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* Fix some regex issues with out-of-range characters and large char ranges.Tom Lane2016-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, our regex code defined CHR_MAX as 0xfffffffe, which is a bad choice because it is outside the range of type "celt" (int32). Characters approaching that limit could lead to infinite loops in logic such as "for (c = a; c <= b; c++)" where c is of type celt but the range bounds are chr. Such loops will work safely only if CHR_MAX+1 is representable in celt, since c must advance to beyond b before the loop will exit. Fortunately, there seems no reason not to restrict CHR_MAX to 0x7ffffffe. It's highly unlikely that Unicode will ever assign codes that high, and none of our other backend encodings need characters beyond that either. In addition to modifying the macro, we have to explicitly enforce character range restrictions on the values of \u, \U, and \x escape sequences, else the limit is trivially bypassed. Also, the code for expanding case-independent character ranges in bracket expressions had a potential integer overflow in its calculation of the number of characters it could generate, which could lead to allocating too small a character vector and then overwriting memory. An attacker with the ability to supply arbitrary regex patterns could easily cause transient DOS via server crashes, and the possibility for privilege escalation has not been ruled out. Quite aside from the integer-overflow problem, the range expansion code was unnecessarily inefficient in that it always produced a result consisting of individual characters, abandoning the knowledge that we had a range to start with. If the input range is large, this requires excessive memory. Change it so that the original range is reported as-is, and then we add on any case-equivalent characters that are outside that range. With this approach, we can bound the number of individual characters allowed without sacrificing much. This patch allows at most 100000 individual characters, which I believe to be more than the number of case pairs existing in Unicode, so that the restriction will never be hit in practice. It's still possible for range() to take awhile given a large character code range, so also add statement-cancel detection to its loop. The downstream function dovec() also lacked cancel detection, and could take a long time given a large output from range(). Per fuzz testing by Greg Stark. Back-patch to all supported branches. Security: CVE-2016-0773
* Force certain "pljava" custom GUCs to be PGC_SUSET.Noah Misch2016-02-05
| | | | | | | Future PL/Java versions will close CVE-2016-0766 by making these GUCs PGC_SUSET. This PostgreSQL change independently mitigates that PL/Java vulnerability, helping sites that update PostgreSQL more frequently than PL/Java. Back-patch to 9.1 (all supported versions).
* When modifying a foreign table, initialize tableoid field properly.Robert Haas2016-02-04
| | | | | | | Failure to do this can cause AFTER ROW triggers or RETURNING expressions that reference this field to misbehave. Etsuro Fujita, reviewed by Thom Brown
* Fix IsValidJsonNumber() to notice trailing non-alphanumeric garbage.Tom Lane2016-02-03
| | | | | | | | | | | Commit e09996ff8dee3f70 was one brick shy of a load: it didn't insist that the detected JSON number be the whole of the supplied string. This allowed inputs such as "2016-01-01" to be misdetected as valid JSON numbers. Per bug #13906 from Dmitry Ryabov. In passing, be more wary of zero-length input (I'm not sure this can happen given current callers, but better safe than sorry), and do some minor cosmetic cleanup.
* Fix startup so that log prefix %h works for the log_connections message.Tom Lane2016-01-26
| | | | | | | We entirely randomly chose to initialize port->remote_host just after printing the log_connections message, when we could perfectly well do it just before, allowing %h and %r to work for that message. Per gripe from Artem Tomyuk.
* Properly install dynloader.h on MSVC buildsBruce Momjian2016-01-19
| | | | | | | | | | | This will enable PL/Java to be cleanly compiled, as dynloader.h is a requirement. Report by Chapman Flack Patch by Michael Paquier Backpatch through 9.1
* Properly close token in sspi authenticationMagnus Hagander2016-01-14
| | | | | | | | We can never leak more than one token, but we shouldn't do that. We don't bother closing it in the error paths since the process will exit shortly anyway. Christian Ullrich
* Clean up some lack-of-STRICT issues in the core code, too.Tom Lane2016-01-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A scan for missed proisstrict markings in the core code turned up these functions: brin_summarize_new_values pg_stat_reset_single_table_counters pg_stat_reset_single_function_counters pg_create_logical_replication_slot pg_create_physical_replication_slot pg_drop_replication_slot The first three of these take OID, so a null argument will normally look like a zero to them, resulting in "ERROR: could not open relation with OID 0" for brin_summarize_new_values, and no action for the pg_stat_reset_XXX functions. The other three will dump core on a null argument, though this is mitigated by the fact that they won't do so until after checking that the caller is superuser or has rolreplication privilege. In addition, the pg_logical_slot_get/peek[_binary]_changes family was intentionally marked nonstrict, but failed to make nullness checks on all the arguments; so again a null-pointer-dereference crash is possible but only for superusers and rolreplication users. Add the missing ARGISNULL checks to the latter functions, and mark the former functions as strict in pg_proc. Make that change in the back branches too, even though we can't force initdb there, just so that installations initdb'd in future won't have the issue. Since none of these bugs rise to the level of security issues (and indeed the pg_stat_reset_XXX functions hardly misbehave at all), it seems sufficient to do this. In addition, fix some order-of-operations oddities in the slot_get_changes family, mostly cosmetic, but not the part that moves the function's last few operations into the PG_TRY block. As it stood, there was significant risk for an error to exit without clearing historical information from the system caches. The slot_get_changes bugs go back to 9.4 where that code was introduced. Back-patch appropriate subsets of the pg_proc changes into all active branches, as well.
