summaryrefslogtreecommitdiff
path: root/src/backend
AgeCommit message (Collapse)Author
2020-12-28Fix inconsistent code with shared invalidations of snapshotsMichael Paquier
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
2020-12-25Invalidate acl.c caches when pg_authid changes.Noah Misch
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
2020-12-24Fix race condition between shutdown and unstarted background workers.Tom Lane
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
2020-12-23Fix portability issues with parsing of recovery_target_xidMichael Paquier
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
2020-12-21Remove "invalid concatenation of jsonb objects" error case.Tom Lane
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
2020-12-18Avoid memcpy() with same source and destination during relmapper init.Tom Lane
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
2020-12-14Revert "Cannot use WL_SOCKET_WRITEABLE without WL_SOCKET_READABLE."Jeff Davis
This reverts commit 3a9e64aa0d96c8ffb6c682b082d0f72b1d373327. Commit 4bad60e3 fixed the root of the problem that 3a9e64aa worked around. This enables proper pipelining of commands after terminating replication, eliminating an undocumented limitation. Discussion: https://postgr.es/m/3d57bc29-4459-578b-79cb-7641baf53c57%40iki.fi Backpatch-through: 9.5
2020-12-08Teach contain_leaked_vars that assignment SubscriptingRefs are leaky.Tom Lane
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
2020-12-01Ensure that expandTableLikeClause() re-examines the same table.Tom Lane
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
2020-12-01Free disk space for dropped relations on commit.Thomas Munro
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
2020-11-30Fix miscomputation of direct_lateral_relids for join relations.Tom Lane
If a PlaceHolderVar is to be evaluated at a join relation, but its value is only needed there and not at higher levels, we neglected to update the joinrel's direct_lateral_relids to include the PHV's source rel. This causes problems because join_is_legal() then won't allow joining the joinrel to the PHV's source rel at all, leading to "failed to build any N-way joins" planner failures. Per report from Andreas Seltenreich. Back-patch to 9.5 where the problem originated. Discussion: https://postgr.es/m/87blfgqa4t.fsf@aurora.ydns.eu
2020-11-28Fix a recently-introduced race condition in LISTEN/NOTIFY handling.Tom Lane
Commit 566372b3d fixed some race conditions involving concurrent SimpleLruTruncate calls, but it introduced new ones in async.c. A newly-listening backend could attempt to read Notify SLRU pages that were in process of being truncated, possibly causing an error. Also, the QUEUE_TAIL pointer could become set to a value that's not equal to the queue position of any backend. While that's fairly harmless in v13 and up (thanks to commit 51004c717), in older branches it resulted in near-permanent disabling of the queue truncation logic, so that continued use of NOTIFY led to queue-fill warnings and eventual inability to send any more notifies. (A server restart is enough to make that go away, but it's still pretty unpleasant.) The core of the problem is confusion about whether QUEUE_TAIL represents the "logical" tail of the queue (i.e., the oldest still-interesting data) or the "physical" tail (the oldest data we've not yet truncated away). To fix, split that into two variables. QUEUE_TAIL regains its definition as the logical tail, and we introduce a new variable to track the oldest un-truncated page. Per report from Mikael Gustavsson. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/1b8561412e8a4f038d7a491c8b922788@smhi.se
2020-11-24Properly check index mark/restore in ExecSupportsMarkRestore.Andrew Gierth
Previously this code assumed that all IndexScan nodes supported mark/restore, which is not true since it depends on optional index AM support functions. This could lead to errors about missing support functions in rare edge cases of mergejoins with no sort keys, where an unordered non-btree index scan was placed on the inner path without a protecting Materialize node. (Normally, the fact that merge join requires ordered input would avoid this error.) Backpatch all the way since this bug is ancient. Per report from Eugen Konkov on irc. Discussion: https://postgr.es/m/87o8jn50be.fsf@news-spur.riddles.org.uk
2020-11-20Skip allocating hash table in EXPLAIN-only mode.Heikki Linnakangas
