that
case the requestor is stuck, and only manual intervention will get us
to the point of being able to shut down.
To fix, cancel pending requests for workers when the postmaster sends
shutdown (SIGTERM) signals, and similarly cancel any new requests that
arrive after that point. (We can optimize things slightly by only
doing the cancellation for workers that have waiters.) To fit within
the existing bgworker APIs, the "cancel" is made to look like the
worker was started and immediately stopped, causing deregistration of
the bgworker entry. Waiting processes would have to deal with
premature worker exit anyway, so this should introduce no bugs that
weren't there before. We do have a side effect that registration
records for restartable bgworkers might disappear when theoretically
they should have remained in place; but since we're shutting down,
that shouldn't matter.
Back-patch to v10. There might be value in putting this into 9.6
as well, but the management of bgworkers is a bit different there
(notably see 8ff518699) and I'm not convinced it's worth the effort
to validate the patch for that branch.
Discussion: https://postgr.es/m/661570.1608673226@sss.pgh.pa.us
The parsing of this parameter has been using strtoul(), which is not
portable across platforms. On most Unix platforms, unsigned long has a
size of 64 bits, while on Windows it is 32 bits. It is common in
recovery scenarios to rely on the output of txid_current() or even the
newer pg_current_xact_id() to get a transaction ID for setting up
recovery_target_xid. The value returned by those functions includes the
epoch in the computed result, which would cause strtoul() to fail where
unsigned long has a size of 32 bits once the epoch is incremented.
WAL records and 2PC data include only information about 32-bit XIDs and
it is not possible to have XIDs across more than one epoch, so
discarding the high bits from the transaction ID set has no impact on
recovery. On the contrary, the use of strtoul() prevents a consistent
behavior across platforms depending on the size of unsigned long.
This commit changes the parsing of recovery_target_xid to use
pg_strtouint64() instead, available down to 9.6. There is one TAP test
stressing recovery with recovery_target_xid, where a tweak based on
pg_reset{xlog,wal} is added to bump the XID epoch so as this change gets
tested, as per an idea from Alexander Lakhin.
Reported-by: Alexander Lakhin
Discussion: https://postgr.es/m/16780-107fd0c0385b1035@postgresql.org
Backpatch-through: 9.6
Bad things happen if the DBA issues "pg_ctl stop -m fast" before
autoprewarm finishes loading its list of blocks to prewarm.
The current worker process successfully terminates early, but
(if this wasn't the last database with blocks to prewarm) the
leader process will just try to launch another worker for the
next database. Since the postmaster is now in PM_WAIT_BACKENDS
state, it ignores the launch request, and the leader just sits
until it's killed manually.
This is mostly the fault of our half-baked design for launching
background workers, but a proper fix for that is likely to be
too invasive to be back-patchable. To ameliorate the situation,
fix apw_load_buffers() to check whether SIGTERM has arrived
just before trying to launch another worker. That leaves us with
only a very narrow window in each worker launch where SIGTERM
could occur between the launch request and successful worker start.
Another issue is that if the leader process does manage to exit,
it unconditionally rewrites autoprewarm.blocks with only the
blocks currently in shared buffers, thus forgetting any blocks
that we hadn't reached yet while prewarming. This seems quite
unhelpful, since the next database start will then not have the
expected prewarming benefit. Fix it to not modify the file if
we shut down before the initial load attempt is complete.
Per bug #16785 from John Thompson. Back-patch to v11 where
the autoprewarm code was introduced.
Discussion: https://postgr.es/m/16785-c0207d8c67fb5f25@postgresql.org
The jsonb || jsonb operator arbitrarily rejected certain combinations
of scalar and non-scalar inputs, while being willing to concatenate
other combinations. This was of course quite undocumented. Rather
than trying to document it, let's just remove the restriction,
creating a uniform rule that unless we are handling an object-to-object
concatenation, non-array inputs are converted to one-element arrays,
resulting in an array-to-array concatenation. (This does not change
the behavior for any case that didn't throw an error before.)