* Fix treatment of *lpNumberOfBytesRecvd == 0: that's a completion condition.Tom Lane2016-01-04
| | | | | | | | | | | | | | | | | | | | | | | | | | pgwin32_recv() has treated a non-error return of zero bytes from WSARecv() as being a reason to block ever since the current implementation was introduced in commit a4c40f140d23cefb. However, so far as one can tell from Microsoft's documentation, that is just wrong: what it means is graceful connection closure (in stream protocols) or receipt of a zero-length message (in message protocols), and neither case should result in blocking here. The only reason the code worked at all was that control then fell into the retry loop, which did *not* treat zero bytes specially, so we'd get out after only wasting some cycles. But as of 9.5 we do not normally reach the retry loop and so the bug is exposed, as reported by Shay Rojansky and diagnosed by Andres Freund. Remove the unnecessary test on the byte count, and rearrange the code in the retry loop so that it looks identical to the initial sequence. Back-patch of commit 90e61df8130dc7051a108ada1219fb0680cb3eb6. The original plan was to apply this only to 9.5 and up, but after discussion and buildfarm testing, it seems better to back-patch. The noblock code path has been at risk of this problem since it was introduced (in 9.0); if it did happen in pre-9.5 branches, the symptom would be that a walsender would wait indefinitely rather than noticing a loss of connection. While we lack proof that the case has been seen in the field, it seems possible that it's happened without being reported.
* Fix overly-strict assertions in spgtextproc.c.Tom Lane2016-01-02
| | | | | | | | | | | | | | | | | spg_text_inner_consistent is capable of reconstructing an empty string to pass down to the next index level; this happens if we have an empty string coming in, no prefix, and a dummy node label. (In practice, what is needed to trigger that is insertion of a whole bunch of empty-string values.) Then, we will arrive at the next level with in->level == 0 and a non-NULL (but zero length) in->reconstructedValue, which is valid but the Assert tests weren't expecting it. Per report from Andreas Seltenreich. This has no impact in non-Assert builds, so should not be a problem in production, but back-patch to all affected branches anyway. In passing, remove a couple of useless variable initializations and shorten the code by not duplicating DatumGetPointer() calls.
* Teach flatten_reloptions() to quote option values safely.Tom Lane2016-01-01
| | | | | | | | | | | | | | | | | | | | | | | | | | flatten_reloptions() supposed that it didn't really need to do anything beyond inserting commas between reloption array elements. However, in principle the value of a reloption could be nearly anything, since the grammar allows a quoted string there. Any restrictions on it would come from validity checking appropriate to the particular option, if any. A reloption value that isn't a simple identifier or number could thus lead to dump/reload failures due to syntax errors in CREATE statements issued by pg_dump. We've gotten away with not worrying about this so far with the core-supported reloptions, but extensions might allow reloption values that cause trouble, as in bug #13840 from Kouhei Sutou. To fix, split the reloption array elements explicitly, and then convert any value that doesn't look like a safe identifier to a string literal. (The details of the quoting rule could be debated, but this way is safe and requires little code.) While we're at it, also quote reloption names if they're not safe identifiers; that may not be a likely problem in the field, but we might as well try to be bulletproof here. It's been like this for a long time, so back-patch to all supported branches. Kouhei Sutou, adjusted some by me
* Add some more defenses against silly estimates to gincostestimate().Tom Lane2016-01-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A report from Andy Colson showed that gincostestimate() was not being nearly paranoid enough about whether to believe the statistics it finds in the index metapage. The problem is that the metapage stats (other than the pending-pages count) are only updated by VACUUM, and in the worst case could still reflect the index's original empty state even when it has grown to many entries. We attempted to deal with that by scaling up the stats to match the current index size, but if nEntries is zero then scaling it up still gives zero. Moreover, the proportion of pages that are entry pages vs. data pages vs. pending pages is unlikely to be estimated very well by scaling if the index is now orders of magnitude larger than before. We can improve matters by expanding the use of the rule-of-thumb estimates I introduced in commit 7fb008c5ee59b040: if the index has grown by more than a cutoff amount (here set at 4X growth) since VACUUM, then use the rule-of-thumb numbers instead of scaling. This might not be exactly right but it seems much less likely to produce insane estimates. I also improved both the scaling estimate and the rule-of-thumb estimate to account for numPendingPages, since it's reasonable to expect that that is accurate in any case, and certainly pages that are in the pending list are not either entry or data pages. As a somewhat separate issue, adjust the estimation equations that are concerned with extra fetches for partial-match searches. These equations suppose that a fraction partialEntries / numEntries of the entry and data pages will be visited as a consequence of a partial-match search. Now, it's physically impossible for that fraction to exceed one, but our estimate of partialEntries is mostly bunk, and our estimate of numEntries isn't exactly gospel either, so we could arrive at a silly value. In the example presented by Andy we were coming out with a value of 100, leading to insane cost estimates. Clamp the fraction to one to avoid that. Like the previous patch, back-patch to all supported branches; this problem can be demonstrated in one form or another in all of them.