This is a backpatch of commit 2cccb627f1, backpatched due to popular demand. Backpatch to all supported versions. Author: Alexey Bashtanov Discussion: https://www.postgresql.org/message-id/36823f65-050d-ae24-aa4d-a37726998240%40imap.cc
2020-11-20Adjust DSM and DSA slot usage constants (back-patch).Thomas Munro
1. Previously, a DSA area would create up to four segments at each size before doubling the size. After this commit, it will create only two at each size, so it ramps up faster and therefore needs fewer slots. 2. Previously, the total limit on DSM slots allowed for 2 per connection. Switch to 5 per connection. This back-patches commit d061ea21 from release 13 into 10-12 based on a field complaint. Discussion: https://postgr.es/m/CAO03teA%2BjE1qt5iWDWzHqaufqBsF6EoOgZphnazps_tr_jDPZA%40mail.gmail.com Discussion: https://postgr.es/m/CA%2BhUKGL6H2BpGbiF7Lj6QiTjTGyTLW_vLR%3DSn2tEBeTcYXiMKw%40mail.gmail.com
2020-11-19Further fixes for CREATE TABLE LIKE: cope with self-referential FKs.Tom Lane
Commit 502898192 was too careless about the order of execution of the additional ALTER TABLE operations generated by expandTableLikeClause. It just stuck them all at the end, which seems okay for most purposes. But it falls down in the case where LIKE is importing a primary key or unique index and the outer CREATE TABLE includes a FOREIGN KEY constraint that needs to depend on that index. Weird as that is, it used to work, so we ought to keep it working. To fix, make parse_utilcmd.c insert LIKE clauses between index-creation and FK-creation commands in the transformed list of commands, and change utility.c so that the commands generated by expandTableLikeClause are executed immediately not at the end. One could imagine scenarios where this wouldn't work either; but currently expandTableLikeClause only makes column default expressions, CHECK constraints, and indexes, and this ordering seems fine for those. Per bug #16730 from Sofoklis Papasofokli. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/16730-b902f7e6e0276b30@postgresql.org
2020-11-16Don't Insert() a VFD entry until it's fully built.Tom Lane
Otherwise, if FDDEBUG is enabled, the debugging output fails because it tries to read the fileName, which isn't set up yet (and should in fact always be NULL). AFAICT, this has been wrong since Berkeley. Before 96bf88d52, it would accidentally fail to crash on platforms where snprintf() is forgiving about being passed a NULL pointer for %s; but the file name intended to be included in the debug output wouldn't ever have shown up. Report and fix by Greg Nancarrow. Although this is only visibly broken in custom-made builds, it still seems worth back-patching to all supported branches, as the FDDEBUG code is pretty useless as it stands. Discussion: https://postgr.es/m/CAJcOf-cUDgm9qYtC_B6XrC6MktMPNRby2p61EtSGZKnfotMArw@mail.gmail.com
2020-11-12doc: wire protocol data type for history file content is byteaBruce Momjian
Document that though the history file content is marked as bytea, it is the same a text, and neither is btyea-escaped or encoding converted. Reported-by: Brar Piening Discussion: https://postgr.es/m/6a1b9cd9-17e3-df67-be55-86102af6bdf5@gmx.de Backpatch-through: 13 - 9.5 (not master)
2020-11-11Remove duplicate code in brin_memtuple_initializeTomas Vondra
Commit 8bf74967dab moved some of the code from brin_new_memtuple to brin_memtuple_initialize, but this resulted in some of the code being duplicate. Fix by removing the duplicate lines and backpatch to 10. Author: Tomas Vondra Backpatch-through: 10 Discussion: https://postgr.es/m/5eb50c97-9a8e-b691-8c40-1b2a55611c4c%40enterprisedb.com
2020-11-10Fix and simplify some usages of TimestampDifference().Tom Lane
Introduce TimestampDifferenceMilliseconds() to simplify callers that would rather have the difference in milliseconds, instead of the select()-oriented seconds-and-microseconds format. This gets rid of at least one integer division per call, and it eliminates some apparently-easy-to-mess-up arithmetic. Two of these call sites were in fact wrong: * pg_prewarm's autoprewarm_main() forgot to multiply the seconds by 1000, thus ending up with a delay 1000X shorter than intended. That doesn't quite make it a busy-wait, but close. * postgres_fdw's pgfdw_get_cleanup_result() thought it needed to compute microseconds not milliseconds, thus ending up with a delay 1000X longer than intended. Somebody along the way had noticed this problem but misdiagnosed the cause, and imposed an ad-hoc 60-second