Per complaint from Joel Jacobson. Back-patch to all supported branches.
Discussion: https://postgr.es/m/163099.1608312033@sss.pgh.pa.us
The separate "cd" command before invoking psql made sense (or at least
I thought so) when it was added in commit ed1939332. But 4e3a61635
removed the supporting text that explained when to use it, making it
just confusing. So drop it.
Also switch from four-dot to three-dot filler for the unsupplied
part of the path, since at least one person has read the four-dot
filler as a typo for "../..". And fix these/those inconsistency.
Discussion: https://postgr.es/m/160837647714.673.5195186835607800484@wrigleys.postgresql.org
A narrow reading of the C standard says that memcpy(x,x,n) is undefined,
although it's hard to envision an implementation that would really
misbehave. However, analysis tools such as valgrind might whine about
this; accordingly, let's band-aid relmapper.c to not do it.
See also 5b630501e, d3f4e8a8a, ad7b48ea0, and other similar fixes.
Apparently, none of those folk tried valgrinding initdb? This has been
like this for long enough that I'm surprised it hasn't been reported
before.
Back-patch, just in case anybody wants to use a back branch on a platform
that complains about this; we back-patched those earlier fixes too.
Discussion: https://postgr.es/m/161790.1608310142@sss.pgh.pa.us
It was not clear how COPY TO behaved with partitioning/inheritance
because the paragraphs were so far apart. Also reword to simplify.
Discussion: https://postgr.es/m/20201203211723.GR24052@telsasoft.com
Author: Justin Pryzby
Backpatch-through: 10
array_get_element and array_get_slice qualify as leakproof, since
they will silently return NULL for bogus subscripts. But
array_set_element and array_set_slice throw errors for such cases,
making them clearly not leakproof. contain_leaked_vars was evidently
written with only the former case in mind, as it gave the wrong answer
for assignment SubscriptingRefs (nee ArrayRefs).
This would be a live security bug, were it not that assignment
SubscriptingRefs can only occur in INSERT and UPDATE target lists,
while we only care about leakproofness for qual expressions; so the
wrong answer can't occur in practice. Still, that's a rather shaky
answer for a security-related question; and maybe in future somebody
will want to ask about leakproofness of a tlist. So it seems wise to
fix and even back-patch this correction.
(We would need some change here anyway for the upcoming
generic-subscripting patch, since extensions might make different
tradeoffs about whether to throw errors. Commit 558d77f20 attempted
to lay groundwork for that by asking check_functions_in_node whether a
SubscriptingRef contains leaky functions; but that idea fails now that
the implementation methods of a SubscriptingRef are not SQL-visible
functions that could be marked leakproof or not.)
Back-patch to 9.6. While 9.5 has the same issue, the code's a bit
different. It seems quite unlikely that we'd introduce any actual bug
in the short time 9.5 has left to live, so the work/risk/reward balance
isn't attractive for changing 9.5.
Discussion: https://postgr.es/m/3143742.1607368115@sss.pgh.pa.us
The SQL standard says that redundant unique constraints are disallowed,
but we long ago decided that throwing an error would be too
user-unfriendly, so we just drop redundant ones. The docs weren't very
clear about that though, as this behavior was only explained for PRIMARY
KEY vs UNIQUE, not UNIQUE vs UNIQUE.
While here, I couldn't resist doing some copy-editing and markup-fixing
on the adjacent text about INCLUDE options.
Per bug #16767 from Matthias vd Meent.
Discussion: https://postgr.es/m/16767-1714a2056ca516d0@postgresql.org
The following routines are called within pgcrypto when handling digests
but there were no checks for failures:
- EVP_MD_CTX_size (can fail with -1 as of 3.0.0)
- EVP_MD_CTX_block_size (can fail with -1 as of 3.0.0)
- EVP_DigestInit_ex
- EVP_DigestUpdate
- EVP_DigestFinal_ex
A set of elog(ERROR) is added by this commit to detect such failures,
that should never happen except in the event of a processing failure
internal to OpenSSL.