* Put back one copyObject() in rewriteTargetView().Tom Lane2015-12-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 6f8cb1e23485bd6d tried to centralize rewriteTargetView's copying of a target view's Query struct. However, it ignored the fact that the jointree->quals field was used twice. This only accidentally failed to fail immediately because the same ChangeVarNodes mutation is applied in both cases, so that we end up with logically identical expression trees for both uses (and, as the code stands, the second ChangeVarNodes call actually does nothing). However, we end up linking *physically* identical expression trees into both an RTE's securityQuals list and the WithCheckOption list. That's pretty dangerous, mainly because prepsecurity.c is utterly cavalier about further munging such structures without copying them first. There may be no live bug in HEAD as a consequence of the fact that we apply preprocess_expression in between here and prepsecurity.c, and that will make a copy of the tree anyway. Or it may just be that the regression tests happen to not trip over it. (I noticed this only because things fell over pretty badly when I tried to relocate the planner's call of expand_security_quals to before expression preprocessing.) In any case it's very fragile because if anyone tried to make the securityQuals and WithCheckOption trees diverge before we reach preprocess_expression, it would not work. The fact that the current code will preprocess securityQuals and WithCheckOptions lists at completely different times in different query levels does nothing to increase my trust that that can't happen. In view of the fact that 9.5.0 is almost upon us and the aforesaid commit has seen exactly zero field testing, the prudent course is to make an extra copy of the quals so that the behavior is not different from what has been in the field during beta.
* Rework internals of changing a type's ownershipAlvaro Herrera2015-12-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This is necessary so that REASSIGN OWNED does the right thing with composite types, to wit, that it also alters ownership of the type's pg_class entry -- previously, the pg_class entry remained owned by the original user, which caused later other failures such as the new owner's inability to use ALTER TYPE to rename an attribute of the affected composite. Also, if the original owner is later dropped, the pg_class entry becomes owned by a non-existant user which is bogus. To fix, create a new routine AlterTypeOwner_oid which knows whether to pass the request to ATExecChangeOwner or deal with it directly, and use that in shdepReassignOwner rather than calling AlterTypeOwnerInternal directly. AlterTypeOwnerInternal is now simpler in that it only modifies the pg_type entry and recurses to handle a possible array type; higher-level tasks are handled by either AlterTypeOwner directly or AlterTypeOwner_oid. I took the opportunity to add a few more objects to the test rig for REASSIGN OWNED, so that more cases are exercised. Additional ones could be added for superuser-only-ownable objects (such as FDWs and event triggers) but I didn't want to push my luck by adding a new superuser to the tests on a backpatchable bug fix. Per bug #13666 reported by Chris Pacejo. This is a backpatch of commit 756e7b4c9db1 to branches 9.1 -- 9.4.
* adjust ACL owners for REASSIGN and ALTER OWNER TOAlvaro Herrera2015-12-21
| | | | | | | | | | | | | | | | | | | | | | When REASSIGN and ALTER OWNER TO are used, both the object owner and ACL list should be changed from the old owner to the new owner. This patch fixes types, foreign data wrappers, and foreign servers to change their ACL list properly; they already changed owners properly. Report by Alexey Bashtanov This is a backpatch of commit 59367fdf97c (for bug #9923) by Bruce Momjian to branches 9.1 - 9.4; it wasn't backpatched originally out of concerns that it would create a backwards compatibility problem, but per discussion related to bug #13666 that turns out to have been misguided. (Therefore, the entry in the 9.5 release notes should be removed.) Note that 9.1 didn't have privileges on types (which were introduced by commit 729205571e81), so this commit only changes foreign-data related objects in that branch. Discussion: http://www.postgresql.org/message-id/20151216224004.GL2618@alvherre.pgsql http://www.postgresql.org/message-id/10227.1450373793@sss.pgh.pa.us
* Make viewquery a copy in rewriteTargetView()Stephen Frost2015-12-21
| | | | | | | | | | | | | | | Rather than expect the Query returned by get_view_query() to be read-only and then copy bits and pieces of it out, simply copy the entire structure when we get it. This addresses an issue where AcquireRewriteLocks, which is called by acquireLocksOnSubLinks(), scribbles on the parsetree passed in, which was actually an entry in relcache, leading to segfaults with certain view definitions. This also future-proofs us a bit for anyone adding more code to this path. The acquireLocksOnSubLinks() was added in commit c3e0ddd40. Back-patch to 9.3 as that commit was.
* Add missing CHECK_FOR_INTERRUPTS in lseg_inside_polyAlvaro Herrera2015-12-14
| | | | | | | | | Apparently, there are bugs in this code that cause it to loop endlessly. That bug still needs more research, but in the meantime it's clear that the loop is missing a check for interrupts so that it can be cancelled timely. Backpatch to 9.1 -- this has been missing since 49475aab8d0d.
* Correct statement to actually be the intended assert statement.Andres Freund2015-12-14
| | | | | | | | | e3f4cfc7 introduced a LWLockHeldByMe() call, without the corresponding Assert() surrounding it. Spotted by Coverity. Backpatch: 9.1+, like the previous commit
* Properly initialize write, flush and replay locations in walsender slotsMagnus Hagander2015-12-13
| | | | | | | | | These would leak random xlog positions if a walsender used for backup would a walsender slot previously used by a replication walsender. In passing also fix a couple of cases where the xlog pointer is directly compared to zero instead of using XLogRecPtrIsInvalid, noted by Michael Paquier.