limit rather than fixing the units. This was relatively harmless in context, because we don't care that much about exactly how long this delay is; still, it's wrong. There are a few more callers of TimestampDifference() that don't have a direct need for seconds-and-microseconds, but can't use TimestampDifferenceMilliseconds() either because they do need microsecond precision or because they might possibly deal with intervals long enough to overflow 32-bit milliseconds. It might be worth inventing another API to improve that, but that seems outside the scope of this patch; so those callers are untouched here. Given the fact that we are fixing some bugs, and the likelihood that future patches might want to back-patch code that uses this new API, back-patch to all supported branches. Alexey Kondratov and Tom Lane Discussion: https://postgr.es/m/3b1c053a21c07c1ed5e00be3b2b855ef@postgrespro.ru
2020-11-09In security-restricted operations, block enqueue of at-commit user code.Noah Misch
Specifically, this blocks DECLARE ... WITH HOLD and firing of deferred triggers within index expressions and materialized view queries. An attacker having permission to create non-temp objects in at least one schema could execute arbitrary SQL functions under the identity of the bootstrap superuser. One can work around the vulnerability by disabling autovacuum and not manually running ANALYZE, CLUSTER, REINDEX, CREATE INDEX, VACUUM FULL, or REFRESH MATERIALIZED VIEW. (Don't restore from pg_dump, since it runs some of those commands.) Plain VACUUM (without FULL) is safe, and all commands are fine when a trusted user owns the target object. Performance may degrade quickly under this workaround, however. Back-patch to 9.5 (all supported versions). Reviewed by Robert Haas. Reported by Etienne Stalmans. Security: CVE-2020-25695
2020-11-09Translation updatesPeter Eisentraut
Source-Git-URL: https://git.postgresql.org/git/pgtranslation/messages.git Source-Git-Hash: 73696049f4e22e6bffd9cf13fdd816b7dd5b6fd8
2020-11-07Properly detoast data in brin_form_tupleTomas Vondra
brin_form_tuple failed to consider the values may be toasted, inserting the toast pointer into the index. This may easily result in index corruption, as the toast data may be deleted and cleaned up by vacuum. The cleanup however does not care about indexes, leaving invalid toast pointers behind, which triggers errors like this: ERROR: missing chunk number 0 for toast value 16433 in pg_toast_16426 A less severe consequence are inconsistent failures due to the index row being too large, depending on whether brin_form_tuple operated on plain or toasted version of the row. For example CREATE TABLE t (val TEXT); INSERT INTO t VALUES ('... long value ...') CREATE INDEX idx ON t USING brin (val); would likely succeed, as the row would likely include toast pointer. Switching the order of INSERT and CREATE INDEX would likely fail: ERROR: index row size 8712 exceeds maximum 8152 for index "idx" because this happens before the row values are toasted. The bug exists since PostgreSQL 9.5 where BRIN indexes were introduced. So backpatch all the way back. Author: Tomas Vondra Reviewed-by: Alvaro Herrera Backpatch-through: 9.5 Discussion: https://postgr.es/m/20201001184133.oq5uq75sb45pu3aw@development Discussion: https://postgr.es/m/20201104010544.zexj52mlldagzowv%40development
2020-11-06Revert "Accept relations of any kind in LOCK TABLE".Tom Lane
Revert 59ab4ac32, as well as the followup fix 33862cb9c, in all branches. We need to think a bit harder about what the behavior of LOCK TABLE on views should be, and there's no time for that before next week's releases. We'll take another crack at this later. Discussion: https://postgr.es/m/16703-e348f58aab3cf6cc@postgresql.org
2020-11-03Guard against core dump from uninitialized subplan.Tom Lane
If the planner erroneously puts a non-parallel-safe SubPlan into a parallelized portion of the query tree, nodeSubplan.c will fail in the worker processes because it finds a null in es_subplanstates, which it's unable to cope with. It seems worth a test-and-elog to make that an error case rather than a core dump case. This probably should have been included in commit 16ebab688, which was responsible for allowing nulls to appear in es_subplanstates to begin with. So, back-patch to v10 where that came in. Discussion: https://postgr.es/m/924226.1604422326@sss.pgh.pa.us
2020-11-03Allow users with BYPASSRLS to alter their own passwords.Tom Lane