Note that it would be possible to use ERR_reason_error_string() to get
more context about such errors, but these refer mainly to the internals
of OpenSSL, so it is not really obvious how useful that would be. This
is left out for simplicity.
Per report from Coverity. Thanks to Tom Lane for the discussion.
Backpatch-through: 9.5
clang only uses the 'i1' type for scalar booleans, not for pointers to
booleans (as the pointer might be pointing into a larger memory
allocation). Therefore a pointer-to-bool needs to the "storage" boolean.
There's no known case of wrong code generation due to this, but it seems quite
possible that it could cause problems (see e.g. 72559438f9).
Author: Andres Freund
Discussion: https://postgr.es/m/20201207212142.wz5tnbk2jsaqzogb@alap3.anarazel.de
Backpatch: 11-, where jit support was added
Until recently 'native' was implicitly included via 'orcjit', but a change
included in LLVM 11 (not yet released) removed a number of such indirect
component references.
Reported-By: Fabien COELHO <coelho@cri.ensmp.fr>
Reported-By: Andres Freund <andres@anarazel.de>
Reported-By: Thomas Munro <thomas.munro@gmail.com>
Author: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20201201064949.mex6kvi2kygby3ni@alap3.anarazel.de
Backpatch: 11-, where jit support was added
pg_rewind looks at the control file to check what timeline a server is on.
But promotion doesn't immediately write a checkpoint, it merely writes
an end-of-recovery WAL record. If pg_rewind runs immediately after
promotion, before the checkpoint has completed, it will think think that
the server is still on the earlier timeline. We ran into this issue a long
time ago already, see commit 484a848a73.
It's a bit bogus that pg_rewind doesn't determine the timeline correctly
until the end-of-recovery checkpoint has completed. We probably should
fix that. But for now work around it by waiting for the checkpoint
to complete before running pg_rewind, like we did in commit 484a848a73.
In the passing, tidy up the new test a little bit. Rerder the INSERTs so
that the comments make more sense, remove a spurious CHECKPOINT call after
pg_rewind has already run, and add --debug option, so that if this fails
again, we'll have more data.
Per buildfarm failure at https://buildfarm.postgresql.org/cgi-bin/show_stage_log.pl?nm=rorqual&dt=2020-12-06%2018%3A32%3A19&stg=pg_rewind-check.
Backpatch to all supported versions.
Discussion: https://www.postgresql.org/message-id/1713707e-e318-761c-d287-5b6a4aa807e8@iki.fi
Buildfarm has been failing sporadically on the new test. I was able to
reproduce this by adding a random 0-10 s delay in the walreceiver, just
before it connects to the primary. There's a race condition where node_3
is promoted before it has fully caught up with node_1, leading to diverged
timelines. When node_1 is later reconfigured as standby following node_3,
it fails to catch up:
LOG: primary server contains no more WAL on requested timeline 1
LOG: new timeline 2 forked off current database system timeline 1 before current recovery point 0/30000A0
That's the situation where you'd need to use pg_rewind, but in this case
it happens already when we are just setting up the actual pg_rewind
scenario we want to test, so change the test so that it waits until
node_3 is connected and fully caught up before promoting it, so that you
get a clean, controlled failover.
Also rewrite some of the comments, for clarity. The existing comments
detailed what each step in the test did, but didn't give a good overview
of the situation the steps were trying to create.
For reasons I don't understand, the test setup had to be written slightly
differently in 9.6 and 9.5 than in later versions. The 9.5/9.6 version
needed node 1 to be reinitialized from backup, whereas in later versions
it could be shut down and reconfigured to be a standby. But even 9.5 should
support "clean switchover", where primary makes sure that pending WAL is
replicated to standby on shutdown. It would be nice to figure out what's
going on there, but that's independent of pg_rewind and the scenario that
this test tests.