* Fix ALTER TABLE ... SET TABLESPACE for unlogged relations.Andres Freund2015-12-12
| | | | | | | | | | | | | | | | | | | | | | | | | | Changing the tablespace of an unlogged relation did not WAL log the creation and content of the init fork. Thus, after a standby is promoted, unlogged relation cannot be accessed anymore, with errors like: ERROR: 58P01: could not open file "pg_tblspc/...": No such file or directory Additionally the init fork was not synced to disk, independent of the configured wal_level, a relatively small durability risk. Investigation of that problem also brought to light that, even for permanent relations, the creation of !main forks was not WAL logged, i.e. no XLOG_SMGR_CREATE record were emitted. That mostly turns out not to be a problem, because these files were created when the actual relation data is copied; nonexistent files are not treated as an error condition during replay. But that doesn't work for empty files, and generally feels a bit haphazard. Luckily, outside init and main forks, empty forks don't occur often or are not a problem. Add the required WAL logging and syncing to disk. Reported-By: Michael Paquier Author: Michael Paquier and Andres Freund Discussion: 20151210163230.GA11331@alap3.anarazel.de Backpatch: 9.1, where unlogged relations were introduced
* For REASSIGN OWNED for foreign user mappingsAlvaro Herrera2015-12-11
| | | | | | | | | | | | | | As reported in bug #13809 by Alexander Ashurkov, the code for REASSIGN OWNED hadn't gotten word about user mappings. Deal with them in the same way default ACLs do, which is to ignore them altogether; they are handled just fine by DROP OWNED. The other foreign object cases are already handled correctly by both commands. Also add a REASSIGN OWNED statement to foreign_data test to exercise the foreign data objects. (The changes are just before the "cleanup" phase, so it shouldn't remove any existing live test.) Reported by Alexander Ashurkov, then independently by Jaime Casanova.
* Still more fixes for planner's handling of LATERAL references.Tom Lane2015-12-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More fuzz testing by Andreas Seltenreich exposed that the planner did not cope well with chains of lateral references. If relation X references Y laterally, and Y references Z laterally, then we will have to scan X on the inside of a nestloop with Z, so for all intents and purposes X is laterally dependent on Z too. The planner did not understand this and would generate intermediate joins that could not be used. While that was usually harmless except for wasting some planning cycles, under the right circumstances it would lead to "failed to build any N-way joins" or "could not devise a query plan" planner failures. To fix that, convert the existing per-relation lateral_relids and lateral_referencers relid sets into their transitive closures; that is, they now show all relations on which a rel is directly or indirectly laterally dependent. This not only fixes the chained-reference problem but allows some of the relevant tests to be made substantially simpler and faster, since they can be reduced to simple bitmap manipulations instead of searches of the LateralJoinInfo list. Also, when a PlaceHolderVar that is due to be evaluated at a join contains lateral references, we should treat those references as indirect lateral dependencies of each of the join's base relations. This prevents us from trying to join any individual base relations to the lateral reference source before the join is formed, which again cannot work. Andreas' testing also exposed another oversight in the "dangerous PlaceHolderVar" test added in commit 85e5e222b1dd02f1. Simply rejecting unsafe join paths in joinpath.c is insufficient, because in some cases we will end up rejecting *all* possible paths for a particular join, again leading to "could not devise a query plan" failures. The restriction has to be known also to join_is_legal and its cohort functions, so that they will not select a join for which that will happen. I chose to move the supporting logic into joinrels.c where the latter functions are. Back-patch to 9.3 where LATERAL support was introduced.
* Fix bug leading to restoring unlogged relations from empty files.Andres Freund2015-12-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the end of crash recovery, unlogged relations are reset to the empty state, using their init fork as the template. The init fork is copied to the main fork without going through shared buffers. Unfortunately WAL replay so far has not necessarily flushed writes from shared buffers to disk at that point. In normal crash recovery, and before the introduction of 'fast promotions' in fd4ced523 / 9.3, the END_OF_RECOVERY checkpoint flushes the buffers out in time. But with fast promotions that's not the case anymore. To fix, force WAL writes targeting the init fork to be flushed immediately (using the new FlushOneBuffer() function). In 9.5+ that flush can centrally be triggered from the code dealing with restoring full page writes (XLogReadBufferForRedoExtended), in earlier releases that responsibility is in the hands of XLOG_HEAP_NEWPAGE's replay function. Backpatch to 9.1, even if this currently is only known to trigger in 9.3+. Flushing earlier is more robust, and it is advantageous to keep the branches similar. Typical symptoms of this bug are errors like 'ERROR: index "..." contains unexpected zero page at block 0' shortly after promoting a node. Reported-By: Thom Brown Author: Andres Freund and Michael Paquier Discussion: 20150326175024.GJ451@alap3.anarazel.de Backpatch: 9.1-
* Simplify LATERAL-related calculations within add_paths_to_joinrel().Tom Lane2015-12-09
| | | | | | | | | | | | | | | | | | While convincing myself that commit 7e19db0c09719d79 would solve both of the problems recently reported by Andreas Seltenreich, I realized that add_paths_to_joinrel's handling of LATERAL restrictions could be made noticeably simpler and faster if we were to retain the minimum possible parameterization for each joinrel (that is, the set of relids supplying unsatisfied lateral references in it). We already retain that for baserels, in RelOptInfo.lateral_relids, so we can use that field for joinrels too. This is a back-port of commit edca44b1525b3d591263d032dc4fe500ea771e0e. I originally intended not to back-patch that, but additional hacking in this area turns out to be needed, making it necessary not optional to compute lateral_relids for joinrels. In preparation for those fixes, sync the relevant code with HEAD as much as practical. (I did not risk rearranging fields of RelOptInfo in released branches, however.)
* Fix another oversight in checking if a join with LATERAL refs is legal.Tom Lane2015-12-07
| | | | | | | | | | | | | | | It was possible for the planner to decide to join a LATERAL subquery to the outer side of an outer join before the outer join itself is completed. Normally that's fine because of the associativity rules, but it doesn't work if the subquery contains a lateral reference to the inner side of the outer join. In such a situation the outer join *must* be done first. join_is_legal() missed this consideration and would allow the join to be attempted, but the actual path-building code correctly decided that no valid join path could be made, sometimes leading to planner errors such as "failed to build any N-way joins". Per report from Andreas Seltenreich. Back-patch to 9.3 where LATERAL support was added.