The intention in commit 491c029db was to require superuserness to change the BYPASSRLS property, but the actual effect of the coding in AlterRole() was to require superuserness to change anything at all about a BYPASSRLS role. Other properties of a BYPASSRLS role should be changeable under the same rules as for a normal role, though. Fix that, and also take care of some documentation omissions related to BYPASSRLS and REPLICATION role properties. Tom Lane and Stephen Frost, per bug report from Wolfgang Walther. Back-patch to all supported branches. Discussion: https://postgr.es/m/a5548a9f-89ee-3167-129d-162b5985fcf8@technowledgy.de
2020-11-02Fix unportable use of getnameinfo() in pg_hba_file_rules view.Tom Lane
fill_hba_line() thought it could get away with passing sizeof(struct sockaddr_storage) rather than the actual addrlen previously returned by getaddrinfo(). While that appears to work on many platforms, it does not work on FreeBSD 11: you get back a failure, which leads to the view showing NULL for the address and netmask columns in all rows. The POSIX spec for getnameinfo() is pretty clearly on FreeBSD's side here: you should pass the actual address length. So it seems plausible that there are other platforms where this coding also fails, and we just hadn't noticed. Also, IMO the fact that getnameinfo() failure leads to a NULL output is pretty bogus in itself. Our pg_getnameinfo_all() wrapper is careful to emit "???" on failure, and we should use that in such cases. NULL should only be emitted in rows that don't have IP addresses. Per bug #16695 from Peter Vandivier. Back-patch to v10 where this code was added. Discussion: https://postgr.es/m/16695-a665558e2f630be7@postgresql.org
2020-10-27Fix use-after-free bug with event triggers and ALTER TABLE.Tom Lane
EventTriggerAlterTableEnd neglected to make sure that it built its output list in the right context. In simple cases this was masked because the function is called in PortalContext which will be sufficiently long-lived anyway; but that doesn't make it not a bug. Commit ced138e8c fixed this in HEAD and v13, but mistakenly chose not to back-patch further. Back-patch the same code change all the way (I didn't bother with the test case though, as it would prove nothing in pre-v13 branches). Per report from Arseny Sher. Original fix by Jehan-Guillaume de Rorthais. Discussion: https://postgr.es/m/877drcyprb.fsf@ars-thinkpad Discussion: https://postgr.es/m/20200902193715.6e0269d4@firost
2020-10-27Accept relations of any kind in LOCK TABLEAlvaro Herrera
The restriction that only tables and views can be locked by LOCK TABLE is quite arbitrary, since the underlying mechanism can lock any relation type. Drop the restriction so that programs such as pg_dump can lock all relations they're interested in, preventing schema changes that could cause a dump to fail after expending much effort. Backpatch to 9.5. Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Reported-by: Wells Oliver <wells.oliver@gmail.com> Discussion: https://postgr.es/m/20201021200659.GA32358@alvherre.pgsql
2020-10-20Avoid invalid alloc size error in shm_mqPeter Eisentraut
In shm_mq_receive(), a huge payload could trigger an unjustified "invalid memory alloc request size" error due to the way the buffer size is increased. Add error checks (documenting the upper limit) and avoid the error by limiting the allocation size to MaxAllocSize. Author: Markus Wanner <markus.wanner@2ndquadrant.com> Discussion: https://www.postgresql.org/message-id/flat/3bb363e7-ac04-0ac4-9fe8-db1148755bfa%402ndquadrant.com
2020-10-20Relax some asserts in merge join costing codeDavid Rowley
In the planner, it was possible, given an extreme enough case containing a large number of joins for the number of estimated rows to become infinite. This could cause problems in initial_cost_mergejoin() where we perform some calculations based on those row estimates. A problem case, presented by Onder Kalaci showed an Assert failure from an Assert checking outerstartsel <= outerendsel. In his test case this was effectively NaN <= Inf, which is false. The NaN outerstartsel came from multiplying the infinite outer_path_rows by 0.0. In master, this problem was fixed by a90c950fc, however, that fix was too invasive for the backbranches. Here we just relax the Asserts to allow them to pass. The worst that appears to happen from this is that we show NaN cost values and infinite row estimates in EXPLAIN. add_path() would have had a hard time doing anything useful with such costs, but that does not really matter as if the row estimates were even close to accurate, such plan would not complete this side of the heat death of the universe. Reported-by: Onder Kalaci Backpatch: 9.5 to 13 Discussion: https://postgr.es/m/DM6PR21MB1211FF360183BCA901B27F04D80B0@DM6PR21MB1211.namprd21.prod.outlook.com