Discussion: https://www.postgresql.org/message-id/b0a3b95b-82d2-6089-6892-40570f8c5e60%40iki.fi
In a few places, the long-version options were listed before the
single-letter ones in the command summary of a few commands. This
didn't match other commands, and didn't match the option ordering later
in the same reference page.
Backpatch-through: 9.5
If the target is a standby server, its WAL doesn't end at the last
checkpoint record, but at minRecoveryPoint. We must scan all the
WAL from the last common checkpoint all the way up to minRecoveryPoint
for modified pages, and also consider that portion when determining
whether the server needs rewinding.
Backpatch to all supported versions.
Author: Ian Barwick and me
Discussion: https://www.postgresql.org/message-id/CABvVfJU-LDWvoz4-Yow3Ay5LZYTuPD7eSjjE4kGyNZpXC6FrVQ%40mail.gmail.com
As it stood, expandTableLikeClause() re-did the same relation_openrv
call that transformTableLikeClause() had done. However there are
scenarios where this would not find the same table as expected.
We hold lock on the LIKE source table, so it can't be renamed or
dropped, but another table could appear before it in the search path.
This explains the odd behavior reported in bug #16758 when cloning a
table as a temp table of the same name. This case worked as expected
before commit 502898192 introduced the need to open the source table
twice, so we should fix it.
To make really sure we get the same table, let's re-open it by OID not
name. That requires adding an OID field to struct TableLikeClause,
which is a little nervous-making from an ABI standpoint, but as long
as it's at the end I don't think there's any serious risk.
Per bug #16758 from Marc Boeren. Like the previous patch,
back-patch to all supported branches.
Discussion: https://postgr.es/m/16758-840e84a6cfab276d@postgresql.org
When committing a transaction that dropped a relation, we previously
truncated only the first segment file to free up disk space (the one
that won't be unlinked until the next checkpoint).
Truncate higher numbered segments too, even though we unlink them on
commit. This frees the disk space immediately, even if other backends
have open file descriptors and might take a long time to get around to
handling shared invalidation events and closing them. Also extend the
same behavior to the first segment, in recovery.
Back-patch to all supported releases.
Bug: #16663
Reported-by: Denis Patron <denis.patron@previnet.it>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Reviewed-by: Neil Chen <carpenter.nail.cz@gmail.com>
Reviewed-by: David Zhang <david.zhang@highgo.ca>
Discussion: https://postgr.es/m/16663-fe97ccf9932fc800%40postgresql.org
Because regular CREATE INDEX commands are independent, and there's no
logical data dependency, it's not immediately obvious that transactions
held by concurrent index builds on one table will block the second phase
of concurrent index creation on an unrelated table, so document this
caveat.
Backpatch this all the way back. In branch master, mention that only
some indexes are involved.
Author: James Coleman <jtc331@gmail.com>
Reviewed-by: David Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CAAaqYe994=PUrn8CJZ4UEo_S-FfRr_3ogERyhtdgHAb2WG_Ufg@mail.gmail.com
Checking for DocBook being installed was valuable when we were on the
OpenSP docs toolchain, because that was rather hard to get installed
fully. Nowadays, as long as you have xmllint and xsltproc installed,
you're good, because those programs will fetch the DocBook files off
the net at need. Moreover, testing this at configure time means that
a network access may well occur whether or not you have any interest
in building the docs later. That can be slow (typically 2 or 3
seconds, though much higher delays have been reported), and it seems
not very nice to be doing an off-machine access without warning, too.
Hence, drop the PGAC_CHECK_DOCBOOK probe, and adjust related
documentation. Without that macro, there's not much left of
config/docbook.m4 at all, so I just removed it.
Back-patch to v11, where we started to use xmllint in the
PGAC_CHECK_DOCBOOK probe.
Discussion: https://postgr.es/m/E2EE6B76-2D96-408A-B961-CAE47D1A86F0@yesql.se
Discussion: https://postgr.es/m/A55A7FC9-FA60-47FE-98B5-139CDC57CE6E@gmail.com