* Make gincostestimate() cope with hypothetical GIN indexes.Tom Lane2015-12-01
| | | | | | | | | | | | | | | | | | | | | | | We tried to fetch statistics data from the index metapage, which does not work if the index isn't actually present. If the index is hypothetical, instead extrapolate some plausible internal statistics based on the index page count provided by the index-advisor plugin. There was already some code in gincostestimate() to invent internal stats in this way, but since it was only meant as a stopgap for pre-9.1 GIN indexes that hadn't been vacuumed since upgrading, it was pretty crude. If we want it to support index advisors, we should try a little harder. A small amount of testing says that it's better to estimate the entry pages as 90% of the index, not 100%. Also, estimating the number of entries (keys) as equal to the heap tuple count could be wildly wrong in either direction. Instead, let's estimate 100 entries per entry page. Perhaps someday somebody will want the index advisor to be able to provide these numbers more directly, but for the moment this should serve. Problem report and initial patch by Julien Rouhaud; modified by me to invent less-bogus internal statistics. Back-patch to all supported branches, since we've supported index advisors since 9.0.
* Fix failure to consider failure cases in GetComboCommandId().Tom Lane2015-11-26
| | | | | | | | | | | | Failure to initially palloc the comboCids array, or to realloc it bigger when needed, left combocid's data structures in an inconsistent state that would cause trouble if the top transaction continues to execute. Noted while examining a user complaint about the amount of memory used for this. (There's not much we can do about that, but it does point up that repalloc failure has a non-negligible chance of occurring here.) In HEAD/9.5, also avoid possible invocation of memcpy() with a null pointer in SerializeComboCIDState; cf commit 13bba0227.
* Adopt the GNU convention for handling tar-archive members exceeding 8GB.Tom Lane2015-11-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The POSIX standard for tar headers requires archive member sizes to be printed in octal with at most 11 digits, limiting the representable file size to 8GB. However, GNU tar and apparently most other modern tars support a convention in which oversized values can be stored in base-256, allowing any practical file to be a tar member. Adopt this convention to remove two limitations: * pg_dump with -Ft output format failed if the contents of any one table exceeded 8GB. * pg_basebackup failed if the data directory contained any file exceeding 8GB. (This would be a fatal problem for installations configured with a table segment size of 8GB or more, and it has also been seen to fail when large core dump files exist in the data directory.) File sizes under 8GB are still printed in octal, so that no compatibility issues are created except in cases that would have failed entirely before. In addition, this patch fixes several bugs in the same area: * In 9.3 and later, we'd defined tarCreateHeader's file-size argument as size_t, which meant that on 32-bit machines it would write a corrupt tar header for file sizes between 4GB and 8GB, even though no error was raised. This broke both "pg_dump -Ft" and pg_basebackup for such cases. * pg_restore from a tar archive would fail on tables of size between 4GB and 8GB, on machines where either "size_t" or "unsigned long" is 32 bits. This happened even with an archive file not affected by the previous bug. * pg_basebackup would fail if there were files of size between 4GB and 8GB, even on 64-bit machines. * In 9.3 and later, "pg_basebackup -Ft" failed entirely, for any file size, on 64-bit big-endian machines. In view of these potential data-loss bugs, back-patch to all supported branches, even though removal of the documented 8GB limit might otherwise be considered a new feature rather than a bug fix.
* Fix handling of inherited check constraints in ALTER COLUMN TYPE (again).Tom Lane2015-11-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous way of reconstructing check constraints was to do a separate "ALTER TABLE ONLY tab ADD CONSTRAINT" for each table in an inheritance hierarchy. However, that way has no hope of reconstructing the check constraints' own inheritance properties correctly, as pointed out in bug #13779 from Jan Dirk Zijlstra. What we should do instead is to do a regular "ALTER TABLE", allowing recursion, at the topmost table that has a particular constraint, and then suppress the work queue entries for inherited instances of the constraint. Annoyingly, we'd tried to fix this behavior before, in commit 5ed6546cf, but we failed to notice that it wasn't reconstructing the pg_constraint field values correctly. As long as I'm touching pg_get_constraintdef_worker anyway, tweak it to always schema-qualify the target table name; this seems like useful backup to the protections installed by commit 5f173040. In HEAD/9.5, get rid of get_constraint_relation_oids, which is now unused. (I could alternatively have modified it to also return conislocal, but that seemed like a pretty single-purpose API, so let's not pretend it has some other use.) It's unused in the back branches as well, but I left it in place just in case some third-party code has decided to use it. In HEAD/9.5, also rename pg_get_constraintdef_string to pg_get_constraintdef_command, as the previous name did nothing to explain what that entry point did differently from others (and its comment was equally useless). Again, that change doesn't seem like material for back-patching. I did a bit of re-pgindenting in tablecmds.c in HEAD/9.5, as well. Otherwise, back-patch to all supported branches.