2020-10-15In the postmaster, rely on the signal infrastructure to block signals.Tom Lane
POSIX sigaction(2) can be told to block a set of signals while a signal handler executes. Make use of that instead of manually blocking and unblocking signals in the postmaster's signal handlers. This should save a few cycles, but more importantly it prevents recursive invocation of signal handlers when many signals arrive in close succession. (Assuming that the platform's signal infrastructure is designed to avoid consuming stack space in that case, but this is demonstrably true at least on Linux.) The existing code has been seen to recurse to the point of stack overflow, either in the postmaster or in a forked-off child. Back-patch of commit 9abb2bfc0. At the time, we'd only seen excess postmaster stack consumption in the buildfarm; but we now have a user report of it, and that commit has aged enough to have a fair amount of confidence that it doesn't break anything. This still doesn't change anything about the way that it works on Windows. Perhaps someone else would like to fix that? Per bug #16673 from David Geier. Back-patch to 9.6. Although the problem exists in principle before that, we've only seen it actually materialize in connection with heavy use of parallel workers, so it doesn't seem necessary to do anything in 9.5; and the relevant code is different there, too. Discussion: https://postgr.es/m/16673-d278c604f8e34ec0@postgresql.org Discussion: https://postgr.es/m/14878.1570820201@sss.pgh.pa.us
2020-10-12Fix memory leak when guc.c decides a setting can't be applied now.Tom Lane
The prohibitValueChange code paths in set_config_option(), which are executed whenever we re-read a PGC_POSTMASTER variable from postgresql.conf, neglected to free anything before exiting. Thus we'd leak the proposed new value of a PGC_STRING variable, as noted by BoChen in bug #16666. For all variable types, if the check hook creates an "extra" chunk, we'd also leak that. These are malloc not palloc chunks, so there is no mechanism for recovering the leaks before process exit. Fortunately, the values are typically not very large, meaning you'd have to go through an awful lot of SIGHUP configuration-reload cycles to make the leakage amount to anything. Still, for a long-lived postmaster process it could potentially be a problem. Oversight in commit 2594cf0e8. Back-patch to all supported branches. Discussion: https://postgr.es/m/16666-2c41a4eec61b03e1@postgresql.org
2020-10-07Fix optimization hazard in gram.y's makeOrderedSetArgs(), redux.Tom Lane
It appears that commit cf63c641c, which intended to prevent misoptimization of the result-building step in makeOrderedSetArgs, didn't go far enough: buildfarm member hornet's version of xlc is now optimizing back to the old, broken behavior in which list_length(directargs) is fetched only after list_concat() has changed that value. I'm not entirely convinced whether that's an undeniable compiler bug or whether it can be justified by a sufficiently aggressive interpretation of C sequence points. So let's just change the code to make it harder to misinterpret. Back-patch to all supported versions, just in case. Discussion: https://postgr.es/m/1830491.1601944935@sss.pgh.pa.us
2020-10-05Fix two latent(?) bugs in equivclass.c.Tom Lane
get_eclass_for_sort_expr() computes expr_relids and nullable_relids early on, even though they won't be needed unless we make a new EquivalenceClass, which we often don't. Aside from the probably-minor inefficiency, there's a memory management problem: these bitmapsets will be built in the caller's context, leading to dangling pointers if that is shorter-lived than root->planner_cxt. This would be a live bug if get_eclass_for_sort_expr() could be called with create_it = true during GEQO join planning. So far as I can find, the core code never does that, but it's hard to be sure that no extensions do, especially since the comments make it clear that that's supposed to be a supported case. Fix by not computing these values until we've switched into planner_cxt to build the new EquivalenceClass. generate_join_implied_equalities() uses inner_rel->relids to look up relevant eclasses, but it ought to be using nominal_inner_relids. This is presently harmless because a child RelOptInfo will always have exactly the same eclass_indexes as its topmost parent; but that might not be true forever, and anyway it makes the code confusing. The first of these is old (introduced by me in f3b3b8d5b), so back-patch to all supported branches. The second only dates to v13, but we might as well back-patch it to keep the code looking similar across branches. Discussion: https://postgr.es/m/1508010.1601832581@sss.pgh.pa.us