* Fix possible internal overflow in numeric division.Tom Lane2015-11-17
| | | | | | | | | | | div_var_fast() postpones propagating carries in the same way as mul_var(), so it has the same corner-case overflow risk we fixed in 246693e5ae8a36f0, namely that the size of the carries has to be accounted for when setting the threshold for executing a carry propagation step. We've not devised a test case illustrating the brokenness, but the required fix seems clear enough. Like the previous fix, back-patch to all active branches. Dean Rasheed
* Speed up ruleutils' name de-duplication code, and fix overlength-name case.Tom Lane2015-11-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 11e131854f8231a21613f834c40fe9d046926387, ruleutils.c has attempted to ensure that each RTE in a query or plan tree has a unique alias name. However, the code that was added for this could be quite slow, even as bad as O(N^3) if N identical RTE names must be replaced, as noted by Jeff Janes. Improve matters by building a transient hash table within set_rtable_names. The hash table in itself reduces the cost of detecting a duplicate from O(N) to O(1), and we can save another factor of N by storing the number of de-duplicated names already created for each entry, so that we don't have to re-try names already created. This way is probably a bit slower overall for small range tables, but almost by definition, such cases should not be a performance problem. In principle the same problem applies to the column-name-de-duplication code; but in practice that seems to be less of a problem, first because N is limited since we don't support extremely wide tables, and second because duplicate column names within an RTE are fairly rare, so that in practice the cost is more like O(N^2) not O(N^3). It would be very much messier to fix the column-name code, so for now I've left that alone. An independent problem in the same area was that the de-duplication code paid no attention to the identifier length limit, and would happily produce identifiers that were longer than NAMEDATALEN and wouldn't be unique after truncation to NAMEDATALEN. This could result in dump/reload failures, or perhaps even views that silently behaved differently than before. We can fix that by shortening the base name as needed. Fix it for both the relation and column name cases. In passing, check for interrupts in set_rtable_names, just in case it's still slow enough to be an issue. Back-patch to 9.3 where this code was introduced.
* Fix ruleutils.c's dumping of whole-row Vars in ROW() and VALUES() contexts.Tom Lane2015-11-15
| | | | | | | | | | | | | | | Normally ruleutils prints a whole-row Var as "foo.*". We already knew that that doesn't work at top level of a SELECT list, because the parser would treat the "*" as a directive to expand the reference into separate columns, not a whole-row Var. However, Joshua Yanovski points out in bug #13776 that the same thing happens at top level of a ROW() construct; and some nosing around in the parser shows that the same is true in VALUES(). Hence, apply the same workaround already devised for the SELECT-list case, namely to add a forced cast to the appropriate rowtype in these cases. (The alternative of just printing "foo" was rejected because it is difficult to avoid ambiguity against plain columns named "foo".) Back-patch to all supported branches.
* Fix enforcement of restrictions inside regexp lookaround constraints.Tom Lane2015-11-07
| | | | | | | | | | | | | | | | | | Lookahead and lookbehind constraints aren't allowed to contain backrefs, and parentheses within them are always considered non-capturing. Or so says the manual. But the regexp parser forgot about these rules once inside a parenthesized subexpression, so that constructs like (\w)(?=(\1)) were accepted (but then not correctly executed --- a case like this acted like (\w)(?=\w), without any enforcement that the two \w's match the same text). And in (?=((foo))) the innermost parentheses would be counted as capturing parentheses, though no text would ever be captured for them. To fix, properly pass down the "type" argument to the recursive invocation of parse(). Back-patch to all supported branches; it was agreed that silent misexecution of such patterns is worse than throwing an error, even though new errors in minor releases are generally not desirable.
* Fix erroneous hash calculations in gin_extract_jsonb_path().Tom Lane2015-11-05
| | | | | | | | | | | | | | | | | | | | The jsonb_path_ops code calculated hash values inconsistently in some cases involving nested arrays and objects. This would result in queries possibly not finding entries that they should find, when using a jsonb_path_ops GIN index for the search. The problem cases involve JSONB values that contain both scalars and sub-objects at the same nesting level, for example an array containing both scalars and sub-arrays. To fix, reset the current stack->hash after processing each value or sub-object, not before; and don't try to be cute about the outermost level's initial hash. Correcting this means that existing jsonb_path_ops indexes may now be inconsistent with the new hash calculation code. The symptom is the same --- searches not finding entries they should find --- but the specific rows affected are likely to be different. Users will need to REINDEX jsonb_path_ops indexes to make sure that all searches work as expected. Per bug #13756 from Daniel Cheng. Back-patch to 9.4 where the faulty logic was introduced.
* shm_mq: Third attempt at fixing nowait behavior in shm_mq_receive.Robert Haas2015-11-03
| | | | | | | | | | | | | Commit a1480ec1d3bacb9acb08ec09f22bc25bc033115b purported to fix the problems with commit b2ccb5f4e6c81305386edb34daf7d1d1e1ee112a, but it didn't completely fix them. The problem is that the checks were performed in the wrong order, leading to a race condition. If the sender attached, sent a message, and detached after the receiver called shm_mq_get_sender and before the receiver called shm_mq_counterparty_gone, we'd incorrectly return SHM_MQ_DETACHED before all messages were read. Repair by reversing the order of operations, and add a long comment explaining why this new logic is (hopefully) correct.