2020-09-30Fix handling of BC years in to_date/to_timestamp.Tom Lane
Previously, a conversion such as to_date('-44-02-01','YYYY-MM-DD') would result in '0045-02-01 BC', as the code attempted to interpret the negative year as BC, but failed to apply the correction needed for our internal handling of BC years. Fix the off-by-one problem. Also, arrange for the combination of a negative year and an explicit "BC" marker to cancel out and produce AD. This is how the negative-century case works, so it seems sane to do likewise. Continue to read "year 0000" as 1 BC. Oracle would throw an error, but we've accepted that case for a long time so I'm hesitant to change it in a back-patch. Per bug #16419 from Saeed Hubaishan. Back-patch to all supported branches. Dar Alathar-Yemen and Tom Lane Discussion: https://postgr.es/m/16419-d8d9db0a7553f01b@postgresql.org
2020-09-29Archive timeline history files in standby if archive_mode is set to "always".Fujii Masao
Previously the standby server didn't archive timeline history files streamed from the primary even when archive_mode is set to "always", while it archives the streamed WAL files. This could cause the PITR to fail because there was no required timeline history file in the archive. The cause of this issue was that walreceiver didn't mark those files as ready for archiving. This commit makes walreceiver mark those streamed timeline history files as ready for archiving if archive_mode=always. Then the archiver process archives the marked timeline history files. Back-patch to all supported versions. Reported-by: Grigory Smolkin Author: Grigory Smolkin, Fujii Masao Reviewed-by: David Zhang, Anastasia Lubennikova Discussion: https://postgr.es/m/54b059d4-2b48-13a4-6f43-95a087c92367@postgrespro.ru
2020-09-26Revise RelationBuildRowSecurity() to avoid memory leaks.Tom Lane
This function leaked some memory while loading qual clauses for an RLS policy. While ordinarily negligible, that could build up in some repeated-reload cases, as reported by Konstantin Knizhnik. We can improve matters by borrowing the coding long used in RelationBuildRuleLock: build stringToNode's result directly in the target context, and remember to explicitly pfree the input string. This patch by no means completely guarantees zero leaks within this function, since we have no real guarantee that the catalog- reading subroutines it calls don't leak anything. However, practical tests suggest that this is enough to resolve the issue. In any case, any remaining leaks are similar to those risked by RelationBuildRuleLock and other relcache-loading subroutines. If we need to fix them, we should adopt a more global approach such as that used by the RECOVER_RELATION_BUILD_MEMORY hack. While here, let's remove the need for an expensive PG_TRY block by using MemoryContextSetParent to reparent an initially-short-lived context for the RLS data. Back-patch to all supported branches. Discussion: https://postgr.es/m/21356c12-8917-8249-b35f-1c447231922b@postgrespro.ru
2020-09-24Fix missing fsync of SLRU directories.Thomas Munro
Harmonize behavior by moving reponsibility for fsyncing directories down into slru.c. In 10 and later, only the multixact directories were missed (see commit 1b02be21), and in older branches all SLRUs were missed. Back-patch to all supported releases. Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Michael Paquier <michael@paquier.xyz> Discussion: https://postgr.es/m/CA%2BhUKGLtsTUOScnNoSMZ-2ZLv%2BwGh01J6kAo_DM8mTRq1sKdSQ%40mail.gmail.com
2020-09-23Avoid possible dangling-pointer access in tsearch_readline_callback.Tom Lane
tsearch_readline() saves the string pointer it returns to the caller for possible use in the associated error context callback. However, the caller will usually pfree that string sometime before it next calls tsearch_readline(), so that there is a window where an ereport will try to print an already-freed string. The built-in users of tsearch_readline() happen to all do that pfree at the bottoms of their loops, so that the window is effectively empty for them. However, this is not documented as a requirement, and contrib/dict_xsyn doesn't do it like that, so it seems likely that third-party dictionaries might have live bugs here. The practical consequences of this seem pretty limited in any case, since production builds wouldn't clobber the freed string immediately, besides which you'd not expect syntax errors in dictionary files being used in production. Still, it's clearly a bug waiting to bite somebody. Fix by pstrdup'ing the string to be saved for the error callback, and then pfree'ing it next time through. It's been like this for a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/48A4FA71-524E-41B9-953A-FD04EF36E2E7@yesql.se
2020-09-17Update parallel BTree scan state when the scan keys can't be satisfied.Amit Kapila
For parallel btree scan to work for array of scan keys, it should reach BTPARALLEL_DONE state once for every distinct combination of array keys. This is required to ensure that the parallel workers don't try to seize blocks at the same time for different scan keys. We missed to update this state when we discovered that the scan keys can't be satisfied. Author: James Hunter Reviewed-by: Amit Kapila Tested-by: Justin Pryzby Backpatch-through: 10, where it was introduced Discussion: https://postgr.es/m/4248CABC-25E3-4809-B4D0-128E1BAABC3C@amazon.com
2020-09-16Fix bogus cache-invalidation logic in logical replication worker.Tom Lane
The code recorded cache invalidation events by zeroing the "localreloid" field of affected cache entries. However, it's possible for an inval event to occur even while we have the entry open and locked. So an ill-timed inval could result in "cache lookup failed for relation 0" errors, if the worker's code tried to use the cleared field. We can fix that by creating a separate bool field to record whether the entry needs to be revalidated. (In the back branches, cram the bool into what had been padding space, to avoid an ABI break in the somewhat unlikely event that any extension is looking at this struct.) Also, rearrange the logic in logicalrep_rel_open so that it does the right thing in cases where table_open would fail. We should retry the lookup by name in that case, but we didn't. The real-world impact of this is probably small. In the first place, the error conditions are very low probability, and in the second place, the worker would just exit and get restarted. We only noticed because in a CLOBBER_CACHE_ALWAYS build, the failure can occur repeatedly, preventing the worker from making progress. Nonetheless, it's clearly a bug, and it impedes a useful type of testing; so back-patch to v10 where this code was introduced. Discussion: https://postgr.es/m/1032727.1600096803@sss.pgh.pa.us
2020-09-13Use the properly transformed RangeVar for expandTableLikeClause().Tom Lane
transformCreateStmt() adjusts the transformed statement's RangeVar to specify the target schema explicitly, for the express reason of making sure that auxiliary statements derived by parse transformation operate on the right table. But the refactoring I did in commit 502898192 got this wrong and passed the untransformed RangeVar to expandTableLikeClause(). This could lead to assertion failures or weird misbehavior if the wrong table was accessed. Per report from Alexander Lakhin. Like the previous patch, back-patch to all supported branches. Discussion: https://postgr.es/m/05051f9d-b32b-cb35-6735-0e9f2ab86b5f@gmail.com
2020-09-10Use _exit(2) for SIGQUIT during ProcessStartupPacket, too.Tom Lane
Bring the signal handling for startup-packet collection into line with the policy established in commits bedadc732 and 8e19a8264, namely don't risk running atexit callbacks when handling SIGQUIT. Ideally, we'd not do so for SIGTERM or timeout interrupts either, but that change seems a bit too risky for the back branches. For now, just improve the comments in this area to describe the risk. Also relocate where BackendInitialize re-disables these interrupts, to minimize the code span where they're active. This doesn't buy a whole lot of safety, but it can't hurt. In passing, rename startup_die() to remove confusion about whether it is for the startup process. Like the previous commits, back-patch to all supported branches. Discussion: https://postgr.es/m/1850884.1599601164@sss.pgh.pa.us