* Fix serialization anomalies due to race conditions on INSERT.Kevin Grittner2015-10-31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On insert the CheckForSerializableConflictIn() test was performed before the page(s) which were going to be modified had been locked (with an exclusive buffer content lock). If another process acquired a relation SIReadLock on the heap and scanned to a page on which an insert was going to occur before the page was so locked, a rw-conflict would be missed, which could allow a serialization anomaly to be missed. The window between the check and the page lock was small, so the bug was generally not noticed unless there was high concurrency with multiple processes inserting into the same table. This was reported by Peter Bailis as bug #11732, by Sean Chittenden as bug #13667, and by others. The race condition was eliminated in heap_insert() by moving the check down below the acquisition of the buffer lock, which had been the very next statement. Because of the loop locking and unlocking multiple buffers in heap_multi_insert() a check was added after all inserts were completed. The check before the start of the inserts was left because it might avoid a large amount of work to detect a serialization anomaly before performing the all of the inserts and the related WAL logging. While investigating this bug, other SSI bugs which were even harder to hit in practice were noticed and fixed, an unnecessary check (covered by another check, so redundant) was removed from heap_update(), and comments were improved. Back-patch to all supported branches. Kevin Grittner and Thomas Munro
* Fix typo in bgworker.cRobert Haas2015-10-30
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* Fix incorrect message in ATWrongRelkindError.Robert Haas2015-10-28
| | | | | | Mistake introduced by commit 3bf3ab8c563699138be02f9dc305b7b77a724307. Etsuro Fujita
* Measure string lengths only onceAlvaro Herrera2015-10-27
| | | | | | | | | | | | | | | | | | | | Bernd Helmle complained that CreateReplicationSlot() was assigning the same value to the same variable twice, so we could remove one of them. Code inspection reveals that we can actually remove both assignments: according to the author the assignment was there for beauty of the strlen line only, and another possible fix to that is to put the strlen in its own line, so do that. To be consistent within the file, refactor all duplicated strlen() calls, which is what we do elsewhere in the backend anyway. In basebackup.c, snprintf already returns the right length; no need for strlen afterwards. Backpatch to 9.4, where replication slots were introduced, to keep code identical. Some of this is older, but the patch doesn't apply cleanly and it's only of cosmetic value anyway. Discussion: http://www.postgresql.org/message-id/BE2FD71DEA35A2287EA5F018@eje.credativ.lan
* shm_mq: Repair breakage from previous commit.Robert Haas2015-10-22
| | | | | | If the counterparty writes some data into the queue and then detaches, it's wrong to return SHM_MQ_DETACHED right away. If we do that, we fail to read whatever was written.
* shm_mq: Fix failure to notice a dead counterparty when nowait is used.Robert Haas2015-10-22
| | | | | | | | | | | | The shm_mq mechanism was intended to optionally notice when the process on the other end of the queue fails to attach to the queue. It does this by allowing the user to pass a BackgroundWorkerHandle; if the background worker in question is launched and dies without attaching to the queue, then we know it never will. This logic works OK in blocking mode, but when called with nowait = true we fail to notice that this has happened due to an asymmetry in the logic. Repair. Reported off-list by Rushabh Lathia. Patch by me.
* Fix incorrect translation of minus-infinity datetimes for json/jsonb.Tom Lane2015-10-20
| | | | | | | | | | | | | Commit bda76c1c8cfb1d11751ba6be88f0242850481733 caused both plus and minus infinity to be rendered as "infinity", which is not only wrong but inconsistent with the pre-9.4 behavior of to_json(). Fix that by duplicating the coding in date_out/timestamp_out/timestamptz_out more closely. Per bug #13687 from Stepan Perlov. Back-patch to 9.4, like the previous commit. In passing, also re-pgindent json.c, since it had gotten a bit messed up by recent patches (and I was already annoyed by indentation-related problems in back-patching this fix ...)
* Fix incorrect handling of lookahead constraints in pg_regprefix().Tom Lane2015-10-19
| | | | | | | | | | | | | | | | | | | pg_regprefix was doing nothing with lookahead constraints, which would be fine if it were the right kind of nothing, but it isn't: we have to terminate our search for a fixed prefix, not just pretend the LACON arc isn't there. Otherwise, if the current state has both a LACON outarc and a single plain-color outarc, we'd falsely conclude that the color represents an addition to the fixed prefix, and generate an extracted index condition that restricts the indexscan too much. (See added regression test case.) Terminating the search is conservative: we could traverse the LACON arc (thus assuming that the constraint can be satisfied at runtime) and then examine the outarcs of the linked-to state. But that would be a lot more work than it seems worth, because writing a LACON followed by a single plain character is a pretty silly thing to do. This makes a difference only in rather contrived cases, but it's a bug, so back-patch to all supported branches.
* Miscellaneous cleanup of regular-expression compiler.Tom Lane2015-10-16
| | | | | | | | | | | | | | | | | Revert our previous addition of "all" flags to copyins() and copyouts(); they're no longer needed, and were never anything but an unsightly hack. Improve a couple of infelicities in the REG_DEBUG code for dumping the NFA data structure, including adding code to count the total number of states and arcs. Add a couple of missed error checks. Add some more documentation in the README file, and some regression tests illustrating cases that exceeded the state-count limit and/or took unreasonable amounts of time before this set of patches. Back-patch to all supported branches.
* Improve memory-usage accounting in regular-expression compiler.Tom Lane2015-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This code previously counted the number of NFA states it created, and complained if a limit was exceeded, so as to prevent bizarre regex patterns from consuming unreasonable time or memory. That's fine as far as it went, but the code paid no attention to how many arcs linked those states. Since regexes can be contrived that have O(N) states but will need O(N^2) arcs after fixempties() processing, it was still possible to blow out memory, and take a long time doing it too. To fix, modify the bookkeeping to count space used by both states and arcs. I did not bother with including the "color map" in the accounting; it can only grow to a few megabytes, which is not a lot in comparison to what we're allowing for states+arcs (about 150MB on 64-bit machines or half that on 32-bit machines). Looking at some of the larger real-world regexes captured in the Tcl regression test suite suggests that the most that is likely to be needed for regexes found in the wild is under 10MB, so I believe that the current limit has enough headroom to make it okay to keep it as a hard-wired limit. In connection with this, redefine REG_ETOOBIG as meaning "regular expression is too complex"; the previous wording of "nfa has too many states" was already somewhat inapropos because of the error code's use for stack depth overrun, and it was not very user-friendly either. Back-patch to all supported branches.