2020-09-10doc: Fix some grammar and inconsistenciesMichael Paquier
Some comments are fixed while on it. Author: Justin Pryzby Discussion: https://postgr.es/m/20200818171702.GK17022@telsasoft.com Backpatch-through: 9.6
2020-09-09Make archiver's SIGQUIT handler exit via _exit().Tom Lane
Commit 8e19a8264 changed the SIGQUIT handlers of almost all server processes not to run atexit callbacks. The archiver process was skipped, perhaps because it's not connected to shared memory; but it's just as true here that running atexit callbacks in a signal handler is unsafe. So let's make it work like the rest. In HEAD and v13, we can use the common SignalHandlerForCrashExit handler. Before that, just tweak pgarch_exit to use _exit(2) explicitly. Like the previous commit, back-patch to all supported branches. Kyotaro Horiguchi, back-patching by me Discussion: https://postgr.es/m/1850884.1599601164@sss.pgh.pa.us
2020-09-06Fix misleading error message about inconsistent moving-aggregate types.Tom Lane
We reported the wrong types when complaining that an aggregate's moving-aggregate implementation is inconsistent with its regular implementation. This was wrong since the feature was introduced, so back-patch to all supported branches. Jeff Janes Discussion: https://postgr.es/m/CAMkU=1x808LH=LPhZp9mNSP0Xd1xDqEd+XeGcvEe48dfE6xV=A@mail.gmail.com
2020-09-04Fix over-eager ping'ing in logical replication receiver.Tom Lane
Commit 3f60f690f only partially fixed the broken-status-tracking issue in LogicalRepApplyLoop: we need ping_sent to have the same lifetime as last_recv_timestamp. The effects are much less serious than what that commit fixed, though. AFAICS this would just lead to extra ping requests being sent, once per second until the sender responds. Still, it's a bug, so backpatch to v10 as before. Discussion: https://postgr.es/m/959627.1599248476@sss.pgh.pa.us
2020-09-03Avoid lockup of a parallel worker when reporting a long error message.Tom Lane
Because sigsetjmp() will restore the initial state with signals blocked, the code path in bgworker.c for reporting an error and exiting would execute that way. Usually this is fairly harmless; but if a parallel worker had an error message exceeding the shared-memory communication buffer size (16K) it would lock up, because it would wait for a resume-sending signal from its parallel leader which it would never detect. To fix, just unblock signals at the appropriate point. This can be shown to fail back to 9.6. The lack of parallel query infrastructure makes it difficult to provide a simple test case for 9.5; but I'm pretty sure the issue exists in some form there as well, so apply the code change there too. Vignesh C, reviewed by Bharath Rupireddy, Robert Haas, and myself Discussion: https://postgr.es/m/CALDaNm1d1hHPZUg3xU4XjtWBOLCrA+-2cJcLpw-cePZ=GgDVfA@mail.gmail.com
2020-08-27Fix code for re-finding scan position in a multicolumn GIN index.Tom Lane
collectMatchBitmap() needs to re-find the index tuple it was previously looking at, after transiently dropping lock on the index page it's on. The tuple should still exist and be at its prior position or somewhere to the right of that, since ginvacuum never removes tuples but concurrent insertions could add one. However, there was a thinko in that logic, to the effect of expecting any inserted tuples to have the same index "attnum" as what we'd been scanning. Since there's no physical separation of tuples with different attnums, it's not terribly hard to devise scenarios where this fails, leading to transient "lost saved point in index" errors. (While I've duplicated this with manual testing, it seems impossible to make a reproducible test case with our available testing technology.) Fix by just continuing the scan when the attnum doesn't match. While here, improve the error message used if we do fail, so that it matches the wording used in btree for a similar case. collectMatchBitmap()'s posting-tree code path was previously not exercised at all by our regression tests. While I can't make a regression test that exhibits the bug, I can at least improve the code coverage here, so do that. The test case I made for this is an extension of one added by 4b754d6c1, so it only works in HEAD and v13; didn't seem worth trying hard to back-patch it. Per bug #16595 from Jesse Kinkead. This has been broken since multicolumn capability was added to GIN (commit 27cb66fdf), so back-patch to all supported branches. Discussion: https://postgr.es/m/16595-633118be8eef9ce2@postgresql.org