* Improve performance of pullback/pushfwd in regular-expression compiler.Tom Lane2015-10-16
| | | | | | | | | | | | | | | | | | | The previous coding would create a new intermediate state every time it wanted to interchange the ordering of two constraint arcs. Certain regex features such as \Y can generate large numbers of parallel constraint arcs, and if we needed to reorder the results of that, we created unreasonable numbers of intermediate states. To improve matters, keep a list of already-created intermediate states associated with the state currently being considered by the outer loop; we can re-use such states to place all the new arcs leading to the same destination or source. I also took the trouble to redefine push() and pull() to have a less risky API: they no longer delete any state or arc that the caller might possibly have a pointer to, except for the specifically-passed constraint arc. This reduces the risk of re-introducing the same type of error seen in the failed patch for CVE-2007-4772. Back-patch to all supported branches.
* Improve performance of fixempties() pass in regular-expression compiler.Tom Lane2015-10-16
| | | | | | | | | | | | | | | The previous coding took something like O(N^4) time to fully process a chain of N EMPTY arcs. We can't really do much better than O(N^2) because we have to insert about that many arcs, but we can do lots better than what's there now. The win comes partly from using mergeins() to amortize de-duplication of arcs across multiple source states, and partly from exploiting knowledge of the ordering of arcs for each state to avoid looking at arcs we don't need to consider during the scan. We do have to be a bit careful of the possible reordering of arcs introduced by the sort-merge coding of the previous commit, but that's not hard to deal with. Back-patch to all supported branches.
* Fix O(N^2) performance problems in regular-expression compiler.Tom Lane2015-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the singly-linked in-arc and out-arc lists to be doubly-linked, so that arc deletion is constant time rather than having worst-case time proportional to the number of other arcs on the connected states. Modify the bulk arc transfer operations copyins(), copyouts(), moveins(), moveouts() so that they use a sort-and-merge algorithm whenever there's more than a small number of arcs to be copied or moved. The previous method is O(N^2) in the number of arcs involved, because it performs duplicate checking independently for each copied arc. The new method may change the ordering of existing arcs for the destination state, but nothing really cares about that. Provide another bulk arc copying method mergeins(), which is unused as of this commit but is needed for the next one. It basically is like copyins(), but the source arcs might not all come from the same state. Replace the O(N^2) bubble-sort algorithm used in carcsort() with a qsort() call. These changes greatly improve the performance of regex compilation for large or complex regexes, at the cost of extra space for arc storage during compilation. The original tradeoff was probably fine when it was made, but now we care more about speed and less about memory consumption. Back-patch to all supported branches.
* Fix regular-expression compiler to handle loops of constraint arcs.Tom Lane2015-10-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's possible to construct regular expressions that contain loops of constraint arcs (that is, ^ $ AHEAD BEHIND or LACON arcs). There's no use in fully traversing such a loop at execution, since you'd just end up in the same NFA state without having consumed any input. Worse, such a loop leads to infinite looping in the pullback/pushfwd stage of compilation, because we keep pushing or pulling the same constraints around the loop in a vain attempt to move them to the pre or post state. Such looping was previously recognized in CVE-2007-4772; but the fix only handled the case of trivial single-state loops (that is, a constraint arc leading back to its source state) ... and not only that, it was incorrect even for that case, because it broke the admittedly-not-very-clearly-stated API contract of the pull() and push() subroutines. The first two regression test cases added by this commit exhibit patterns that result in assertion failures because of that (though there seem to be no ill effects in non-assert builds). The other new test cases exhibit multi-state constraint loops; in an unpatched build they will run until the NFA state-count limit is exceeded. To fix, remove the code added for CVE-2007-4772, and instead create a general-purpose constraint-loop-breaking phase of regex compilation that executes before we do pullback/pushfwd. Since we never need to traverse a constraint loop fully, we can just break the loop at any chosen spot, if we add clone states that can replicate any sequence of arc transitions that would've traversed just part of the loop. Also add some commentary clarifying why we have to have all these machinations in the first place. This class of problems has been known for some time --- we had a report from Marc Mamin about two years ago, for example, and there are related complaints in the Tcl bug tracker. I had discussed a fix of this kind off-list with Henry Spencer, but didn't get around to doing something about it until the issue was rediscovered by Greg Stark recently. Back-patch to all supported branches.
* On Windows, ensure shared memory handle gets closed if not being used.Tom Lane2015-10-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Postmaster child processes that aren't supposed to be attached to shared memory were not bothering to close the shared memory mapping handle they inherit from the postmaster process. That's mostly harmless, since the handle vanishes anyway when the child process exits -- but the syslogger process, if used, doesn't get killed and restarted during recovery from a backend crash. That meant that Windows doesn't see the shared memory mapping as becoming free, so it doesn't delete it and the postmaster is unable to create a new one, resulting in failure to recover from crashes whenever logging_collector is turned on. Per report from Dmitry Vasilyev. It's a bit astonishing that we'd not figured this out long ago, since it's been broken from the very beginnings of out native Windows support; probably some previously-unexplained trouble reports trace to this. A secondary problem is that on Cygwin (perhaps only in older versions?), exec() may not detach from the shared memory segment after all, in which case these child processes did remain attached to shared memory, posing the risk of an unexpected shared memory clobber if they went off the rails somehow. That may be a long-gone bug, but we can deal with it now if it's still live, by detaching within the infrastructure introduced here to deal with closing the handle. Back-patch to all supported branches. Tom Lane and Amit Kapila